Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI

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Kenwood TH-F6A Computer Control Reference
K9DCI Steve Noskowicz, 2005-2011

All rights reserved

Ver 2.0.1
This is a condensed and edited version, with additional information, of the information in a document by John May, K6MAY, entitled: Kenwood TH-F6A/TH-F7E Protocol Specification By John May, K6MAY
http://www.k6may.com/KenwoodTHF6Tip1.shtml
Fine Print While care was taken to be accurate, this document may contain errors and may not contain all functional commands. The starting point for this document was John May's document. During the preparation of this document all errors found were corrected, yet some may still be present. Not all commands were exhaustively examined and some may have errors or omissions. No investigation was done looking for non printing command op-codes and many of the things stated here were seen as being correct, but were not exhaustively studied under all conditions or for all commands. The home brew level converter shown herein and both a terminal program and Excel macros doing serial I/O on a PC were used to examine and verify the behavior of commands and verify the changes and additions to the information in John's document. Send any comments or corrections to me at my call at the ARRL forwarding service (callsign@arrl.net)
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI Version history
1.0 9/04 original released version.

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1.1 10/4/04 Wording cleanup in front, note that PV is not permanent. Change from the word "Request" to "Sent" in the Modify examples. 1.11 3/3/05 changed Mhz to MHz. 1.12 4/6/05 Added scan aborts page 5 and clarified the command exceptions on the bottom of page 7. Added URL for John's doc. Clarified the level converter Q3 circuit description. 1.2 8/2/05 Improved notes about Fine Step on page 4 and in Command Parameter Tables, Pg 8 and Commands FQ & FST on pg 18. 1.3 11/6/06 Corrected note about Air Band 8.33 kHz steps programming and added references in respective commands. Also added some clarification of Control (active) receiver. Fixed MR example. Mem number in radio response shown is 20, but note said 013. Fixed MW Note and example to show that the split byte may be either 0 or 1 to erase a memory. PL code 39 in table, page p, was incorrectly shown as 49. Mention that there are three Call channels in CR and CW commands. Added Call channel Tx Split Read example. Call channels have no alpha Name capability. Improved the notes on 6.25, 8.33 and 12.5 kHz step programming. Added notes indicating the Tx Step must be the same as the Rx Step. 1.4 (2/9/07) Added clarification of Call channel selection in MC command. 1.5 (3/23/07) Level converter page. Added comment about the live mic. Added comment about optional 1uH chokes and rearranged the connector descriptions. 1.6a (8/11/07) Level converter. Corrected note to read Q2 (was a nonexistent Q3). Clarified that the F6 mic input is live in PC mode. Page 8. Note added for Rx A Steps. TSP Operands were reversed. MGL command: Added note reminding about the space after the command MD command. Only applicable to Rx B. Rx A only does FM. 1.7 (10/14/07) Clarified that VMC does not change control Rx (except for INFO). 1.8 (10/21/07) Level converter: Added connector info, Mic and Earphone to converter schematic.
1.9 (10/25 - 1/10/08) Added notes about off-receiver response for several commands. Changed Sets to Set/Read on several command descriptions. Added units change note to FL command. Added MCP note on Pg 7. Added "Rx" to Frequency Parameter Table Pg 8. Added "<" to 470 in Modulation table. Completed additional detail on Air 8.33 and Fine Step programming. Removed reference to 6.25 and 12.5 kHz steps as being awkward. Misc cleanup. Corrected LF to CR for command terminator character, Pg. 4. Added Appendix. 2.0.1 2/24/2011 Corrected typo on page 4 (ca > can)

Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI Command
ANT APO ARO ASC ATT BAL BAT BC BEL BEP BY CKEY CNT CR CW DATP DL DLK DM DMN DW ELK FL FQ FST ID LAN LK LMP MC MD MES

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Description
Antenna, Bar Enable Automatic Power Off Auto Repeater Offset Auto Simplex Check Attenuator Enable Balance Volumes between receivers Battery Type Band (Receiver) Control Bell alert on received signal Beep for keypad Busy (Squelch) CALL Key set up Contrast of display Call Channel Read [ much information ] Call Channel Write Data Packet Speed Dual Listen Enable DTMF Lockout during transmit DTMF Memory content DTMF Memory Name (Alpha) Down Enable Locked tuning Frequency Limits Frequency and Step Size & (Fine Step Enable) Fine Step Tuning (Size) Identity of Radio Language for menu names Lock Keypad Lamp Memory Channel activate (MR) Modulation Type Message at Power-On
Menu Item 5 n/a n/a n/a 30 n/a n/a 19 n/a n/a n/a 28 n/a 10 n/a 7 n/a n/a n/a n/a 27 n/a n/a n/a n/a 15
MGL MNA MNF MR MRM MW NAR NSFT PC PT PV RBN RX SCR SQ SR SV TH TSP TT TX TXH TXS TYD UP VMC VOX VR VW VXB VXD VXG

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Memory Group Link Memory Name Memory Name Frequency display toggle Memory Read (0-400, Lx, Ux, I-x, Pri) Memory Recall Method Memory Write (0-400, Lx, Ux, Ix, Pri) Narrow FM Noise Shift (Beat Shift) Power Control (Tx Output) Pause Time DTMF (character pause) Program VFO Limits Receive Band Number Receive Scan Resume Squelch Setting System Reset Save Battery (time) Tx Hold for 1750 Tone Speed DTMF Transmit Tone Transmit Tx Hold (between DTMF digits) Transmit Stop (inhibit) Type ID (of radio) Up VFO, MR, CALL recall mode VOX Enable VFO Read VFO Write VOX on Busy (squelch) VOX Drop Delay VOX Gain
Menu Item 2 n/a n/a n/a 3 n/a n/a n/a n/a 1 n/a n/a n/a n/a n/a n/a n/a n/a n/a 21
No commands are known for Any radio scan mode including Group (MHZ), MR, VFO, Visual, CTCSS & DCS scans. Either to enter the mode, or tell when it stops on a channel or tone. Channel-only display mode (see manual for this). Permanent Band limit change (FL), monitor (un squelch) button, S-Meter level, remote control code & mode. FYI: Kenwood's MCP vers 0 beta sends VOX 0 first when uploading (thus it is not in the file) and also sends the following invalid requests: CR 3,0; VR 3; PV 3; PC 2; PC 3; NAR 3; NAR 5.

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Command Parameter Tables
NOTE: Most commands have the respective parameter tables in the command description. These are the larger tables used in the various read and write commands. Frequency Band Table [band] Rx [ham] 0 A [ham] 1 A [ham] 2 A 4 B 5 B 6 B 7 B Band 3 appears to be invalid. Name - Freq MHz. [band] Rx Name - Freq MHz. 2m 137-<B Air 108-<137 1.25m 216-<B 2m 137-<174 70cm 410-<470 A B VHF TV 174-<216 AM 0.1-<1.8 B B 1.25m 216-<400 HF 1.8-<29.7 C B 70cm 400-<470 6m 29.7-<54 D B UHF TV 470-<806 FM 54-<108 E B 23cm 806-<1300 The cellular band is locked out 824-849 & 869-894 on the TH-F6 Split Use yes yes no no no no no no no no no no no

Rx Frequency Parameter Table. See commands CW, MR, MW, VR, VW. Field Value Description freq digits in Hz. step 0-B See Step Table. Tx Step MUST = Rx shift/offset 0, 1, = none or split, 1 = positive, 2 = negative rev 0, = Normal, 1 = Reverse T and R. T-PL enable 0, = Tx PL Tone on R-PL enable 0, = CTCSS on (overrides T-PL) DCS enable 0, = DCS on (overrides R & T PL) tone # 00-41 See Sub audible Table CTCSS # 00-41 See Sub audible Table DCS # 000-103 See DCS Code Table Tx freq offset 9 digits 9 digits in Hz. <=59.95 MHz. mod 0-5 See Modulation Table Scan Lockout 0, = Scan, 1 = Skip
Setting multiple sub audibles (=1) is accepted, however, only the furthest to the right (CT,DCS) is active. See CALL READ, CR, for a typical [freq] string. SPLIT OPERATION NOTES: Split refers to a non standard or non-automatic transmit frequency offset (see ARO). From the keypad, to load the Tx frequency requires holding the PTT while either pushing the MENU joystick or the MR button. For computer programming, the split character (byte) determines if the Rx or Tx frequency is being stored. Only the frequency and step size are sent or echoed when modifying or reading the split Tx freq. The Tx Step MUST be the same as the Rx Step. See the CW, MW and VW commands. Step Table The radio is tuned to multiples of these steps. Modulation Table [step] Step Size [step] Step Size [mod] Modulation Range 0 5.0 kHz (< 470 MHz.) 6 15.0 kHz (< 470 MHz.) 0 FM 0.1 <1300 MHz. 1 6.25 kHz (< 470 MHz.) 7 20.0 kHz 1 WFM 29.7 <1300 MHz. 2 8.33 kHz (Air band ) 8 25.0 kHz 2 AM 0.1 <1300 MHz. 3 9.0 kHz (AM band) 9 30.0 kHz 3 LSB 0.1 <470 MHz. 4 10.0 kHz A 50.0 kHz 4 USB 0.1 <470 MHz. 5 12.5 kHz B 100.0 kHz 5 CW 0.1 <470 MHz. Only these are available at 470 Mhz. and above. In the Air band for 8.33 kHz steps, most frequencies ending in 333 or 667 must be rounded to the nearest 10 Hz. i.e.330 and.670. Some ("00118,108.330") can not. If programmed (e.g. FQ) as.333 or.667, Fine Step is turned on in whatever step size it was on (it is not set to the best step). Turning Fine Step on with VMC 1,4 changes the display, turning it off with VMC 1,0 does not change the display. Rx A only does 5, 6.25, 10, 12.5, 15, 20, 25, 30, 50 and 100 KHz. (not 8.33 or 9kHz.) Fine Step Table [val] Step Size Hz Hz Hz Hz Fine Step only available on Rx B SSB, CW and AM and only <470 MHz. When in Fine step, FM and WFM will be unavailable. Via computer, Fine Step is automatically enabled if needed and available. This requires the frequency to be specified to the correct step multiple.

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Command Parameter Tables (cont.)
Sub Audible Code # Table # Tone # Tone 00 67.85.69.88.71.91.74.94.77.97.79.100.82.103.5 # 20 Tone 107.2 110.9 114.8 118.8 123.0 127.3 131.8 # 27 Tone 136.5 141.3 146.2 151.4 156.7 162.2 167.9 # 34 Tone 173.8 179.9 186.2 192.8 203.5 206.5 210.7 # 41 Tone 218.1 225.7 229.1 233.6 241.8 250.3 254.1

Attenuator Enable / Disable

Menu Item n/a

Description: Enable/Disable, or read the attenuator. Use to attenuate nearby or extremely strong signals to prevent overload. The attenuator is approximately 20 DB when ON. Command: Status Request: ATT Modify: ATT [State] Response: ATT [State] Where: [State] State 0 No Atten. 1 Atten. in line Example: Sent: ATT Response: ATT 1 Sent: ATT 0 Response: ATT 0 Request status of attenuator. Response: attenuator is on. Turn attenuator off. Confirm: attenuator is off.

Balance Receiver Volumes

Description: Set/Read the volume balance between A and B bands. Command: Status Request: BAL Modify: BAL [val] Response: BAL [val] Where: [val] A Rx B Rx 0 100% 0% 1 75% 25% 2 50% 50% 3 25% 75% 4 0% 100% Notes: Default value is 2 (both A and B bands equal). Example: Sent: BAL Request Balance setting. Response: BAL 2 Response: Balance is set to 2. Sent: BAL 0 Set balance to 100% Rx A. Response: BAL 0 Confirm: balance to 100% Rx A.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI BAT Battery Type
Description: Set/Read the battery type. Used for estimating the remaining battery capacity. Command: Status Request: BAT Modify: BAT [val] Response: BAT [val] Where: [val] Type 0 Lithium 1 Alkaline Example: Sent: BAT Request battery type. Response: BAT 0 Response: battery type is lithium. Sent: BAT 1 Set battery type to alkaline. Response: BAT 1 Confirm: battery type is alkaline.

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Menu Item 30

Band (Receiver) Control

Description: Set/Read the Control (active) receiver. Selects the A Rx or B Rx for Control. Command: Status Request: BC Modify: BC [Rx] Response: BC [Rx] Where: [Rx] A/B 0 A 1 B Notes: See ASC, DL, FQ, FST and VMC. Example: Sent: BC Request Rx control status. Response: BC 0 Response: Control set to Rx A. Sent: BC 1 Make Rx B Control. Response: BC 1 Confirm: Control is on Rx B.
Bell Alert on Received Signal
Description: Enable/Disable, or read the bell (tone) alert function. Provides an audible alarm when signals are received. Command: Status Request: BEL [Rx] Modify: BEL [Rx],[val] Response: BEL [Rx],[val] Where: [Rx] A/B [val] State 0 A 0 Off 1 B 1 On Notes: The response is "N" for the off Rx (DL off). See DL. Example: Sent: BEL 0 Request Status of tone alert on Rx A. Response: BEL 0,0 Response: tone alert is off. Sent: BEL 1,1 Enable tone alert for Rx B. Response: BEL 1,1 Confirm: tone alert is enabled for Rx B.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI BEP Beep for keypad
Description: Enable/Disable, or read the beep function. Command: Status Request: BEP Modify: BEP [val] Response: BEP [val] Where: [val] State 0 Off 1 On Example: Sent: BEP Request Status of beep function. Response: BEP 1 Response: beep function is on. Sent: BEP 0 Turn keypad beeps off. Response: BEP 0 Confirm: beep function is off.

ham spt

Request call channel data. 2M, Split Rx.
freq stp of R T CT DCS T# C# D# Offset Mode lockout)
Response: CR 0,0,00141990000,6,0,0,0,0,0,25,09,001,000700000,0 (no Sent CR 0,1
Request Call channel split Tx data for 2M

freq stp

Response: CR 0,1,00146880000,0 Interpretation of the above response. Parameter: result Code in string
ham (Band) Split Freq Step Offset Rev Tone-enable PL-enable DCS-enable tone-freq PL freq DCS code Offset Mode 2M Rx freq 141.kHz. none off off off off 151.4 88.700KHz FM (0) (0) (00141990000) (6) (0) (0) (0) (0) (0) (25) (09) (011) (000700000) (0)
Tx Step Must be same as Rx Step. Responds with N if no Tx programmed. Details
Band Table [0, 1, 2 only) Split Operation Notes 11 digits in Hz. Step Table Frequency Parameter Table Frequency Parameter Table Frequency Parameter Table Frequency Parameter Table Frequency Parameter Table Sub audible Table Sub audible Table DCS Code Table 9 digits in Hz. Modulation Table
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI CW Call Channel Write

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Description: Enters data to one of the three ham band Call channel. Menu Item n/a Function: Saves data associated with the Call channel Command: Modify: CW [split],[freq] No Status Request, see CR. Response: CW Where: [split] see Split Channel Table and Notes in Command Parameter Tables at front. [freq] see Frequency Parameter Table in Command Parameter Tables at front. Notes: Scan Lockout excluded. No ham band parameter is required. The frequency determines the frequency band. There appears to be no Call channel clear capability. Call channels have no Name. Example:
split freq stp of R T CT DCS T# C# DCS Offset Mode lockout)
Sent: CW 0,00141990000,6,0,0,0,0,0,25,09,001,000700000,0 (no Load call channel data. Also clears the Split Tx data. Response: CW Confirmation response is only the mnemonic.

split freq stp

Sent: CW 1,00141590000,KHz. split Load call channel split Tx data. Response: CW Confirmation response is only the mnemonic.

Data Packet Speed

Menu Item 28
Description: Set/Read Packet interface Speed. Options are 1200 or 9600 bps. Command: Status Request: DATP Modify: DATP [val] Response: DATP [val] Where: [val] Speed bps bps Example: Sent: DATP Request Packet Speed. Response: DATP 0 Transceiver responds Packet Speed in 1200 bps. Sent: DATP 1 Set interface for a Packet Speed of 9600 bps. Response: DATP 1 Confirm: 9600 baud

Enable Locked Tuning

Menu Item 07
Description: Enable/Disable, or Read Enable Tune while locked. Frequency can be tuned when transceiver is locked. See Lock Keypad, LK Command: Status Request: ELK Modify: ELK [val] Response: ELK [val] Where: [val] State 0 Off No tuning when locked. 1 On tuning while locked. Example: Sent: ELK Request Status of Tune Enable. Response: ELK 0 Response: Tune Enable is off. Sent: ELK 1 Turn Tune Enable on. Response: ELK 1 Confirm: Tune Enable is on.

Frequency Limits

Description: Request a list of fixed band limits for receiver bands. Menu Item n/a Command: Status Request: FL [Rx] Response: FL [Rx], [list] Where: [Rx] A/B Rx 0 A 1 B [list] is 7 digits in 10 KHz. steps below 108 MHz and 5 digits in MHz. above 108 MHz. Notes: There appears to be no modifying command. These appear to be fixed and not related to the memory locations LO through U9 nor the PV command. The response is the same regardless of the state of DL. Also note change in units between 0010800,00108 from 10 KHz. to MHz. Example: Sent: FL 0 Request frequency limits of A Rx. Response: FL 0,00137,00174,00216,00260,00410,00470 Transceiver Responds with limits of A Rx. Sent: FL 1 Request frequency limits of B Rx. Response: FL 1,0000010,0000180,0000180,0002970,0002970,0005400,0005400,0010800, 00108,00137,00137,00174,00174,00216,00216,00400,00400,00470,00470,00806,00806,01300
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI FQ Frequency, Step & (Fine Step enable/disable)

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Description: Reads / Immediately sets the Control (active) synthesizer frequency and step size. Menu Item n/a Command: Status Request: FQ Modify: FQ [freq], [step] Response: FQ [freq], [step] Where: [freq] is an eleven (11) digit frequency in Hz. [step] Step Size [step] Step Size 0 5.0 kHz (< 470 MHz.) 6 15.0 kHz (< 470 MHz.) 1 6.25 kHz (< 470 MHz.) 7 * 20.0 kHz 2 8.33 kHz (Air band) 8 * 25.0 kHz 3 9.0 kHz (AM band) 9 * 30.0 kHz 4 * 10.0 kHz A * 50.0 kHz 5 * 12.5 kHz B * 100.0 kHz * Only these above 470 Mhz. For Air band 8.33 kHz steps, see Step Table Note on page 8. Notes: FQ does not change the name text showing in the display if on an MR, INFO or CALL channel. Fine Step is enabled (VMC 1, 3) and frequency set when the frequency is on any Fine Step multiple rounded to the Hz., but the Fine Step size is not changed to make it appropriate. See FST & Appendix. Example: Sent: FQ Request current frequency and step. Response: FQ 00052910000,0 Response: 52.91 MHz with 5.0 kHz step Sent: FQ 00105500000,4 Set transceiver to 105.500 MHz with a 10.0 kHz step Response: FQ 00105500000,4 Confirm:

Fine Step Tuning (Size)

Description: Set/Read fine-tuning step size on Rx B only. Does not enable Fine Step. Menu Item n/a Only available below 470 MHz. and in SSB, CW and AM. When enabled, FM and WFM are unavailable. Command: Status Request: FST Modify: FST [val] Response: FST [val] Where: [val] Step Size Hz Hz Hz Hz Notes: Only this command changes the Fine step size. See VMC and FQ for Fine Step enable / disable. Example: Sent: FST Request fine-tuning step size. Response: FST 0 Response: step size is 33 Hz. Sent: FST 2 Set the fine tuning step size to 500 Hz. Response: FST 2 Confirm: FINE Step 500 Hz.

Identity of Radio

Description: Requests the radio identification. Commonly used to validate that the radio is in communication with computer. Command: Status Request: ID Response: ID [id] Where: ID = TH-F6 Example: Sent: ID Request ID of transceiver. Response: ID TH-F6 Response: it is a TH-F6.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI LAN Language of Menu
Description: Set/Read menu item language - English or Japanese (Katakana). Command: Status Request: LAN to get language. Modify: LAN [lang] to set language. Response: LAN [lang] Where: [lang] Language 0 English 1 Japanese (Katakana) Example: Sent: LAN Request menu language. Response: LAN 0 Response: language is English. Sent: LAN 1 Set menu language to Japanese. Response: LAN 1 Confirm: Menu in Japanese.

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Menu Item 27

Lock Keypad

Description: Enable/Disable, or Read the keypad lockout. Disables most keys to prevent accidental activation See Enable Locked Tuning, ELK Command: Status Request: LK Modify: LK [val] Response: LK [val] Where: [val] State 0 Unlocked 1 Locked Example: Sent: LK Request Status of keypad lock. Response: LK 0 Response: not locked. Sent: LK 1 Lock keypad. Response: LK 1 Confirm: keypad is locked.
Description: Turn on/off, or Read the display light. Command: Status Request: LMP Modify: LMP [val] Response: LMP [val] Where: [val] State 0 Off 1 On Example: Sent: LMP Request lamp status. Response: LMP 0 Response: lamp is off. Sent: LMP 1 Turn lamp on. Response: LMP 1 Confirm: lamp on.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI MC Memory Channel Activate (MR)

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Description: Set/Read the Memory Group Links. Menu Item 02 Command: Status Request: MGL Modify: MGL [string] Response: MGL [string] Where: [string] Group numbers (0-7) which are shown are combined into one large scan group. Notes: * = space character. Though meaningless, it is valid for only one group to be marked for linking. Example: Remember the normal space after the "MGL". Sent: MGL Request the Status of memory group link. Response: MGL**1*3*5*7 Response: 1,3,5,7 groups are linked. Sent: MGL***2***6* Request that groups 2 and 6 be linked. Response: MGL***2***6* Confirm.

Memory Name

Description: Set/Read alphanumeric name of memory location. Menu Item n/a Command: Status Request: MNA [mem] Modify: MNA [mem],[name] Response: MNA [mem],[name] Where: [mem] Memory Type 400 memory locations L0 Llower scan limit locations U0 Uupper scan limit locations I-0 I-information channels PR1, PRpriority channels Notes: [name] is a maximum of eight (8) characters, extras are ignored. Request gets a response of "N" if no alpha is programmed. Ending with the comma clears the name. Example: Sent: MNA 001 Request name of memory location 001 Response: MNA 001,RPTR Response: location 001 is RPTR Sent: MNA 256,NASA-TV Set name of location 256 to NASA-TV. Response: MNA 256,NASA-TV Confirm: location 256 is NASA-TV. Sent: MNA Pr1, Erase name (include comma at end) Response: MNA Pr1, Confirm: location name erased (comma is present).
Memory Name / Freq Display
Description: Set/Read alpha/frequency mode for the display. Command: Status Request: MNF Modify: MNF [val] Response: MNF [val] Where: [val] Mode 0 Name 1 Frequency Notes: Changes mode of both A and B displays. Example: Sent: MNF Request the Name/Freq status of display. Response: MNF 0 Response: display shows memory Names. Sent: MNF 1 Enable display to show Frequencies. Response: MNF 1 Confirm: Frequencies are displayed.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI MR Memory Read
Description: Reads a memory location. See Command Parameter Tables at front. Command: Status Request: MR [split], [mem] Response: MR [split], [mem],[freq] Where: [mem] Memory Type 400 memory locations. L0 Llower scan limit locations. U0 Uupper scan limit locations. I-0 I-information channels. PR1, PRpriority channels. [split] see Split Channel operation notes in Command Parameter Tables at front. [freq] see Frequency Parameter Table in Command Parameter Tables at front.

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Notes: N is the response for an empty (unprogrammed) memory location. For Air band 8.33 kHz steps, see Step Table Note on page 8. Example: Sent: MR 0,020 Read Rx memory location 020.
split mem freq stp of R T CT DCS T# C# D# Offset Mod lock
Response: MR 0,020,00147120000,0,0,0,0,1,0,14,12,000,000000000,0,0 Values from location 020. 147.12, no offset, 100HZ CTSS tone. Sent: MR 1,080

split mem

Read split Tx memory location 80.
Response: MR 1,020,00146120000,MHz. neg split. Responds with "N" if not programmed as a split.

Memory Recall Method

Description: Set/Read the memory recall method. Menu Item 03 When set to "Current band" tuning in VFO or MR only cycles through the current Frequency band. Requires that the band key be pushed or the joystick pushed left/right to go to select stored frequencies in other frequency bands. Stepping through the bands follows the frequency band numbers shown in the PV and RBN commands. Command: Status Request: MRM Modify: MRM [val] Response: MRM [val] Where: [val] Method 0 All bands 1 Current band Example: Sent: MRM Request current Memory Recall restriction. Response: MRM 0 Response: MRM is All Bands. Sent: MRM 1 Set MRM to Current Band. Response: MRM 1 Confirm: MRM is Current Band.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI MW Memory Write

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Description: Store frequency and data in a memory location or clear it. Menu Item n/a Command: Modify: MW [split],[mem],[freq] Response: MW [split],[mem],[freq] Where: [split] see Split Operation notes in the Command Parameter Tables at front. [mem] Memory Type 400 memory locations. L0 Llower scan limit locations. U0 Uupper scan limit locations. I-0 I-information channels. PR1, PRpriority channels. [freq] see Frequency Parameter Table in the Command Parameter Tables at front. Note: Writing with split = either 0 or 1 and no parameters after the channel location [mem] clears the memory location. If the target memory is active, the radio is put into VFO mode. If an INFO location is cleared, the radio is put into VFO mode, but the factory default Weather frequency and name is restored. All the above channels can have a split programmed and be used as a normal Rx and Tx ham band channel. Offsets and splits can be programmed in non ham band frequencies and the reverse function operates. However the limit for Split offset was not studied (at 1296 a Tx split frequency of 894 can be programmed) For Air band 8.33 kHz steps, see Step Table Note on page 8. Example:
split mem freq stp of R T CT DCS T# C# D# offset Mod lock
Sent: MW 0,020,00147120000,0,1,0,0,1,0,14,12,000,000600000,0,0 Set memory location 020 to 147.12 MHz with a 5.0 kHz step, FM, CTSS=100.0 Hz. No offset, reverse, tone, DCS or lockout. Response: MW Confirmation response is only the mnemonic.

split mem freq stp

Sent: MW 1,020,00146120000,0 Set split Tx freq, 146.12 Tx Step MUST be the same as the Rx. Response: MW Confirmation response is only the mnemonic.

Sent: MW 0,020 Response: MW
Clears entire Rx, Tx and mnemonic data. Split byte may be either 0 or 1. Confirmation response is only the mnemonic.

Narrow FM

Menu Item 29
Description: Enable/Disable, or Read the Narrow FM modulation of a Ham band. Function: Selects between: Off - wide FM (5 KHz) deviation or On - narrow FM (2.5 KHz) deviation. Command: Status Request: NAR [ham] Modify: NAR [ham],[nar] Response: NAR [ham],[nar] Where: [ham] Ham Band [nar] State 0 2m 0 Wide 1 1.25m 1 Narrow 2 70cm Notes: An unmodified F6 accepts this command. The receive audio gain is increased. Example: Sent: NAR 0 Request FM width setting of 2m FM. Response: NAR 0,0 Response: FM wide. Sent: NAR 1,1 Set the 1.25 m band modulation to narrow FM. Response: NAR 1,1 Confirm: 1.25 m band narrow FM.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI NSFT Noise Shift (Beat Shift)
Description: Set/Read Beat Shift function. Pick one to reduce harmonics from microprocessors clock oscillator. Command: Status Request: NSFT Modify: NSFT [sft] Response: NSFT [sft] Where: [sft] State 0 Off 1 On Example: Sent: NSFT Request Status of Beat Shift. Response: NSFT 1 Response: Beat Shift is on. Sent: NSFT 0 Turn beat Shift off. Response: NSFT 0 Confirm: Shift off.

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Menu Item 25

Power Control (Tx power)

Description: Set/Read the transmit power assigned to each receiver. Command: Status Request: PC [Rx] Modify: PC [Rx], [pwr] Response: PC [Rx], [pwr] Where: [Rx] A/B Rx [pwr] Level 0 A 0 H 1 B 1 L 2 EL Notes: The response is valid regardless of the state of DL. Example: Sent: PC 0 Request power output for Rx A Response: PC 0,0 Response: power output is High on Rx A. Sent: PC 1,2 Set power level assigned to Rx B to EL. Response: PC 1,2 Confirm: Rx B is EL.
Pause Time, DTMF (character)

Menu Item 13

Description: Set/Read the DTMF memory character space duration. Command: Status Request: PT Modify: PT [val] Response: PT [val] Where: [val] Duration [val] Duration ms ms ms ms ms ms ms Example: Sent: PT Request DTMF pause duration. Response: PT 2 Response: pause duration is 500 ms. Sent: PT 5 Set pause to 1500 ms. Response: PT 5 Confirm: pause of 1500 ms.

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Menu Item 01

Squelch Setting

Description: Set/Read the squelch level. Command: Status Request: SQ [Rx] Modify: SQ [Rx], [lev] Response: SQ [Rx], [lev] Where: [Rx] A/B [lev] Setting 0 A 00 Open 1 B 05 Tight [lev] is a value from 00-05. Notes: The response is "N" for the off Rx (DL off). See BC, DL, FQ, FST and VMC. Example: Sent: SQ 0 Request squelch level for Rx A. Response: SQ 0,05 Response: squelch level for Rx A is 05. Sent: SQ 1,01 Set Rx B squelch to level 01. Response: SQ 1,01 Confirm. Rx B squelch level 01.

System Reset

Menu Item 31
Description: Performs selected reset function. Command: Modify: SR [val] Response: No Response: Where: [val] Reset 0 No 1 VFO Example: Sent: SR 1 Perform VFO Reset. Response: None is sent.

[val] 2 3

Reset Menu Full
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI SV Save Battery
Description: Set/Read the Battery saver time off-time. Command: Status Request: SV Modify: SV [val] Response: SV [val] Where: [val] Time (s) [val] Time (s) 0 Off 5 1.0 (default) 1 0.2.0.3.0.4.0.5.0 Example: Sent: SV Request Battery Saver time. Response: SV 5 Transceiver reports 1.0 sec. Sent: SV 7 Set the save off-time to 3.0 sec. Response: SV 7 Confirm: 3.0 sec.

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Menu Item 17

Tx Hold for 1750

Description: Enable/Disable, or Read the 1750 Hz Transmitter hold function. Menu Item 24 When enabled, holds the radio in transmit for 2 seconds after the CALL button released then the CALL 1750 Hz tone function is enabled (TH-F7E only). Command: Status Request: TH Modify: TH [val] Response: TH [val] Where: [val] State 0 Off 1 On Example: Sent: TH Request: of 1750 Hz Hold function. Response: TH 0 Response: 1750 Hz Hold is off. Sent: TH 1 Enable the 1750 Hz. Tx Hold. Response: TH 1 Confirm: 1750 Hz Hold on

Tone Speed DTMF

Menu Item 11
Description: Set/Read the DTMF memory send Speed. Command: Status Request: TSP Modify: TSP [val] Response: TSP [val] Where: [val] Speed 0 Fast 1 Slow Example: Sent: TSP Request current DTMF Speed. Response: TSP 0 Response: Speed is slow. Sent: TSP 1 Set DTMF Speed to fast. Response: TSP 1 Confirm: fast speed.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI TT Transmit Tone
Description: Transit a 1750Hz tone until a RX command is received. Command: Modify: TT Response: TT Notes: May be stopped by RX command. Example: Sent: TT Transmit a 1750 Hz tone. Response: TT Confirm.

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Transmit
Description: Switch transceiver to transmit until RX command received. Command: Modify: TX Response: TX [Rx] Example: Sent: TX Key the transmitter. Response: TX 1 Confirm: transmitting via Rx B

Tx hold DTMF

Menu Item 12
Description: Enable/Disable, or Read the 2 second hold after DTMF button press. Command: Status Request: THX Modify: THX [val] Response: THX [val] Where: [val] State 0 Off de-key upon key release 1 On 2 second hold Example: Sent: TXH Request Status of DTMF Hold. Response: TXH 0 Response: DTMF Hold is off. Sent: TXH 1 Enable DTMF Tx Hold. Response: TXH 1 Confirm: DTMF hold on.

Transmit Stop (Inhibit)

Menu Item 08
Description: Inhibits Transmit function from computer and PTT button. Prevents accidental or unauthorized transmission. Command: Status Request: TXS Modify: TXS [val] Response: TXS [val] Where: [val] State 0 Off Transmitting possible 1 On Transmitter disabled Notes: The display shows "TX INHIBIT!" when PTT pressed while disabled. Example: Sent: TXS Get state of Transmitter Inhibit. Response: TXS 0 Transmitter Inhibit is off. Sent: TXS 1 Inhibit Transmit. Response: TXS 1 Confirm: transmission inhibited.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI TYD Type ID of radio
Description: Displays the radio type. Command: Status Request: TYD Example: Sent: TYD Request radio type. Response: TYD KK,0F Confirm:

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Description: Moves up one memory location or one frequency step. Menu Item n/a Command: Modify: UP Response: UP Notes: Same as rotating Tuning Control one click clockwise. With Fine Step enabled, this steps to the next nearest multiple of the current Fine Step whether or not it started on a multiple. See DW. Example: Sent: UP Have transceiver move up. Response: UP Confirm:
VFO, MR, CALL, INFO & Fine Step
Description: Select VFO, MR, CALL, or INFO memory of the active (control) Rx. (each frequency Menu Item n/a band, 0-E, has a VFO memory) VMC does not change the control Rx except for VMC 0,4. Command: Status Request: VMC [Rx] Modify: VMC [Rx], [vmc]. Response: VMC [Rx], [vmc] Where: [Rx] A/B [vmc] Mode 0 A 0 VFO also Fine Step Tuning off 1 B 1 MR 2 CALL VMC 0,3 is invalid (N response) 3 Fine Step Enable (VFO mode Rx A only) VMC 0,4 switches from Rx A to B 4 INFO channels recall (always sets Rx B) Notes: The response is "N" for the off Rx (DL off) and for the non control Rx (DL on). See BC, FQ and FST. Starting from MR, CALL or INFO, VMC 1,0 is needed before VMC 1,3. Example: VMC 1,4 updates the display, turning Fine off with VMC 1,0 does not. Sent: VMC 0 Request vmc of A Rx. Response: VMC 0,0 Transceiver responds A Rx is in VFO. Sent: VMC 1,1 Set Rx B to MR. Response: VMC 1,1 Confirm: Rx B MR

VOX Transmit Enable

Description: Enable / Disable VOX. Command: Status Request: VOX Modify: VOX [vox] Response: VOX [vox] Where: [vox] Example: Sent: VOX Response: VOX 0 Sent: VOX 1
State Off Enabled Request to enable VOX. Response: VOX is off. Enable VOX.
Response: VOX 1 Confirm: VOX is on.

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VFO Read
Description: Reads data of the specified band VFO. Menu Item n/a See parameter tables in Command Parameter Tables at front. Command: Status Request: VR [band] Response: VR [band],[freq] Where: [band] Rx Name - Freq MHz. [band] Rx Name - Freq MHz. [ham] 0 A 2m 137-B Air 108-137 [ham] 1 A 1.25m 216-B 2m 137-174 [ham] 2 A 70cm 410-470 A B VHF TV 174-B AM 0.1-1.8 B B 1.25m 216-B HF 1.8-29.7 C B 70cm 400-B 6m 29.7-54 D B UHF TV 470-B FM 54-108 E B 23cm 806-1300 The cellular band is locked out 824-849 & 869-894 [freq] See Freq Parameter Table in Command Parameter Tables at front. Scan Lockout excluded. Note: The band number here also specifies the associated receiver. This addresses ONLY the VFO setting, not a Tx frequency for split. For Air band 8.33 kHz steps, see Step Table Note on page 8. Example: Sent: VR 9 Request data for Rx B 2 m VFO band.

band freq stp of R T CT DCS T# C# D# offset Mod
Response: VR 9,00145330000,0,1,0,1,0,0,41,00,000,000600000,0 A frequency of 145.33 MHz. CTCSS is on at 254.1 Hz. Neg. offset of 600 KHz., FM

VFO Write

Description: Loads data into the specified band VFO, but does not activate it. See RBN. Menu Item n/a See Command Parameter Tables at front. Command: Modify: VW [band],[freq] There is no Status Request, see VR. Response: VW Where: [band] is from the Command Parameter Tables at front. [freq] See Freq Parameter Table, Command Parameter Tables at front. Scan Lockout excluded. Note: See Receive Band number RBN & VMC to listen on a VFO frequency. This loads ONLY the VFO setting, not a Tx frequency for split. See BC, RBN and VMC. For Air band 8.33 kHz steps, see Step Table Note on page 8. Example:
Sent: VW 9,00145330000,0,1,0,1,0,0,41,00,000,000600000,0 Request VFO to 145.33 MHz. CT = 254.1 Hz. Offset of 600 KHz., FM Response: VW Confirmation response is only the mnemonic.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI VXB VOX On Busy
Description: Force VOX transmission even if Rx A or B squelch open. Command: Status Request: VXB Modify: VXB [val] Response: VXB [val] Where: [State] State 0 Off - Audio will not cause key-up if squelch opens. 1 On - Audio will activate the VOX if squelch is open. Note: Does not disable VOX if it is enabled. Example: Sent: VXB Request Status Request of VOX on Busy. Response: VXB 0 Transceiver responds VOX on Busy is off. Sent: VXB 1 Enable VOX on Busy. Response: VXB 1 Confirm: VOX on Busy is on.

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Menu Item 20

VOX Drop Delay

Menu Item 22
Description: Set/Read the VOX dropout Delay time. Command: Status Request: VXD Modify: VXD [val] Response: VXD [val] Where: [val] Time [val] Time ms ms ms ms ms ms ms ms Note: Does not disable VOX if it is enabled. Example: Sent: VXD Request VOX delay time. Response: VXD 1 Response: VOX delay time is 500 ms. Sent: VXD 0 Set VOX delay time to 250 ms. Response: VXD 0 Confirm: VOX dropout delay time is 250 ms.

VOX Gain

Menu Item 21
Description: Set/Read the VOX Gain. Command: Status Request: VXG Modify: VXG [val] Response: VXG [val] Where: [val] is a number from 0 to 9. The default value is 4. Note: Does not disable VOX if it is enabled. Example: Sent: VXG Request VOX gain. Response: VXG 4 Response: VOX gain is 4. Sent: VXG 9 Set VOX gain to level 9. Response: VXG 9 Confirm: VOX gain level is 9.
Kenwood TH-F6A Control Reference Ver 2.0.1, Steve Noskowicz, K9DCI Appendix
Air Band 8.33 kHz. step programming.

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From the radio keyboard, you can only enter to the 1 kHz. digit. To get the 'odd' frequencies (x.33 and x.67) you enter it as a rounded up frequency and the radio accepts it down to the next lower multiple. 8.33 kHz. steps Enter Result 118.009 -> 118.00833 118.517 -> 118.51667 I haven't checked the entire MHz. range, but for several one MHz. segments, the following is what I observed. Not all frequencies can be programmed with the FQ command. The first 100 kHz. of each MHz. (e.g. 119.000 119.100) can be programmed by rounding the FQ frequency to the nearest 10 Hz. (as displayed on the radio). Starting in this first 100 kHz., you can also use UP and DW to step into the unprogrammable region above the first 100 kHz. FQ command FQ 00119000000,2 FQ 00119008330,2 FQ 00119016670,2

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PY1NR provides feedback and re-endorses previous statements on turning the FETs around PY1NRFeedback
From: ts-940@yahoogroups.com [mailto:ts-940@yahoogroups.com] On Behalf Of John Rotondi Sent: Friday, 17 March 2006 10:51 p.m. To: ts-940@yahoogroups.com Subject: [ts-940] FET Reversal Fix Notes Dear Fellow TS-940 usersJust a quick post to let others know this information, which you can use as you see fit: I have now fixed 2 TS-940SATs according to the findings of PY1NR who first detailed the reversal of 2 FETs in the TS-940, based on factory mistakes in the PCB silk-screening. After doing my own radio, I absolutely found a significant increase in received signal levels, with no audible increase in noise floor. I wondered why other users were not rushing to do the fix- and then saw several posts denying the validity of the fix. However, since I did not effectively document this in a scientific manner, I could not effectively offer valid 'proof' of the results. When I mentioned this to one of my RACES group leaders- who also owns a TS-940- he decided that we would to do the 'fix' to his unit- but this time, we would document the results using a repeatable local test signal. The documented results: after each FET was reversed, we found a 1 S-unit improvement in received signal level using our local test signal in the 20 meter band, for a total of 2 S-units receive gain improvement. Now, there is much conjecture regarding the dB value of S-units, and other TS-940 users may know what these 2 S-units on the TS-940 meter mean in terms of dB. Generally, from my research, each Sunit may represent 5 or 6 dB of signal, which means the fix has increased receive gain 10 to 12 db. Certainly nothing to sneeze at: being able to give one of the finest receivers made the full scope of RF gain that it was originally intended to have - at no cost, and without negative repercussions? As the bands wane on the downside of the sunspot cycle, and running only a vertical 10 feet off the ground, I am finding I can use all the noise-free gain available to hear DX! At any rate, this was my experience, which I humbly offer to the TS-940 user community. Wishing you all good DX! 73, John, WA2OOB Ventura, CA

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layout of the AGC identical to the TS-930. KINR_email KI4NR advises the rising S meter caused is leaking in C128 and C130. On the Editors radio C128 has been replaced and does not fix the rising S meter. When time permits C130 [and / or other AGC capacitors] will be replaced and when replacement has been shown to remove the rising S meter this web page will be updated to confirm that. At that time this section of the web page will be restructured to separate communications about IF circuit diagram from the rising S meter problem.
Kenwood appears to have done the following: Please note there are 2 mistakes. 1. First incorrectly labelled the schematic: (with resistor values around the wrong way)
2. Then incorrectly labelled the PC board [to correct the mistakes on the schematic] so correct resister values put in circuit. (For example the position of R150 was labelled as R149 on the PC Board, which resulted in a 150K resistor being put at the R150 position.)

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Areas in grey below should be disregarded.
Significantly improves the AGC timing function: After modification: - You hear weak signals a lot better. - S meter with AGC SLOW ON becomes quite responsive and lively in the region of S1 to S4 signals. --Before S meter did not move much in S1 to S4 region. --Before it would take a strong signal to lift the meter suddenly to S4. I always wondered why the TS-940 behaved differently to other transceivers [TS-930S, TS950SDX] which react much faster over S1 to S4.
Mike KC8ZNW on 25/4/05 describes this same behaviour to the Kenwood.net.
Hello everyone I have a question about the movement of my 940's meter. It seems

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that it barely moves on some signals which are perfectly readable, other sigs give me 8 or 9 and I have even heard an occasional 10DB+ movement. My TS830S will give me a 2 or 3 sunit increase when I switch the antenna to it for the same signal. Is this an effect of the sensitivity of the receive section? Or do I have a malfunction? In addition my VFO exhibits the occasional hiccup on the last 2 digits on small movements of the knob. I understand this may be caused by solder joints. TIA, Mike KC8ZNW
Executive Summary of AGC Mod Its easy to modify a TS-940S to hear better (or as well as) a TS-950SDX. When fixed, TS-940 really pulls out those very weak signals. Simply swapping 2 resistors around, will enable this rig to hear as Kenwood designed and intended in Kenwoods original circuit diagram. The error is on the IF board: Kenwood printed labels for R149 and R150 around the wrong way!!! As assembled by the factory, (the outcome is) in the main signal path, a 2,200 Kilo-Ohm resistor ends up where a 150 Kilo-Ohm Resistor should be. Being 14 times larger the 2,200 Kilo-Ohm resistor (incorrectly) significantly degrades the signal. Swap the resistors around and the receiver hearing improves significantly!!! Kenwood have confirmed the resistors are in the wrong place. Their emails are below: Probably these resistors in the wrong place occurs in every TS-940S produced.

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worked LZ1YE and YV5YMA right after on 17 meters! Very low noise compared to before the swap. I highly recommend it. Thanks to everyone here, and Jeff ZL4AI, Mike KC8ZNW I'm still debating the transistor gain swap..????
From: ts-940@yahoogroups.com [mailto:ts-940@yahoogroups.com] On Behalf Of Dale Sent: Tuesday, 12 July 2005 5:37 a.m. To: ts-940@yahoogroups.com Subject: [ts-940] Re: AGC mod works great!! Hello Mike, I'm having both mods done to my 940 now and I hope the out come is like yours. I'll post after I get my 940 back and let everyone know how it goes. I have a very late model serial number which is 20700050 and it still had both mistakes in it, so I hope this will improve on the already great recieve on the 940. 73 and enjoy your improved TS-940S. Dale, KD5UVV --- In ts-940@yahoogroups.com, "mikeferyok" <mikeferyok@y.> wrote: > My friend and I did the R149-R150 swap and it improved the gain and > noise level. Adjusted the VR3 for a proper zero on the meter and > worked LZ1YE and YV5YMA right after on 17 meters! > Very low noise compared to before the swap. I highly recommend it. > Thanks to everyone here, and Jeff ZL4AI, Mike KC8ZNW > I'm still debating the transistor gain swap..????
-----Original Message----From: Articles@eham.net [mailto:Articles@eham.net] Sent: Sunday, 24 July 2005 3:52 p.m. To: jaking@es.co.nz Subject: [Articles] Improve TS-940 Receiver for Weak Signals Posted By KB9IV Well I finally got around to the AGC mod. What a fantastic difference.it also improves CW to my ears. In addition the AGC mod also seems to improve useable weak sensitivity and decreases distortion. Forget the "FET reverse" project. NO difference here, it's not worth the risk and time. Best 73, Bill KB9IV
-----Original Message----From: Bill & Becky [mailto:wmarvin@hickorytech.net] Sent: Sunday, 24 July 2005 4:00 p.m. To: jaking@es.co.nz Subject: 940 AGC Change Hello Jeff, Thank you for the info on the "AGC" correction. What a fantastic difference here!!

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Makes a good 940 a great 940.I can now hear much better not. FET reversal change useless.not worth the bother. Have a Great Day!! 73 Bill KB9IV.Minnesota

I found the

6. http://www.eham.net/articles/11090
-----Original Message----From: John [mailto:hydroaction@cfl.rr.com] Sent: Friday, 29 July 2005 4:03 a.m. To: jaking@es.co.nz Subject: Your 940 observations Jeff I appreciate your efforts on the 940. I have to say the AGC deal is not quite right. I have work on more 940 that I can remember. I have known for years the silk screening of the numbers on the circuit board is wrong. but the resistor placement on the board is correct. also the service manual is wrong on the schematic. The 2.2 Meg ohm resistor is in parallel with C-127..the 68K or 150K resistor is in series with C-126 which give you the base line time constant when AGC switch is in the fast postion. This is the CORRECT arrangement. Also if you look at the TS -930 that has the identical AGC circuit this is how it is on that radio too. The reason why you get the AGC rise when the radio has been sitting is the Capacitors are leaky and by swapping the resistors around helps correct that problem. I have had 940's have the rising S meter problem and changing and the caps C128, C130 in the AGC fixed it. This circuit is a Hi impedance type with FET very sensitive and crazy things happen. I have check many, many 940 I have repaired new and old serial numbers and have not found one yet that had the resistors in wrong. Look at the TS930 schematic to see what I am taking about. 73 John KI4NR Editors note:

THE INITIAL PROBLEM SYMPTOMS:
ZL4AI discovered this while searching for the a fault described below AGC: Only happens in SSB: If TS-940 left not running for a couple of days, when you turn it on, with the AGC turned off or set in fast position, then the meter needle goes to up 25db + 9 (approx). The signal is diminished like RF gain turned up. Over the next 25 minutes the meter needle slowly moves it way back to S0. SSB in normal position, and TS-940 turned on this does not happen. Needle is initially at s0. During the first 25 minutes if you switch between off - fast - normal then the needle goes back to zero in less time. say 20 minutes. If TS-940 left for a couple of months, and then turned on same behaviour but worse. Meter needle goes full scale right in all positions (off - fast normal) It takes longer say 40 minutes for the needle to move to the s0. then ts-940 functions as described above. =========================================================================
After R149 and R150 changed back to positions Kenwood intended in the circuit diagram, the result was: -The fault of the rising S meter when cold disappeared. - S meter dropped back to S1 on both AGC OFF and AGC SLOW, with no antenna signal. Needed to adjust VR3 to bring the S Meter to S0.
ACKNOWLEDGEMENTS TO PERSONS WHO HELPED SOLVE THIS T.Soranaka Kenwood Japan was most helpful. You will see in the emails below Kenwood have readily confirmed that these components are around the wrong way. Then in a third communication (above) confirmed they are correctly installed.

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Traian Belinas traian@deck.ro who diagnosed the problem and really understands these circuits. Traian appears to have amazing skill and after reading the symptoms pointed me to look at R149. From there it became obvious the circuit was not assembled according to the circuit diagram.
Garey Barrell 'k4oah@mindspring.com' Who provide some very useful advice on functions of components and explanations how to read the circuit diagrams. ==============================================================

A CAUTION:

Not all IF boards are identical. I installed another IF board installed as per factory spec with R149 and R 150 in their other components position in my TS-940. It did not have the rising S meter problem. But it was not sensitive to weak signals
==============================================================
COMMUNICATIONS WITH KENWOOD JAPAN BELOW:
-----Original Message----From: Customer Service Section [mailto:css@kenwood.co.jp] Sent: Tuesday, 15 March 20057:11 p.m. To: jaking@es.co.nz Subject: Re: Question about TS-940 R149 and R 150: Appear to be in wrong places! Dear Customer, Thank you for your reply. I suppose that currently R149 and R150 are mounted correctly as the screen printing lettering R149 and R150 are reversed. Please confirm actual resistors comparing the circuit diagram. The circuit diagram is correct. Yours sincerely, T.Soranaka ++++++++++++++++++++++++++++ CustomerSupportCenter Kenwood Corporation (Japan) URL: http://www.kenwood.com/ Email: css@kenwood.co.jp ++++++++++++++++++++++++++++

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----- Original Message ----From: Jeff King To: 'Customer Service Section' Cc: k4oah@mindspring.com ; traian@deck.ro ; Bill Bailey ; Ken McVie Sent: Tuesday, March 15, 20051:53 PM Subject: RE: Question about TS-940 R149 and R 150: Appear to be in wrong places! Dear T.Soranaka Thank you for your advice. Could you please advise if it would be advisable to swap R149 with R 150 and vice versa, so the TS-940 functions in accordance with the circuit diagram? Yours sincerely Jeff King -----Original Message----From: Customer Service Section [mailto:css@kenwood.co.jp] Sent: Monday, 14 March 200510:29 p.m. To: jaking@es.co.nz Cc: kcc-amateur@kenwoodusa.com; sabura.tech@kenwood.com.au Subject: Re: Question about TS-940 R149 and R 150: Appear to be in wrong places! Dear Customer, We are sorry for inconvnience. I have checked with our communication department as to R149 and R150. Unfortunately reference number of R149 and R150 on the borad are reversed. R150 and R149 are 2.2M and 68K or 150K respectively as shown in the Service Manual. Yours sincerely, T.Soranaka ++++++++++++++++++++++++++++ CustomerSupportCenter Kenwood Corporation (Japan) URL: http://www.kenwood.com/ Email: css@kenwood.co.jp ++++++++++++++++++++++++++++ ----- Original Message ----From: Jeff King To: css@kenwood.co.jp ; kcc-amateur@kenwoodusa.com ; sabura.tech@kenwood.com.au Cc: k4oah@mindspring.com ; traian@deck.ro ; Bill Bailey ; Ken McVie Sent: Saturday, March 12, 20056:41 AM Subject: Question about TS-940 R149 and R 150: Appear to be in wrong places! Dear Kenwood Customers Services, I have found that when emailing Kenwood USA about a Kenwood USA product I got redirected to contact a Kenwood representative close to my home location. I am not sure who is best to send this to. So I am sending it onto to all Kenwood contacts. Thank you for your recent replies. While trying to find a fault in my TS-940 I have been going over the IF board. It appears to me when the board was made it was marked with the screen printing lettering of R149 being where R150 should be and vice versa. I have followed the board traces both in the Service Manual and on the back of a board, and these resistors both seem to be in the wrong place. This means: Specified in First Service Manual:

===========================================================================
-----Original Message-----

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From: thomas hohlfeld [mailto:thomas_hohlfeld@hotmail.com] Sent: Wednesday, 27 April 2005 10:42 a.m. To: jaking@es.co.nz Subject: RE: ts-940 Hi Jeff, thank you for your reply and congrats for the informative web site. I read about the PIN diode mod in a web message. I replaced diodes D9 through D20 of the RF board by the PIN types BA479. I did not replace D3-D8 because these switch a frequency too low for the BA478 to be an effective PIN. I checked the BA478 and found them to be good at frequencies above 2 to 3 MHz. The BA479 have been offered in different versions and it is important to use those which are designed for HF (not VHF). Certainly, other PIN diodes may also be useful. The IMD of my 940 improved by about 5 dBm after this mod. For re-alignment of the receiver, I mainly followed the instructions of the service manual for the RF and IF amplifier stages (I did not align oscillator and PLL circuits). I have a sweep generator (Rohde & Schwarz SWOB 5 equipped with log amplifier), which was very helpful to optimise the bandpass filters on the RF board. I established RX sensitivity with a HP8640B RF generator together with a home made audio voltage detector to determine an audio increase by 10 dB. I have two of the HP8640B, so that I am able to determine receiver IMD. The HP8640B are quite famous, since they produce a very clean RF signal and are sold at a reasonable price. By the way, I own two TS940 and use one of them for experimental modifications which are more critical, so that I would not really recommend others to reproduce them. If you are interested anyway, I will report on that later. Its past midnight now. 73 for today, Thomas >From: "Jeff King" <jaking@es.co.nz> >Reply-To: <jaking@es.co.nz> >To: <thomas_hohlfeld@hotmail.com> >Subject: RE: [ts-940] Re: Why don't more people use this group? >Date: Mon, 25 Apr 2005 09:09:42 +1200 > >Thomas > >I found your review of the FETS most interesting. >My reason for writing is to ask you to tell me more about the pin diode modifications you have undertaken. >Where are these diodes and what do you do to replace them? >What else did you do to realign receive? >How did you establish the 0.15 uV sensitivity.? > >Yours sincerely >Jeff King ZL4AI

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QRG. But I compared the generation of harmonics by the Kenwood diode and the BA479 at lower frequencies and found the BA479 still to be better than the Kenwood diode even at frequencies down to 100KHz. The above measurements also show that the BA479 has a slightly higher insertion loss than the Kenwood diode. This is a well known disadvantage of pin diodes (also adressed in the excellent articles on your web page). In the case of the BA479, however, the effect is less than 1dB and therefore probably negligable in the 50 Ohm system of the TS-940. To confirm this, I also used a dB meter to determine the insertion loss of two Kenwood diodes in series compared with two BA479 in series. At 17 mA diode current, two Kenwood diodes produce a loss of -0.2dB at 1.75 and -0.1 dB at 3.5 though 28 MHz. Two BA479 in series cause a loss of 0.8 dB at 1.75 and 3.5MHz and -0.7dB at 7 through 28MHz. So there is a clear difference, but probably without much importance. What are the consequences? As long as a broadband antenna feeds the TS-940, the front-end before the bandpass (diodes D3, D5. D19) will probably be improved by changing into suitable pin diodes, such as the BA479. Those who use the TS-940 only with a beam antenna (e.g. 20-10m), which is unlikely to deliver large signals at 80 and 160m, will probably not have much benefit. The two switching diodes between the bandpass filters and the preamplifier may also be replaced by pin diodes at the lower bands (D6, D8. D14 and D21). I would not recommend to exchange D16, D18 and D20, because the original diodes are already excellent at the higher bands and the pin diodes would add nothing else than a (minimal) increase of insertion loss. In addition to the front-end diodes, there are also numerous switching diodes in the IF unit. Particularly those before the 8MHz crystal filters may be considered for replacement by pin diodes. I can imagine that this will improve narrow-band intermodulation. Id be curious if anybody else has experience with this. If not, I may check out this point in future. --------------Your last mail says you ordered 40 BA479 diodes, so it seems you found a source. I for myself also ordered 50 BA479 from Schuricht, here in Germany. Its good to have some on stock for future projects and people say these parts are likely to be replaced by SMD types in future. If you still need BA479, let me know and I will try to help. By the way, there are probably excellent alternatives. The TS-940 uses in its front-end an attenuation pad which is part of the AGC (D23 and 26, MI204). I tested these and found they are even a little better than the BA479. The problem with these is that they are hard to obtain. --------------Thank you for mailing the discussion on the reversed Q10/Q4 problem. Although I was unable to find a difference in my test setup (as I reported earlier), it is certainly possible that there is an asymmetry of the internal capacitances that did not become apparent in my measurements. I think I should try out this mod and do some measurements, but it may take a little until Ill have time. It would also be interesting to see how the increase in sensitivity, if it really occurs, will change the receivers dynamic range. --------------Finally, my congratulations for your exciting web page! You did a very good job in digging out all the fascinating information about and around the TS-940. Its a pleasure to contribute. Best regards,

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out on SSB, the IC meter read over 16a. The ohm meter read 8.5a to 9a Adjument of the IC meter adjust pot fixed that. Then, on a fishing expedition, I look at the micro processor board, and fixed several fish eyed solder joints, no help, but made me feel better. Then, under the Het. Osc. on the PLL unit there was a piece of black conductive foam that had deteriorated. Also, it had a green/white residue covering it. I cleaned all of it, and removed the rest of the foam. It helped alot. I had to readjust VR2 back down to 110w or so, and the CW output jumped up to 15-18w. But still, that is it on CW. Thanks for all of your help! Keith Spainhour, KT4XW
PLL BOARD 2: Remove the Wax from the VCOs
From: Garey Barrell <k4oah@.> Date: Thu Oct 9, 2003 1:49 pm Subject: Re: [ts-940] Welcome k4oah Fred This is an indication that one or more of the PLL's are unlocked. It will only get worse! The two VCO's under the speaker (two layers down, of course!) are "potted" with a sort of beeswax. Over time this wax becomes contaminated and the VCO's become unreliable. I fixed mine by using a heat gun (judiciously) to melt the wax out of these two compartments. Standing the transceiver on end, tipping it toward me and putting a piece of cardboard under the shield can to catch the wax as it drips out. Some will run out 'under' the shield, but it can be picked off with a Q-tip stick or other. The alignment was not changed in either circuit, but it wouldn't hurt to check the adjustments in those two areas after the "meltdown". They are simple peaking adjustments. Solder troubles are more common in the TS-440 and TS-930, but could be a problem in the 940 as well. My AVR board had a LOT of solder problems, but I have not reworked VCO areas. 73, Garey - K4OAH Atlanta
PLL BOARD 3: Identify which PLL is not locked
From: "k8aicurt" <k8ai@.> Date: Tue Nov 30, 2004 1:57 pm Subject: Re: PLL unlock k8aicurt

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Well, I finally got it working. There is a line on the PLL board that goes to the control unit that's labeled "UL". This line goes low if one of the individual PLL IC's is in unlock from both the PLL board and the carrier board. If you have dots on the display, first disconnect connector #2 on the PLL board and check the voltage at connector #5 pin 5. If the voltage is "high" (~4.6V) then the unlock is on the carrier board. If the voltage is still low (~0V) then replace the #2 connector and then check the voltage on the individual IC's. Check the voltage on IC8 pin 2, IC9 pin 2, IC19 pin 2 and IC17 pin 7. The one(s) that has(have) a low voltage on them are the PLL's out-of-lock. Troubleshoot that PLL circuit. Curt, K8AI

PLL Board 4:

PLL Board and RF Board and PLL out of lock
kc0bi <kc0bi@yahoo.com> wrote: Hello everyone. I am troubleshooting a TS-940S and it has at least two problems I tackled the easy one first - it had a bad optical encoder and I replaced it with a known good pull from a TS430S. This unit definitely has PLL problems - the exact frequency that it fails changes with heat but the general problem is this: Above 10 MHz it works correctly in USB and LSB - below 10 MHz it works only in USB. There is an area between approximately 9 MHz and 10 MHz where it is probably unlocked but the frequency display still works - and that point changes with heat. Below 9 MHz it gives the "all-dots" display indicating PLL unlock (but seems to still work in USB). I am using the built-in 100 kHz calibrator as a signal. After a period of time the nice sounding sine wave becomes a very "ratty" sounding tone. This is true regardless of which sideband and at any frequency I've tried. Does anyone have an idea of where to start looking? One of the PLL's must be losing lock. Thanks in advance and 73, Harold W0HJW (formerly KC0BI) From: [mailto:TS930S@yahoogroups.com] On Behalf Of Bill K0ZL Sent: Wednesday, 19 October 2005 11:47 p.m. To: TS930S@yahoogroups.com Subject: Re: [TS930S] TS-940S Phase-Lock-Loop Problems? Drop your RF unit down (rig up on it's left side) and resolder all around the VCO area, which is about the front 2-3" of the board. Also resolder around the RF RX preamp and first mixer area (that is on the same unit, the narrower shielded area, about mid-way back. Be patient, you have about a two hour job there. Use bright light and drugstore reading glasses to make sure you get them all and watch for bridges as you solder. Much easier to find and clean them "as you go" rather than discover them later. Next, get the PLL unit out, scrape the adhesive pad from under the VCO nearest the front right cornner of the board (as the rig is facing you), and Resolder that area about 1 sq inch.

The TS-940 Service manual on pages 72-73 is not very easy to understand: ZL4AI have prepared the extended service instructions: Measurement Item 6.1 S meter Condition BAND: 14.175MHz SSG output : 14.175 MHz 0dB/u SSG output: 8dB /u AGC: FAST SSG output: 40dB /u SSG output: 100dB /u

Test equipment

Adjustment Terminal Unit IF Part VR3 Method Adjust meter nee for mechanical f Set the VR1 to CCW ADJ to S1 ADJ to S9 Verify full scale Repeat ADJ S1 a S9

SSG AF V.M SP SCOPE

RF 6.2 S meter 6.3 6.4 6.5 Red are items Kenwood missed out IF IF

VR1 VR1 VR4

dBm values quite interesting to compare with other expert observations, tahts S Meters are not linear: To: <amps@contesting.com> Subject: [AMPS] s meter calibration From: w7iuv@nis4u.com (Larry Molitor) Date: Tue, 13 Jun 2000 22:57:40 +0100 At 07:45 AM 6/13/00 +0100, Ian White, G3SEK wrote: >According to the lab reviews in the magazines, most modern receivers seem to be calibrated so that the difference between S9 and S9+20 is pretty close to 20dB. Below S9, the scale looks linear but the dB per S- point is not1 It typically takes many more dB to get from S2 to S3 than it does to get from S8 to S0 - often less than 3dB per S-point at the top end. >It doesn't have to be that way - there are engineering solutions that could easily deliver the full IARU specification - but when everybody on HF is "five nine" anyway, who cares any more?

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> >73 from Ian G3SEK Ian and all, As has been said before, the manufacturers correctly assume that the majority of buyers are technical idiots. Have a S-meter that has 1 dB per S-unit and about 5 uV for S 9 is a good marketing thing. Besides it's a lot cheaper to build. I would hope that anyone who actually cares about such things would take the time to "calibrate" the meter on their store-bought radio. Since I do this with all my radios, I would not care to pay extra for a manufacture to make a feeble attempt at a real meter. Using a HP8648C generator (at 14.1 MHz) this last time, I produced the following chart for my FT1000D: S1 = -103.5 dBm S2 = -101.5 dBm S3 = -98 dBm S4 = -94 dBm S5 = -90 dBm S6 = -85 dBm S7 = -80 dBm S8 = -75 dBm S9 = -70 dBm +10 = -60 dBm +20 = -51 dBm +30 = -42 dBm +40 = -33 dBm +50 = -24 dBm As you can see, it's kinda poor at the bottom end, but quickly stabilizes at about 5 dB per S-unit. With S-9 being within 3 dB of 50 microvolts and 5 dB per S-unit, this particular FT1000D has the best Smeter out of the 10 or so radios I've checked. With a chart like this handy, it gives you a real good idea just how good the other guys antenna is or how much gain his amp really has. While the guy on the other end is usually an idiot and won't believe what you tell him, at least you will know for sure. Since it's so easy to do this, I'm surprised there aren't more folks with handy little charts for their radios. I know, not everyone has a room full of good test equipment. But I bet most people on this list know someone who does or has access to it one way or another. Give it a whirl, you might be amazed! 73, Larry - W7IUV

TS-940 AVERAGE OUTPUT POWER SSB
On the air conversations concerning a kenwood newsletter mod to change ALC delay time called for putting a 2.2k ohm across the top of r137 and r104 on the control p.c.b , along with a.47 mfd cap between pin 1 and pin 2 of connector 8 on the control board. The mod is excellent except.47 mfd is far too much. instead use a.005 to.01 mfd to keep from over driving. electrolytic not necessary, but if used, make sure nagative goes to shield wire pin.

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USE OF TS940S FSK RECEIVE FOR HF PACKET
TS940S owners may wish to use FSK mode for HF packet. FSK cannot be used for Packet transmit because the shift is 170Hz, and Packet requires 200Hz shift. This necessitates using LSB with AFSK. I'm not aware of any way to adjust the shift, and 170Hz is required for FSK on AMTOR and RTTY. It would still be nice to use FSK for receive, the primary advantage being the availability of CW filters which are inaccessible in LSB mode. By using the SPLIT capability you can use LSB for transmit and FSK for receive. Tune in signals with VFO-A on LSB. Then press A=B, switch to VFO-B, enable FSK, enable RIT and tune the offset to exactly -2.3KHz. Then enable SPLIT. When listening to signals, depression of T-F-SET will allow you to listen alternately with each VFO; the signal tones should be identical. If they are not, adjust the RIT on VFO-B (FSK mode) until they are. Optional CW filters are switched in by selecting the NAR ("narrow") filters with the NAR/WIDE switch (LED indicates NAR). I have found that this arrangement works quite well, and enhances the readability of received packets, especially under heavy QRM and fading. It is easier to adjust the CW filters (NAR/WIDE and VBT in WIDE mode) than the SSB Slope Tune controls. I would like to hear from other TS940S users who have tried this technique or others that enhance HF Packet operation. Send replies to WA1FMM @ W8AKF. 73.Dan / WA1FMM / Thousand Oaks, CA.
INQUIRY REGARDING USE OF ADDITIONAL RECVR.
I would be most interested in getting Information on how to use an additional receiver at the same time as the TS-940S is in operation (receiving, of course). (ED Note: We covered adding another receiver to 930, Issue 59, Page 54.) The User's Manual covers use of an additional receiver in lieu of the receiver of the 940 receiver section. I am the owner of a 75A4 which I've modified and updated over the 30 years I've had the receiver, and I find no other receiver comparable to it in many most significant ways. So I would very much like to know how to connect the 75A4 into the TS-940S for use simultaneously with the receive section of the latter. If this subject has already been covered in a previous newsletter, please tell me how to get a copy. (ED Note: Nothing published on this in back issues.) I'm confused as to whether I need to cut diode 130 and 135 on digital Unit B in order for the Xcvr to operate over the same frequency range as the receiver. Somewhere I noted that only diode 130 need be cut. (ED Note: Kenwood Newsletter No. 54 clearly states: D135 is for MARS frequency only. D130 is for Gen.Cover- age Transmit.)

GEIL CHIP

a chip available from Giehl electronics in Cincinnati that will slow the tuning rate to 2 khz per revolution on the main dial of a kenwood ts-940

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FEEDBACK FROM READERS
-----Original Message----From: DGB [mailto:dwibos@netnet.net] Sent: Tuesday, 5 April 2005 6:46 p.m. To: jaking@es.co.nz Subject: Re: [Kenwood] TS-940 Full description of AGC timing improvement which significantly improves receiver performance > Excellent job on your efforts/compilations Jeff. 73 Dwight W9YQ
-----Original Message----From: Curtis Benjamin [mailto:benjamic@michigan.gov] Sent: Wednesday, 11 May 2005 1:39 a.m. To: jaking@es.co.nz Subject: Thanks Jeff, thanks for setting up the TS-940 page. I hope it "takes off" and becomes "the" spot for '940 info. Curt
-----Original Message----From: Ed [mailto:ca.urso2@verizon.net] Sent: Monday, 23 May 2005 7:18 a.m. To: jaking@es.co.nz Subject: TS-940S Reciprocal Mix.Noise Mod - Correction Jeff: Congrats on your fine TS-940 Web Page. Keep up the good work! I wish to point out a text error in the letter from Rich, WZ4Z, regarding resistors R120 and R129 in the PLL Unit which should be corrected to 3.3KOhms each, NOT 3.3 Ohms as stated. This refers to a Kenwood fix given in their Bulletin 917 dated 3/2/87. Also, your AGC Timing Correction was applied on my rig (SN 806XXXX) and worked great! Sure enough, resistors R149 (68K on my equip) and R150 2.2Meg had been incorrectly installed by the Mfr. The board markings for those resistors were wrong. I am also following with great interest reversals noted by PY1NR. the developments regarding FETs

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73, Ed Alves KD6EU USA
-----Original Message----From: EL34GUY@aol.com [mailto:EL34GUY@aol.com] Sent: Thursday, 2 June 2005 3:37 p.m. To: jaking@es.co.nz Subject: ts-940 stuff Hi Jeff, Im getting my first 940 hopefully sometime next week. Ive been reading your website and it has some very helpful comments and recommendations. How hard was it to make the resistor mods you describe on the IF board? Also, I found an SO-1 for mine, how difficult are they to put it? Have you done any pin diode modifications? Thanks for the great website, 73 Mark W0NCL ==================================================================
-----Original Message----From: Traian Belinas [mailto:traian.belinas@deck.ro] Sent: Monday, 13 June 2005 5:05 p.m. To: jaking@es.co.nz Cc: eduardo@guisard.com; 'thomas hohlfeld' Subject: Re: TS-940S - Some few considerations
Hi all, Jeff, thank you for keeping me informed about the TS940 work and about your website, and please continue doing it. Please also pass any usefull info to me also, I am interrested about. Using switches for comparison of the normal/reverse FET state may be not feasible, even in the case of using shielded cables. The added hardware (switches and cables) will unbalance the mixer in the case of Q4 or may cause other Rx problems in the case of Q10, so the comparison may not be made this way or can be irrelevant. A better aproach shall be using hole contact pins for the FETs and reversing them one or another position for comparison. Don't let the contact pins there, don't forget removing them as the Q10 runs at high drain current, and so it runs normally very hot and its cooling is made mostly by the terminals conduction and by the PCB traces path.

-----Original Message----From: Eduardo Guisard [mailto:eduardo@guisard.com] Sent: Saturday, 11 June 2005 10:51 a.m. To: jaking@es.co.nz Subject: TS-940S Hello Jeff, I read the comments about the FIELD EFFECT TRANSISTORS AROUND THE WRONG WAY. I am PY1BR and together with PY1NR, we include all details about this MOD in my website www.guisard.com. The error was found by PY1NR. We know that in some cases the differences in the Rx performance or gain may not be important if you correct the FET position on the PCB. Please, let everybody know through your homepage about all comments we received from many Hams in http://www.guisard.com/Index_reviews.htm. There are many people around the world that agree with improvements after the FET's correction. Thanks and regards EG - PY1BR