This modification is read 535 times.
(IC-1275) Restoration of pass band tuning
Problem: ICOM has chosen to remove the PBT in the later models, and replace it with a "data level adjustment". This change removes the possibility to profit from the PBT in case of QRM or to use the PBT as a cheap CW-filter. Furthermore the two extra IF-mixings is done with only a minimum of filtering, making the receiver very susceptible to spurious IF breakthrough. This is often heard as high-pitch tones or as a high IF noise level. Solution: The solution is to re-wire the "data level" potentiometer so that it adjusts the PBT VXO-oscillator, and to re-install FI3. FI3 is a 455kHz ceramic SSB filter and can be bought under the type number: MURATA CFJ 455 K6. Implementation:
remove the capacitor (C61) fitted in place of FI3 solder in FI3 readjust R72 for proper IF gain cut wire PBTV (pin 4, P1/J1, MAIN, yellow) about 5cm from the plug (P1) cut wire AMO2 (pin 3, P2/J18, MAIN, red) close to the plug (P2) cut wire AMO3 (pin 4, P2/J18, MAIN, metal baird) close to the plug (P2) connect PBTV wire (the end not connected to the plug) with AMO2 wire (the end not connected to the plug) connect AMO3 (the end not connected to the plug) to +8V e.g. by tapping (pin 1, J4, MAIN, brown). connect the wire stubs on the plug (AMO2 & AMO3) together is you wish to use external modulation input for PACKET etc. adjust the coil next to X2 (PBT VXO) for correct middle PBT setting
This modification is read 520 times.
(IC-1275) Splitting into RX- and TX paths
Problem: This is a general transceiver problem. If you want to use the transceiver as part of a bigger setup (i.e. with external PA & preamp or with a transverter), it is convenient to have separate access to the RX and the TX of the transceiver. Otherwise you need two coaxial switches every time you add a new accessory. With split RX/TX paths you only need one switch - at the antenna. Furthermore split RX/TX paths eliminates the need for a change-over sequencer. On the other hand it is also nice to have the transceiver working normally when you are using it barefoot. Solution: The solution is to jump wire the RX path (between RX and the RX/TX switching) trough the rear side of the transceiver with 2 BNC connectors. In normal state these connectors are connected via a short cable. In case you need to "split up" the transceiver, you remove the short coax cable, and you obtain direct access to the RX. The TX is still available using the common connector. note: If you are always using your transceiver barefoot, without connecting any PA, preamp or transverter, this modification will offer no benefit.

Cut the lead (FM8V) conneted to (pin5, J6, potmeter PCB, green) about 4 cm from the plug
Connect the short plug end with R14 (on the potmeter PCB) by soldering it to the end that is connected to the plug (+8V) This will enable the FM RF GAIN in SSB/CW.

cut R30 open

This disables the SSB/CW RF GAIN, and you now have a variable input attenuation with a dynamic range of 10dB (IC275 with MI308/1nF) to 16 dB (IC475). Note: The IC-275 might have a shared PIN diode for FM RF GAIN and TX/RX switching. If you choose to split up the RX/TX paths, you must install a new PIN diode (MI301 or equivalent) on the RF YGR PCB to implement this modification. See the note under the section dealing with spliting the RX/TX paths.
This modification is read 515 times.

(IC-1275) Tuning speed

The tunning speed is set to a defaults of 100Hz, 1kHz, 5kHz or 1MHz depending on front plate setting and mode. These settings can be manipulated by D41 - 46 at the front plate. At least a setting of 10kHz is also available.
This modification is read 510 times.
(IC-1275) Frequency range & CTCSS tones
The IC-275 have capability to cover 138 - 174 MHz and the IC-475 has capability to cover 430 - 450 MHz. Because of hardware restrictions they might not be fully up to specifications in all of the band, but an extended range can be interesting for e.g. use with a transverter. It seems that the IC-275 has a parallel wide band preamp, that can be switch via the WBT pin on RF-YGR PCB. In the European versions the transceivers are wired for 1750 Hz repeater call, and they have no CTCSS capability. The transceivers have a built-in CTCSS encoder, so these functions can be restored. Both of these version dependent functions can be set by the diode matrix: D20 - D24 in the logic unit. I do not know the exact mapping, but a lot can be derived from studying the different frequency ranges and the diode matrix coding table found on the schematic diagram.
This modification is read 527 times.

Schematic of the ICOM IC-210.
Size: 1867 * 1355 = 265 Kb Part 1 of 4
Size: 1867 * 1355 = 245 Kb Part 2 of 4
Size: 1867 * 1355 = 265 Kb Part 3 of 4
Size: 1867 * 1355 = 255 Kb Part 4 of 4
This modification is read 321 times.

21-03-1999

(IC-2100) Icom IC-2100H Extended Transmit Mod
For the first time anywhere on the web, the Icom IC-2100H extended frequency transmit modification and mod instruction sheet. The socessor to the very popular IC-2000 unit, the IC-2100H has been around for a few months now and is selling for about $200 at most hamfests. The unit uncludes PL encode/decode, and 55 watts out at high power. But up until now the modification insturctions have been unavailable! Brought to you by: Spectracom Communications, for all your commerical radio needs call 732-989-1091 or e-mail to Spectracom98@webtv.net.MODIFICATION.NET W3EAX, Amateur Radio Association at the U of Maryland KB3CVD, UMBC Amateur Radio Club And amateur stations KC2AEI and W2SJW. Please give us credit when copying these instructions! 1. Hold down the second and third front function buttons while turning the radio on. Now turn it back OFF. 2. Carefully remove the large tuning knob and remove the two hex screws that hold the faceplate on. Pull the faceplate straight of the body without tilting it (you run the risk of bending the pin connectors behind the faceplate). 3. Turn the faceplate over and locate the main ic chip, set at a 45-degree angle. Just to the lower left and right of the IC, you will see the main pin connectors. Under the lower right corner of the left pin connector, you should see a marking on the pc board labeled as "D16". just below this should be the matching diode, close to the bottom edge of the board. Remove this diode and carefully re-assemble the radio(watch those faceplate pins!! The radio will now TX 136-174 Mhz. As far as i know, you do not have to reset the memory to make the mod work( i have 70 outof-band memories stored, all of them worked without resetting the unit!!!!! September 5, 1998 - KC2AEI
Thanks to Chris KB3HPF for the pics. Date: 03-02-2002 Subject: ic-2100h mod So D-16 is the diode to cut, or the one that looks like it? What is the number of the one you cut? Date: 06-03-2002 Subject: ic-2100H mod I just performed the mod and it worked like a charm. I would however, recommend only lifting one leg of the chip in case you screwed up and did the wrong one. User comment From: k1phs User comment From: Jason

"x"= D4 1SV50. Connect wire direct to cathode side of diode.
Front of the icom ic27h. viewed from bottom. Bring a thin single core shield audio cable through the hole on the rear of the set where the power cable comes out, there was quite enough space on my radio. Feed this cable up the side of the radio to the front panel and along to the PLL UNIT where the
other wires come in. Take the cable over to the VCO UNIT enclosure, where there are 2 small holes. Pick the hole closest to D4, solder the shield to the outside of the metal case and feed the inner conductor through the hole and direct solder to the cathode of D4 1SV50, keep the lead as short as possible.
This modification is read 740 times.
(IC-2700) IC-2700 RX/TX expansion
RX Expansion Modification 1. 2. 3. 4. 5. 6. Remove Top Cover. (6 Screws) Remove Bottom Cover. (6 Screws) Remove Front Display. (4 Screws) Locate the Logic Board. Remove W1 from the logic. Hold [SET], [SPCH] and turn radio on.

Expanded Frequency Range

AM Mode FM Mode 118-136 MHz 138-174 MHz 350-470 MHz
Tx Expansion Modification 1. Remove D16 and D17 2. Hold [FUNC], [A], [CLR] and turn the radio on. Expanded Frequency Range
FM Mode 138-174 MHz 350-470 MHz
That's what Icom's sheet said. I didn't follow it when I modified my radio and it worked very well. Here's what I did: 1. Remove power and antenna from the rig. 2. Remove the face plate from the rig (careful with the small hookup cable that attaches to the logic board). 3. Locate the "Zero-Ohm Resistor" W1 and cut it out with a fine-tipped set of wire cutters. W1 is clearly marked on the board and is along the top edge, just to the right of center of the logic board. In my rig, W1 looked like a 1/8 Watt resistor, solid white in colour. 4. Using the same pair of fine-tipped cutters, remove D16 and D17. They're the first two diodes slightly below W1, going towards the LEFT side of the rig. 5. Carefully re-attach the face plate, mic, antenna and power. 6. Press SET and SPCH together and power on the rig. Keep the buttons depressed for about 4-5 seconds as the radio goes through a reset. ALL MEMORY INFORMATION IS LOST!!!. 7. Re-program in your memories and there you have it! Futile Attempt at a diagram:
Front View with face plate detached. ________________________________________________________________________ | DDDDD W | | | | D67 | | ____ | | |HEAD| ___ | | ~~~~ |MIC| | |______________________________________________________________________| Where D = Surface Mount Diode Package W = Jumper W1

HEAD MIC

R O U N D B A T T E R Y ! ! ! # D # ! # D # ! # D # ! # D #

-#WW#-

-#D#-#D#- -#D# ! -#D#- -#D#! ! ! ! -#D#- -***-
This modification is read 932 times.
(IC-281) Extended Transmit for IC-281
By removing one of the diodes in the area mentioned above extended transmit is purported to be possible. I have not verified this since I don't need this capability but it is supposed to significantly extend the transmit capability in the VHF band. To enable extended transmit remove the diode that is most near the right hand bottom part of the board as indicated in the diagram above with -***-. Reassemble and reset CPU per instruction manual. Note:When you reset the CPU you loose all memory and have too re-program all.
This modification is read 899 times.
(IC-2AT) Coverage IC-2AT 140-150 MHz
If you have studied the schematic diagram for this radio, you will notice that pins 15 and 16 are not indicated on the programmable divider chip IC1 (TC9122). By simply connecting pin 15 thru a switch to pin 1, you will be able to move the radio up in frequency by 10 MHZ. Some of these radios were sold without covering 140-150 MHZ. The modification for this extended coverage is described below: 1. Open up the radio and locate the FLEXIBLE BOARD, this connects the thumbwheel switches to the MAIN BOARD. 2. At the MAIN BOARD end of the FLEXIBLE BOARD, add a jumper at location C4. There should already be a jumper at location C2.
3. At the thumbwheel switch end of the FLEXIBLE BOARD, remove the jumper which connects C3 and COM. 4. Reassemble the radio. Coverage is now 140-150 MHZ.(MARS/CAP) Now, if you activate the switch described above, the radio will now operate in the 150-160 MHZ range, after L3 adjustment, described below.
This modification is read 1054 times.
(IC-2AT) Operation and L3 ADJUSTMENT
1. Activate switch and dial up a known active frequency. 2. Adjust L3 until PLL locks up and radio begins receiving. (you need an active frequency to tell when this happens) 3. To return to 140-150 MHZ, repeat above steps with switch off. Notes and disclaimer 1. 2. 3. 4. Drill a hole in the case of the radio so that L3 can be adjusted from outside of the radio. The above information is presented for educational purposes only, and is not an endorsement of any particular practice. This MOD has been in operation for 6 years with no ill effects on the radio This MOD courtesy N2MOD.
This modification is read 885 times.
(IC-2GAT) Out-of-band transmit mod for IC-2GAT handheld 2M transceiver
Back side of display board: _____________________________________ I D505 I D507 D504 ___ I ___ ___ I___I I I I___I I___I -- + -I D506 Q506. I I I _o_-----_o_ J I hole for I I___I I I___I. I on/off-vol I o o I o o I control I I I I__________________ I -----K---------I I add diode: 1N914 or equiv. I I I

Picture 1 - The Murata filter fitted to the Main Unit PBA after the modification. Modification procedure 1. Remove all connections to the set, eg; power, antenna, mic, accessory leads etc. 2. Remove the 9 screws holding on the bottom cover. Position the radio so the front of it is towards you. All the mods are done to the Main Unit PCB (the largest PCB).
3. Remove the six screws holding down the Main Unit PCB. (Or is that seven??? I have a habit of losing the damn things!) 4. Disconnect the coaxial lead plugged into J2 on the right hand side of the Main Unit PCB. 5. Disconnect the internal speaker feed to J17, located at the rear right hand side of the PCB, next to the external speaker jack. Disconnecting these two feeds will make it easier to turn the PCB over to gain access to the solder-side. 6. Carefully pry the PCB loose. The "Ext Sp" and "Key" jacks on the back of the PCB make this quite awkward. The PCB will need to move towards the front of the radio in order to clear the rear panel. 7. When it's in the clear, the rear side of the PCB can now be flipped over. 8. Remove C279 (0.0047uF). This is located front left - see picture 2. 9. Remove the link near C279 designated as W159. 10. De-solder the other nearby holes associated with the filter. (These holes will be immediately obvious if you have a look at the pin-out of the filter).
Picture 2 - Location of filter area on Main Unit PBA 11. Solder the CFJ455K5 filter in position. 12. Re-orientate the PCB back to its normal position. 13. The blue wire going to the PCB just near J10 needs to be cut, preferably as close to the pin as possible. J10 is located front left of the PCB, near where the filter was just installed. You will find this much easier to do if you temporarily remove the connector plugged into J10. This blue wire is the "PBTV" line, the Pass Band Tuning Volts line, and was fixed to +4 volts, ie; set for the centre of the "normal" passband. Now there are a number of ways of providing this line with the adjustable 0 - 8 volts that is required. I shall now describe the method I used - using the (waste of space) "Data Level" control. 14. Disconnect the connector that goes to J20. This is the feed that goes off to the "Data Level" pot. Put this aside for now. 15. De-solder and remove J20 from the PCB. 16. In J20s place I mounted a vertical 10kohm trimpot - see picture 3.

Checkout Place the "new radio" into USB mode and note the enhancement of the highs at the CW end of the "Data Level" control, err make that the "PBT" control, and the enhancement of the lows at the CCW end of the control. Now, place the radio in the LSB mode and note the complementary effect. Needless to say, any modifications done outside of an Icom service centre will no doubt void any warranties on the radio. Having the PBT has been handy when trying to zero-beat TV carriers, although the bass response of the small internal speaker is not particularly good. A larger external speaker or headphones here will help. The poor bass response could be improved by increasing the value of C192, a 0.1uF capacitor in the audio line. I feel the PBT feature would be more useful in Europe than it has proved to be over here in VK, for the simple reason; there aren't as many 6MX ops over here - even with Summer Es - so QRM from another nearby station is rare. Happy "PBTing" and good DX! Thanks to http://www.qsl.net/vk4cp/ for the modification.
This modification is read 600 times.
(IC-701) Extended frequency converage on the ICOM IC-701 HF Transceiver
Grounding pin 14 on the rear panel accessory connector will extend the frequency ranges to:
Band - Extended coverage - Factory coverage ---------------------------------------------160m 1.0 - 3.0 MHz 1.8 - 2.0 MHz 80m 40m 3.0 7.0 5.0 MHz 9.0 MHz 3.5 7.0 7.3 4.0 MHz 7.5 MHz 7.5 MHz Receive Only

14.0 - 16.0 MHz

14.0 - 15.2 MHz 14.35 - 15.2 MHz Receive Only 21.0 28.0 29.7 - 21.5 MHz - 30.0 MHz - 30.0 MHz Receive Only

15m 10m

21.0 - 22.0 MHz 28.0 - 30.0 MHz
This modification is read 935 times.
(IC-701) Computer control of ICOM 701 via accessory connecter
The August 1984 issue of QST (page 19) has an article on computer controlling the ICOM IC-701 HF transceiver by it's rear panel accessory connector. Although the article describes controlling the radio by a dedicated Three-Chip Microcomputer which can be built for $20 (the cost of the three chips) if you already have some common parts. This project can easily be adapted to control the radio by an IBM PC. Please refer to the QST article for more information. The same interface and control commands also work for the IC-211 and IC-245 transceivers.

Bild 1 Stromlaufplan

Ausschneiden Bild 2 PC-Stecker
Bild 3 Layout ( vergrssert )

Bild 4 Lochrasterplatine

Bild 5 Lochrasterplatine Ltseite
This modification is read 3018 times.

(IC-706) FM Transmit Fix

(This article appeared in "Six News" Issue 59 and "Radio & Communications" April 1999)
Is your 706 not transmitting on FM properly? This maybe why Having taken my Icom IC-706 back for service twice before for the same fault, I was not prepared to be inconvenienced a third time! As it turns out IC-706s all over the World have been exhibiting the same fault. Ive had e-mail from other unhappy IC-706 owners as far away as the U.S.A. and the U.K. Upon checking the previous Fault Reports I noticed that the FM VCO had been tweaked. Hmmm There is a 9MHz VCO active during FM mode only which is modulated from the mic amp. Fault condition symptoms are;
Very low Output power (enough to be heard on a nearby receiver on the shack bench but that's about it). Carrier frequency is NOT what the dial indicates, typically 5 - 30kHz on the low side. Carrier tends to wander and sounds spurious.
The culprit I discovered that C267 a miniature SMT trimmer capacitor located see picture - 9mm to the right of the 9.0115 MHz IF Filter on the Main Unit was not re-flowed to the PCB to a satisfactory standard. There was insufficient solder paste applied during the printing process and the end result being a poor solder joint and an intermittent 9MHz VCO. After re-touching both pins of C267 with fresh solder it's performed faultlessly since. Although access to the offending area is easy you will need a very fine tip on your iron to get to the trimmer pin on the filter side without damaging the capacitor itself and disturbing two nearby 0603 chip capacitors. I cannot stress enough to successfully carry this repair out you need a very very fine tipped soldering iron, and ensure the tip is in good order.
Equipment Required Youll require the following tools;
Small Phillips-head screwdriver. Accurate Frequency Counter.

q q q q q

(Another receiver will do). Dummy Load, Power Meter & coax patch leads. Soldering iron with very fine tip. Fine solder 0.7 or 0.5mm. <![endif]--> De-solder wick if required.

From: "Len SantaMaria, KC2ADV" This file may be freely distributed as long as it remains intact, with no modifications, additions, or deletions. DISCLAIMER: I assume no responsibility for damage or inaccuracies contained in this document. In other words, USE THIS AT YOUR OWN RISK. It worked for me, however I don't know if it will work for you. WARNING #1: This mod requires the ability to remove surface mount diodes. Only those who are qualified to do this should attempt this mod. WARNING #2: This mod seems to erase all memory channels, etc. You may want to save this info for reprogramming. Disassembly: 1. 2. 3. 4. 5. Face the front of the radio towards you. Remove the three screws in a row across the middle of the top of the radio. Remove the two screws at the top rear (on the sides) of the radio. Pry the top cover off from the back. Disconnect the speaker at the connector. Modification: 6. Near the top rear of the main circuit board, there is an small, oblong metal can. Directly below the right side of this can is two surface mount diodes with a white silk-screened box around them. There is also what appears to be a circuit board part number just to the left of it (mine says B4916D). Remove the LEFT diode in the box. 7. To the left of this, there is a test point marked CP3. Just to the left and above this test point is another box with two *vertically* mounted surface-mount diodes (Note: there is also a place for 5 more *horizontally* mounted diodes, with 3 installed). Remove the LEFT vertically oriented diode. Reassembly: 8. Reconnect the speaker. 9. Put the top cover back on. Insert the top cover tabs into the slots and lower into position. 10. Replace all of the screws. My radio did not require a reset, however I did lose all of my channel memories. It seems to be able to transmit everywhere except below.5 Mhz. I have not tested the power output at all frequencies yet.
I hope this helps everyone who have been waiting patiently for this mod. Any comments can be directed to me: Len - KC2ADV email: lenny@handy-man.com.MODIFICATION.NET From: "Rafel" jarel@box43.gnet.pl If you can read this, its come from Your www: Len - KC2ADV email: lenny@handy-man.com. wrote:
. >Modification: >6. Near the top rear of the main circuit board, there is an small, oblong >metal can. Directly below the right side of this can is two surface mount >diodes with a white silk-screened box around them. There is also what >appears to be a circuit board part number just to the left of it (mine >says B4916D). Remove the LEFT diode in the box. >7. To the left of this, there is a test point marked CP3. Just to the left >and above this test point is another box with two *vertically* mounted >surface-mount diodes (Note: there is also a place for 5 more *horizontally* >mounted diodes, with 3 installed). Remove the LEFT vertically oriented >diode.

PA3HGT@ON1CED.WVL.BEL.EU

Here is two pictures from astra.
Here is anothe two photo from kb1vi

Date: 23-02-2002

From: Greg/K6QPV San Diego, CA. USA
Subject: Making 756P continuous Xmit 1.6 - 29.999 MHz Mods desired to use 756P as Xverter on 24 MHz which is out of its stock Tx range. I followed the suggested steps for making 756P continuous Xmit from 1.6 - 29.999. Bottom cover removed by 10 screws (6 on bottom and 4 on sides), no need to remove feet. CPU box is connected to mother board via two multi-conductor connectors. Easy to gently "rock" it back and forth, pops right off. Diodes on my Ver #2 were instantly identifiable. Heated one end, used very small blade knife to lift desoldered end. Left diodes connected and "hanging" by other end. Total time required approx 10 minutes. Piece of cake. No observable reduction in operation upon firing it up.
This modification is read 3371 times.

10-02-2002

(IC-756PRO) ICOM IC-756PRO CW Filter Shape Selection
Author: Greg Ordy - ordy@seed-solutions.com.MODIFICATION.NET

by Greg Ordy

Introduction The Undocumented BPF Indicator Two Ways to Specify the Filter Width Do It Yourself The Difference

Introduction

The ICOM 756PRO documentation is silent when it comes to describing the CW filter shape factor, and how it can be selected. ICOM tried to improve the situation with a brief mention of this topic in its Advanced Operation Guide for the 756PRO, but it does not clearly describe how to select the filter shape. I will try to do a little better on this page. I would like to thank Rob Peebles, W8LX, for bringing these capabilities of the radio to my attention. The 756PRO receive audio, coming out of a digital signal processing (DSP) intermediate frequency (IF) stage, is much different in character than other purely analog receivers. I have captured some of my impressions on another page. On CW, the filter response created by the DSP is extremely sharp. That is, signals outside of the passband are substantially attenuated. In the analog domain, sharp filters can lead to ringing, and other artifacts. Digital filters can have similar problems. In addition, it has been claimed that the 756PRO receiver highlights flaws (key clicks) in the transmitted signal. In other words, it hears the clicks better than other receivers. These various factors lead to CW receiver performance which some operators do not like. One suggestion to improve performance has been to alter the CW filter shape. Perhaps if the filter was not as sharp, the artifacts would not be as pronounced. Apparently a special DSP ROM (software) is available in Japan, but information on this modification has been difficult to obtain, and in any case, changing the DSP software is claimed to be a major project, in terms of taking apart the radio to access the relevant parts. It turns out that for filter widths of 500 Hz and less, it is possible to select one of two filter shape factors. One is the sharp CW filter, and the other appears to be the SSB shape factor, which is not as sharp. Calling one the CW shape factor and the other the SSB shape factor is my own terminology. Rob Peebles, W8LX, estimated the sharp CW shape factor to be 1.5, and the SSB shape factor to be 2.0. This page describes how to select the two different shape factors (in the CW mode, it cannot be selected in SSB mode).

Removing 1F unit 1. Pull the 2 knobs off and then unscrew the unit. 2. Unscrew 3 screws, G and 2 screws. H from the 1F unit. 3. Unsolder 2 points, J then remove the 1F unit.
This modification is read 2262 times.
(IC-T8) IC-T8 AM/FM/Wfm function
A few weeks ago ,I send out a request for info on the ICT8e to see if anyone knew how to select AM/FM/WFM. I had a few replies all saying that the rig selects the mode for a given part of its' Rx range. I have now found that in certain parts of its' Rx range, the pressing + holding of the "SET" H/L button opens the "MO" (Mode command ) It only works in certain places ! Apart from the fixed bands, the following might be of interest. (might!) 174.005 - 229.995 user select FM or WFM. 300.000 - 399.995 user select AM or FM. 470.005 - 799.990 user select FM or WFM. Not sure how useful Fm/Wfm is in the 174 + range, AM for aircraft in the 300 range might be of some use, WFM in the 470 + range to resolve TV sound. Date: 13-01-2002 Subject: Channel 69 In the US, the 799.99/800.000 MHz switch prevents you from listening to channel 69 Audio properly. Its carrier is at 805.75 MHz.
This modification is read 1375 times.

21-10-1998

(IC-T8) Software mods to open the RX-band
Date: 03-10-1998 15:00 From: KC8DHN@N8MA
Heres what to do. Hold the BAND and the SQL buttons then turn the radio on that will open up the rx. This will allow you to listen to some of the VHF TV channels and all of the UHF TV Channels I got this from a friend who got it from a guy at Icom. After Expansion, the following approximate frequencies and Modes become available:
75.99 107.99 135.229.99 399.99 599.869 999.99 Mhz Mhz Mhz Mhz Mhz Mhz Mhz Mhz Mhz Mhz NBF WFM AM NFM FM AM NFM NFM NFM NFM
73's KC8DHN Chris Supplement: Also, in certain freq ranges try hold SET/H/L button and look for mode menu -- AM/FM/WFM
This modification is read 1445 times.

16-05-1999

(IC-T8) Problem with the battery pack
Author: Louis Albert - lalbert@uakron.edu.MODIFICATION.NET The T-8 has been selling like wild fire and the batteries have been breaking just as fast! The battery has a spring plastic tab that holds the battery on the back of the transceiver. It's a good idea in that there are no tools required to remove the battery but after flexing a few times it BREAKS! This renders the battery and the radio useless. ICOM has been replacing the batteries free but it is the same type of plastic, so they also BREAK. I have received opinions from two individuals familiar with plastic. One is an engineer and the other, a tester in the lab of an independent manufacturer. They both say that the fundamental design of the tab is wrong in that no mater what type of plastic is used, the tab will eventually break at the flex point. They both went on to say that with the proper formulation of the plastic, the tab may possibly last the life of the battery. A portion of the written statement follows: "There are two problems with the design of the battery pack that effect the performance of the snap. The material appears to be either talc or fiber filled which will increase the impact strength of the material, but will also decrease the materials flexibility. The second issue is that the snap geometry itself is flawed. A well designed snap wing should be tapered in thickness so that the strain is evenly distributed along its length." "In the case of the ICOM battery snap the strain is concentrated at the base of the snap in the U shaped area. It can be seen that the outer fibers of the U are strained past the materials allowable limit even under normal operation of the snap. Two solutions are available, change the material of the battery pack, or change the geometry of the snap."

This modification is read 959 times.
(IC-W2A) IC-W2A Weak transmit audio
Trouble: Weak transmit audio, deviation below the specifications, high end of the speech spectrum missing. Tools needed: A good soldering iron with a sharp tip, desoldering braid, solder, sharp-nosed pliers, small cross-point screwdrivers. Cure: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Open the radio case following the instructions in the owner's manual (p. 45). In radios fitted with the UT-63 board, pull out the board. Unscrew the two small screws holding the tin plate against the bottom ends of the band modules. Pull out the plate. Pull out the band modules. Now you see the microfone fitted to the mother board. It should fit neatly against the inside of the fascia panel. If it doesn't, carry on. Unsolder the microphone leads from the mother board. BE CAREFUL not to overheat the board and the wire insulation. Pull out the microphone and the rubber gasket. Re-install the gasket. Pull in the microphone so that it fits inside the gasket well and press it firmly to the end. Re-solder the mic wires. Install the band modules, the tin plate and don't forget the screws. Replace the rear panel. Tighten the 7 screws. Test the audio response.
This modification is read 891 times.
(IC-W2E) IC-W2E Expand frequency
Display test / Rx Expanding; Turn the porto off, press the #,3 and the B, hold this buttons, now turn on your porto (Red Button), you will see now all the functions who are in the lcd display. When you quit pressing the #,3 and the B button, your porto can now go (On Display) from 100khz <> 999.90Mhz at the 2m Display, and on the 70cm Display he will go from 100khz <> 1310.00Mhz, of course he will not recieve from 100khz <> 1310Mhz, but the low vfo receive at least from 126Mhz <> 190Mhz, the high vfo receive at least from 390Mhz <> 999Mhz, with some steps between 390Mhz <> 999Mhz where he not receive signals, because the vfo is out of his lock. Enter Freq via keyboard; When you enter a freq (in vfo mode) by pressing enter (ENT) you will see that you can press only the last 3 digits, this is simply to change by pressing the function button (above the ptt) and the set (8) button, push now with the ^/scan until you see on the display 'PL', now you can dial 1 - 10 -100 = 1Mhz - 10Mhz - 100Mhz, set this option to 100 (dial), now you press the clr (*). Done !!!! If you now press enter (#) (in vfo mode) you will see that you now can press the whole freq. The same for the other vfo, this go's the same for 1Mhz - 10Mhz PL function. Steps with the dial; Dialing a freq go's with steps in Khz, by pressing the function key (above the ptt) the steps will be now steps of 10Mhz. Here are some RX reports by JBE;

No PBT shift __|__ 3rd IF / ___/ ^ / | | | | ^ \___ / _/ ^ LSB shifted ____| / | | | | ^ \_____ USB shifted |____ /| / | _____/ ^ | | ^ \_

shifted b/w

I haven't performed this mod on my R71 (I have to install PBT tuning first - I got one of the ones without PBT), so you're on your own with this one. I expect that the close-in dynamic range will be worse when using this flavor of PBT on the R71, since the 2nd IF filter is bypassed
(R-71) R-71A Memory Notes
I have heard that a new company named Willco is going to sell no fail memory for the Icom radios. Two models, one with 64 channels for around $70 and a 1000 memory channels for around $149 will replace the small battery backup unit. The Willco board will use standard AA batteries. When the batteries die in the Willco unit, the radio won't fail and need servicing as is now the case. (However, the memories would need to be re-programmed.) Using the lock button and memory switch, one steps through the banks of 32 channels each. One channel in each bank can be used to store the channel number for display to identify the bank number according to the maker. Willco's address is P.O. box 788 NewLenox Il. 60451 If someone orders one, let me know what you think of it. I am not sure which radios other than the R-71A in which it will work.
David L. Wilson Department of Mathematics Mary Washington College Fredericksburg, VA 22401 dwilson@s850.mwc.edu Phone: H (703)898-1084 W (703)899-4744 Amateur callsign: AC4IU (ex-KD4ASW/KO4EQ) Lat./Long.: 40 N/ 51 W
This modification is read 794 times.

08-11-1998

(R-7100) Modify your Icom R7100 to provide an output directly from the discriminator
This is an involved operation and should NOT be attempted by anyone who does not feel at home with fine electronics work. It is very easy to do serious damage to your radio if you don't know what you're doing. Please read through this document in its entirety before attempting to carry out the modification. It is almost essential that you print this out in order to have it handy while carrying out the modification. The diagram at the end of the article will be of great use. Right, let's get down to the nitty gritty. You are going to need just one electronic component - a capacitor of a value of between 220n and 10u. It can be either polar or non-polar. In addition, you will need a length of screened audio cable, any type should work but the smaller it is the better. You will need some form of connector to put on the one end of the screened lead - a minijack socket or phono connector would be good. Of course you'll also need a few basic electronics tools such as a screwdriver, soldering iron, sidecutters etc. With the front panel of the radio towards you, as you would have it for normal use, locate the four retaining screws on top of the top cover. These are located near each corner. Remove these four screws. Do not remove the three screws located around the speaker grille. On each side of the radio are two further retaining screws (a total of four). Remove these. The top cover may now be lifted off the radio taking care to observe the speaker cable. The speaker is fixed to the inside of the top cover. There is a connector in the speaker cable which should be unplugged to free the top cover completely. Looking down on the receiver, locate the converter unit. This is the PCB closest to the external antenna connector at the left rear of the receiver. Now locate the coaxial connecter at the extreme left rear of the converter unit PCB (see diagram). The cable connected at this point bends over and travels downwards into the bottom half of the receiver. Disconnect this cable by pulling directly upwards. The connector is farily delicate so do not use too much force. Now comes the part that requires great care. Take it slowly and do it properly. The entire top chassis has to be detached in order to reach the main unit PCB beneath. There are four screws that need to be removed to accomplish this. Two of these are located on the rear panel of the receiver. Looking at the radio from the rear now, you will see a row of connectors for such things as external speaker etc. Just next to each end of this row of connectors are the two screws you need to remove. Remove them. The remaining two screws are on the top of the unit. Position the radio as you had it before (normal operating position). Looking down on the radio, you should see four screws near the front. Two of these go through the top of the plasic front panel and two of them go through the metal chassis (see diagram). Remove the two screws that go through the metal chassis. Now CAREFULLY lift the top chassis and swing it clear of the radio. Note that there are many wires linking the top chassis to the bottom. Take care not to strain these. there should be enough slack (just) to allow you to swing the top part out and away from the bottom and lower it onto the surface you're working on. Now you should have a clear view of the main unit PCB. This is where you will be making a connection. In order to locate the point on the PCB where you will connect the screened cable you will need a ruler or tape measure. The connection point is approximately half way from the back to the front and approximately one quarter of the way from left to right. This is just to give you a general idea of where to look. (see diagram) Now, using your ruler, measure inwards 55mm (2 1/8") from the left edge of the radio towards the right. Imagine a line running through this point from the front of the radio to the back. Now, measure 120mm (4 3/4") from the rear towards the front along the imaginery line. At this spot on the PCB (see diagram) you should see a wire link marked "W100". This point (the wire link) is output of the discriminator. Connect one side of the capacitor to this wire link. If the cap is a polar type then the positive lead goes to the wire link.