This modification is read 1146 times.
(IC-02) IC-02A Modified PLL rigs
The modification to the IC-02A to increase the receiver is fairly straight forward although a little delicate. The programming diodes are located on the board directly behind the front panel, and are located in the corner of the board. They are little rectangular black three leaded devices. The proceedure to modify the radio is as follows: 1. Remove diode D2 - use a very small iron and solder wick to remove most of the solder, then lift the diode GENTLY while heating the single tab side. After getting the first tab free, proceed to the other two tabs, lifting them one at a time. Do NOT use a large iron or too much heat. 2. Take the diode and locate in the position labled D5. Carefully solder the diode in place. 3. Reassemble the radio except for the back.
4. Program the radio to the local weather channel (162.400 or 162.550) in the following manner: 0 or 0 NOTE: the programming proceedure now requires that you enter the ten's of Mhz when entering a frequency. 5. Look at the back of the radio. In approximately the center of the exposed board is a metal can with two adjustments. The top adjustment is a metal screw (actually a trimmer capacitor) while the bottom adjustment is a black slug with a small rectangular adjusting slot 6. With the squelch open, adjust the lower black core counterclockwise approximately 1 1/4 turns until you receive the weather station. As soon as you receive the weather, STOP turning the adjustment. 7. Replace the back on the radio and you are in business. With this modification, the radio will tune from 140.000 Mhz to something over 162.550 without difficulty. Just remember that you must enter the ten's of Mhz when entering a frequency. This modification does not affect the transmitter which still covers 140.000 to 151.995 Mhz. Please note: This mod does not retune any of the RF stages of the receiver so the sensitivity is down some at the weather frequency, however, I have no difficulty receiving it at thirty to forty miles. I do have the ICOM service manual on the IC-02A. I purchased it from Delaware Amateur Supply at a local hamfest several weeks ago. According to the manual, the VCO on the PLL should cover 25 Mhz. minimum.
This modification is read 1203 times.
(IC-02) Low audio speaker mike on IC2A, 3A, 4A OR 02AT
If you own one of the IC2A, 3A, or O2AT series Hand-helds, you may be interested in reading on. I know my hearing is pretty good, but have you ever tried to listen to the audio coming out of your speaker mike on the above ICOM's? For the most part, it's pretty low. I may be the last guy to figure out a cure for this, but here it is anyway. On the O2AT, etc., there is a groove on the back near the top of the rig that is just the right size to accept the HM9 speaker mike turned 90 degrees so that the mike plug fits in that groove in the rear of the rig. Thus alllowing all the audio to be heard from the internal speaker of the rig, usually much better than the speaker mike. Now, in the case of the 2A series, etc., the fix is more complex. These rigs don't have that handy groove built in, so I decided a groove had to be made to accept this configuration. I thought long and hard about a minute, before getting the "Dremel" out and making my own slot or groove. It works well on both hand-helds I have. In fact, you can hook up an external speaker for even more loudness in the auto. So, give it a try or see me for a demo.

4. The other side of the resistor should be wired to the small switch (the switch can be mounted on the back of the transceiver, there's an hole in the heatsink which you can use to insert the wires to the transceiver. 5. The other side of the switch should be tied to 5V (you can find a 5V terminal at J2 pin 2, j2 & j1 located near the VCO at the front of the print it is a 2*4pin sip connector, j2 is closer to the VCO. UHF MODIFICATION 1. Open the lower cover of the transceiver. 2. Locate D17 on the board (this diode is wired under the board, just beside L22. there are 2 holes, I am talking about the one located closer to the antenna) 3. Solder another 12K resistor in the same way it was done in the vhf to the anode of D17 just under the print ( the anode is the left pin of the diode ,the pin which located closer to the power amplifier. 4. The other side of the resistor should be wired to the other small switch. 5. The other side of the switch should be tied to 5V (for example to the right pin of the regulator IC7) Explanation When you turn this switch on, it turns the diodes on, and attenuates the received signal. This modification was tested, but you will do it on your own risk.
This modification is read 756 times.
(IC-2340) Some mods for the IC-2340H
The diodes D12 to D20 and D10 + D8 on the logic board is the diodes that control frequencyrange and model version.
[Logic board] -----------------------------------------------------------------------------------+ -----| W1 | | | J 7 D14 D15 D12 D13 | +-------------------------------+ +----+ +----+ +----+ +----+ | | | | | | | | | | | | | | +----+ +----+ +----+ +----+ | +-------------------------------+ | +-----+ +----+ +----+ +----+ | | | | | | | | | | +-----+ +----+ +----+ +----+ | D18 D19 D16 D17 | | +---------+ +--------+ | | | | | | +---------+ +--------+ | D10 D8 | -----------------------------------------------------------------------------------+

Minirepeater:

Remove D16 on logic board. (Not necessary on USA version) Set the desired QRG on each band. Push the [VHF MAIN] + [UHF MAIN] VFO knob and push [SET] at the same time. The memory channel indication changes to "L" (L=Minirepeater mode)

ik2xyu@ik2hdg.ilom.ita.eu (packet) or fcimardi@vnet.ibm.com (Int.Email) ik2xyu@it.ibm.com
This modification is read 713 times.

25-10-2000

(IC-3230) IC-3230 repeater function
Author: Jon L - k4iii If you look at the IC-3220 repeater mod on this site, you will find a mod that will also work with the IC-3230. It states that holding down the "set" and "band" buttons for a couple of seconds will cause the 2 "L's" to blink. This will place the Icom 3230 into crossband repeater mode just as it does with the IC-3220. I tried this and it works with my IC-3230. I'm not sure whether it is stated in the 3230 manual since it is so large and I did not come accross it.
(IC-37) some audio mods for IC-37
Here is a list, transcribed from "220 Notes", of modifications for the ICOM model IC-37A. The 27A and 47A should be very similar: "We have been using [this mod sheet] in the Southwest Coast ever since the [IC-]'37 was in production. This one is the latest revision. "The design problems of the '37 are greater than ICOM would lead you to believe. The [IC-]'38 has solved a great majority of the '37a problems. However, the microphone and the UHF pigtail problems still remain. "The fix for the microphone on both rigs is the same. [see below] The fix for the UHF pigtail on the '38 involves removing the pigtail, and installing a bulkhead chassis mount BNC connector in the hole left by the pigtail assembly. Some elongation of the BNC connector holes is necessary for a good fit. A short coaxial jumper may then be installed from the board to the connector. Now, here is the official Condor Connection IC-37 modification sheet. 1. To restore high-frequency receiver audio response, replace C-103 on the main unit with a.0022 uf mylar capacitor (that's 2200 pf). 2. To restore LOW-frequency receiver audio response, replace C-106 with a.22 uf mylar capacitor. 3. To eliminate the distortion in the transmit audio, install a 4.7k ohm resistor inside the microphone case, in series with the white lead coming from microphone element. Once the resistor is installed, set the DTMF level pot to the middle of its range (this pot is the only one inside the microphone case). To complete the mod, set R88 inside the radio to the desired "mike" level. 4. To improve the receiver sensitivity, power output, SWR at the radio, and reliability, remove the RG-58 pigtail and the UHF connector extending from the rear of the radio. Install a BNC chassis mount, screw-in connector (UG-1094/U) in the hole left in the back of the radio. The new connector will screw in as if the modification was done at the factory. 5. To greatly reduce chassis heating in the receive mode, remove the following components: R66, R67, R68, Q32, D42, and D44 in the main unit. Install a 7808 [3-pin voltage regulator] on the transmitter power amp shield behind the space reserved for the optional voice synthesiser. Thermal compound is recommended. Hook the input of the 7808 to the point where R67 and R68 used to connect. Hook the output of the 7808, in series with a 1N4001 diode, to J14-1. The cathode of the diode goes to the connector goes to the connector, and the anode goes to the 7808. "---Mark Gilmore, WB6RHQ Newbury Park, CA." top of page

+------------------------+ | | [XX] [XX] [XX] [XX] [XX] +-O Solder wire into this hole ^

* *** *

8. Solder a small wire into this hole. Be careful not to apply too much heat; use a low-wattage soldering iron. Be careful not to damage the PCB or the grey cable coming out of J8. Use a magnifying glass. 9. Run the other end of the wire you just soldered to the front of the radio and attach it to the yellow wire you just cut. 10. Re-assemble the radio.
This modification is read 3273 times.
(IC-706) IC-MHz to 200 MHz bandpass filter
From: gary@ke4zv.atl.ga.us (Gary Coffman) Ok, here's the computer simulation info I promised. I modeled the 60 MHz to 200 MHz bandpass response. To say the least, it sucked rocks. There are two poles, one at about 136 MHz and the other at about 160.5 MHz. Response is nice and flat from 60 MHz to 120 MHz with less than 4 db of ripple, but it takes a dive from there. In the 130 MHz to 170 MHz range, the loss is at least 36 db, rising back to only 30 db at 200 MHz. Image rejection at 280 MHz is only 26 db. Now the ideal fix is to change the inductors so that L49 is 27nH, L40 is 22 nH, and change C152 to 30pF. That gives a lovely passband across 60 MHz to 200 MHz, and gives strong image rejection at 280 MHz and up, with one of the nulls falling right on that frequency. The factory ought to do that. Unfortunately, examination shows these coils aren't easy to modify. So there's another way that still gives a pretty good response. If you remove C53 and C153, you'll get full response, though with a dip of 4 db in the 160 MHz to 180 MHz range, and only 26 db of image rejection at 280 MHz. But if you increase the value of C152 to 32pF by tacking the removed C153 across it, response flattens and tightens in the upper VHF range, and image rejection improves to 31 db at 280 MHz. That's about as good as we're going to get without replacing L49 and L40 and C152 with the recomended values. Here's the ARRL Radio Designer file for the filter.
************************************************** *ARRL Radio Designer v1.0 *IC-MHz to 200 MHz bandpass filter * Gary Coffman KE4ZV 1/18/96 ************************************************** Blk **Component data inductors L22:1.2uH L49:82nH L40:68nH L25:0.15uH L26:0.18uH L27:1.2uH

;ideal 27nH ;ideal 22nH

**Component data capacitors C51:.001uF C154:20pF C153:0pF C152:32pF C53:0pF C151:24pF C52:18pF C54:220pF C55:22pF C56:82pF C57:27pF **Node list IND L=L22 CAP C=C51 CAP C=C154 IND L=L49 CAP C=C153 CAP C=C152 IND L=L40 CAP C=C53 CAP C=C52 CAP C=C151 CAP C=C54 IND L=L25 CAP C=C55 CAP C=C56 IND L=L26 CAP C=C57 IND L=L27 BPF:2POR END **Frequency block FREQ

This modification is read 3614 times.
(IC-706) IC-706 Microphone Audio Response Improvement

Author: PE1MHO

This mod was submitted by Pete PE1MHO. CAREFULLY open the microphone. (There's a little spring in there that will fly out and get lost in the carpet, never to appear again. ) Remove the circular metal plate that holds the electret capsule in place, and GENTLY pull out the capsule. You'll find what can best be described as a "Q"-shaped rubber gasket - remove this and throw it away. Reassemble everything - that's all there is to it. You will now have a microphone with a bit more punch, but most importantly the audio bandpass is a lot better.
The difference as measured on an audio spectrum analyzer was quite significant. I'm not sure if this helps for the Mk II and Mk IIG - maybe Icom have already adapted them. Thanks to http://www.qsl.net/vk4cp/ for the modification.
This modification is read 3702 times.

25-08-2001

(IC-706) Improved VHF recieve mod (see also yellow wire mod)
Caution: This is quite involved. If you are not too good you might be advised to get someone who has the experience to handle this mod! This mod requires the service manual, a propane torch for desoldering the SMDs, and desoldering braid for cleanup. The two VHF Rx filters are on the PA unit, between the EXT SP jack and L29 L30 (two tunable metal boxes). The wide filter is used if the B8W signal is active ([60--144[ and [148--200] range). L29 and L30 form the 144-148 band pass filter, with a 2 dB loss. The wide filter works from 60--120 MHz, see plotrxold.pdf. Since transmitting below 120MHz is impossible due to spurious emission at ftx+70MHz, I decided to modify the rx filter for a 110--180 MHz operation. Note that the low pass VHF input filter has a -7dB roll-off at 160 MHz. New component values:
C57 C56 C55 C54 C151 1nF 47pF 18pF 32.6pF (27+5.6) 15pF L26 L25 C52 C53 C152 150nH 120nH 0pF 15pF 15pF L40 L49 C51 C153 C154 39nH 33nH 1nF 12pF 1.8pF
Caps in 0603 size, Farnell or Johanson. Inductors in 1008CS size, Coilcraft. Results are in plotrxnew.pdf and p_nf.pdf. Noise figure data.
This modification is read 3583 times.

> > Do you have any documentation and/or suggestions on how to build or > design the 50 MHz through 902 MHz units ? > > Chris
I don't have anything explicitly written but it is very much along the lines of the microwave stuff I showed. The LOs are partly there already:
Band 50M 144 LO 30M 120M circuit 3 X 10 (2n5179 tripler from 10M) I'm presently using the 100 MHz Xtal circuit with a 120 M xtal but 6X20M with filtering would work too. 2X 100M (single stage of 2n5179) Just like 260M LO shown Like 1010M 6th harm of 100M and 20M PLL reference

200M 410/420 620M

Only 420 and 900 even need to use another of the PLL boards. The others just take a single stage. I have 50,144 and 220 done. 400 is sitting 90% completed. I have PA bricks for 50 and 400 waiting to be used. As I said, 144 and 1296 have been running for years. I build the RF decks in metal "shoeboxes". I pipe the LO and IF(with tx switching as DC on the line) to each deck which lets me remote them if I want to. The only thing I really need to add that I haven't is an ALC line coming back from each PA to control the 735 so that I keep things linear. Linearity hasn't been a problem but like any of the current commercially available transverters it is possible to overdrive things. 73 Glenn n6gn
This modification is read 2199 times.
(IC-735) TX Mod For ICOM 735
The mod for gen/cov tx for the IC-735 involves removing D33 and D34 from the main board. You'll have to lift the PA module up to do this, locate the diodes and simply snip one end of each. Very simple, but it's amazing just how many screws need removing in the process!
This modification is read 2017 times.
(IC-735) IC-735 Remote Working
I have finally got the remote control working on the IC735. The interface is home-made and uses just 2 transistors, 1 diode, 5 resistors, DB25 and a DB15(to get 5v from games port). The software is a major re-hash of VK7TM's FT757 effort in ARA. All functions are driven from the XT keyboard and the software allows scanning of a LARGE number of frequencies on the same or on different bands. The trials and tribulations of all this effort were NOT assisted in any way by the manufacturers local office in Melbourne. A call for information was not very successful. (try it and see!) If you are contemplating the idea of turning your IC735 into a multi-channel HF scanner, I may be contacted @ VK3YZW BBS. The software is suitable for use with XT/AT Clone. Available control functions: Send a new frequency to the radio from the keyboard. Send a new Mode to the radio. Select VFO A or VFO B. Select a different memory channel Enable the selected memory channel Write current Freq/Mode to selected memory channel. Write current Freq/Mode to last used VFO. Read/Edit/Use a frequency file from Disk. SCAN frequencies in a frequency file. The frequency files contain frequency/mode/description of station all of which is displayed on the screen when the file is active.

This modification is read 1157 times.
(IC-751) How to replace the lithium battery in your ICOM radio
Note: All this information is based upon the IC-751; if your radio is a different model the board references may be different. 1. Go to Radio Shack or your favorite supplier and buy a lithium battery to replace the one in your radio. The actual type used is a BR2325 (3.0 volt 165 mAh), which Radio Shack does not carry. You can order this one from Digikey. I bought a CR2450 at Radio Shack (3.0 volt 500 mAh), which was the largest capacity unit they had in about the same size. I had to solder some short leads to this battery (quickly to avoid overheating), before I could attach it to the RAM board. 2. Find a 5 volt power source to run the RAM board during the transplant. I used a modular plug-in unit rated at 4.5 volts @ 60 ma. I connected a 500 Mfd. capacitor to this supply and then added a resistive divider to reduce the voltage to 5 volts. You may need to re-adjust this divider to supply 5.0 volts after connecting it to the RAM board. Connect several feet of wire to the divider output, which will go to the RAM board. 3. Remove the covers from your ICOM radio to expose the plug-in RAM board, which I found on the bottom of my radio. 4. Turn the power on and locate the 5.0 volt and ground pins, which bring power to the board. In my ICOM radio service manual I found a board overlay for the 'RAM Unit', which shows the two connectors and labels the connections. While looking down at the board note two connectors on opposite sides of the board. Both connectors are closer to the same end of the board. The pin closest to the end of the board on the longest connector (J1) is pin 12, which is the 5 volt input. The pin closest to the end of the board on the shorter connector (J2) is pin 1, which is ground. If you connect a voltmeter between these two pins you should measure 5.0 volts. These are the pins you will connect your external power to. 5. Turn off the power to your radio and remove the one samll screw that holds the RAM unit to the main board (you need a jewlers' screwdriver). Now you can remove the RAM board from the radio; remember from now on you do not want to touch any tools or other metal items to the board or it's components. 6. With the board removed you now need to solder the two wires from your 5 volt power source to the board. You can solder to the small metal piece that is on the side of the connector toward the inside of the board; this will keep solder out of the connector pins. First make sure that your soldering iron does not have any direct ground connection to the board power source. 7. After the external power source is connected, turn it on and measure the voltage being supplied to the board. You may need to adjust the values of the dividers to get between 4.5 and 5.5 volts. Disconect the power while making modifications. 8. Now, with the 5 volts connected and on, you are ready to remove the old battery. Use an insulated tool to pry the battery off while heating the solder connections on the backside of the board. Only touch one of the battery connections at a time. Here you need to be careful not to touch any of the board traces or component leads. 9. Once the old battery is removed, you can solder the new one in place, being sure that the polarity is correct. Now carefully

This modification is read 486 times.
(IC-901) IC-901A Frequency Ranges
Here are the frequency coverage ranges for the various band modules and the modifications to the control head diodes to get these extended ranges:
Band 10m 6m 2m 1200 Range (MHz) 28-40 40-54 138-174 216-236 400-479 1240-1300 RX diode no no 25 no out out change change out change TX diode 23 no in in in in in change
To modify, remove the back of the control head and add or remove diodes from the marked pads as described in the above table. Notes: coverages are for RX. TX may not work over entire range, but will come close. RX sensitivity is front-end tuning dependant. 10m, 6m, 2m and 1200 modules will have OK RX sensitivity over most of their range. 220 RX sensivity is unknown over its' range. 440 RX sensitivity will cover about 25 MHz with good sensitivity, tuning out of the box is from about 438-463. The 3 helicals can be retuned to any where in the 400-479 MHz range, but you can still only get the 25 MHz or so spread. If you have severe intermod problems while listening to 440 MHz frequencies, I would recommend retuning the helicals down in frequency to attenuate the strong 450-460 MHz signals from the front end. The intermod will almost completely go away. Of course, the sensitivity above 450 MHz will suffer, but most of the signals you would probably be interested in listening to will probably be quite strong to start with, so you will probably still hear them just fine. If you have access to a tracking generator and spectrum analyser, there is a small two pin jack on the UHF board from which you can monitor the helical response. Connect the tracking generator to the antenna jack and the spectrum analyser to the two pin jack.
This modification is read 602 times.
(IC-901) Memory and microprocessor reset
Memory and microprocessor reset - turn power on while holding down check and memory write buttons.
(IC-901) Crossband repeat
Crossband repeat - turn power on while holding down check and lock buttons. If crossband repeat has been engaged, the "lock" display will flash. PL can not be selected in either band for crossband repeat to work. If you need PL to operate the repeater you are linked to, generate it on the radio you are using to talk to the 901. The PL will pass through the 901 just fine to access the linked system. Since the radio is in the locked mode, you can't change frequencies or bands during crossband repeat. To disengage crossband repeat, turn off power or press lock button. If there is no audio during crossband repeat, open up the front of the dual-band unit by removing the plastic cover behind where the control head would plug in if the 901 is not used in the remote-control head configuration and look for a slide switch mounted on the edge of one of the vertical circuit boards and slide it the other way. The switch does not seem to come in any pre-determined configuration from ICOM, so some radios work OK for crossband repeat right out of the box, and some require the switch to be in the opposite position.

Using a sharp knife and a lot of care, scratch away the solder mask to reveal bare copper on the trace. Use a piece of wire wrap wire to repair the cut trace (bridge the trace to the via). Back on the top side, short the pads for the resistor that are open (this is the lower case "R" on the left, off by itself). Reassemble the radio. If you used the "more correct" way, make sure you get all the screws and cables back in. Plug it in, turn it on, fire up the software. Tune a frequency you couldn't before. If you can tune it with the software, and the squelch is open, you're working! If it's not working, review everything we described. Make sure you didn't short any pins. I can't offer you much more help if it didn't work. Remember, you screw up your radio, it's not my fault. I don't work for Icom, I don't represent Icom. I don't endorse listening to frequencies you're not supposed to, and can't be held liable for anything that happens, anywhere in the universe, as a result of you making this mod, or even thinking about making this mod (Gawd, I hate lawyers. CYA!). This mod was done completely from our own experience and background, and did not reference any material. We don't know about these people selling the mod on the 'net, but we didn't steal it from them. Hope this helps. If you've got any suggestions to improve how to make this mod, please send e-mail. If you made this mod, let us know how it went. Also, if you want a list of the PCR-1000 commands we know about, drop us e-mail, or use DejaNews(tm) and search the alt.radio.scanner groups for the post (look for PCR-1000 in the subject). - Chris, KD4DTS (Thanks to Alan Adamson, NE1H for his being ready and willing to sacrifice his radio to a higher cause, and his drawing).
This modification is read 2922 times.

14-03-2001

(IC-PCR1000) ICOM PCR1000 Software
The software is for RF tuning and alignment of the Icom PCR1000. This software is designed to be used along with the software supplied with the PCR1000. It will not work properly if used alone. This software has been tested under Windows 95 and Windows 98 but may not run properly if you have changed the IRQ's or Addresses of COM1: and COM2: from the default settings in Windows. This software will not run properly under some versions of Windows 2000. I have been told that this software is capable of changing the 'band plan' on the PCR1000, allowing you to unlock blocked frequency ranges in some versions of the PCR1000. (I have not verified this, since there also seems to be hardware modifications to do the same thing.) Make sure you have backup copies of all.INI and.DAT files before you unzip or copy these files to your PCR1000 software directory. To install, unzip the archive in the same directory your Icom PCR1000 software is installed in.

This modification is read 3324 times.
(IC-R71) RAM Card Backup Battery Replacement Instructions
This modification is read 737 times.

18-11-2001

(IC-R71) RAM board programming interface & R71A modification
11 December 1999 by Andrew Gerald, N2CBU eMail-1: Lorand@QwestInternet.net eMail-2: N2CBU@ARRL.NET A word of caution before you begin: It's possible that due to a wiring error, parallel port error or software incompatibility you might erase the contents of your RAM module. If your RAM module is from an R71A you can restore its contents from the enclosed "ORIG-R71.BIN" file. I do not have any other "recovery" files and until some become available I urge caution. Perhaps it would be wise to test your interface on a RAM module from a R71A first before reading RAM modules from other radios. I will add "recovery" files for the other radios to this archive if they are sent to me. *** Note-1: If the "WP" Write-Protect pin (see J2 on the interface schematic) is tied to ground instead of to +5v the critical lower RAM locations in the module are write protected. A simple modification to the interface board would be to add a write protect switch. *** Note-2: If the "/WR" Write pin (see J2 on the interface schematic) is left unconnected when testing the interface then the entire RAM will be write protected. Thus you can test without much chance of erasing the contents of the RAM module. Icom RAM board programming interface & R71A modification notes You will need a CD4040 IC, a 78L05 voltage regulator, an 8-pin strip of 1" tall 0.1" spaced header pins, a 12-pin strip of 1" tall 0.1" spaced header pins, a DB25M, a length of ribbon or other type cable, and a piece of perf board. For the prototype I used a Radio Shack part number 276-149 prototyping board. It should be noted that my prototype does not have an on-board voltage regulator. I included the regulator on a subsequent board I built in 1991 which I gave away. All parts may be obtained from Digikey (www.digikey.com) and certainly from other sources. A suitable header pin strip is Digikey part number "S1081-36" but any similar header pin material will work. Circuit layout is simple, just take a look at the ram module in the R71 and imagine how the header material will have to be positioned. What you want to do is make a "socket" on the programming adapter which looks just like the "socket" in the R71A. Build up the circuit on a small piece of perf board with the 4040 in the center. The long side of the header pins will have to be bent slightly outwards for the ram module to fit. The ribbon cable from the PC will attach near the smaller header strip.

Turn off the radio Press and hold the band and squelch buttons. Turn on the radio while holding these buttons, wait for 5 seconds before you release the band and squelch buttons. Now the receiver should be opened up as far as it will go.
Date: 31-12-2001 Subject: All IC-W32-A Pushbutton Mods

From: Scott KF4JDP Terry

Not functional any longer,Tried all of them and none of them work. If anyone has an explaination please E-MAIL me Thanks Scott 73 Date: 22-03-2002 Subject: IC-W32A Firmware Change Apparently Icom made a firmware change at some point to comply with FCC guidelines regarding cellular telephone reception. There may have been other issues relating to it, but the short version of it is W32A's after a certain point no longer had the "super-extended" receive the earlier units did. It usually revolves around cell-phone reception though. I mean, God forbid if we overhear someone order a pizza or something. R. Evans KE4RWS
This modification is read 2466 times.
From: Randy Evans, KE4RWS

12-09-1999

(IC-W32) IC-W32 TX modification. Only a picture.

03-02-2001

(IC-W32) ICW32 E Crossband repeater
Author: Dr. Werner Furlan - furlan@gmx.net.MODIFICATION.NET
A. Aktivieren des Crossband-Repeater-Betriebs beim Handfunkgeraet IC-W32E: 1. VHF- und UHF-Frequenzen einstellen. 2. Squelch-Funktionen in beiden Baendern auf Rauschunterdrueckung stellen. 3. LOCK aktivieren. 4. Ausschalten 5. SQL+MAIN+BAND gleichzeitig gedrueckt halten und einschalten. Schluessel im Display blinkt. B. Deaktivieren des Crossband-Repeater-Betriebs: SQL halten und LOCK druecken. 73! Werner OE9FWV
This modification is read 1739 times.

31-07-2001

(IC-W32) Icom IC-W32A programming glitch
Author: Bryce, K1GAX - k1gax@juno.com.MODIFICATION.NET
There is a programming glitch in the RT Systems Icom Programming Software (Version 2.05) that does not allow later serial numbers of the Icom IC-W32A to be programmed properly. This does not affect the earlier serial numbers of the W32A. If you are trying to program a later model W32A with the cloning software and it will not accept the data from the PC, there is a simple fix. Somewhere along the way, Icom changed the range of the expanded receive and made the expanded receive standard on the later versions of the W32A. In programming the radio using the programming software (on the later serial numbers), do not check the "Expanded Rx" box in the software. Checking this block on the later serial numbers will cause the programming not to take in the radio when transferring from the PC. 73, Bryce, K1GAX k1gax@arrl.net

C231 C232 C234 C236 C237

from from from from from
1000 pf to 68 pf.01 uf to 1000 pf. (You can use the capacitor which used to be C231.) 100 pf to 22 pf. 47 pf to 22 pf. 680 pf to 100 pf. (You can use the capacitor which used to be C234.)
Solder a 10 microhenry inductor in parallel with L204, a 20 microhenry inductor. Changes for BS-8 Module I haven't tried the BS-8 module, but encourage you to try using it as is, without modification unless neces- sary. These steps are needed only if you cannot find settings of the side mounted aligment controls that get the display to behave as specified in the owner's manual: 1. Remove C233, the 33 pf disc capacitor, from the printed circuit board. 2. Replace coil L204, the 4.7 microhenry inductor, with a 6 or 7 microhenry inductor. Alignment Follow the alignment procedure in the SM-220 owner's manual to adjust the panadaptor. This consists of adjusting 2 potentiometers and 1 trimmer capacitor through holes thoughtfully provided in the side of the cabinet. The alignment instructions rely on the use of the internal Marker Generator to generate a signal at the center of the passband. If you haven't converted the Marker Generator circuit, you can tune your receiver to a frequency with a signal present at a known frequency (like 162.550 MHz - the National Weather Service), and use that as a frequency standard. Most of the time spent in aligment will be in alternate adjustments between the trimmer capacitor and the wide band sweep potentiometer, which interact with each other. Wider Bandwidth The SCAN WIDTH switch on the stock SM-220 can be set to display a 40 KHz or a 200 KHz wide picture. I adjusted my modified SM-220 to display a 100 KHz or a 500 KHz wide picture. By adjusting the controls on the side of the SM-220, wider bandwidths are possible, but wider bandwidths make it more difficult to resolve individual signals close to each other in frequency. As the bandwidth gets wider, the horizontal sweep loses linearity, causing the graticule calibration lines to be inaccurate. Connection to R-7000 As mentioned earlier, a DC voltage is present at the R-7000 IF output connector and is used to power an ICOM TV accessory. A direct connection between the R-7000 IF output connector and SM-220 would damage at least one of these units. To block the DC voltage, a 0.1 microfarad capacitor was soldered inside the R-7000, between the IF output jack and the adjacent jack labeled "spare". Connection between the R-7000 and SM-220 is then made using a short length of RG-58/U coaxial cable, with one end plugged into the R-7000 "spare" jack, and the other end plugged into the rear of the SM-220. This leaves the original IF output jack undisturbed so it can be used with the TV adaptor accessory. Vertical Sensitivity When I connected my modified SM-220 to my R7000, the SM-220 would display only the strongest of signals. To improve the display sensitivity, I inserted a 20 dB gain RF amplifier between the R7000 and SM-220. The amplifier was a spare Ameco PLF2 FET receiver preamp, adjusted for 10.7 MHz, but other amplifiers can be used, provided they have at least a 500 KHz bandwidth, and sufficient gain, at 10.7 MHz. False Readings - Images The SM-220 circuit is like a superheterodyne receiver. The panadaptor itself has a 455 KHz IF, and like other superheterodyne receivers with a low IF frequency, is prone to images. An image is manifested as a false pip, which moves across the screen as the receiver is tuned, and is 910 KHz (twice the IF) away from the actual signal. The images discussed here are in the SM-220, not in the receiver. Images are bothersome on the strongest sig- nals, like those 300 watt paging transmitters that saturate the county with RF, belching out out strange digital noises or voices (now illegal to monitor). Use With Other Receivers The modified SM-220 can be used with other receivers having a 10.7 MHz IF. In other receivers, one would need to find the

wide switch.XX.XX. narrow switch bottom of radio ^ | XX=solder | bridge
D. Inspect your work. Carefully return the front assembly to its proper position and secure the four flathead mounting screws. Re-install the bottom cover. E. Turn ON the filter switch (S1) on the main PC board. This switch will already be on if an optional CW narrow filter has been installed. S1 is a small slide switch not far from the center of the board. F. You may wish to verify that everything is working OK so far. If so, be sure that all tools, etc. are out of harm's way and reconnect power, antenna and an external speaker to the receiver. The bandwidth switches should work the same as before, except that (1) there will be no receive with both switches pushed in and (2) there will be no receive with the "narrow" switch pushed in unless an optional CW filter is installed. Disconnect power again once the tests are complete. G. Locate D37 on the main PC board right next to IC3 near the center of the board. Cut the top (cathode) lead of the diode, leaving enough wire on both sides of the cut to make connections to. Bend the wire lead on the diode up. Solder a jumper wire from the cathode lead of D37 to the cathode (top) lead of D39 (located on the opposite side of IC3). H. PERFORM THIS STEP ONLY IF YOU WISH TO MAKE THE "IF-SHIFT" MODIFICATION FOR THE SSB/CW/RTTY "BOTH SWITCHES OUT" POSITION, AS DISCUSSED IN THE PREVIOUS TEXT. IF YOU ONLY WANT THE EXTRA AM BANDWIDTH, SKIP TO STEP "I." Cut the top (cathode) lead of D44, leaving enough wire on both sides of the cut to make connections to. Bend the wire lead on the diode up and solder a jumper wire from it to the top (cathode) lead of D42 (located near filter switch S1). I. A switching diode must be connected from pin 4 of IC3 to the top (cathode) lead of D36 (located right next to D37). A second diode must be connected from pin 4 of IC3 to the lead sticking out of the PC board which was clipped from D44. If D44 was not clipped in step H, the diode just connects to top (cathode) lead of D44. To make the IC3 connection, tin both pin 4 and the lead which will connect to it; then place the two in contact with each other and heat up the connection. I performed this step by first soldering the anode of one of the switching diodes to the anode of the second; right where the lead enters its base. I then cut the anode lead of the first diode to a fairly short length and soldered it to pin 4 so that the two diodes were held in a vertical position just a tad above the IC. I then clipped the two cathode leads very short and ran insulated jumper wires from one cathode to D36 and from the other cathode to the D44 clipped lead coming out of the PC board. However you decide to do it, make sure the IC3 connection does not short out any other pins and make sure the switching diode leads cannot come in contact with any other components. J. Inspect your work and verify all steps were done properly. Make sure all tools are out of harm's way and test the modification. If everything works OK, reassemble the receiver. Note that with this modification, the narrow button must be in the "out" position for the FM unit (if installed) to function properly.