Modifications for the ICOM - RogerK

4. Program the radio to the local weather channel (162.400 or 162.550) in the following manner: 6 2 4 0 0 or 6 2 5 5 0NOTE: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. Thetop adjustment is a metal screw (actually a trimmer capacitor) while the bottom adjustment is a black slug with a smallrectangular adjusting slot6. With the squelch open, adjust the lower black core counterclockwise approximately 1 1/4 turns until you receive theweather 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 thatyou must enter the ten's of Mhz when entering a frequency. This modification does not affect the transmitter which still covers140.000 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 weatherfrequency, 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 severalweeks ago.According to the manual, the VCO on the PLL should cover 25 Mhz. minimum.This modification is read 1203 times.top of page19-07-1998(IC-02) Low audio speaker mike on IC2A, 3A, 4A OR 02ATIf you own one of the IC2A, 3A, or O2AT series Hand-helds, you may be interested in reading on. I know my hearing is prettygood, 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 onthe 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 mikeplug 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, usuallymuch 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 agroove had to be made to accept this configuration. I thought long and hard about a minute, before getting the "Dremel" out andmaking my own slot or groove. It works well on both hand-helds I have. In fact, you can hook up an external speaker for evenmore loudness in the auto. So, give it a try or see me for a demo.This modification is read 1034 times.top of page19-07-1998(IC-02) ICOM 02/03/04 & Vox UnitThe ICOM Family of Hand-Held Radios (02/03/04 AT) are well suited for packet radio given the many available power supplyoptions.The big problem is getting the PTT to operate " CLEANLY " while not compromising the audio level from the TNC when using theresistor or resistor/capacitor interfaces suggested in some manuals.I am using the ICOM HS10-SA Vox unit to interface the ICOM 02/04 AT here.It has worked somewhat well for some time but Iwas always plagued with a MINIMUM 200 msec transmit "hang " delay until I tore it apart for examination and correction.The small " delay " pot on the front of the unit is in series with a 2.2 Megohm resistor (R-19 on the board). The adjustable pot isalso about 2 megohms as well. This combination allows a MINIMUM VOX "hang" transmit delay of 200 msec.By identifiying the solder connections for R-19 on the back of the PC board and placing a low value resistor ( or jumper ) inparallel....I was able to achieve a ZERO "hang" transmit delay time with the delay pot in the FULL COUNTER-CLOCKWISEposition. The minimum 200 msec delay has been defeated.This modification is read 1050 times.top of page