Subject: OUT OF BAND MODIFICATION FOR ICOM IC-04
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1. On the logic matrix, remove D402.
2. Add D402, D403 and D404 with the cathode at 4 o'clock and the anode at 12
o'clock. (You may use any signal diode such as 1N914)
3. Add D405 with the cathode at 8 o'clock and the anode at 12 o'clock.
4. If you have a newer 04AT, the VCO cover will have holes in it that
allow access to the tuning coils. If you have an older 04AT you will
have to cut a hole in the VCO cover using a pair of small diagonals (be
careful!).
5. Retune the VCO to cover your desired frequency spread. My 04AT goes from
441 to 473 MHz, which is pretty good.
6. Any frequency may be entered directly on the keypad (starting with the 10
MHz digit).
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*** Be careful not to transmit out-of-band, or accidentally operate on
any non-amateur, unless you are authorized to do so.
DO NOT JEOPARDIZE YOUR LICENSE!
===== AUDIO MODIFICATION FOR ICOM IC02 AND IC04 RADIOS =====
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This audio mod works on the 02 and 04AT. It increases the level of audio, as
well as rolling off some of the lows. Sounds real nice. It involves the
circuit around Q105.
1. Replace C119 with a .01 uF cap (disc ceramic is fine).
2. Parallel R131 with a 1 uF cap (use a tantalum cap).
3. Parallel R132 with a .01 uF cap (disc ceramic is fine).
This is not the same mod as the one International Radio is advertising, which
involves changing C117.
I tried an AB-1 Audiolaster from Engineering Consulting, and was very
unhappy with the results. I am very pleased with the audio given by this mod
(much cheaper too!).
[EOF]
SOURCE: The QRZ Windows Ham Radio CDROM |
