Technical Aspects of Amateur Radio
This page has miscellaneous notes of a technical nature. Double check this information against your radio as the configurations may vary. I am not responsible if the information is not correct.
Icom IC-202S
The Icom IC-202S uses a 500 ohm dynamic microphone, and a four pin mike connector.
The power connector for the Icom IC-202S radio is a mini-IEC plug, also called the KT-601 plug. The IC-202S uses pin 1 (lower left, looking towards the radio) for the battery charger, pin 2 (lower right) for the ground, and pin 3 (top pin) for the positive 12 VDC input. It is the same power plug used for the Kenwood TR-9130 memory backup connector, and the Kenwood TR-2200.
A substitute power cable is the AOR DC-3000 power cable, however, the DC-3000 has only two of the pins (1 and 2) wired. Alternate power cords for the IC-202S might be gotten from the power supply of an external Hayes Microcomputer Smartmodem, the 300, 1200 and 2400 baud models.
The 1200 baud modem number was 07-00038. The power supply number was 52-00005. It has three wires: (Pin 1, Lower Left, Black), (Pin 2, Lower Right, Red), (Pin 3, Top, Yellow)
The 2400 baud power supply number was 52-00008. Pin-outs 2 and 3 have been verified to have continuity. However, the plug fits very snug into the connector. The plug is keyed (there is a notch on the bottom of the plug connector).
The Smartmodem Optima 9600 series has a coaxial barrel connector and is not usable. P/N 5110AM. The V-Series Smartmodem 9600 series uses a coaxial barrel connector and is not usable. P/N 1004AM.
Table not verified, facing the radio
| Pin Location | Pin No | Function | Hayes Power Cord Wire Color | Comment |
|---|---|---|---|---|
| Lower Left | 1 | Charger | Black | |
| Lower Right | 2 | Ground (Negative) | Red | |
| Top | 3 | +12 VDC | Yellow |
Icom IC-215
The Icom IC-215 radio uses a 4-pin round Icom microphone connector and a 500-ohm dynamic microphone. The power cable is coaxial connector with the center pin tied to 12V negative ground, and the outer ring positive.
Crystal Holder Type: HC-25/u
RX Crystal Freq=(RX Freq-10.7)/9
TX Crystal Freq=(TX Freq)/8
CL is 20 pF, with regard to the crystal load capacitance.
Icom IC-22A
The Icom IC-22A radio uses a 3-pin round Icom microphone connector and a 500-ohm dynamic microphone. The power cable is built into the radio.
The crystal is the same as the IC-215.
Icom IC-22S
The Icom IC-22S radio uses a 4-pin round Icom microphone connector and the same microphone as the IC-215. Power cable is the Icom 4-pin Molex power connector.
Icom IC-22U
The Icom IC-22U radio uses an 8-pin round Icom microphone connector and the HM-8 microphone. Power cable is the Icom 4-pin Molex power connector.
Icom IC-271H and IC-x71 RAM
The Icom IC-271A and IC-271H radios uses a RAM board that's powered by a lithium battery. A similar unit is used on the IC-R71, IC-745, IC-751, IC-471, IC-1271 radios. With age and time, these batteries fail, leaving the RAM board inoperable. Roberto Nardo in Italy has a replacement RAM board available that is non-volatile. Check this link for details.
patcomm PC-500
The patcomm PC-500 uses a Tyco AMP two-pin Mate-N-Lok connector. Looking at the radio, the left pin is the negative power lead, and the right pin is the positive power lead. Use a 5 amp fuse in-line for current protection, as there is a crowbar diode just inside the power connector.
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