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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.

Find out more by contacting:  rhashiro(remove this part)@hawaiiantel.net
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Updated: January 16, 2011

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