Back to Index Additional Alinco Information
Compiled by Mike Morris WA6ILQ
Maintained by Robert Meister WA1MIK

The DR135TE, DR-235T and DR-435TE radios are popular with the IRLP folks as they are inexpensive. Unfortunately the internal CTCSS decoder has very poor performance. I mean it is really bad - it's slow to open and can take from 1/2 second to as long as four seconds (!) to close.

Glen Roe WA6MHA uses one as a point-to-point link from an IRLP node to the local repeater. He ended up disabling the internal decoder and adding a TS 64 Decoder. He documented the procedure here (a local copy), or you can go to for the original writeup (offsite link).

Microphone Jack Pinout
Many Alinco radios use a round 8 pin mic jack with 7 pins around the outside and one in the middle. Click here for a photo. There are tiny numbers molded into the plastic on the plug and jack. Several Alinco and Kenwood radios use this pinout:
1Mic audio
3Down button
4Up button
5+5VDC out (for DTMF encoder, keypad backlight, or both)
6Audio output (paralleled with the speaker jack)
7Mic audio ground (the shield of pin 1)
8Ground for PTT, up and down buttons, speaker audio and 5vDC
  Many radios that use the 8-pin modular mic jack ("RJ-45" style) use this pinout: With the locking tab down, and looking into the connector or at the back of the plug the pins are numbered from left to right.
1+8v DC out (max is 10mA)
2CLO (data out for PC programming)
4PTT (input port for transmitter control. DTMF sent on this pin will control the radio.)
5Mic audio GND
6Mic audio
7GND for PTT
8CLI (data in for PC programming)

"Data" Jack Pinout
Many Alinco radios have a DE-9 connector on the back of the radio. When the EJ-41/U optional TNC board (for the DR-135, DR-235, DR-435, or DR06 radios) is not installed the ribbon cable from the connector is plugged into the control board and audio, COR and PTT signals appear on the pins as per the left side pinout below for connection to an external TNC. When the EJ-41U board is installed the ribbon cable is moved to that board and the pinout changes to the right hand list below. The EJ-41/U instruction manual is here and a photo is here. Note that the EJ-41/U designed to fill the basic packet communication functions, such as keyboard operations and APRS. For more elaborate operations requiring KISS mode, digipeater mailbox functions or node operations, do not use the EJ-41/U, instead use an external TNC like a KPC, an AEA, etc.
Without EJ-41/U optional TNC board
1COR signal, open collector, active low. Use a 10K resisitor from this pin to pin 8 as a pull-up resistor.
2Receiver audio output. The audio on this pin is not de-emphasized. Used for 9600 baud packet data.
3Transmitter audio input. The audio on this pin is not pre-emphasized. Used for 9600 baud packet data.
4Receiver audio output. The audio on this pin is de-emphasized. Used for 1200 baud packet.
6No connection
7PTT input
8+5vDC out, max current is 50 mA.
9Transmitter audio input. The audio on this pin is pre-emphasized. Used for 1200 baud packet.
With EJ-41/U optional TNC board
1Leave unused
2Serial data in from computer
3Serial data out to computer
4Leave unused
6Leave unused
7Leave unused
8Leave unused
9Leave unused

Heavily Biased Personal Opinion:

I do not recommend Alinco mobiles for use as a point-to-point link radio or as a repeater transmit radio. Buy a used YaeComWood or even a Motorola GM300 - but watch the duty cycle. Why? For one, the CTCSS decoder in the Alinco is slow to decode and does not release properly. Adding an outside decoder (like a Communications Specialists TS-64) fixes that but why should the customer have to buy another piece of hardware to patch Alinco's bad design?
Alinco should fix their design - or copy the one in the cheapest Yaesu, Kenwood or Icom - any of those does a better job. It's not a difficult design, even my old Motrac did it better, and it was built in 1962, 50 years ago.

Secondly, the Alincos seem to work when new, but you have to leave them in carrier squelch. Plus, over time I have had nothing but trouble. I was helping a gentleman that was putting up a 2m repeater on a extreme budget. It took an original and three replacement radios over 17 months at one location before we got something that lasted - and no, we were not abusing the duty cycle, nor was the operational temperature out of spec (how do you abuse the duty cycle on a UHF control receiver?)
As a carrier squelch mobile, or as a packet radio, they are great... especially as a "first radio" for a new ham.

Contact Information:

The author can be contacted at: his-callsign // at // repeater-builder // dot // com.

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