FCC Licensed Amateur Radio Operator, Extra Class

Alinco DR-605 Mic Cable Repair

I haven’t posted to this site in quite some time because I’ve been very busy with broadcast engineering projects. So I thought I’d take time out to do a few repairs on my Alinco DR-605 dual band mobile and share a few pics to show the improvements. I chose to start out by repairing the RJ45 plug end of the mic cable, which — as you can see — was looking pretty ragged and on the verge of totally letting me down.

The factory Alinco microphones are well known for the cable jacket getting brittle and breaking. Mine was no exception.

After cutting back the bad end of the cable, I added some heat shrink tubing to the plug end for reinforcement and installed a new RJ45 connector. Much better.

Confirming the wiring pattern, which is (in my mic’s case, looking top wire to the lowest wire), Grey, White, Orange, Red, Shield (which I tinned with solder), Yellow, Violet, Green. Obviously, we’re looking at the bottom side of the RJ45 on the RJ45 plug.

Testing the radio after repairing the mic to make sure it’s keying and that there is audio from the microphone to modulate the radio

With the microphone keyed, the DR-605 is producing good peak power with the 123.0 Hz PL right on frequency, and when I talked or whistled into the mic, it would show around 3.5 kHz of modulation, Good to go.

A successful start to getting this trusty old mobile (which I’ve been using almost exclusively as a base station rig here in the repair lab) back into better condition. The Alinco EMS-45 microphone checks out well, with all buttons functioning as expected.

With this sub-project completed, my next repair task on this DR-605 will be replacing the blown backlight lamps in the front panel display. I’ll actually be replacing the old, burned-out incandescent lamps with LED illumination, which will necessitate a little solder trace modification for the purpose of adding current limiting resistors. I haven’t yet decided whether or install “warm white” LED’s or blue.) I hope to have that done soon, but duty calls, so it’s time to pack up the tools and get back to doing what pays the mortgage, keeps food on the table, and keeps radio and television stations on the air and sounding good 😉

73 from KK4ICE,
(a.k.a., “The Iceman”)

Updated: January 23, 2021 — 8:57 am
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