T500 Squelch knob reversal


The squelch control on the T500s work the ‘opposite’ way to most amateur radios. That is, to turn the squelch threshold up, you turn the knob anti-clockwise, while turning it clockwise will lower it. I found this a little annoying, and realised that as the squelch control was just a small potentiometer, it couldn’t be too hard to reverse this. So, here it is – a little bit of track cutting and soldering is required.


Locate the bottom of the squelch pot – there are four pins at the front, along with two larger mechanical mountings further back.

For simplicity, I have numbered these pins from 1 to 4, from left to right, as viewed with the bottom of the PCB facing uppermost, with the front of the radio facing AWAY FROM you.

You need to do four things:

1) Cut the track leading to pin 1.
2) Connect pin 1 to ground, which can be done by scraping a little enamel off the nearby ground plane and bridging the two with solder.
3) Cut the tracks linking pin 3 to ground (it’s linked to the ground planes on both sides)
4) Using a small piece of wire, connect the track that was originally connected to pin 1 to pin 3.

Once these steps are completed, the net effect will be that pins 1 and 3 have been swapped round.

You should be left with something looking like this (front of the radio at the top of the photo):


That’s it – the squelch should now work the ‘right’ way round.