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.