Self quieting problem MTS2000 midband

radio-link · Post by **radio-link** » Thu Apr 21, 2005 9:04 am

Hi!

I have a MTS2000 on my bench, special firmware for german authorities (MTS2013-FuG13b), equipped with DVP, and it developed an annoying problem with self produced noise, opening the squelch and rendering the radio almost ununsable.

My first thought was the display controller, or some ground problem on the front part, so I swapped the whole front part, with no success - the problem did not move to the other (working) radio.

It is not present all the time, sounds almost like the frequency is temperature dependant. It sounds like about 1500 Hz mixed with white noise, giving some harsh, grinding sound, absolutely annoying. Squelch is already set to 0.5µV, with no success, closing it further would give away to much of the RX sensitivity.

Any ideas out there? It really drives me nuts :(

Splat · Post by **Splat** » Thu Apr 21, 2005 10:28 am

It might be a shielding/harmonics problem the Jedi line had. Check here:
http://batboard.batlabs.com/viewtopic.p ... edi+shield

radio-link · Post by **radio-link** » Fri Apr 22, 2005 8:39 am

Splat wrote:It might be a shielding/harmonics problem the Jedi line had. Check here:
http://batboard.batlabs.com/viewtopic.p ... edi+shield

Thanks for the hint. I have thoroughly read through it, found it more addressed to TX noise, but today I took the MTS2000 apart once again, and when having a close look at the area where the controller board is pressed against the chassis I found that the solder was black or had even almost gone in some places. So I heated up and gave all those traces some new, shiny solder, put the radio together again - and now I am waiting for the noise. In two hours of waiting it did not reappear, so maybe that was it?! Will take it to the bedroom this evening, giving the beast the chance to awake me when it decides to make noise again.

I keep you posted :)

Splat · Post by **Splat** » Fri Apr 22, 2005 12:02 pm

Yeah, bad or cracked solder joints can definitely cause problems. Hopefully you fixed it. Good luck. Let us know what happens.

radio-link · Post by **radio-link** » Sun Apr 24, 2005 9:58 am

Splat wrote:Yeah, bad or cracked solder joints can definitely cause problems. Hopefully you fixed it. Good luck. Let us know what happens.

The radio had been turned on for 24 hours or so, without any more noise. Looks that really the blackened ground traces had caused the trouble!

Splat · Post by **Splat** » Sun Apr 24, 2005 10:00 am

Excellent! Glad you fixed your problem. It's amazing what a little solder here and there will do.