XTS5000 Scratchy Audio

[KJ6PNN]

View attachment Xts5k_Copy.mp3


HI,

I have a M1 5K R split..

I had some previous issues detailed in this thread:

http://communications.support/threads/7099-XTS-5000-Voice-announcement-crackling

I'm making a new thread, as I have a completely different issue.

Basically, there is a scratching/crackling sound in analog tx audio. It covers the audio for the first second or so, and then on and off after that. A couple of notes:

The radio was just aligned by a professional tech, and got a clean bill of health, so whatever the issue is, it does not show up on a service monitor.

The issue is worse on the band edge. On 440 Ham frequencies, it's not that noticeable, unless you are looking for it. However, at 460, you can easily tell that something is wrong.

I have attached an audio sample. The noise in all from the problem. There was no wind, and I made sure not to rub the mic. I have tried with both the internal mic and a RSM.

I appreciate any help. I really would like to avoid flat rating it to Mexico.

Thanks

Matt

 

[MTS2000DES]

I had a VHF XTS5000 that had this exact same problem. The trading partner did a full PM on it before shipping out.I tried reseating the boards and cleaning the flex going into the ZIF connector and VOCON interconnect and it would not go away. It was just a slight staticky sound on analog, regardless of RX RSSI. I also checked the little piece of coax that connects to the RF board for being loose. Nothing seemed to make it go away. It did not affect digital, just analog.

He ended up undoing our deal, I never heard the final diagnosis. IIRC it was an older unit (circa 2003/2004) with all original hardware.

 

[Mars]

Sounds like RFI getting into the audio circuit before it's passing through the DSP.

- What type of battery are you using? (some aftermarket batteries are known to cause these issues!)
- Have you checked the SMA connector for damage/dirt? Arcing could be causing that RFI noise
- Bad grounds within the radio. Have you tried reflowing the vocon? Whip out the DSM and find the analog stages before it hits the DSP
- Does it do it with an external antenna or just the duck? (again, RFI/shielding issues)
- Long shot, but could the crackling be an analog representation of unwanted FSK? (i.e. rapidly drifting reference oscillator)
- Have you tried swapping housings? Could be a bad flex assembly.

 

[KJ6PNN]

I am using a /\/\ impres battery.

Yes, I have.

I am not good enough on a bench to re-flow anything.

I am out of town working, I will give an external antenna a try when I get back

What would be the fix for a FSK? Replace the RF board?

I have a M3 housing on the way, I will put it on and try. However, I don't think that is the problem. The radio is almost NOS, the seller actually claimed it was never used, but there was a few marks on the case where a RSM was attached.

I have another question. Can a bad battery permanently damage a radio? I had an xts3000 uhf (What this 5K is replacing), when I bought it I got an aftermarket battery to go with it. The radio exhibited almost the exact same symptoms, however, the scratching changed if you shook the radio, something the 5K is not doing. I did use that AM battery on this radio a few times before I got my impres batteries. The battery was changed in a legit /\/\ charger though.

Thanks,

Matt

 

[MotFAN]

Matt, it cannot.