SDS100/SDS200: SDS100 Control Channel after repair

[Stecomp]

Just got my SDS100 back from Uniden repair to fix the cold solder joint issue. Started optimistically with WX and air band receiving fine. My normal P25 simulcast system is unable to lock on the known control channel sitting right next to the SDS200 to confirm. All settings seem the same as before and never was a problem with finding CC. When I take off antenna it still shows i am getting a full signal bar just like it did before sending it in when the problem first appeared - what does that mean? Another P25 system is also unable to acquire CC but when I take the antenna of for that system the signal bar drops as you would expect.

Tried a site hold, removed non CC freqs and is also happening on a similar neighboring system with different CCs. When I turn the system off and then back on it will briefly acquire the CC but then starts scanning the other channels and RSSI drops to -30dBn.

Looks like back to Texas unless I'm missing something. Turn around time was a little less than 2 weeks on the positive side.

 

[tvengr]

RSSI drops to -30dBn.

I believe you may have a misunderstanding of RSSI. -30 is an indication of an extremely strong signal. The larger the number, the weaker the signal. Signal level indication that high occurs with the cold solder joint problem. I don't believe it was fixed.

 

[hiegtx]

Just got my SDS100 back from Uniden repair to fix the cold solder joint issue. Started optimistically with WX and air band receiving fine. My normal P25 simulcast system is unable to lock on the known control channel sitting right next to the SDS200 to confirm. All settings seem the same as before and never was a problem with finding CC. When I take off antenna it still shows i am getting a full signal bar just like it did before sending it in when the problem first appeared - what does that mean? Another P25 system is also unable to acquire CC but when I take the antenna of for that system the signal bar drops as you would expect.

Tried a site hold, removed non CC freqs and is also happening on a similar neighboring system with different CCs. When I turn the system off and then back on it will briefly acquire the CC but then starts scanning the other channels and RSSI drops to -30dBn.

Looks like back to Texas unless I'm missing something. Turn around time was a little less than 2 weeks on the positive side.

From your description, unfortunately leans toward a return trip to repair.

I would call Uniden & insist that they pay for the return shipping, since it was not working when you got it back. Repairs have a 90 day warranty, but in your case, it was basically D.O.A. when it landed at your door.

Just to rule out something else, I would try a different antenna. I would also format, use 'Clear User Data" info' and them write a fresh set of programming to the card, and see if that makes a difference. If it does not, then I suspect it will need a return trip.

See this page for contact info.

Uniden Support Center

 

[hiegtx]

I don't believe it was fixed.

That's my thinking as well.

 

[Stecomp]

Thanks, understand the function but meant it is lower than usual 85-100. Agree on the return.

 

[Stecomp]

That's my thinking as well.

Tried the different antenna approach and will try the format, thanks Steve.

 

[hiegtx]

Tried the different antenna approach and will try the format, thanks Steve.

While I have my doubts it might work, it's easy to try and does not cost anything but a few minutes of your time. Many of the issues reported with the various database scanners trace back to a card issue. In some cases where that was completely unexpected, like when the scanner randomly reboots itself or freezes up..

 

[Stecomp]

They didn't specify any specific repair code, like J401 etc. but just generic Repair Solder Joint. It did fix the reception on conventional channels. Has that low number RSSI been associated with previous solder issues with antenna removed?

 

[tvengr]

Just to rule out something else, I would try a different antenna.

If the antenna were bad, the signal strength should be much lower.

 

[hiegtx]

If the antenna were bad, the signal strength should be much lower.

True, but no harm in trying a different one, just to rule that out.

 

[GTR8000]

When I turn the system off and then back on it will briefly acquire the CC but then starts scanning the other channels and RSSI drops to -30dBn.

I believe you may have a misunderstanding of RSSI. -30 is an indication of an extremely strong signal.

Thanks, understand the function but meant it is lower than usual 85-100.

Let's try this again. -30 dBm is a higher/better value than -85 or -100 dBm. It's not "dropping" or going "lower" when it shows -30 instead of -85 or -100, it's increasing. You're dealing with negative integers, keep that in mind.

That being said, you really shouldn't be seeing an RSSI of -30 dBm on a trunked control channel unless you're 100 feet from the transmitter, as -30 dBm is an extremely strong signal. Seems to me something isn't right if the scanner is claiming that's the RSSI even with the antenna off.

 

[Stecomp]

You're dealing with negative integers, keep that in mind.

Understood, just poorly phrased on my part. Interestingly after leaving it off for a bit, having previously turned off and on, the scanner resumed normal operations with RSSI numbers as expected and matching my 200. Obviously early results so will wait and see.

 

[GTR8000]

If you were seeing such a high RSSI with the antenna off, it's possible that there is some sort of localized interference. What bands are the P25 systems in?

 

[Stecomp]

If you were seeing such a high RSSI with the antenna off, it's possible that there is some sort of localized interference. What bands are the P25 systems in?

850-860, almost 5 years with this scanner and several others never had interference issues. Scanner back to that -30dBm reading and no longer picking up anything.

 

[RMason]

Scanner back to that -30dBm reading and no longer picking up anything.

Yep - that can be indicative of a cold solder joint making intermittent contact. Sounds like a trip back to Uniden is in order. Unfortunately, they seem to have a "habit" of not fixing the cold solder joint the first time.

 

[buddrousa]

The Strong -30DB is a sign of the cold solder joint problem. Call and get a RMA ASAP