SDS100/SDS200: Odd RSSI Display Issue

[ShyFlyer]

I recently noticed an odd issue with the RSSI indicator on my SDS100. Sometimes this indicator doesn't display at all (i.e. zero to one bar), sometimes it displays as one should expect it too as transmissions are received. After careful observation, it seems that the temperature of the unit is a factor. When the unit is below room temperature, the RSSI displays normally. Once the unit warms up, it no longer displays or only indicates one bar.

Adding to the mystery is that I don't seem to be missing any transmissions. Additionally, the transmissions received don't seem to be any more garbled (digital systems) or contain any more static (analog systems) than normal. To verify this, I placed it side by side with my BCD436, using the same model antenna, and scanning the exact same system, sites, and talkgroups. The SDS locked onto the same sites and talkgroups the BCD did, at nearly the same exact times, and the audio from both was of the same quality.

I recently updated the firmware on the SDS, but I can't recall if this issue appeared before or after that update.

 

[Colin9690]

That is strange. I too did the update and am not experiencing the issues you're having. I'm staring at my -100 now, it's been on for about 50 hours straight and RSSIs display as they should. They were just fine before the firmware update too though, so no change on my end.

 

[MStep]

Strange, yes, but these anomalies at not unexpected. There are two issues which may or may not be related. And multiple faults are always a pain to track down. I would first see if you can install the older version of the firmware to see if the condition still exists. If not, I would suspect a problem with the newer firmware. If the condition still exists when you use the older firmware, then you might have a heat issue with your unit.

A few more reports in this thread from those who have installed the newer firmware might help you verify where the problem lies.

 

[Ubbe]

It could be the J401 connector cold solder joint issue. One pin in the connector could be related to RSSI info and if you push and compress the scanner at the point between display and the three soft buttons you should notice if the indication comes back.

Heat generated issues are mostly mechanical related as heat makes metal expand.

/Ubbe

 

[ShyFlyer]

It could be the J401 connector cold solder joint issue.

That was my initial thought when I noticed the RSSI not showing up. I read up on some of the previous cold solder joint threads but didn't see anything other than issues relating to reception quality, something that I still don't experience, though I likely will if the SDS remains in service. I'll ship it off to Uniden eventually. For now I'll just refrain from using it in my truck to keep the issue for worsening. The BCD still works like a champ, fortunately.

Thanks everyone!

 

[Ubbe]

I read up on some of the previous cold solder joint threads but didn't see anything other than issues relating to reception quality

With the cold solder joint it also are often seen to indicate -40dBm RSSI values even when not receiving any signal, so signal strength anomalies are often a result from that bad soldering.

/Ubbe