Video: Strange SDS100 issue versus BCD436

racin06 · Jun 17, 2018

Video: SDS100 issue versus BCD436

See video below. As you can see, the SDS100 isn't picking up the TG transmission in which the BCD436 is picking up...the SDS100 just flashes the TG on and off rapidly. This condition exists with the new beta firmware and with the previous firmware, as well. This is the system being monitored:
https://www.radioreference.com/apps/db/?siteId=13059. This condition isn't occurring on all transmissions; however, it is quite frequent. Any ideas on the cause of this condition? Both scanners are using the same Remtronix 800Mhz antenna. Audio is from the BCD346.

https://vimeo.com/275524419

Click on "Vimeo" at bottom right for best viewing in larger window.

jonwienke · Jun 17, 2018

That's a firmware bug. Record a log, and post it in the beta firmware thread.

racin06 · Jun 17, 2018

Thanks, I will record the log and post in the beta firmware thread. How do you know with certainty, this is a firmware bug?

jonwienke · Jun 17, 2018

The SDS100 is reading the control channel well enough to know that a transmission is in progress on the active talkgroup, and it correctly identifies the active talkgroup the whole time. If it can do that, then the problem is not weak signal, RF interference, or a problem with the receiver upstream of the ADC. If any of those things were the problem, the unit would not detect a transmission was in progress, and would not consistently identify the correct talkgroup during the transmission. It's also not encryption, because the 436 can decode the transmission.

Something is erroring when the unit is trying to switch to the voice channel, and kicking it back to the control channel, where it sees an active transmission, tries to switch to the voice channel, errors, and so on in a loop until the transmission ends. So that is definitely a firmware issue.

phask · Jun 17, 2018

Any difference if moved farther apart?

FWIW - one BETA tester was in the Indy area and had few issues - simulcast Hell.

racin06 · Jun 17, 2018

Thanks much for the explanation!

Ubbe · Jun 17, 2018

When it moves to the voice channel the signal strength indicator goes from full strengh to nothing as if it goes to the wrong frequency. Do both scanners have the exact same setup, in the frequency bandplan in that system?

/Ubbe

policefreak · Jun 17, 2018

I seem to remember a fw bug like this on the BCD996P2 on phase 2 transmissions. It was reading the CC perfectly but going to an incorrect voice channel and I would see the flickering. You should let it display the frequencies and watch to see if its going to an incorrect voice channel when this happens.

mancow · Jun 17, 2018

I wonder if there is a "birdie" on that voice channel? I would have enabled detail display and tried to see what freq it was trying to go to and try listening in conventional mode. Perhaps they could code in the ability to use IFX with trunking as an additional tool to eliminate offending frequencies.

jonwienke · Jun 17, 2018

IFX applies equally to trunked and conventional freqs. But I don't think that's the problem. I've seen similar behavior before. At the time I thought it was because the oscillating talkgroup was encrypted--I was hearing traffic from other talkgroups from the same system & site just fine. It was always just the one talkgroup jumping back and forth between the control channel and voice channel.

troymail · Jun 18, 2018

I agree - it appears that the CC is saying "switch to frequency X" and the radio does but isn't seeing a signal so it returns to the CC only to be told "switch to frequency X" again (over and over).

Looks like the squelch is on 3 - seems like other reports suggest that the normal "2" (at least on the 436) isn't good enough and you need to set it to "1"....

KR7CQ · Jun 21, 2018

troymail said:
I agree - it appears that the CC is saying "switch to frequency X" and the radio does but isn't seeing a signal so it returns to the CC only to be told "switch to frequency X" again (over and over).

Looks like the squelch is on 3 - seems like other reports suggest that the normal "2" (at least on the 436) isn't good enough and you need to set it to "1"....

Exactly, same problem I and others that I met with saw. The reason is said to be "interference" (never mind that the 436 and G4 had no issue in the same spots). This is "OK" because "different devices handle interference different".

jonwienke · Jun 21, 2018

Thats not interference, it's a firmware bug. If RFI was the problem, the scanner wouldn't be able to receive the control channel in the first place, and you wouldn't see the same talkgroup flashing over and over--it would be random garbage, if anything at all.

JamesO · Jun 21, 2018

Ideal situation would be to run a Debug Log on BOTH the SDS100 and the 436HP at the same time
operating in the same manner on the same system and submit these Debug Logs to Uniden. It would make the problem crystal clear to the Engineering staff when they compared what the 2 radios were doing.

My guess is a simple problem in the coding. Not an unusual problem. Unfortunately many software/firmware folks are a bit sloppy at times.

racin06 · Jun 23, 2018

Some have asked for a video of the problem with the SDS100 display on full details. See below. Please excuse a couple of moments of my wife banging pots and pans in the kitchen...LOL.

https://vimeo.com/276659475

werinshades · Jun 23, 2018

racin06 said:
Some have asked for a video of the problem with the SDS100 display on full details. See below. Please excuse a couple of moments of my wife banging pots and pans in the kitchen...LOL.

https://vimeo.com/276659475

I hope you submitted a debug file as it was mentioned. Something looks odd there. When I first received my SDS 100, my display did something similar. I checked my programming and still had the attenuator on that I had to use on my 436/536 to even try to get some P25 simulcast reception. Turned it off and all was back to normal.

troymail · Jun 24, 2018

racin06 said:
Some have asked for a video of the problem with the SDS100 display on full details. See below. Please excuse a couple of moments of my wife banging pots and pans in the kitchen...LOL.

https://vimeo.com/276659475

It looks like overall poor reception or something causing interference with occasional clear reception (there are times where the radio is holding the control channel and others where it is searching for one). How far are you from the system? Does it act the same way when you leave the house and/or try receiving from a different location?

jonwienke · Jun 24, 2018

It's not a poor reception issue. The scanner isn't having any trouble receiving the control channel. Note that the frequency isn't changing, which it would be if the scanner was cycling through site frequencies looking for a usable control channel. It knows when there is a transmission, the problem is that when it switches to the voice channel an error occurs and it immediately switches back to the control channel, where it sees thare is an transmission, so it switches to the voice channe, where an error occurs...in an endless loop until the transmission ends.

If reception was the problem, the scanner would be cycling through site frequencies looking for a control channel, and any talkgroups it tried to switch to would be random garbage. Switching to the same talkgroup repeatedly is proof that it is (a) receiving the control channel, and (b) getting good decode regarding the ID of the active talkgroup.

Definitely a firmware bug borking the switch from the control channel to the voice channel.

Ubbe · Jun 24, 2018

I looked closely at the video and it is a reception problem. On the voice channel 857.2125 the signal goes between -50dBm and -110dBm and down to nothing. When the signal are above -110dBm it starts to decode and with some voice breaks up. The -50dBm value could be from the control channel as the rssi value seems to be delayed and hangs on from the previous channel.

Set the SDS100 manually to the 857.2125MHz frequency analog conventionally mode with open squelch and listen to the signal and watch the rssi strenght. It looks as if the SDS100 gets signal overload from an adjacent frequency. That is if the 436 works ok on that frequency. Othervwise the power amplifier of the basestation are starting to fail. Turn the dial to check if an adjacent frequency also have a strong signal of -50dBm. No scanner grade receiver can handle that neighbour channel interference.

/Ubbe

trido · Jun 24, 2018

racin06 said:
Some have asked for a video of the problem with the SDS100 display on full details. See below. Please excuse a couple of moments of my wife banging pots and pans in the kitchen...LOL.

https://vimeo.com/276659475

I received my Uniden SDS100 and thus far I can say with confidence that it is a huge upgrade over the Uniden BCD346T, particularity when monitoring LSM systems and the signal strength gain is also very apparent.
Jim, wasnt your sds 100 working fine the first few days?

Maybe you have but what about going back to orig firmware? Are you on one of the betas?

Video: Strange SDS100 issue versus BCD436

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