SDS100/SDS200: Squelch/Antenna

[Ubbe]

Maybe mobile phones are powerful enough and the bandfilter in the scanner pass the whole frequency range 760-1300MHz so anything in that range could have an impact to your reception of signals within that frequency range. When mobile phones are idle they periodicly transmit something like 2-3 second bursts and the interval depends of if you are in a weak coverage area, that will generate more of those bursts to try and interogate for a better site, but probably not more often than each 10 minute.

Have you tried your new antenna?

/Ubbe

 

[Dexter2]

Ah okay, I'm no science wiz so I'm definitely learning here. I asked because I know where I have a lot of electronics TV's and music stereos, the radio doesn't really work.

Unfortunately, the antenna hasn't arrived yet. Its two days late and just arrived at my post office this morning. Is there a big difference between the 810 and 820 antennas?

 

[Dexter2]

Maybe mobile phones are powerful enough and the bandfilter in the scanner pass the whole frequency range 760-1300MHz so anything in that range could have an impact to your reception of signals within that frequency range. When mobile phones are idle they periodicly transmit something like 2-3 second bursts and the interval depends of if you are in a weak coverage area, that will generate more of those bursts to try and interogate for a better site, but probably not more often than each 10 minute.

Have you tried your new antenna?

/Ubbe

After posting the other message, the antenna came in. I brought the radio into my living room where I have most issues and resettled all settings. To me, this antenna looks slanted as well after it is twisted on, but it definitely is connected.

So, just like before nothing worked as is. The P25 was dead in the water, I tried the EDAC and this was the first time this one twitches and I could hear the car person perfectly clear but the dispatcher was a loud squelch shh....shh.....shh no voice sound. I then changed the Global Auto Filter from Normal to Off and the EDAC still flickered and the RSSI improved by actually showing up on the P25. I lowered the the Squelch to 1 and the EDAC works fine, but not the Analog because Squelch is on 1. The P25 now is present on the screen but has very high NOISE and strong signal. I moved the radio into the middle of my table (kind of out of reach) and both P25 and EDAC work perfectly, NOISE and RSSI are on great levels. Now, I'm assuming if I want to include the Analog, I just have to move the radio back into the back room and raise squelch to 2.

 

[nessnet]

"I moved the radio into the middle of my table (kind of out of reach) and both P25 and EDAC work perfectly, NOISE and RSSI are on great levels.

It sounds like a classic case of RFI...(?)

Of course, at higher freqs, the difference in positioning can be a factor certainly. When it does rec'v in the middle of the table, what exactly is the RSSI? Is it >100 - or <100?

Maybe sequentially turn off anything that can be interfering (wi-fi, cordless phone - anything that emits RF - even microwave ovens, air purifiers and switching power supplies can emit RFI).

If you power something down and your problem disappears, voila...

 

[Dexter2]

It sounds like a classic case of RFI...(?)

Of course, at higher freqs, the difference in positioning can be a factor certainly. When it does rec'v in the middle of the table, what exactly is the RSSI? Is it >100 - or <100?

Maybe sequentially turn off anything that can be interfering (wi-fi, cordless phone - anything that emits RF - even microwave ovens, air purifiers and switching power supplies can emit RFI).

If you power something down and your problem disappears, voila...

It's below 100. like -40/-50.

That would be my ultimate guess. Even in my office, I have to have it behind my laptop or just in front of my printer. I used to have it on the window sill but then the exact position started to become a nuance, so I've been just leaving it in my back room with the volume on high. That's when I thought, bringing it outside would solve everything and that ship sailed quickly.

 

[nessnet]

It's below 100. like -40/-50.

If it's -40 or -50, you basically are on top of the transmitter.
I saw some weird behavior (odd, too strong RSSI readings) on a 100 when I was playing with filters. Not saying that is your issue here, but -40 to -50 or even -60 is a quite strong signal, which doesn't sound like what is going on here(?)

Or... as Ubbe points out on a regular basis, the chip Uniden uses is quite wide. Meaning that another freq within a fairly wide range on either side could certainly be a culprit.

 

[Dexter2]

If it's -40 or -50, you basically are on top of the transmitter.
I saw some weird behavior (odd, too strong RSSI readings) on a 100 when I was playing with filters. Not saying that is your issue here, but -40 to -50 or even -60 is a quite strong signal, which doesn't sound like what is going on here(?)

Or... as Ubbe points out on a regular basis, the chip Uniden uses is quite wide. Meaning that another freq within a fairly wide range on either side could certainly be a culprit.

That's what I'm trying to pinpoint, as when I do a quick save there have been times a totally different system came through that I'm not familiar of.. Now I'm wondering, was the 100 a good purchase haha.

 

[nessnet]

Now I'm wondering, was the 100 a good purchase haha.

It is - and it isn't.
Yes, it certainly isn't perfect - far from it in certain regards (ex: VHF and the above). But, it excels in some things, (ex: simulcast), so like many things in life it's a calculated trade-off.

 

[jonwienke]

The only time I've ever seen a -40dBm RSSI on my SDS100 was when the solder joints were having issues after it came back from Uniden. I have NEVER seen -40dBm when the scanner was working correctly.

 

[nessnet]

Dexter2:
Jon states what I suspected when I saw the -40/-50. You said, " That would be my ultimate guess". Did you actually see these RSSI readings, or speculating? If you actually saw these, I think the recommendation is going to be to pack it off to Uniden (or Jon). You have something wrong and the radio is in need of repair.

 

[Dexter2]

Hi guys - So, yes when I have Filters off and Squelch on 1 the RSSI is between -40/-50 and it has a full RSSI bar graph (except in my problem rooms). The same thing happens when Squelch is on 2 though that's when the system flickers. If I don't change anything, the RSSI goes to -60/-70 and the bar graph shows that proportion on the EDAC and it works as I assume it should or it all goes blank on the P25 and I receive no activity period. Now, this afternoon, I tried to leave the radio in my back room with squelch on 2 with this new antenna and again, it seems after 7pm, I receive consistent activity even if its in spurts as really there is no activity as the night continues.

What is the RSSI supposed to be?

I haven't tried unplugging my devices yet, as the NOISE is always extremely high in my living room, unless I keep it directly in the middle of my table angled weirdly. I even tried switching Squelch to 2 in the middle of a conversation, it works but then goes right back to flickering like two conversations later.

What is the steps and costs for doing business with Uniden? So far, I've read many abstract experiences. With financials and mail delay being many of our constraints, I need to educate my self some more.

 

[Dexter2]

I just went and checked on it, as I heard activity. It was D-ERROR - 0, NOISE - ###'s, RSSI -95. The bar graph was about a quarter full I believe.

 

[jonwienke]

Hi guys - So, yes when I have Filters off and Squelch on 1 the RSSI is between -40/-50 and it has a full RSSI bar graph (except in my problem rooms). The same thing happens when Squelch is on 2 though that's when the system flickers. If I don't change anything, the RSSI goes to -60/-70 and the bar graph shows that proportion on the EDAC and it works as I assume it should or it all goes blank on the P25 and I receive no activity period. Now, this afternoon, I tried to leave the radio in my back room with squelch on 2 with this new antenna and again, it seems after 7pm, I receive consistent activity even if its in spurts as really there is no activity as the night continues.

What is the RSSI supposed to be?

I haven't tried unplugging my devices yet, as the NOISE is always extremely high in my living room, unless I keep it directly in the middle of my table angled weirdly. I even tried switching Squelch to 2 in the middle of a conversation, it works but then goes right back to flickering like two conversations later.

What is the steps and costs for doing business with Uniden? So far, I've read many abstract experiences. With financials and mail delay being many of our constraints, I need to educate my self some more.

Read this thread in its entirety:

SDS100/SDS200: - Cold Solder Joint

As I've mentioned elsewhere, I sent my SDS100 in for the cold solder joint issue, and after about a month away from home, it came back working again. Until today. The A/C in my house is broken, and ambient has been 85F or so the last couple days, and so the SDS100 has been running warmer than...

forums.radioreference.com

It's a bit long, but there are several firsthand accounts of customer experiences with Uniden repair (including mine), compared with...an alternative.

 

[Dexter2]

Thank you, will definitely look into this. When I went to bed, I put Global Auto Filter to Wide Invert and Squelch on 2 and RSSI went to -60 with full bar graph. I received three conversations, that I recall. This morning, I unplugged a stereo in my living room and now the radio works with Squelch on 2 and GAF off, but the radio is currently angled on its back (I have it on a deck of cards facing the window. This is a first.

 

[nessnet]

Dexter2: I strongly suspect you have something physically wrong with the radio.

Even if you were sitting right next to a transmitter, these RSSI readings are way to high.
Something is wrong. Talk to Jon about getting it fixed (if out of warranty).

 

[Dexter2]

Thanks, its been like this from jump. I reached out to where I purchased it from within a week and never gotten a response. This is how I found RadioReference and you folks here. I just reached the warranty limit this past October/November.

I just tried all avenues here because I'm not able to ship it to Uniden and it is very strange to me that I have no problems with other systems. As you may have seen in another thread, I went back to Full Database today and I was receiving activity for systems even further away from the ones I've been having issues with and I live locally lol.

 

[nessnet]

... it is very strange to me that I have no problems with other systems. As you may have seen in another thread, I went back to Full Database today and I was receiving activity for systems even further away from the ones I've been having issues with and I live locally lol.

Confusing then.....
If a physical problem, it would (should) be across the board. But, just certain systems (frequencies??), is puzzling.

I've been in and around the RF biz for (cough) decades and thought I've seen them all.... But, then again, there always is that new, odd one.

I'm swinging back to suspecting RFI then.

 

[Ubbe]

I was receiving activity for systems even further away from the ones I've been having issues with and I live locally lol.

Your issues are probably frequency dependent. Look at the frequencies for the systems that work and compare to the frequencies that are problematic.

I have a system that use 4-5 sites with 4-5 frequencies each and they are close in frequency. The SDS100 have almost as good reception from a frequency some 250KHz and 325KHz away from its tuned frequency and this system has bleedover from those channels and different filter settings and IFX only replace one bleedover channel with another. There's no solution for that situation when the receiver have these internal mixing products. All sites in that system are at -90 to -105dBm levels and the strongest signal I have in all bands are -80dBm, so there's no overload issues with the SDS100 receiver.

Test of internal interferencies SDS100

/Ubbe

 

[Dexter2]

Your issues are probably frequency dependent. Look at the frequencies for the systems that work and compare to the frequencies that are problematic.

I have a system that use 4-5 sites with 4-5 frequencies each and they are close in frequency. The SDS100 have almost as good reception from a frequency some 250KHz and 325KHz away from its tuned frequency and this system has bleedover from those channels and different filter settings and IFX only replace one bleedover channel with another. There's no solution for that situation when the receiver have these internal mixing products. All sites in that system are at -90 to -105dBm levels and the strongest signal I have in all bands are -80dBm, so there's no overload issues with the SDS100 receiver.

Test of internal interferencies SDS100

/Ubbe

If I had to guess, I would say that is spot on because indeed the frequencies are all in similar range even for the other systems (though its not the exact frequency as programmed).

How would I do that test you did and it is a bit reliving knowing this issue rather than not being able to fix it.

Thank you as always.

 

[jonwienke]

A SDR stick is your best bet for hunting down RFI.