Squelch/Antenna

jonwienke

More Info Coming Soon!
Premium Subscriber
Joined
Jul 18, 2014
Messages
12,466
Location
VA
No, it's a usb device. The RTL-SDR sticks are about $20. Get a USB extension and a cheap SMA antenna that covers the problem band, and download SDR# and install it on a laptop. You'll be able to see about 2MHz of bandwidth on the screen.
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
So purchase the SDR stick, SMA antenna, and USB extension cable. Plug each together into laptop, place SDS100 in my living room with the most issues with Squelch on 2 Global Auto Filter - Normal. Then simply, follow the instructions from SDR#?
 

jonwienke

More Info Coming Soon!
Premium Subscriber
Joined
Jul 18, 2014
Messages
12,466
Location
VA
Not quite. SDR# won't give you "instructions" per se but it will show you activity in a swath of frequencies. If you're having RFI issues you'll see the interference visually, and with an extension cord you'll be able to use the SDR kind of like a handheld metal detector but looking for a signal source instead of metal.
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
If it finds anything, is there a remedy or simply keep the radio from whatever areas I find?
 

jonwienke

More Info Coming Soon!
Premium Subscriber
Joined
Jul 18, 2014
Messages
12,466
Location
VA
That depends on where and what it is. If it's a defective LED light fixture, you can turn it off or replace it. If it's something off your property, your options are a lot more limited.
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
I have an interesting update for today. In case you've seen my other new thread about a low frequency 49.20000 and there may be a camera or mictophone where I live. This is what I noticed:

When scanning through the lower frequencies, mostly RSSI is blank but the few frequencies that did pop up with an RSSI the measure was between -96 and -119. With the 49.2 frequency it was consistent -40/-50 100% of the time. This was in the back room on the charger Squelch on 2 and Filter as Normal. Now I notice, the RSSI changes once off the charger. As soon as I unplugged -40 became -60 full bar graph still. Now, when I brought the radio into my living room where I have the most issues receiving the P25, the RSSI on 49.2 went from -60 to -96. Whatever it is camera, microphone must be in the public hallway outside my door.

This may be the culprit all along as to why I've been having issues.
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
Can firmware have any affect? I resetted and cleared the radio, and added the system via the full database and not sentinel and the radio now works with Global Auto Filter as Normal. I still have the same issue with Squelch but in my back room I receive a lot more consistent activity with Squelch on 2 and RSSI is -60/-50.
 

nessnet

Member
Premium Subscriber
Joined
Jan 22, 2007
Messages
639
Location
Eastside of Lake WA
... RSSI is -60/-50.
You literally would have to be on top of / right next to a transmitter to get a -50, or -60 for that matter.
Or something is really putting out VERY strong RFI. VERY strong....!

These RSSI numbers indicate something is wrong, somewhere....
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
Oh see thats where I'm always confused, I thought the lower the negative and D-ERROR at 0 the better. What is a good RSSI then or should be?
 

nessnet

Member
Premium Subscriber
Joined
Jan 22, 2007
Messages
639
Location
Eastside of Lake WA
Oh see thats where I'm always confused, I thought the lower the negative and D-ERROR at 0 the better. What is a good RSSI then or should be?
Yes, an RSSI of -70 is better than -90 and yes the lower the digital error, the better.
I'd say a really good strong signal is in the -70s (like actually looking at the transmitter/unobstructed line of sight). I consider in the -80 range to still be good. It is when you start getting below -100, that it is a weak signal. If I remember correctly at -110/-112, the radio won't even decode. (Someone please correct me if this is erroneous).

But again, -60 or -50 is (to me) an indicator you have something that is not right.
 
Last edited:

jonwienke

More Info Coming Soon!
Premium Subscriber
Joined
Jul 18, 2014
Messages
12,466
Location
VA
-100dBm is where the decode error starts spiking up, and anything below -110dBm is going to be difficult to recceive well. I see -60dBm in the wild on a fairly regular basis, but -50 or -40 (there aren't any other steps in between -60 and -40) not so much. I've seen -50 a couple times, but the only time I ever saw -40 was when my scanner was having solder joint issues.
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
Thank you guys. See that's definitely interesting. When my RSSI is above -100, the D-ERROR is either blank or really high. I'm noticing it depends on the system. If I Filters applied, its typically -60 for the EDAC and P25. If I receive activity on the EDAC then it raises to about -75 when there is voice/talking. The conventional is usually always in the -90's with high NOISE, unless there's conversation then NOISE lowers greatly and RSSi raises -100's.

For the P25, with Filters its -60, but it never stays the frequencies cycle, DATA and signal bars constantly go in and out, while RSSI remains at -50/-60 except when the frequencies cycle then it goes blank.
 

nessnet

Member
Premium Subscriber
Joined
Jan 22, 2007
Messages
639
Location
Eastside of Lake WA
Thank you guys. See that's definitely interesting. When my RSSI is above -100, the D-ERROR is either blank or really high. I'm noticing it depends on the system. If I Filters applied, its typically -60 for the EDAC and P25. If I receive activity on the EDAC then it raises to about -75 when there is voice/talking. The conventional is usually always in the -90's with high NOISE, unless there's conversation then NOISE lowers greatly and RSSi raises -100's.

For the P25, with Filters its -60, but it never stays the frequencies cycle, DATA and signal bars constantly go in and out, while RSSI remains at -50/-60 except when the frequencies cycle then it goes blank.
When Paul (Uniden) first put filters in the firmware, I played around with them. I did notice weirdness (-60ish) RSSI), which I knew wasn't right for where I was at the time. So, filters could be a suspect here....(?)

For yucks... Have you tried setting your global filter to off - not normal, off. Make sure all of your individual filters are set to global (this sets them to whatever you choose for the global filter). The downside is that if you have an RFI situation, it could make it worse. (it won't actually hurt anything in the radio...)

If this doesn't seem to do anything, I suggest the radio goes off to Uniden - or Jon.
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
Yeah that's what I've been doing, and everything improved but that's when RSSI went to -40/-55.

I even Youtubed to try and learn how RSSI works.

I have one other P25 to use to compare to, as I've never had any issue with it. Though I don't listen to it often.
 

jonwienke

More Info Coming Soon!
Premium Subscriber
Joined
Jul 18, 2014
Messages
12,466
Location
VA
Thank you guys. See that's definitely interesting. When my RSSI is above -100, the D-ERROR is either blank or really high. I'm noticing it depends on the system. If I Filters applied, its typically -60 for the EDAC and P25. If I receive activity on the EDAC then it raises to about -75 when there is voice/talking. The conventional is usually always in the -90's with high NOISE, unless there's conversation then NOISE lowers greatly and RSSi raises -100's.

For the P25, with Filters its -60, but it never stays the frequencies cycle, DATA and signal bars constantly go in and out, while RSSI remains at -50/-60 except when the frequencies cycle then it goes blank.
Have you ever watched this?
 

Dexter2

Member
Joined
Nov 2, 2019
Messages
342
Hi Jon - Yes this past summer. I've never experienced that or that noise.

I brought the radio into my office so I can type to you guys. I tried four systems; EDAC, Conventional, P25 (problem). and perfect P25 to compare. I have Squelch on 2 and Global Auto Filter to Normal, Hold Time is 255 and Use NAC. I will then turn Filter Off, and then turn Squelch to 1 to compare all three aspects which all four systems. Results as follows:

Conventional
-115 average RSSI Low NOISE during transmissions only
No RSSI High NOISE with frequencies rotating

When Squelch is on 1, its the loud squelch sound.

No difference with Filter change.

EDAC
-97 average then would move to -60 with a full bar graph RSSI Low NOISE, D-ERROR and "DATA" are blank while signal bar does show
During transmissions, UID appears, RSSI goes to -97 or -60 depending who is talking. Still no D-ERROR or "DATA".

Moving Squelch to 1, RSSI increases to around -102, everything else is the same.

Removing Filter RSSI goes to -45 with full bar graph, during transmissions it goes to -40 everything else is the same.

Perfect P25
High NOISE, Signal bars and RSSI keep blinking -60, DATA appeared flashed twice - no activity, frequencies rotating. As time went on, it would try to show a Lower NOISE and -55 full bar graph but nothing else and was not successful. When the people that live above me used some water source, that's when DATA appeared, low NOISE, -60 RSSI with full bar graph and NAC blinked but it did not stay long still no activity.

When I lowered Squelch to 1, a transmission almost came in, but same as above except D-ERROR now showed between 20 and 45.

Removed Filter-DATA appears, D-ERROR appears 0 mostly with Low NOISE. Depending on the department (within the same system) the RSSI is -45, -70's, -90's during transmissions and DATA becomes P25 or LINK and UID shows.

Problem P25
Frequencies rotate, D-ERROR blank, High NOISE and signal bars blink. If DATA appears RSSI becomes -60 full bar graph, D-ERROR becomes 0 up to 11 - and Low NOISE no activity. When DATA disappears, RSSI stays at -60 but NOISE elevates. Last check it showed DATA, D-ERROR as 0, medium high NOISE and -60 RSSI full bar but did not last long.

Removed Filter - same as above but -60 becomes -45. Last check D-ERROR was blank, RSSI -45 blinking and fluctuating NOISE. The best visual I got was DATA and signal bars show with D-ERROR - 0, Low NOISE, -40 RSSI no activity.

Moved Squelch to 1 - same as above except very high NOISE with -45 and sometimes flips to -110's. I moved the radio behind my computer but opposite of my fax machine and DATA appears with full signal bars, D-ERROR is 0, NOISE is low, RSSI is -40 full bar holding on control frequency, just waiting for activity now.
 

jonwienke

More Info Coming Soon!
Premium Subscriber
Joined
Jul 18, 2014
Messages
12,466
Location
VA
-40dBm means an abnormally strong signal, like you're parked at the base of the transmitter tower strong. The only way I've been able to get RSSI that high with a correctly working scanner is to key up a HT within a few feet of the scanner antenna. 5 watts at 5 feet got mostly -40, with a couple blips of -35. So either you have something wrong with your SDS100, or you have some seriously horrible RFI generating maybe a watt or more of garbage RF.
 
Top