SDS100 -116db

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WoodburyMan

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Greetings!

I have a SDS100 and SDS200. I run them both off the same profile, and simply go to Target Model >>SDSx00, then save and write to the appropriate model scanner when updating my lists.

Recently my SDS100 has had some strange behavior. I cannot track down when it started. Within the last few weeks for sure. There's a local P25 P2 trunked system. My favorite lists have only the CC's for each site in them to reduce scan times. When it locks on a control channel, no matter how strong or weak, it always reads "-116db" (ie the weakest signal it will register) no matter what. Other than that, it functions normally. It will display the site's Site info, LCN, and "P25 Data" signs, and will track to frequencies in the followed TG's just fine and I will hear the audio clear as day, although it will report the absolute 0 bars for signal and -116db for signal strength. It's REALLY strange. Sometimes it will flash -60db, then back to -116db. This happens with all filter settings (Off, Normal, Wide, etc). SDS200 with same antenna will pick up signal, and display regular results when locked on the same channel. This also happens with other signals, not just the P25 P2 trunked system. Local analog, P25, and DMR I pick up it will do the same. The Local P25 P2 trunked control signal is just the easiest to test it on, as it's constant signal, when local audio is only on calls and are far and few between usually. This also happens with different antennas on my SDS100 as well.

Any ideas what may be going on? (I already tried factory reset, and unplugged battery for extended period of time).
 

bravo14

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What Firmware are you using & are you using filters also? I notice on vhf/uhf I have to use wide normal and 700-900 (Trunking) band its either wide normal or wide invert
 

jonwienke

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Something is wrong with your SDS100. Assuming the firmware is up to date, it shouldn't do that. And it's not a filter setting problem, or the SDS200 woild be doing the same thing. Sounds like a trip to Uniden is in order.
 

eaf1956

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One of my SDS 200s seems to always read -60dBm for every site. Once in a great while it displays correctly. Really odd to get full bars and -60dBm signal on a tower on my fringe reception area and the same reading on local towers. The other 200 scanning ONLY the local simulcast systems varies RSSI strength. And yes when scanning only the simulcast system the 1st scanner mostly displays -60dBm.
 

u2brent

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Try powering the radio from the other usb (The port above the one labeled "charge"; If you have the right cable laying around) and see if the problem persists. Mine (sds100) has just started exhibiting similar fluctuations on the rssi display and it stops if I power through the top port.. I think it's gonna have to go back.. It just started doing it. Waiting for it to get worse.. :cautious: Before sending to repair.. Perhaps something about the charging circuits is going bad or putting out an interference.
 

WoodburyMan

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What Firmware are you using & are you using filters also? I notice on vhf/uhf I have to use wide normal and 700-900 (Trunking) band its either wide normal or wide invert
Latest, 1.10.00 Main, 1.02.01 Sub.
I tried all filters, Normal, Invert, Wide, Wide Invert, Off, and all the Auto's with the same results more or less (Normal usually even on my SDS200 doesn't work well with any local signals I have as well). I also usually use Wide Normal for our 700-900mhz Trunking System here, does work best. Generally works well on some VHF 155mhz P25 I have, sometimes I use Wide-Invert on them.

Something is wrong with your SDS100. Assuming the firmware is up to date, it shouldn't do that. And it's not a filter setting problem, or the SDS200 woild be doing the same thing. Sounds like a trip to Uniden is in order.
Looking like it.. it's just strange because... it works! It just doesn't display the signal level properly. It's able to decode and work everything.. just no way to tell what signal level it is.
One of my SDS 200s seems to always read -60dBm for every site. Once in a great while it displays correctly. Really odd to get full bars and -60dBm signal on a tower on my fringe reception area and the same reading on local towers. The other 200 scanning ONLY the local simulcast systems varies RSSI strength. And yes when scanning only the simulcast system the 1st scanner mostly displays -60dBm.
I did have this issue on my SDS200. That's usually due to simulcast site distortion. You may have two sites for the same Simulcast site in range. Picking up both signals, with both having slightly off timings, results in that type of behavior. In my case, I had a bad antenna setup. I have UHF/VHF antenna coupled to a 700-900mhz directional yagi. The UHF/VHF picked up just enough of the 700-900mhz band that it would cause distortion similar to simulcast distortion where the scanner "sees" two signals because of timing being off. Sometimes the SDS's can work through it, sometimes not so much, but it causes RSSI to be off. Ultimately I used a filter on my VHF/UHF antenna to cap it at 460mhz so I do not get that distortion.
Try powering the radio from the other usb (The port above the one labeled "charge"; If you have the right cable laying around) and see if the problem persists. Mine (sds100) has just started exhibiting similar fluctuations on the rssi display and it stops if I power through the top port.. I think it's gonna have to go back.. It just started doing it. Waiting for it to get worse.. :cautious: Before sending to repair.. Perhaps something about the charging circuits is going bad or putting out an interference.
Good idea. I did give this a try, I used both USB1 and USB2, without the battery, and see if it got any better. Same issue unfortunately.. so it may be time to send it in for repair. Although a really odd issue as signals will come in, just the total wrong RSSI. Ex I get good data signal at -116 and no voice distortion on P25 like it's normal -100db or so I would get with my SDS200 in the same location.
 

ka3jjz

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A very similar incident was reported here


Mike
 

WoodburyMan

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A very similar incident was reported here


Mike
Yeah seems related perhaps. I have my SDS200 hooked up to ProScan, some interface issues like that make sense. This is just the plain SDS100 on its own though.
 

WoodburyMan

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Fun note. Driving today I was using this and noted that it not only just display "-116db" but when I get closer to some sites (They have some sites lined along the highways I was driving on) it would show -55db and -60db constantly. So either -55db, -60db, or -116db. Nothing in between. Weird. But it works fine. Just RSSI display is off and signal strength.

For fun I also reflashed the latest main and sub firmware for the SDS, no joy. Same behavior. A wipe of all user data too, running scans from just the database resulted in the same behavior too.
 

WoodburyMan

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I sent my unit in, they got it on December 5th, Received it in December 9th, and today December 27th updated to "In line to be shipped" with a comment on it stating "COLD SOLDER JOINT". So it must have been the usual SDS100 problem with signal reception just manifesting itself in a different way. It has a ship date estimate of Jan 6th, can't wait to get it back! :)
 
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