SDS100/SDS200: SDS100 Reception Issues

[caterpillar16]

Greetings….I have owned my SDS100 for about a year now. I am in the panhandle of Florida, mostly monitoring VHF and UHF DMR, with a little bit of analog mixed in. Firmware is 1.26.01. I am using the stock antenna, a Diamond RH77CA with BNC adapter, as well as a Remtronix REM-842S. I’m not sure that any of them are a lot better than the other in my particular situation. Squelch Level is set at 2. I noticed a few nights ago during some rough weather that my Anytone 878 was picking up a neighboring agency on VHF DMR with very clear signal and the SDS100 never heard a thing. I handle the radio programming for my fire department and started checking the scanner on one of the analog repeater channels we use. The tower is about a mile away. Having someone across town call over the repeater and conduct a radio test, this scanner never hears the signal, which seems strange. I’ve also noticed that very few of the local DMR signals will register below a -100 RSSI. I even had someone stand on the other side of our fire station property and key up another analog simplex channel we use and the scanner heard the signal, but the RSSI was never better than -100. Is it possible that I have an issue with the SMA connection on the radio body? I’ve never dropped the radio, and nothing feels loose.

 

[dmfalk]

Check to see if the RAN or Color Code has changed.

 

[caterpillar16]

Check to see if the RAN or Color Code has changed.

Color codes have not changed.

 

[buddrousa]

Just for clarification -90 db is a better signal than -100 db
does it hear the weather channels
has the scanner been exposed near a very strong signal

 

[caterpillar16]

Just for clarification -90 db is a better signal than -100 db
does it hear the weather channels
has the scanner been exposed near a very strong signal

Yes it does receive the local WX frequency. When I referenced the RSSI numbers, what I intended to say was that the best RSSI I see is usually around 100 but I have seen it in the 90s for a couple of local repeaters. The most exposure I can think of would be from a nearby portable radio transmitting inside the same vehicle. I just didn't think an Anytone portable radio would be that much better at receiving than my SDS100.

 

[buddrousa]

We have seen people post here that had scanners on outside antennas and keyed a 100 watt radio with the antenna a few feet away that damaged the front-end diodes that had to be replaced. How far is the weather station from you?
This is on DMR Uniden has problems with SIMPLEX DMR. Does the scanner receive the signal any better if it is paused on the channel vers scanning the channel?

 

[caterpillar16]

We have seen people post here that had scanners on outside antennas and keyed a 100 watt radio with the antenna a few feet away that damaged the front-end diodes that had to be replaced. How far is the weather station from you?
This is on DMR Uniden has problems with SIMPLEX DMR. Does the scanner receive the signal any better if it is paused on the channel vers scanning the channel?

The WX station is less than 10 miles away on one of the tallest broadcast towers in the state, although I'll admit I don't know how high it is located on the tower. I am having issues with DMR stations on a repeater, as well as at least one analog repeater, the latter of which is on a tower less than two miles from me. One of the DMR repeaters I am listening to is in a neighboring county and my scanner just doesn't hear it when every other radio does. I have indeed stopped the scanner on the desired channel to see if it would hear the traffic, but it doesn't seem to make a difference. I mentioned the firmware in my original post because I am certain I did not have this issue prior to upgrading the FW several days ago. I can't imagine that's the issue, but nothing else has happened to the radio to lead me to believe anything internal is broken.

 

[buddrousa]

We have seen firmware help some and make problems for others. You may can find the older version of firmware and manual install and go back.

 

[Ubbe]

Is it possible that I have an issue with the SMA connection on the radio body? I’ve never dropped the radio, and nothing feels loose.

The antenna connector are soldered directly to the RF circuit board and its solder can crack. In older scanners, but probably not in a 1 year old one, the circuit board where misaligned and where pulling on the antenna connectors soldering point and any mechanical pressure could crack that soldering. In most other scanners there's a short coaxial cable used between antenna connector and the circuit board that allows the antenna conector to flex, as it in most cases will do when a longer antenna are attached to the scanner.

But as already mentioned it can also be a too high RF energy source that have damaged the input circuit in the scanner. But before shipping the scanner to Uniden to be repaired you should try another antenna and double check that the antenna connector are not loose when wiggling the antenna, and monitor a NOAA channel while doing that to see if the signal strength suddenly goes up that indicates a mechanical problem.

I can't remember if the SDS100 came with a BNC adapter, the 436 did, that will allow you to test using any BNC fitted antenna.

/Ubbe

 

[tvengr]

I can't remember if the SDS100 came with a BNC adapter,

Yes, it does. Mine did.

 

[Chris0516]

I can't remember if the SDS100 came with a BNC adapter, the 436 did, that will allow you to test using any BNC fitted antenna.

/Ubbe

Mine did. I just haven't used it, because. I have only used my REM-842S antenna.