scans but never stops on an active channel.

[W4KRR]

I recently noticed my SDS200 seemed to be too quiet. I checked it, and it scans normally, but it won't stop on any active channels. If I manually hold on a frequency or talkgroup, I can hear activity, but only on the stronger stations. It seems as if the receive sensitivity has suddenly dropped off. if it's scanning, it will simply pass over any active channels. I tried the factory reset, but it made no difference. Thoughts?

 

[doctordialtone]

Thoughts?

It's always good to swap out the SD card as a troubleshooting step.

A bad SD card can cause all kinds of weird problems.

 

[Whiskey3JMC]

Can you provide a[n] RR database link to the channels you're having trouble monitoring? Could be several possibilities: Disabled service types, avoids, among others. Also providing signal strength & RSSI values would help too

 

[nessnet]

I have had to re-boot a 200 on occasion, because I thought it was too quiet. Not sure if anything was wrong, but did it anyway. Also, I've had both a 100 and a 200 suddenly do a nothing to scan, (by itself), so gremlins can appear.... The SD card is always the 1st suspect.

Other than SD, two main things come to mind. Internal issue with the 200, or you have a new source of RFI. New WiFi router or new cordless phone, etc in the house?

 

[W4KRR]

I think I solved the issue. Apparently is was a bad antenna and/or antenna cable. I switched to a different antenna and is appears to be working now. I should have tried that first, but it was working fine two days ago.

As an example: On a strong local NOAA weather frequency: -98dBm on the "bad" antenna with strong buzzing interference which sounds sort of like analog television video buzz. The other antenna: -92dBm with no interference.

However, on a strong local P25 Phase II trunked system (Broward County FL system ID 997) I am getting around -100 dBm with either antenna. However there is no audible interference on the P25 system.

So either it's a bad antenna or cable, or a new source of interference that wasn't there previously. No new electronics here AFAIK.

 

[Ubbe]

However, on a strong local P25 Phase II trunked system (Broward County FL system ID 997) I am getting around -100 dBm with either antenna.

Do you recall if it was stronger prior to when this issue happened?
Try enabling the attenuator. That should reduce the signal by 20dB but if you only go from -100dBm to -110dBm or better then it is an interfering signal on another frequency in the frequency band that sets off the RF AGC that will reduces the gain in the scanner.

/Ubbe

 

[W4KRR]

Do you recall if it was stronger prior to when this issue happened?
Try enabling the attenuator. That should reduce the signal by 20dB but if you only go from -100dBm to -110dBm or better then it is an interfering signal on another frequency in the frequency band that sets off the RF AGC that will reduces the gain in the scanner.

/Ubbe

Thanks to all who replied.
I believe I have traced the problem to a faulty power supply on an Electroline 8 port splitter. It has worked well for years, but in the past few days I noticed a lot of noise on analog frequencies, especially VHF AM aircraft. Then I noticed today the SDS200 was scanning, but never stopped on any traffic, except for a strong local trunked system. I bypassed the Electroline splitter and connected the antenna directly, and the problem went away. I found that when I replaced the Electroline's power supply, the noise disappeared and the scanner began behaving normally, even when connected to the splitter.

 

[buddrousa]

Thanks for posting the answer it will help many down the road