SDS100/SDS200: SDS200e 156.0000

[Innes_scott]

Hi All.

I am new to this forum as I just found it through a Google search for a fault I have with my new scanner.

I bought a Sds200e for listening to marine and I can’t really do this due to a problem with interference on 156.000 which is there even with the antenna disconnected.

I found that a member (pyeman99) had the very same issue in 2019 but I can’t contact them as this is my first post and since I’m new I’m unable to contact other members.

Can anyone help as this is the main reason I purchased this unit and I feel it’s a total waste of money as I can’t scan while 156.000 is in the scan memory as it constant stops on it and all I here is interference.

 

[KevinC]

The SDS200 has it as well, it's an internally generated signal so you can't get rid of it.

 

[Innes_scott]

The SDS200 has it as well, it's an internally generated signal so you can't get rid of it.

Thanks. So there is no way of having that frequency in my scan favourites without it stopping on it all the time? It’s really the only frequency I wanted to listen to.

 

[buddrousa]

Look at the SDS manual for IFX and see if that helps you out.

Easier to Read SDS100/200 Digital Scanner Manual

SDS Sentinel Software Manual

 

[dmfalk]

Function+ 7 (IFX) is your friend. Not too many radios out there offer intermediate frequency (IF) intermix fixes, and this helps....

 

[KevinC]

Function+ 7 (IFX) is your friend. Not too many radios out there offer intermediate frequency (IF) intermix fixes, and this helps....

But not in this case. I tried and it didn't help.

 

[Dewey]

Interesting ... I just tried this on my US SDS100 (4/2021) and no interference. My wife gets to sleep in today due to the snowstorm, so I can't go upstairs and check the 200 until she wakes.

EDIT: Just to be sure, I opened the squelch up from the "2" where I keep it set and did hear this birdie. Since I had to open the squelch to hear it, I wonder how much blocking it would do for an actual 156.00 signal.

 

[Ubbe]

It gets stronger when I remove the antenna coax from my SDS100E, so its internal and independent of IFX. Due to the nature of the receiver in SDS100 I have 4 or 5 of those birdies at different frequencies I am monitoring. When looking at a spectrum using a RTL-SDR I can also see a signal at 155.997 and another at 156.001 that also are internal of the RTL-SDR and independent of if antenna are connected or not. Several of my other scanners receive a carrier from 156.000 so it's just a bad frequency to be monitoring with some scanners.

I have been programming many 2-way radios and also repaired them and some models cannot be used at 156.000MHz due to this internal birdie in them. In some radios there where a function called clock-shift that could be applied that added a capacitance to the CPU's crystal that then moved any birdies to a frequency where they wouldn't interfere.

/Ubbe