SDS200e

[pyeman99]

Does anyone notice an internally generated signal on 156.00 Mhz.
This is not helpful as it is Marine channel Zero.
Tried IFX & filters settings.
Carrier is there without antenna connected.
A friend bought a SDS200e same time both same problem.
Thanks Keith

 

[nessnet]

I just checked - nope.... (200)

 

[paparazzo]

Did you tried the IFX option? If your issue is related to the Scanner it should dissapear once you switched on IFX.

 

[pyeman99]

Thanks both reply's.
Tried IFX also filters.
Does it with no antenna connected, guess it's a harmonic of an internal clock.
Both are E versions.

 

[pyeman99]

Further to this.
The level of the carrier is -104 dbm

 

[jonwienke]

The level of the carrier is -104 dbm

Is that with or without an antenna attached to the BNC jack? Does it change when you connect an antenna, or stay the same? What happens if you connect a 50-ohm terminator or dummy load?

 

[pyeman99]

With a 50 ohm terminator signal level is -108
With antenna -107

 

[jonwienke]

I don't have a SDS200e, but the SDS200 doesn't seem to have that issue.

 

[pyeman99]

Thanks maybe some difference in clock frequencies in the e variant.
Have tried different PSU.
Ours has the latest firmware.Think the frequency coverage is different from the E version to the US one.
Have inquired with the European distributor & ask they put one on the bench & try it.

 

[jonwienke]

It's weird that IFX has no effect on the signal. Normally that will fix a birdie.

 

[u2brent]

FWIW,
BCD436HP has the same issue with 156.000
makes monitoring KD21584 (QUARRYVILLE, BOROUGH OF) FCC Callsign Details pretty much impossible

 

[jonwienke]

FWIW,
BCD436HP has the same issue with 156.000
makes monitoring KD21584 (QUARRYVILLE, BOROUGH OF) FCC Callsign Details pretty much impossible

My 436 doesn't have a birdie there. Does your 436 have C1 installed?

 

[u2brent]

My 436 doesn't have a birdie there. Does your 436 have C1 installed?

Have no idea.. SDS100 will hang on it too..

I'd have to program the same freq XXX amount of times for any/each possible tone option.. but if they actually use csq forget about it... (Really not sure thay actually use it anymore)

 

[kruser]

I have it here as well on both, an SDS 100 and 200. Nothing on any of the x36HP models.

The clean carrier actually picks up a fair amount of static if I attach a rubber duck or an outdoor antenna to either SDS model but you can tell the signal is still there.
The RSSI stays at -106 with the duck on the SDS100 but with an outdoor antenna, I lose any true RSSI readings as it falses to -60 due to all the RF in my very near vicinity. I did not play with a duck on the 200 but I did disconnect the outdoor. When I did that, the 156 signal goes full quieting just like on the SDS100. Then the 200 also showed an RSSI of -107.

As the OP said, IFX makes no difference. The different filters also make no difference.
It seems that it is getting in after the IF stage.

I tuned the frequency above and below 156.0 and the carrier seems to be more centered on 155.9975 than it does if I tune above to 156.0025. I basically lose the carrier at 156.005 but can still hear it at 155.995 but not as strong as 156 or 155.9975.

For reference, my 436HP does have C1 installed.

This is probably the only one I've heard where IFX does not alter the signal.

 

[jonwienke]

Have no idea.. SDS100 will hang on it too..

I've got 4 SDS100s in front of me, and none of them hang on 156.000:


I've only got one 436, but it doesn't hang on that freq either...

 

[kruser]

I'd have to program the same freq XXX amount of times for any/each possible tone option.. but if they actually use csq forget about it... (Really not sure thay actually use it anymore)

Put that one in Tone Search and watch for a detected tone to display when they are talking. As long as it makes it over the birdie, that may work and allow you to monitor that channel.

 

[kruser]

I've got 4 SDS100s in front of me, and none of them hang on 156.000:

I've only got one 436, but it doesn't hang on that freq either...

Who knows. Possibly a simple component change during build.

I've searched through a ton of common and uncommon ranges with both SDS models as well as the x36HP models and never really came across anything that bothered me so if these exist, they must be far and few between.

The marine band is one of the bands I don't normally monitor which may explain why it never popped up here before.

Unless more are reported (where IFX does noting), it's something I'm not going to worry about.

Hey, maybe they forgot to install C1

 

[KevinC]

My SDS100 has a constant signal on 156.000.

 

[kruser]

My SDS100 has a constant signal on 156.000.

Does anything change when you attach or detach any antenna?
My 156 carrier actually gets a bit of static when I hookup a duck but that could just be from the very high RF environment I'm in.

 

[KevinC]

Does anything change when you attach or detach any antenna?
My 156 carrier actually gets a bit of static when I hookup a duck but that could just be from the very high RF environment I'm in.

Yes, mine gets noisy on an external antenna (GRE 800) as well and probably due to external influence as you suggested.