Re: Strange jumping spectrum in ELAD FDM SW-2

Keith McGinnis
 

Of course I Murphy's law struck and about 10 minutes ago the jumping started after not seeing it here for quite some time. When I tune outside of FM (say 82 mhz) no jumping is noted. Checked around the house to see if anyone turned anything on and no one did.

Let's see when it goes away.

Keith
Hingham MA

On 6/16/2017 6:40 PM, Keith longwave@... [elad_sdr_en] wrote:
Guido I've had this from time to time both at home and one time mobile
(actually in the car) while on a dx trip. During the trip we were
within a few miles of some transmitters (don't recall what kind). I
haven't seen this behavior (knock on wood) in a while now and didn't
think to check with my other SDR's at the time.
Keith
Hingham MA
On 6/16/2017 6:24 PM, 'Guido Schotmans ' guidoschotmans@...
[elad_sdr_en] wrote:
Hello,
Since some time I have a strange issue with my ELAD FDM S2. Now and then the
spectrum starts to jump up and down for a some minutes but recently it is
happening much more often and for a longer time. It is only happening in
the regular broadcast FM band. Not in the OIRT band. After some time it goes
away automatically. I don't see the jumps in SDR-radio V3 in combination
with the Elad but I think that software is just smoothing the jumps away.
You can see in in this short video:
https://youtu.be/zRvXUA1p6Vw
Note that the amplitudes and noise floor are both jumping.
Here two pictures from the beginning and the end of the band.
https://app.box.com/s/yb2n5610s91elxm9iw3yr98uhmfvpy4u
and
https://app.box.com/s/m7sr87rqc9okzygf4jg2v0usbf1koazc
So you'll see that the dancing noise floor is not occurring further away
from the FM broadcast band.
I am wondering what can be the cause of this. I have checked the connections
and they seem to be OK. As said it only happens in the FM-band. Can this be
caused by some kind of external interference or is the chance that it has to
do with a hardware failure more likely ?
I hope somebody can help me.
73,
Guido.
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