Ferrite, Ferrite and more Ferrite then!
Any suggestions as to where best to place clip on cores?
Mains lead?
Power lead from PSU (Icom PS55) to rig (IC735)?
All leads from ZLP interface to laptop? (Dell D610) (I currently have
ferrite clip ons on the microphone and speaker leads from ZLP to laptop)
Dell Laptop PSU?
All the above??
With best regards
Jim
Dr. James Cowburn
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Graham
Sent: 16 September 2009 21:59
To: [email protected]
Subject: Re: LF: Re: G7NKS multiple spots
JIm,
I think you find that is caused by 50 hz mains hum .... may be a hum loop
in the audio system / pc-tx earthling , not likely to be psu problem as
frequency is 50 (fund) and 150 ( 3 rd harm)
I had a similar problem with my valve HF set , that was a slight ripple on
the PA HT line caused by the 100% duty cycle of wspr, not part of the
design criteria for ssb/cw , caused spots to appear +/- 100 Hz due to
the full wave rectification in the psu
G .
--------------------------------------------------
From: "James Moritz" <[email protected]>
Sent: Wednesday, September 16, 2009 9:40 PM
To: <[email protected]>
Subject: LF: Re: G7NKS multiple spots
>
> Dear Jim, LF Group,
>
>
>> Me too. I am getting 3 traces (!) from Jim M (he is 9+10 and audible!)
>> and
>> a biggish one from Gus too
>
> I am seeing low-level (about -25dB) sidebands on your signal at +/-50Hz
> and
> +/-150Hz, which are giving rise to the extra spots. I think something
> similar is happening when you receive my signal. I am not getting similar
> multiple spots from other nearby stations, nor am I seeing the same
> sidebands on other strong signals, so I think they must originate in your
> station somewhere - possibly audio being affected by mains noise, or some
> sort of residual FM of an oscillator in your rig?
>
> Cheers, Jim Moritz
> 73 de M0BMU
>
>
>
>
> No virus found in this incoming message.
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> 09/16/09 11:21:00
>
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