[Elecraft] Six meter birdies.

[Dr. Werner Furlan]

hi all, 

I am also suffering from birdies especially (but not only) on 6m. 
I have them on the main receiver and on the subreceiver, but on different 
frequencies. (found them on 40m and 20m too)
Many of them are low volume and don't bother me in real life, but some are 
really loud (up to S6) and show a microfonic effect when I tap on the cover 
of the K3. On the loudest one I can also hear a ticking sound when I turn the 
VFO back and forth over the birdie reagion. The intensity can be tuned with 
touching or taping on the synthesizer board and sometimes touching the 
koax cables makes a difference. 

Two friends of me with K3's also have similar birdies, one worse, one less.
One K3 from another ham friend does not show them. 

Of course all my coax cables are connected, the shield of the cables is ok 
and all screws of the K3 housing are tight. Different routing of the coax 
cables does not help, and btw, with the limited space after adding the KRX3 
there are not so many possibilities left to route the cables. 

On 7 Jan 2009 at 13:01, Geoffrey Mackenzie-Kennedy wrote:

> Wes Stewart N7WS wrote:
> 
> > I'm still playing with my new K3 and finally got around to listening
> > on 6-meters.  There are so many birdies as to make it unusable.
> >
> > At first I thought they might be external, and some were generated
> > in my Lenovo laptop, but shutting it down and terminating the K3
> > antenna port with a load doesn't eliminate them.
> >
> > When listening to the same frequencies with an Icom IC-R10 with a
> > whip antenna next to the K3 I don't hear a thing.
> >
> > Ideas?
> >
> > Wes  N7WS
> 
> ----------------------------------------------------------
> 
> Wes,
> 
> >>From what you have said these birdies are being generated inside the
> >>K3, if 
> I am right to assume that only the power supply and nothing else
> except the dummy antenna load is connected to your K3, and that
> turning your Icom IC-R10 on or off makes no difference to any birdies'
> level or frequency.
> 
> I do wonder if you have a fault in your K3 when you say 'so many
> birdies', I get the impression that something is unstable on 6m but
> perhaps not on the lower frequency bands. There might be a poor solder
> connection to a bypass capacitor for example, which could result in
> problems on 6m but not on the lower frequency bands certainly if two
> or more capacitors are used in parallel,or some SMD capacitor has
> failed due to mechanical stress. It might be worthwhile to
> troubleshoot.
> 
> Some of these internal birdies that you are hearing are probably
> legitimate members of the birdie family created by the receiver's
> spurious response(s) hearing one or more of the receiver's
> oscillators, or their products. The frequency of these birdies can be
> predicted and their level can vary greatly between identical
> receivers, also the routing of internal cables can become "fussy" if
> shielding is inadequate or RF grounds 'float'. However this latter
> issue is best left to the designer.
> 
> 73,
> Geoff
> GM4ESD
> 
> 
> 
> 
> 
> 
> 
> 
> 


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