I wanted to copy the reflector (messages below) on an
exchange between Piotr and myself about the 10m birdy
problem on the Omni 6. I'd like to encourage Omni
reflectorites so inclined, to put our heads together
about beefing up the internal grounding and shielding,
which is evidently a major cause of the problem.
Also, a note that different units seem to exhibit this
problem to a much lesser or greater degree.
73,
Barry N1EU
-------------------------------
(read bottom message first)
Hi Piotr,
Your english is excellent, so don't worry about that
at all!
Thanks for the great info!!! I can't try your
experiment with the main tuning knob because my main
tuning knob is dead right now because of the encoder
problem. I will try it after I replace the encoder.
Everything you say gives me hope that we can improve
the situation. Someone once told me that it could be
improved by resoldering all the holes on both sides of
the logic board.
This is probably related to the issue you mention that
the Omni doesn't have plated through holes. I would
really like to try more than that - try some of the
things you are speaking of. Maybe add extensive
grounding and shielding to some of the boards and
cables. Tie the grounds on both sides of the board
together. Make sure all the grounds are bonded well
together.
I wonder how difficult it is to remove the logic
board? Guess it is just a matter of pulling all those
connectors, and then the board will pop right out.
I used to have a problem where I could hear display
noise in the receiver. When I pushed buttons that
changed the display, I could hear the tones change.
Different digits produced different tones. I'm sure
this is related to the same problem.
73,
Barry
--- Piotr Tomczak <pito@nera.no> wrote:
> You hit the string..."birdies"
>
> I talked to TenTec and they neglect to comment it
> saying that
> it is normal in a digital rig.
>
> I have experimented with the 'birdies', they are
> very low but
> noticable when there is low noise from the band...
> specialy on 24 and 28 Mhz
>
> I noticed that they became higher or lower depending
>
> where one hold his hand on the tuning wheel. Try it!
>
> If I hold the wheel in the way so I screen the
> display with my hand,
> (left hand on the wheel with fingers on the alu list
> of the Omni)
> the noise nearly disapear. Does it at your rig ???
>
> I used my second rig (TR7-Drake) and sensed where
> they are comming from.
> It is the Logic board which sends the noise. It
> travelrs through the
> connection to the display, keypad and encoder, I
> belive the connection
> cables work as antennas.
>
> I looked at some doble sided boards in OMNI too,
> they do not have "plated"
> holes to connect the ground foil on both side of a
> board.
>
> I intend to resolder components, which have one leg
> to the ground,
> solter it on both sides. It should reduce the
> overall noise of the RX.
>
> I have thought what with the birdies and cables to
> keypad and display.
> I probably try some coper RFI tape and maybe put
> some ferrite clumps.
>
> The problem is that I do have very little time at
> home to do all I want
> at the same time..
>
> Any sugestions ??? Any observations ???
>
> Sorry for my lenguage, English is not my best
> side...
>
> Piotr LA9HFA
=====
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