[TenTec] Omni VI ckicks in fast QSK

[Barry N1EU]

I think this issue is also going to depend on which ROM version is
installed in the Omni 6, because Ten-Tec made a lot of changes to the
keying over time.

Barry N1EU

On Mon, Nov 21, 2016 at 2:53 PM, Steve Ellington <steven4lq at gmail.com>
wrote:

> I just worked over an Omni VI ver 1 and fast QSK was very smooth. I hate
> clicks too!
> There's lots of little transients floating around the chassis when you key
> the rig. I've used the scope to help track them down.
> Ground the scope to the chassis, hook a few inches of wire to the probe,
> crank up the scope gain, key the rig and move the probe around to sniff out
> the offending electric fields. You could also form a small loop antenna
> between the probe and ground.
> I believe you will find it!  73
>
> On Mon, Nov 21, 2016 at 2:47 PM, gerd Groos <df9ts.cw at gmail.com> wrote:
>
> > Thanks a lot Steve for pointing this posting out to me. Re-cabling and
> > screening audio cables will certainly do know harm. This will be next on
> my
> > todo list.
> >
> > So far I re-cabled the logic board (put caps on all ICs, ran direct
> 5V&GND
> > cables to all ICs) which helped me get the birdies way down and calm the
> > audio noise a bit.
> >
> > 73
> >
> > Gerd.
> >
> > 2016-11-21 20:37 GMT+01:00 Steve Ellington <steven4lq at gmail.com>:
> >
> > > Gerd:
> > > I found this in the archives. It may or may not help. 73
> > >
> > > *2/14/99*
> > > Several weeks ago, someone on the list indicated that they could not
> rid
> > > their Omni Six of audible "clicks" while listening with headphones. I
> > > suggested removing plug 52 on the AF/IF Circuit board, but apparently,
> > this
> > > did not help.
> > >
> > > After making yet another mod to my Omni Six last weekend, I noticed the
> > > same problem for the first time: I was hearing audible clicks, to the
> > point
> > > of being annoying regardless of any front panel setting, including
> power
> > > and AF loudness.
> > >
> > > This weekend, I jumped in to find the cause. On my particular Omni Six,
> > > several areas were contributing to the clicks. Through a combination of
> > > regrounding, using shielded audio cable, and rerouting cables, I have
> my
> > > Omni back to the point where no or clicks thumps are heard whatsoever.
> > The
> > > following steps may be of help to those who wish to minimize clicks in
> > > their Omnis:
> > >
> > > 1) I'm a firm believer in removing plug 52 from the IF/AF circuit
> board.
> > > Pull it, and tie-wrap it out of harms way.
> > >
> > > 2) Ground the heatsink tab of U8, the audio power amplifier. By pushing
> > U8
> > > against the side chassis, a hole can be drilled for placement of a #4
> > screw
> > > which now grounds and heat-sinks U8 to the chassis.
> > >
> > > 3) Many audio cables use ribbon cable. I replaced several of these with
> > > single-pair shielded cable to the AF pot, FIXED AUDIO Plug 57, and cut
> > two
> > > audio circuit traces on the AF/IF Board that were running too close to
> > > other witching circuitry.
> > >
> > > 4) Cut the nylon tie-wrap that holds the cable bundle along side the
> > > chassis near U8, separate and twist the wires, finding the right
> > > combination that minimizes the clicks.
> > >
> > > On Mon, Nov 21, 2016 at 1:22 PM, gerd Groos <df9ts.cw at gmail.com>
> wrote:
> > >
> > > > Hello,
> > > > I friend borrowed me an Omni VI, which is producing very disturbing
> > > > audio-clicks in fast QSK mode, at any CW speeds, even with very slow
> > > > keying.
> > > >
> > > > The clicks are louder than the received signal and quite distracting.
> > > >
> > > > I am including symptoms below for those who want to read on. Any
> ideas,
> > > and
> > > > suggestions highly welcome.
> > > >
> > > > 73
> > > >
> > > > Gerd DF9TS.
> > > >
> > > > ===
> > > >
> > > > The TRX is click-free when connected to a dummy load. Symptoms appear
> > > with
> > > > antenna signal (or white noise) on the receiver input.
> > > >
> > > > The clicks are produced in fast QSK only on key release ("key up")
> > only.
> > > > "Key down" is not producing clicks.
> > > > TX signal is ok and click-less and without chirp (as verified with
> 2nd
> > > > receiver). RX audio signal is with these clicks.
> > > >
> > > > I verified the "TD". "T" and "R" signals generated for internal tx/rx
> > > > switching with a scope. They look similar to a quick Spice
> simulation I
> > > did
> > > > of the circuit. I did however not see a lag between "T" going down
> and
> > > "R"
> > > > going up.
> > > >
> > > > Slow QSK is without such clicks.
> > > >
> > > > On "slow QSK" the RX audio comes back up  slowly on "key up".
> > > > On "fast QSK" the RX audio comes back immediately on "key up".
> > > >
> > > > This makes me wonder if the cause is a timing issue on "key up".
> > > >
> > > > I did align the TRX following the manual, twice. BFO is well aligned
> > > also.
> > > > The rig behaves as expected. Sensitivity and filters ok.
> > > >
> > > > Removing connector 52, extensively discussed in this list, makes no
> > > > difference for this OMNI VI´s clicking.
> > > >
> > > > The clicks are present on Loudspeaker as well as on "Audio Out" cinch
> > > > socket.
> > > >
> > > > Tnx for reading this far ;-)
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