[Elecraft] Heil Pro 7 headset with KX3 - RF feedback?

[Julia Tuttle]

I'd believe it! I've gotten weird noise artifacts before that were actually
"the monitor level is so low that the DAC is running out of bits". Mine
showed up most obviously as harmonics in the sidetone. Try adjusting the
monitor level in CW mode and see if you hear your issue at the lowest
levels but not higher. If you do, you could get an inline attenuator for
the headphones so you can run the AF gain and monitor levels high enough to
sound better.

Cheers,

Julie

On Thu, Jun 17, 2021 at 2:21 PM Rich <rwnewbould at comcast.net> wrote:

> A couple thoughts and questions:
>
> Are you hearing the "RF?" in the headphones?
>
> If so you may want to increase your MONITOR Level.   I have heard what I
> thought was RF in my headphones.  On the air reports were good audio no
> RF.   I believe the real issue was that a LOW Monitor level setting was
> not enough to drive the headphone speakers.   That is my quess, no
> technical data to back that up. When I increased the MONITOR Level the
> audio in my ears was perfect.
>
> Has anyone told you that there is RF on your TX signal?
>
> I would think RF from a 15watt radio should be easily cured with some
> MIX 31 snap on ferrittes
>
> Rich
>
>
>
> On 6/16/2021 23:23 PM, Drew Arnett wrote:
> > Hi,
> >
> > In the KX3 for Field Day department, we plan to use it for the GOTA
> > station for phone on HF.  (Yes, will have antennas not on top of each
> > other and bandpass filters on ALL radios.)  Would be great to setup
> > with a headset and foot switch.
> >
> > Last weekend, I used my KX3 barefoot on 6 and with a
> > transverters-store.com transverter (also barefoot) for 2.  6m antenna
> > was 2 elements about 15 ft above the ground and 2m antenna 6 elements
> > at 10 feet above the ground.
> >
> > I worked a couple of contacts on 2m phone with the headset.  Later,
> > when I tried to use the headset for phone on 6, seemed like I was
> > having a feedback problem.  Cabling was the stock cabling that comes
> > with the Heil Pro 7 headset and a footswitch.  Monitor was on and set
> > to 4.
> >
> > So, ALC didn't indicate anything at the normal level (60), and
> > increasing it very abruptly caused horrible sounding audio.  (Yes,
> > acts like positive feedback.)
> >
> > I have a small electret mic on a 1/8 plug thing I bought some time ago
> > from the computer store.  (Meant at the time for adding mic to
> > laptops.)  I have a 1/8" audio extension cable for it.  I plugged that
> > in instead of the headset mic and it seemed to act normally.
> >
> > Is this purely an RF from the TX antenna getting into the mic audio
> > problem or is it something else?
> >
> > Best practice to avoid this problem?
> >
> > On my todo list:
> > - ask here
> > - look at KX3 schematic to see if it has RF ingress mitigation on the
> mic jack
> > - ask Heil
> > - unplug the Heil mic element and gator clip my cheap electret mic on
> > instead and try on 6m in driveway with identical antenna/mast/radio
> > setup
> > - look for or assemble an RF filter to inline with the mic jack (tough
> > to do with this little time
> > before field day)
> >
> > Thanks and best regards,
> >
> > Drew
> > n7da
> >
> > ps.  Other than this, KX3 was great in the VHF test.  Worked great
> > with the transverter on 2 and was a lot of fun running barefoot with
> > the sporadic E opening Saturday afternoon & evening.
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