Thanks, Bruce - that is exactly what I was going to try this evening
before I got called out on another matter. That is what Paul suggested,
and I'll have it wired by tomorrow night or over the weekend. Your
description of the problem is exactly what I'm experiencing.
73, Duane
On Thu, 22 Jul 2004 18:24:59 -0400 Bruce Small <bsmall@adelphia.net>
writes:
> Duane, et al:
>
> I know just what you are talking about, having walked down this path
> two
> months ago when my Orion arrived.
>
> Paul knows what he is talking about; trust him. This is not an RF
> problem - when I used a configuration with the PTT ground tied to
> pin 2
> of the TT connector (as the stock Heil adapter cables do), closing
> the
> PTT switch would produce spurious audio tones in the background,
> even
> with the microphone disconnected - thus RF output was next to
> nothing.
>
> With the Pro Set Plus connected, Mic Gain had to be up to near 100
> in
> order to provide sufficient audio drive, and the audio sounded
> distorted. Turning on speech processing, even at a setting of 1,
> rendered the signal just about unreadable due to distortion.
>
> This is also not a ground loop problem. Removing every other piece
> of
> gear from the operating table, leaving just the Orion and power
> supply
> made no difference. Using a different power supply also made no
> difference.
>
> My woes ended when I made up a cable with a 1/8" jack (Mic In)
> connected
> to pins 1 and 2 of the TT 4-pin connector, and a 1/4" jack (PTT)
> connected to pin 3 and to the cable shield. Using this to connect
> the
> ProSet Plus to the Orion, I now use a Mic Gain setting of about 35,
>
> speech processing works the way it is supposed to, and on-the-air
> audio
> sounds fine. Keep pin 2 isolated from the cable shield/connector
> shell,
> and you will be happy.
>
> Good luck,
>
> Bruce, KM2L
>
> Duane A Calvin wrote:
>
> >Paul's words were that pin 2 should never be tied to chassis
> ground.
> >That is essentially what Heil's page recommends - a general
> >recommendation, not Orion-specific. (Pin 2 connects to the shield
> of the
> >ProSet microphone cable.) Also, Heil uses this pin as the return
> for the
> >PTT switch, while Paul said this should go to chassis ground (i.e.,
> >connector shell.)
> >
> >My original postings last month go into the detail of the problem -
> I
> >won't repeat it here. I do not think I have an RF problem, and
> still
> >need to rule out ground loops. [...]
> >
> >
> >I'll let the list know what I find that fixes it on the off chance
> that
> >someone else has the same problem later on.
> >
> > 73, Duane
> >
> >
> >
> >Duane Calvin, AC5AA
> >Austin, Texas
> >_______________________________________________
> >TenTec mailing list
> >TenTec@contesting.com
> >http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
> >
>
> _______________________________________________
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>
>
--------------------------------------
Duane Calvin, AC5AA
Austin, Texas
http://home.austin.rr.com/ac5aa
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