Hi Grant,
Have got to disagree with on this subject.Another poster noted that the DC
resistance from the shell of the mike jack was abt 6 OHMS and asked to
anyone else to try it-the DC reisistance on my Jupiter to the back chassis
ground point reads abt 8 ohms.No way this should occur-if the shell is NOT
grounded to DC potential,all kind of RFI problems will occur;pls do NOT say
"its an RF in the shack problem,or ur ant is too close to the rig".
This why T/T has NEVER built a handheld rig!Its hard to say the antenna is
too close to rig when its a handheld.Why this audio port "floats"above gnd
is a mystery to me also.
73 de Bill W4NJF;A Jupiter owner with the same problem.
----- Original Message -----
From: "Grant Youngman" <nq5t@comcast.net>
To: <tentec@contesting.com>
Sent: Friday, November 14, 2003 11:07 AM
Subject: Re: [TenTec] Orion and MIKEs
> >
> > If you run a new ground wire (I used insulated stranded 18 Ga.) from
> > mic pin #2 (ground) to the same board that mic connector goes to and
> > then to the rear lug on the rig, this will eliminate the 6 ohms in the
> > audio chain. But not in the IF and RF chain. separate lines will have
> > to be installed to remedy that issue.
>
> One last comment on this bothersome subject ... no flame intended.
>
> The other thing you will accomplish by fiddling with this is to create
> unwanted ground loops that may cause all manner of problems. The 6
> ohms is not an issue. Adding is a few extra ground wires may seem
> harmless, but destroying the signal and power ground engineering that's
> in a complex mixed mode analog and digital device is simply not
> advisable.
>
> This begs for enough trouble as far as the audio path is concerned. In
> the RF/IF/digital sections of the radio an extra ground path or two could
> wreak real havoc.
>
> I'll go back to my original statement which is that if RF feedback is a
> problem then the way to rectify it is to clean up the RF environment in
the
> radio room.
>
> Grant/NQ5T
>
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