The symptoms sound like RF feedback via the microphone circuit.
Since the problem just started occurring, look for disconnected
cables, loose connections, corrosion, etc. The dummy load test
suggests RF on the feedline, tuner or antenna is getting back into
your rig.
In addition to checking the mic cable shield and the coax cable to
your antenna tuner, make sure your station's RF ground is short and
low impedance. That it connects to the rig, tuner, power supply and
ground.
Whether you use a #0000 cable or copper foil or whatever, a
suitable DC ground (one or more rods) and an RF ground (radial
counterpoise lines away from the shack) at the end is important.
Make absolutely certain the ground line is NOT a 1/4 wavelength at
any frequency.
73 Bill N4LG
At 10:23 AM 12/4/2007, KB8OCA wrote:
>HI everyone,
>
> >From the title you can see I own a TenTec 561 Corsair II, and it
> has been working very well so far ... until this past Saturday evening.
>The TenTec is connected to a G5RV via a manual tuner, which all
>has been working very well for me.
>
>The problem now is, that folks are saying my audio is all garbled
>to a point where they can not understand one work I am saying.
>Also, when I key the radio, the power meter immediately goes up
>mid scale, without me making any sound what so ever.
>
>I then decided to work with my ALC control, speech processor and
>the drive control, but that had very little effect. Even is my ALC
>is turned all the way clockwise, speech processor is off, and
>drive is let's say at 0.5, I can hear a beeping sound right away.
>Despite all of this, my SWR indication is correct, below 1.2 : 1
>
>I then disconnected the tuner and antenna, and connected a dummy
>load directly to the radio.
>Now everything seems to be back to normal. I can adjust the radio
>the way I expected it etc.
>
> >From that I assume I am having antenna problems, the thing that
> does not make any sense however is my SWR, which is perfect .....
>
>Do any of you have any ideas what might be happening here ?
>
>Like I said this started all of a sudden. It was working Saturday
>morning, and by Saturday evening it was like described above. It
>was still the same on Sunday, and yesterday as well, so something
>sure changed.
>
>Thanks for your help.
>
>73,
>KB8OCA
>_______________________________________________
>TenTec mailing list
>TenTec@contesting.com
>http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|