Gary:
I'm investigating this exact problem with Heil Sound right now.
Also, Kevin sent me an article with some additional helpful information on
the problem, including the serial numbers of the TS480 rigs most likely to
be affected.
Will keep everyone posted.
73 from Tom Behler: KB8TYJ
----- Original Message -----
From: "Gary Tillinghast" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 10, 2011 10:12 PM
Subject: Re: KB8TYJ 20-meter RFI problem solved, I think finally!
Hi Tom, There was a thread going around on the Yahoo groups about using
other mikes on the TS480 radios. It seems that the original mike for the
TS480 radios will work fine, but using other mikes, one use to have to
change the pin 3 and pin 5 around in order to eliminate the feed back loop.
This might be a thought to investigate. Gary KB2YAA
----- Original Message -----
From: "tom behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, March 10, 2011 8:35 AM
Subject: KB8TYJ 20-meter RFI problem solved, I think finally!
Hi, all.
I think I have finally gotten to the bottom of my RFI problem on 20 meters
when using the Alpha Delta DXCC antenna.
Now, all I have to do is figure out how to fix it, and how to replace what
little hair I still have that has been pulled out in the process.
My problem is with the cable for my Heil Gold Line mic! Thanks to Kevin
(K7RX) for giving me the clue.
I used headphones to monitor my transmit audio, first with the stock mic
that came with the TS480. Crystal clear audio on both 100 watts, and 600
watts using the amp. Then, switched back to the Heil. Crystal clear audio
on 100 watts, but terribly distorted audio using 600 watts and the amp.
Tried putting an RF choke around the Heil mic cable, which reduced the
RF-generated audio distortion considerably but not completely.
Just for grins, I tried the Heil set-up on 40 meters with both low and high
power, and had crystal clear audio both times.
So, obviously, that mic cable is doing something to me on 20 meters.
Will write to the folks at Heil for their suggestions, and would appreciate
any thoughts any of you have as well.
I'm relieved, but now have to figure out what to do to correct the
situation, if I'm going to use my Heil gold line mic on 20 meters with the
Alpha Delta DXCC.
73 from Tom Behler: KB8TYJ
|
