[Yaesu] unusual 80m problem-additional info

[Jim Hargrave]

John,

You could also have some RF feedback into the radio even though the meter
indicates a good match.

It has been suggested that you add a length of coax to the line and observe
the behavior. I would certainly try that. I would suggest you install an RF
choke either at the antenna or the tuner. You can make a coil out of coax
and that might help. A reasonable diameter is 5 -8 in. I use a 3 pound
coffee can for my form. I have  a small loop coil at the feed point in the
shack and at the base of each antenna cable where they go into my antenna
switch box on the tower.

I have owned several Collins radios and they recommended a coax length  of
21 ft to change the current/voltage position in the feed line.

Good luck!

   * 73's Jim W5IFP *


   >----- Original Message -----
   >From: "John Geiger" <aa5jg at yahoo.com>
   >To: <ft100 at yahoogroups.com>; <yaesu at Mailman.qth.net>
   >Sent: Thursday, April 16, 2009 7:18 AM
   >Subject: [Yaesu] unusual 80m problem-additional info
   >
   >
   >>
   >> Here is some additional information about the problem which I
   >just discovered.  At the top end of the 80m band (3.900) it is
   >putting out the full 100 watts, as you decrease in frequency
   >the power also decreases.  At 3.700 it is doing about 50 watts,
   >and at 3.525mhz it is doing 25 watts.  Hopefully this
   >additional information will lead to a solution.  It is seeing a
   >1:1 SWR (thanks to the tuner) at all of these frequencies.
   >>
   >> 73s John AA5JG
   >>
   >>
   >>
   >>
   >______________________________________________________________
   >Yaesu mailing list
   >Home: http://mailman.qth.net/mailman/listinfo/yaesu
   >Help: http://mailman.qth.net/mmfaq.htm
   >Post: mailto:Yaesu at mailman.qth.net
   >
   >This list hosted by: http://www.qsl.net
   >Please help support this email list: http://www.qsl.net/donate.html