[Yaesu] unusual 80m problem-additional info

[John Geiger]

Yes, that is something that I need to check into with the coax.  I have run other rigs (including other FT100s) on this setup with no problem.  I just tried out an Icom 7000 on it and it was doing full power.  This is the first time I have seen something like this.  Just to try, I loaded up my 6  meter yagi on 80m with the tuner. It did load but I am sure the performance would be terrible.  However, the FT100D was putting out full power into the 6m antenna, so it is just something strange between the antenna, coax, tuner, and rig.  Will have to keep exploring.

73s JOhn AA5JG

--- On Thu, 4/16/09, Jim Hargrave <w5ifp at gvtc.com> wrote:

> From: Jim Hargrave <w5ifp at gvtc.com>
> Subject: Re: [Yaesu] unusual 80m problem-additional info
> To: "Yaesu" <yaesu at mailman.qth.net>
> Date: Thursday, April 16, 2009, 5:29 PM
> 
> 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
>    >>
>    >>
>    >>
>    >>
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