[1000mp] RE: [Yaesu] SWR Meter and FT-1000MP

Mon, 11 Mar 2002 09:12:48 -0500

> ----- Original Message -----
> From: "Pawel, SP7PS" <[email protected]>
> To: "YAESU Reflector" <[email protected]>; "FT-1000MP Reflector"
> <[email protected]>
> Sent: Sunday, March 10, 2002 6:56 PM
> Subject: [Yaesu] SWR Meter and FT-1000MP
>
>
> I put 50 Ohm dummy load instead of antenna and made a test. And it was a
> big  surprise for me to see difference between MP's SWR and external YAESU
> YS-60 SWR meter. First I tried with 50 Watts and external SWR meters
> shows 1:1.  But MP shows 1:1.3. So I increase the power to 100 Watts and
> external SWR meter still shows 1:1.0, but internal rised to 1:1.7. Is
> that something wrong with my MP?

Pawel,

It is possible that the SWR bridge in your 'MP is not properly balanced
(nulled).  Most of the Breune type circuits have a trimmer capacitor
in a capacitive voltage divider connected from the center conductor of
the line.  If the bridge is not properly balanced, some forward power
will be interpreted as reflected power yielding an incorrect (and
variable) SWR.

73,

   ... Joe, K4IK