[Yaesu] FT1000-D SWR Sensor problem

Sat Jun 26 18:04:40 EDT 2004

Tom,
I had this same problem last year.
A question on this mailing list led me to check out the diodes in the SWR
sensing circuit where I found two (out of four) to be apparently blown.
Fortunately the board on which they're mounted is located in a convenient
spot on the top of the rig under a shield cover (same as in the MP). Once
inside that compartment, the board can be removed very easily since it's
just screwed in and has removable connectors for all the connections.
Locate the diodes using the schematic in the owners manual - you don't need
the service manual for this.
I ordered replacement diodes from Mouser. Meanwhile so I could operate
that weekend, I soldered in similar diodes (but not Schottky diodes which I
believe are called for in this circuit) in place of all four and everything
worked fine. Got the right ones later.
I'm still not sure what blew those diodes but I suspect something like
static discharge from a dipole left connected during a storm.
73,
Chris, W2PA
yaesu-bounces at mailman.qth.net wrote on 06/26/2004 01:01:09 PM:
> Hi Just experienced what appears to be a failure in the SWR
> sensing circuit where it shows high swr when actually there is no
> swr problem. I checked by connecting directly to Dummy load with
> known good coax, etc. I did notice prior to complete failure that
> occasionally the auto tuner was acting funny in that it was not
> tuning normally and now believe that was because the swr circuit
> was acting up. Even now I notice that once in a while the
> indication of high swr will go away and all will be fine for a bit
> then back to bad.
>> I do not have a service manual so any insights to this problem
> (possibly this is a systemic problem with this radio?) would be
> greatly appreciated.
>> 73, thanks
> Tom, W1XS
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