[Yaesu] FT8100R Receiver Stage going?

[Dave Maley]

Yaesu seems to be having trouble properly mounting the RF blocks
on the heat sinks.  I think the small heatsink and fan combo would
work if a proper bond is made.  There just not much room for error
in modern radios.  The FT 5100/5200 uses a SAV-24 for the VHF PA.
It's quite expensive from Yaesu.  RF Parts has an SAV-18 with the
same ratings, but about 2db less gain.  Cost was about one half.  I'm
getting 40-45 watts out.  Make sure there is absolutely no 
contamination or tarnish on either surface before carefully applying
a very thin layer of high-quality heat-sink compound to both surfaces.  Then 
make sure the mounts are properly torqued.  RF Parts will provide
specs.  It looks like some shops get a little sloppy here.  Good 
Luck.  Dave   WA0ZZG
AR

> Date:          Mon, 13 Apr 1998 10:29:47 -0400
> From:          Daniel Senie <dts@senie.com>
> Organization:  Amaranth Networks, Inc.
> To:            "Mills, Chuck" <millscl@msx.upmc.edu>, yaesu@contesting.com
> Subject:       Re: [Yaesu] FT8100R Receiver Stage going?

> Of 3 FT-8100R radios I own, one went back at age 3 months for a $350
> repair (covered by warantee) that involved a new PA module, new VCO
> components, etc. Another one has a significant deviation in one circuit
> from the schematic, and nobody at Yaesu will tell me why. I intend to
> undo that change at some point (it's in the mute circuit).
> 
> I also own two FT5200s, one of which has blown up its PA twice. The
> first time it cost me a bundle to have Yaesu fix it, and I haven't sent
> it out again. I may just write it off.
> 
> Yaesu likes to build these tiny radios with fans on the heat sinks, but
> doesn't know how to make those fans keep working. The 5200 works off of
> a temperature sensor, and the blown 5200 doesn't spin its fan no matter
> how hot it gets.
> 
> Bottom line, I don't intend to consider Yaesu next time I buy mobile
> rigs, and generally recommend friends look at other brands. And look for
> radios that use proper thermal design with heat sinks, not fans.
> 
> Dan
> 
> Mills, Chuck wrote:
> > 
> > Hi there....
> >     I have an FT8100R that seems to have burnt out part of the receiver
> > stage.  Has anyone seen this happen on their rig?  One day, while
> > transmitting, I smelled componets burning, stopped transmitting and
> > noticed that I had almost no receive
> > whatsoever.  Has this happened to anyone???
> > 
> >     Also, high SWR seems to cause a sticking in TX mode on 2m.  Has
> > Yaesu owned
> > up to a fix on this problem?
> > 
> > Thanks,
> > Chuck / W3YNI
> > 
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