Yaesu
[Top] [All Lists]

[Yaesu] FT8100R Receiver Stage going?

To: <yaesu@contesting.com>
Subject: [Yaesu] FT8100R Receiver Stage going?
From: KF0FX@aol.com (KF0FX)
Date: Mon, 13 Apr 1998 16:57:26 EDT
In a message dated 4/13/98 9:22:07 AM Central Daylight Time,
millscl@msx.upmc.edu writes:

<<     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?
  >>

Well, I don't know if this applies but.....

The FT8500 seems to have a problem with high SWR, like when people mod it for
out of band and then go and transmit on 155.88 using their Larson dual-bander.
The 8500 has been known to blow the Tx/Rx pin diodes under high SWR
conditions.

I hear this from an associate of mine that, er, sells a lot of Yaesu
equipment.  When asked about the 8500, he thought it was a good radio but
didn't recommend using it in a situation where the transmitter would encounter
a "high" SWR.

FWIW to show that some Yaesu equipment can take some abuse, I tried the
following experiment one night:
1.  Cluttered up my work bench with all sorts of coax cables and test
equipment.
2.  Jumbled up the cables so I couldn't tell where they were coming from and
where they were going.
3.  Connected a 110 watt GE Mastr II repeater transmitter's output through a
watt meter to the antenna jack on my Yaesu FT-212  (sitting right next to the
dummy load).
4.  Turned on the GE transmitter, monitoring the quality of the audio received
by the FT-212.  (Signal was full quieting!)
5.  Observed an unusually high SWR for my dummy load (about 2:1), but
otherwise output from the GE was nominal.
6.  Determined that the dummy was the one holding down the mic button on the
GE.  Turned transmitter off.
7.  Connected the FT-212 to Cushman test set.  Determined that FT-212 still
met spec for both Tx and Rx!
8.  Made a note never to sell my FT-212.

73's
Chris, KF0FX
KF0FX@aol.com

--
FAQ on WWW:               http://www.qsl.net/k7on/yaesu.html
Submissions:              yaesu@contesting.com
Administrative requests:  yaesu-REQUEST@contesting.com
Problems:                 owner-yaesu@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm

<Prev in Thread] Current Thread [Next in Thread>