[Kenwood] 850S

[Carlos Avellanet [kf4rrn]]

I beg to differ with you Ron.  I have as my main station radio a 2xxxxx
serial number TS-850S/AT and have not had a single problem (knock on wood)
with it and it has the 6631 chips still in it.  This radio has been used
every single day in almost all bands both SSB and CW everyday for quite some
time now.  On the contrary, it has been a very capable and reliable radio.
I would not have any heart burn on selling or buying a functional 2xxxxx
radio at any time.

Just my two cents worth,
Carlos. KF4RRN


>
> Hello,
>
> I decided to make this posting only so it might help someone on this list
> troubleshoot a 850 with similar symptoms to those I had. BTW, most of
these
> problems are very well documented at N6TR's fine site dedicated to the
850.
>
> I bought the radio from a K0 is Greenbay, who sold it as MINT. He claimed
he
> used the radio only for spotting during contests.  BTW, this was a 2xxxxxx
> serial no unit, WELL KNOWN for DDS failure. Back then I didn't know the
> stigma attached to 2xxxxxx serial no. 850s! When the radio arrived I
noticed
> the following.
>
> 1) Monitor function stops after warm up
> 2) Erratic slope tuning
> 3) Distorted Audio on transmit after half hour or so
> 4) Receiver audio seemed muddy
>
> What followed soon after was the transmitter going completely dead.
However,
> much my surprise, I found that the radio transmitted normal when I had the
> DSP100 kicked in (bought a few weeks later). A few weeks later the
receiver
> also went dead and this time the DSP100 didn't help!
>
> Back in Sri Lanka, with no repair facility, I was left looking at a dead
> radio and not knowing how to find the components or for a start, where the
> problem was!. The many posts I made here and elsewhere didn't bring much
by
> way of tech advise. However, a fellow ham very kindly offered to fix it if
I
> shipped the radio or the boards stateside.
>
> Finally, I consulted N6TR, "ham of the year 2003"  Thanks to Tree, I now
> have a fully functional 850s. Tree, replaced all 4 DDS chips in a faulty
> board he had and sent it to me. I still have to send my faulty board to
him
> to figure out if all or how many 6631s were bad. Incidentally, Kenwood
> themselves realized this quality problem back in the 90s and started to
use
> the 66312s in their later production runs. The carrier board (that Tree
sent
> me) swap cured ALL my problems.
>
> Tree truly desrves the award and has shown immense ham spirit and a
> willingness to assist DX stations in "distress" !!!
> .
> DON'T buy a 2xxxx 850 unless the DDS has been changed. If it has lasted so
> far, it will most like fail eventually.Watch out for these symptoms. The
> monitor may seem a function you can live without, but it is an EARLY
> warning. In my case, the seller was smart! It is quite possible that not
all
> 6631s will fail, but unless you alrealy own a 2xxxxx  srerial no. 850, I
see
> NO REASON to gamble with buying one! I thought mine was a deal at 650$
with
> a pair of optional filters thrown in!
>
> Always reserch your radios before buying them. There are many hams here
who
> can tell you that certain production runs were known for certain  faults,
> how to determine year of manufacture etc (perhaps the name of the JA YL
who
> assmbled them?!!!!!!).
>
> 73,
> Ron, 4S7RO
>
> - - -
>
> Your moderator for this list is:
> Larry Wilson KE1HZ kenwood-owner@mailman.qth.net
>
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