OK, now I understand.
I remember reading about the oscillation issue before, but even though I
have made several hundred 6m contest QSO's in the past year mine has
never had a problem. My rig was a "one owner", but was practically
unused when I bought it. But, it did have one repair. Another common
problem with the '897 is the RIT knob is very fragile. Just before
shipping the rig to me the previous owner knocked the rig over on a
table, the knob hit and broke. He sent it in and had it repaired.
I'll bet while they were fixing the knob, the PCB board was tightened.
And so, no 6m problems with my rig...
I know I couldn't believe that I would be "lucky" enough to get one
without a problem. It usually works the other way for me!
I'm also on the 897 yahoo group, but I have to admit I ignore most of
the traffic there. Most of it seems to be the same "entry level"
questions / info over and over... I'll likely drop that list soon.
73
Dan
--
K9ZF /R no budget Rover ***QRP-l #1269 Check out the Rover Resource Page at:
<http://www.qsl.net/n9rla> List Administrator for: InHam+grid-loc+ham-books
Ask me how to join the Indiana Ham Mailing list!
Alex wrote:
>> I would NOT recommend a FT 857 or 897 for contesting. Both
>> have a problem with 6 meters that ultimately ends up with a trip for
>> repair associated with the final amp stage. This problem has been
>> around for years, starts with an oscillation and ends up with low
>> output or blown finals.
>>
>
> I had that issue years ago with my 897, oscillating on 6m that is. I wrote
> about it on the 897 group on Yahoo. I bet you can still find it in the
> archives.
>
> Usually the first indication is a high SWR indication, on the display, on a
> well matched antenna system (not on a dummy load!). This indicates that the
> rig is oscillating on a frequency outside the range for which the antenna
> system provides a good match. The cause is bad grounding of the PCB, which
> in turn allows for all kinds of RF paths to exists, causing RF feedback and
> break the amplifier stages into oscillation. The remedy is simple. Tighten
> all screws that mount the PCB(s) onto the chassis. I found that in my rig
> *all* screws were .25 turn loose. I don't know if they just don't apply
> enough torque on the screws on the assembly line, or if the slight expansion
> and contracting of the chassis due to temperature variations is the cause.
> However, my rig has never displayed the problem since I tightened the
> screws.
>
> 73,
> --Alex KR1ST
> http://www.kr1st.com
> http://www.airlinkexpress.org
>
>
_______________________________________________
VHFcontesting mailing list
VHFcontesting@contesting.com
http://lists.contesting.com/mailman/listinfo/vhfcontesting
|