Re: [TenTec] Using Scout w/external keyer

[w8au@sssnet.com]

At 04:20 PM 08/26/2003, Andrew Moore wrote:

> > I understand the Scout has a problem with drift when using the internal 
> > keyer, especially at higher speeds.  I guess this is a result of the way 
> > the micropocessor handles frequency correction during keying.
> >
> > Am I correct in assuming that this problem goes away with the use of an 
> > external keyer?
>
>
> Good question John -- please summarize to the list; I'd be very interested 
> in knowing the answer too.
> -------------------------------------------------------(snip)--------------------------

These legends get recycled periodically and no doubt will continue as long 
as the Scout
remains popular.....

While it is true that high speed CW with internal keyer CAN allow some 
frequency movement
due to less correction sampling of the PTO, it is not a fixed fact.
I have used the internal keyer for average 35 wpm CW ever since I got my 
first Scout and
have not had the "tell-tale" freq shifting.    However, I also have a 
friend who had a
real "lemon" and it was notorious for doing that, no matter if an external 
keyer was used!
After having two (still have one about ten years old) I find that the 
temperature compensation
of the PTO is a factor here.   With PTO's that had good temp compensation, 
there was not
much movement to correct and consequently fairly rock-solid stability.
Then there is the poorly compensated PTO which moves much faster and does
appear to move frequency when the freq correction comes into play.

My Scout is one of the oldest, being built "pre-production."  It has been 
CW mobile it's entire life
and still exhibits excellent stability.   Every few years I lift the RISC 
microprocessor out of it's socket
and "reseat" it, to reestablish good electrical connections....   that's 
about all the Preventive Maintenance
needed.

Being mobile during the winter does require some "working with" the PTO, 
since going from sub freezing
temps to 120degrees in the heater blast is an extreme that will cause the 
PTO to move beyond it's 700 cps lock range.
During winter WX I manually do a few "off-on" power resets to re-center the 
PTO locking range until
the rig comes up to ambient temperature.  This way listeners aren't 
disturbed by any freq jumps.

Have fun, all you owners of "pre-owned" Scouts....

Perry   w8au







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