Chirp

[Darwin D. Geiselbrecht]

In a message dated 1/10/99 8:10:41 AM Central Standard Time,
hardiem at intergate.bc.ca writes:

> Recently my HW-16/HG-10 signal was reported as "unique", ... (snip)
>The
>  independent power supply idea described earlier on the list sounds like a
>  very good idea but ... has anyone tried (now I'll put my asbestos suit on)
>  a solid state mod such as a zener or two on a 7 pin plug in place of the
>  0B2?
>

No need to go that far HI.  The OB2 makes an excellent regulator in this
service
and the fact that you are seeing almost no variation key up to key down
confirms
that it is probably doing its job.  A look with a scope would confirm it, but
it is likely
OK dynamically also.

The HG-10 is prone to difficulties associated with the neon bulb keyer and the
time
constants in the grid circuit.   One thing to look at is watching the neon
bulb
in the keying circuit with high speed dits to ensure that it is consistently
following
the keying.  I had to change both the bulb and the series resistance to make
mine
 key right. That's an empirical exercise because of variation in the neons and
the
magnitude of the blocking voltage from the transmitter.  I use mine with a
DX-60B.

I believe there was an article in an old issue of Electric Radio or CQ that
dealt with
the time constants in the grid circuit, and was intended to address the chirp
problem.
I have not made that mod, as mine is acceptable without it. But perhaps
someone on
 the list can put us on to it.

  Good luck 73 - Darwin K5DOA

--- --- --- --- --- --- --- --- --- --- --- --- --- --
To subscribe: listserv at listserv.tempe.gov
and in body: subscribe HEATH yourfirstname yourlastname
To unsubscribe:  listserv at listserv.tempe.gov
and in body: signoff HEATH
Archives for HEATH: http://www.tempe.gov/archives
--- --- --- --- --- --- --- --- --- --- --- --- --- --