SA-2040 Tuning Tips?

[Darwin D. Geiselbrecht]

In a message dated 5/30/98 10:02:12 AM Central Daylight Time,
fvencar at NTPLX.NET writes:

>
>  Picked-up an SA-2040 (without manual) and would like help on tuning the
> tuner. I have used switched inductor tuners where basically you set the
> loading and tuning caps to 50% and switched the inductor around, listening
> for the greatest received signal strength or noise, etc. How does one do it
> with this type tuner?


George - do pretty well like you do for the tapped coil tuner except easier
and with better resolution.  Tuning for maximum sig (or noise) will put you in
the
neighborhood and then it is best to tune for minimum VSWR.  A noise
bridge out of the handbook, a MFJ-259, or a something similiar will also  let
you do this without putting a sig out.  There is no magic and no subsitute
for tweaking all three knobs. They interact, so you have to juggle a bit to
find the right setting.  At 7050 on 40 meters into a fairly flat VSWR dipole
to begin with, my SA-2040 counter is about 110 es other caps about 25 - 35.
The counter moves down to 103 if I move up about 75 Kc. Your results will
vary.

For the longest coil contact life I make it a practice not to move the roller
 inductor with anything but a tiny amount of RF on the tuner or, better yet
 none at all.  So my approach is set the coil, twittle with the caps, reset
the
 coil, twittle, etc - Hoping moving towards a VSWR null point. Been using my
SA-2040 at a kw since they first came out (1980 or so?) with no problems -
so I guess this helps avoids pitting on the coil/roller contact.

I hope you have a VSWR bridge. To get max benefit from the tuner you really
need a bridge of some sort. Who needs a manual? They are for the other guys!
;<)
 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
--- --- --- --- --- --- --- --- --- --- --- --- --- --