[TenTec] Using Manual Ant Tuner With Pegasus
Mark Erbaugh
mark@microenh.com
Tue, 5 Feb 2002 00:33:15 -0500
CDF,
> I am about to buy a Pegasus and I was
> wondering what is the safe way to tune your
> antenna with a manual tuner using this radio.
> Thanks,
The exact procedure will vary depending on the particular tuner, but here
are some general suggestions.
1) preset the tuner to the approximate settings from the last time you used
that frequency / antenna. if you don't know the settings, set the capacitors
to max and adjust the inductor for the highest receive signal level. If you
have a device such as MFJ's "MatchMaker for Tuner" you can use that in this
step.
2) set the Pegasus to a reduced power. 10 to 20 watts should be all you
need. With the TenTec software supplied with the Pegasus, you will need to
remember to reduce the RF output setting. If you use N4PY's shareware
(recommended), it will remember a separate power setting for TUNE mode. You
want to use reduced power for a few reasons:
- full power doesn't make tuning any easier
- full power will cause more QRM
- if you pass through a very bad match during tuning, full power could draw
too much current which could blow the fuse or trip your magnetic circuit
breaker (if you have on installed) or worse, blow a final. The stock Pegasus
has no final overcurrent protection other than the 25A fuse.
3) click the TUNE button. this will generate carrier
4) if the tuner has an inductor and two capacitors, adjust the inductor for
the minimum reflected power. depending on the design of the inductor you may
be able to adjust the inductor with power supplied or not. Check the tuner
manual.
5) alternately adjust the two capacitors for a minimum reflected power. You
should be able to adjust the capacitors with power applied in almost any
tuner design. If you are unable to obtain a decent match, try readjusting
the inductor. If the tuner has fixed positions for the inductor (as opposed
to a continuously variable "roller"), try one or two positions on either
side.
6) turn off carrier
73,
Mark