I used to have a Tuner-Tuner (fixed 50 ohm noise bridge) but kept
blowing the fuse by transmitting through it.
Now have an MFJ-212 Matchmaker. Same concept but with auto-bypass and a
momentary ON button.
These devices are great for my setup. I use the Matchmaker to tune my
tuner for flat SWR. No signal on the air, no stress to the rig, no QRM.
My amp is an Ameritron ALS-600 Solid State No-Tune amp. So, the tuner
that is adjusted with the Matchmaker is ready for either the exciter or
the amp.
Even the second or two of transmission using an auto-tuner bugs me. The
frequency may sound clear, but I may be QRMing someone inside my skip zone.
This system has been fast and easy for me. YMMV.
73 de K1ESE
John
Dr. Gerald N. Johnson wrote:
On Mon, 2007-08-06 at 15:11 -0500, Stuart Rohre wrote:
All,
Always tune up a rig and linear and tuner into a dummy load before applying
an antenna. Then, you should have less range of adjustment to fine tune the
tuner to the antenna.
Only if the antenna is near resonance. Otherwise the tuner should be
pretuned with an antenna analyzer or noise bridge or tuner tuner (fixed
Z noise bridge. The rig and linear used with that tuner should be tuned
into a dummy load and all that tuning can be facilitated by keeping a
tuning chart with good logging dials on the adjustable components.
I find peaking receive through the tuner speeds adjustments when I've
neglected to look at my tuning chart.
And, if possible, use an antenna analyzer to make sure the tuner settings
are either correct for the intended antenna, (separately with the linear
disconnected), or tune the antenna using the antenna analyzer as the source.
That minimizes the on air time of the linear while tuning up. Actually, the
goal is to NOT tune up the linear on the air.
For sure, but when the only tuning instrument is a SWR bridge that runs
at full transmitter power, tuning on the air will be done.
73,
Stuart
K5KVH
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