[ICOM] Amp tuning

[Ed Senior]

Hi Bob,

You will probably get a lot of responses to your questions!

1.  Your rig's built in tuner will NOT tune your antenna
      "through the amp."  But if your amp is working properly,
      its input should present a low SWR to your rig.  Most
      likely, you can (and should) switch your rig's tuner OFF
      when driving the amp.

2.  You MAY need a high-power antenna tuner between
      your amp and the antenna, depending on whether or not
      your amp's output can be adjusted to handle the load
      presented by the antenna.  Many amps can handle load
      SWRs up to 3:1 with no problem.

3.   People usually use CW to tune their amps.  (Start at a
      reduced power level, and go to full drive only for the
      last bit of fine tuning!)

If you have any good buddies in your area who are used to
tuning up big amps, you might invite one over to show you
how it's done.  (Expen$ive mistakes are possible, alas.)

73 and good luck,

Ed, W6LOL

----- Original Message ----- 
From: "Bob Bennett" <bbbnntt at optonline.net>
To: <icom at mailman.qth.net>
Sent: Wednesday, September 13, 2006 7:09 PM
Subject: [ICOM] Amp tuning


> I have an Icom 756 Pro III and just hooked it up to my old Detron
> GLA-1000 amp. I have two questions:
>
>    1. The station has a g5r3 that the Icom automatic tuning feature has
>       been tuning quite well. Now that I have the amp do I need to use
>       another tuner between the amp and the antenna, or does the Icom
>       tuner tune the G5RV through the amp. The SWR reading on the
>       radio’s meter is showing an SWR between 1.0 and 1.5. The meter on
>       the MFJ Versa Tuner (coax direct) in line after the amp is showing
>       an SWR as hi as 3.0.
>    2. When tuning my amps, I have been tuning them using FM. I have
>       never been confident with hellllloooooo on ssb and my whistling
>       skill is as bad as my singing. It this (FM tuning, not singing)
>       harmful to the amp?
>
> Bob/KG2RP
>
>
>