[Mobile-Portable] Re: Question about HF mobile - SWR "Sensitivity" - CAUTION

[Jim Miller]

It is a good idea to begin any testing or adjustment of a manually operated
tuner into an unknown load using LOW power.  Adjust the tuner to minimize
the SWR and then ease the power up until you have it adjusted at full power.
This will ease strain on the radio.  For the 706 (also 746?), there is a
"module" you can get that will automatically lower the output power to 5 or
10 watts when the tune button is pressed.  This eliminates the need to go
into the menu system to do this.

73, de Jim KG0KP

----- Original Message ----- 
From: "Gary Pearce KN4AQ" <kn4aq at arrl.net>
To: "Mobile-Portable Reflector" <mobile-portable at mailman.qth.net>
Sent: Tuesday, July 17, 2007 6:17 AM
Subject: [Mobile-Portable] Re: Question about HF mobile - SWR "Sensitivity"


> At 06:10 PM 7/12/2007, you wrote:
> >Ok guys another question about this mobile setup of mine.
> >
> >I put the 706 in low power and Swr is flat, I bump it up to medium or
high
> >power and swr's go abt 2.3:1...
> >
> >Why do they do that on high power?
> >
> >73,
> >Brian
>
> I have the same experience with my 706.  Here's why...
>
> You'll notice that the 706 lacks the "sensitivity" control found on most
> external SWR meters.  The meter is not designed to operate at low power.
> The manual says that when measuring SWR, "Confirm that the output power is
> over 30 W." (page 38).  So the meter is not giving you an accurate reading
> at low power.  Your SWR is really about 2.3:1.
>
> 73,
> Gary KN4AQ
>
>
>
> ARVN: Amateur Radio//Video News
> Gary Pearce KN4AQ
> 508 Spencer Crest Ct.
> Cary, NC 27513
> kn4aq at arvidnews.com
> 919-380-9944
> www.ARVidNews.com
>
>
> ----
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>