[Elecraft] High SWR problem

Sun Aug 17 18:33:01 2003

On 17/8/03 10:50 pm, "Ron D'Eau Claire" <[email protected]> wrote:

Hi Ron

Thanks v. much, I'll try on another band (where 20m isn't a multiple or
major fraction thereof).

Edward

> CW mode makes it easier to tune up <G> - the output is more stable while you
> twist the ATU controls. You can switch to SSB to ID if you don't want to use
> CW, but it's perfectly legal to use CW in any part of the bands.
> 
> A quick check is to try to load up on 40. As you go down in frequency the
> antenna becomes electrically shorter, less efficient and generally easier to
> "tune up" with an ATU.
> 
> If you can adjust for low SWR on 40 or 80, at least you know your coax
> connections are OK and the ATU/SWR Meter combo works.
> 
> If so, then I'd change the length of the antenna. A half wave end fed is a
> very efficient combination - if you get the wire up high enough - but can be
> very hard to match. The adjustments, as others pointed out, become very
> touchy. Many (most?) commercial ATU's cannot handle antennas whose length is
> very close to an electrical wavelength or even two wavelengths long in many
> cases. The impedance at the feedpoint climbs to a value too high for the ATU
> to handle. Changing the length of the wire only a few feet on 20 meters will
> make a big change in the impedance and should bring it within the range of
> the ATU.
> 
> Ron AC7AC
> 
> 
> 
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> On Behalf Of Edward Kenworthy
> Sent: Sunday, August 17, 2003 1:45 PM
> To: [email protected]
> Subject: Re: [Elecraft] High SWR problem
> 
> 
> On a related note, I'm using SSB and saying a long "aaaaaahhhhhh" down the
> mike when trying to adjust my ATU (even if no-one's listening it's still
> embarrassing to have to append one's call sign after that ;-) Would I be
> better off using AM for a continuous carrier ?
> 
> Edward
> 
> 
> 
> 
> _______________________________________________
> Elecraft mailing list: [email protected]
> You must be subscribed to post to the list.
> To subscribe or unsubscribe see:
> http://mailman.qth.net/mailman/listinfo/elecraft
> Elecraft Web Page: http://www.elecraft.com
> Also see: http://www.elecraft.com/elecraft_list_guidelines.htm