[Elecraft] New KAT500 pics from the Visalia DX convention

Guy Olinger K2AV olinger at bellsouth.net
Tue Apr 24 17:52:55 EDT 2012


10:1 SWR at 1.5 kW mandates voltages and currents that require, among other
very expensive items, vacuum variable caps, [high current AND high voltage]
relay design and contacts, and inductors that can handle ridiculous
reactive currents.  And I'm sure you want it in the same form factor,
right?  If you want to see something actually built for that, try

     http://www.rfconcepts.com/PRODUCTS/New-Products/Alpha4040

There probably is not a reasonable antenna that you cannot partially match
at the antenna feed to reduce SWR over the coax, and save a lot of loss in
the process, to get it at significantly less than 3:1 looking into the
coax. An example of this is using a 3:1 turns ratio autotransformer (not a
balun) at the base of an end-fed halfwave.  Feeding 9:1 stepped down Z over
the coax is not so bad, and it's within the range of just about any tuner I
ever saw.

If you're getting 10:1 out of a piece of coax, you're using up your amp to
cover the loss in the coax from running power through it at a ridiculous
and hugely lossy SWR.

73, Guy.

On Tue, Apr 24, 2012 at 4:11 PM, Tim Tucker <ae6lx at worldwidedx.com> wrote:

> Any plans soon on a legal limit (1.5 KW+) auto tuner that can handle 10:1
> SWR?  Reading the site, it looks like the KAT500 will the power, but only
> at 3:1 SWR.
>
>
> -----------------------------------------
> Owner, worldwidedx.com
> AE6LX, Amateur Radio
> NNN0ITA, Navy MARS
> NNN0GAF FOUR, Southern CA Director Assistant for Training, Navy MARS
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