Ed -
According to Elecraft, the KAT500 can match 10:1 SWR at 500 watts, on
any band 80 to 10 meters. It can also match 3:1 SWR at 1000 watts on
those same bands. The 160 meter and 6 meter capabilities are a bit
more limited, but it will still match a fairly wide range of loads. By
This seems so in many cases but it is very doublet length dependent.
I ran one case in TLW with 45' of 450 ohm line that came out as 13 ohms.
With a 4:1 balun you'd probably be dropping this further. High
current and most likely not a match.
The best suggestion is to model the antenna at
...@mailman.qth.net] on
behalf of Brian Alsop [als...@nc.rr.com]
Sent: Thursday, November 15, 2012 7:02 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] More KAT500
This seems so in many cases but it is very doublet length dependent.
I ran one case in TLW with 45' of 450 ohm line that came out
There is a common error in assuming that a 4:1 balun should be used with
450 ohm (or 300 ohm) transmission line.
The impedance at the shack end of the line has nothing to do with the
characteristic impedance of the line, and the feedpoint impedance may
actually be quite low. If you have a 5
[elecraft-boun...@mailman.qth.net] on
behalf of Brian Alsop [als...@nc.rr.com]
Sent: Thursday, November 15, 2012 7:02 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] More KAT500
This seems so in many cases but it is very doublet length dependent.
I ran one case in TLW with 45' of 450 ohm line
:02 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] More KAT500
This seems so in many cases but it is very doublet length dependent.
I ran one case in TLW with 45' of 450 ohm line that came out as 13 ohms.
With a 4:1 balun you'd probably be dropping this further. High
current
: elecraft-boun...@mailman.qth.net [elecraft-boun...@mailman.qth.net]
on behalf of Brian Alsop [als...@nc.rr.com]
Sent: Thursday, November 15, 2012 7:02 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] More KAT500
This seems so in many cases but it is very doublet length dependent
Folks,
I am trying to understand the tuning approach taken by the KAT500,
specifically how it relates to the PTT line. The KAT500 manual (Rev. A) on
page 13 spells out precautions to take when using the KAT500 with a
non-Elecraft amplifier. This appears to be necessary to protect some
Ed,
The KAT500 is not *that* automatic. It will not automatically re-tune
even if it senses a high SWR. You must tell it to tune. Once it has
been tuned to each antenna and bend segment, returning to that set of
tuning parameters is automatic - just go to that frequency and antenna
and the
That's not true, Don... the KAT500 *will* auto-tune if/when VSWR
exceeds a (configurable, per-band) threshold.
A lot of consideration is being put into different ways of handling
hot-switching situations with various types of amplifiers. The
currently-posted provisional manual may not be
OK, that is a revelation to me. Sorry that I did not read that in the
manual.
I stand down in light of more informed designers and testers..
73,
Don W3FPR
On 11/5/2012 4:31 PM, iain macdonnell - N6ML wrote:
That's not true, Don... the KAT500 *will* auto-tune if/when VSWR
exceeds a
Well, it does actually say this in the manual:
In AUTO mode, if you QSY such that the SWR rises above 1.8:1 the
KAT500 will automatically retune
when you transmit on the new frequency. The KAT500 will open the key
line to disable your amplifier
briefly until the tune cycle is completed. The new
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