[Elecraft] KAT500 usage model?

[Don Wilhelm]

Jim,

It sounds like you have a bit of space to work with, so let me suggest 
my wire antennas that come into the shack on 3 feedlines (could be 
reduced to 2 with remote feedline switching).  One antenna is a 
broadband 80 meter dipole (actually an inverted Vee) with its center at 
48 feet.  That antenna is featured in the ARRL Antenna Book 19th Edition 
page 19-16.  At right angles to the 80 meter elements are the 40 meter 
elements giving me an 80 and 40 meter antenna that has less than a 2:1 
SWR over the bands (OK. I lied a little, SWR goes to 2.3 above 2.9 kHz).
The second dipole is a set of parallel dipoles for 20, 15 and 10 
meters.  The 3 wires are separated by one foot using PVC supports for 
the separators.  The 3rd antenna is similar, but is a parallel dipole 
for 30, 17 and 12 meters.

The net result is that antennas for all bands are 80 through 10 are 
resonant, and a 3 way antenna switch is sufficient to access all of them.

If you want to expand to 160 meters and 6 meters, 2 more antennas and 
feedlines are required - I would suggest an inverted "L" for 160 and 
either a dipole or a beam for 6 meters, but that means 2 more feedlines.

Figuring out your antenna switching system when the number of feedlines 
exceeds 3 is a challenge, and there is no one answer - it all depends on 
your desires and your aspirations.

I have not addressed beams, but they can be injected into the 
feedline/remote antenna relay/ in-shack feedline selection equation.

Personally, I have 3 HF feedlines running into the shack, and 3 VHF/UHF 
feedlines.  I have the 160/80/40 BC trapper and a GAP Titan vertical as 
well.  While the VHF/UHF system is currently incomplete, I should be 
able to do both satellite and terrestrial VHF/UHF as well as HF antenna 
selection from the shack when it is done.  I have made several attempts 
at automating that selection with the Elecraft KRC2 as well as 
extensions and devices of my creation, but have fallen back to manual 
selection of the antenna.  In contest stations, quick and easy and 
non-ambiguous antenna selection is important, but not so for my station 
- I have installed enough indicators to tell me what relay should have 
been activated, and if the SWR indicates something other than what is 
expected, I know that something along the way has failed - give up that 
band  for today and troubleshoot tomorrow.

If anyone is interested in my  in-shack  switching system that allows 
the priority one transceiver to taqke one feedline, and a 2nd 
transceiver to take a 2nd feedline, leaving the 3rd feedline for a 3rd 
transceiver,  I will send the rough sketch schematics  to you - just 
ask.  The switches have many poles that make that selection possible and 
were salvaged from RS-232 or DB-25 switch boxes.

73,
Don W3FPR

On 6/17/2012 8:33 PM, Jim Miller wrote:
> I should have added some context to my question. I'm considering adding the
> KPA500 at some point. I currently have a hexbeam for 20-6m which has <1.5
> SWR so I doubt the KAT500 would be a benefit there.
>
> I currently have a non-resonant dipole for 80-30m which I occasionally use
> as a hatted vertical. Both configurations are supported by a 125 remote
> tuner under the feedpoint via a 50ft length of window line. The run to the
> shack is 100ft of Buryflex.
>
> I can see that the dipole configuration would require a remotable 500w
> tuner if it remains. But I'm considering alternatives which won't require
> putting the tuner outside. Resonant dipoles for 30m and 40m are a
> possibility and perhaps a vertical for 80m. If alll were resonant I
> wouldn't need anything other than an antenna switch to move among them.
>
> Jim ab3cv
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