[CQ-Contest] Coax Stubs for SO2R

[Roberts, Will]

Hey Jeff,

I use only tuned stubs for SO2R with my Six Pak. I don't have any other filtering. I connect the stubs on the antenna side coax connectors on the Six Pak with one or more T connectors. There is 75' of coax between the Six Pak switch box and the stations. It seems to work reasonably well. There is a little interstation interference, but most of that is just on harmonic frequencies, so it is manageable. Make sure your stubs are cut well as N3RR mentioned. Mine were cut by W2JVN. Also, make sure that the T connectors are high quality. I had initially used some cheap Chinese T connectors that came apart under the strain of the stubs pulling on them. In one case, a T connector developed an intermittent that allowed increased interference. All replaced by Amphenols now.

73,

Will AA4NC



From: Jeff Clarke <ku8e at bellsouth.net<mailto:ku8e at bellsouth.net>>

To: cq-contest at contesting.com<mailto:cq-contest at contesting.com>

Subject: [CQ-Contest] Coax Stubs for SO2R

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Wondering how those of you using a Six Pack antenna switch hookup your stubs? I have two coax cables from the Six Pack coming into the shack going to each radio. Each station has a multi band Dunestar switchable filter. For the most part the Dunestar works well but since I recently added an KPA500 to my run station, when I'm on 40 meters with the amp it gets into 20 meters on station #2 pretty bad. Are you all using a T connector and have the stubs for each band on a manual multi position antenna switch?



Also does anyone know if the Dunestar's are tuned for a specific part of the band. On 80 meters mine seems to have a very high SWR when I switch it in even though the SWR on the KPA500 looks good.



Jeff