[TowerTalk] How to mod a 40m 4-square for 10m use?

[Michael Tope]

Mike,

This presentation goes into excruciating detail on how to make all the 
necessary design calculation to setup and optimize the Comtek style 
hybrid in a 4 square array: 
https://www.kkn.net/dayton2011/Demystifying%20the%20hybrid%20coupler-vers-FOR%20k3lr.pdf

The presentation focuses on an 80 meter design, but there should be no 
reason you can't change the frequency to 28 MHz and re-run the 
calculations to scale it for 10 meters. Without diving into the details 
of the design, the extent to which stray reactance in the layout and 
frequency dependent component limitations compromise performance at 28 
MHz is not clear to me. It sounds like a fun experiment.

Good luck!

73, Mike W4EF.........................

On 1/22/2022 2:22 PM, Mike Smith VE9AA wrote:
> I am trying to go to all 4-squares like my contesting 4-sq buddy John, N8UM
> in TN.
>
> I am nearly there, having just installed a 15m one in time for CQWW CW.
>
> There are no new dedicated 10m 4-squares to be found commercially, if my
> internet searching skills
> are telling me the truth, so recently I bought a 40m 4-Square (Older Comtek,
> NOS)  and am hoping to mod it for 10m, but I have no idea where to start.
>
> I'll PRESUME the capacitors need to be a different value in the exterior
> switch box, but to what?...anyone have a schematic for a Comtek 4-square?
> (the outdoor portion)
>
> Apparently Tim, K3LR (DX Engineering) was not happy with the performance
> from the 10m Comtek 4-squares, so is not selling them anymore. I can
> definitely respect that decision to not produce a top-notch product.  I am
> not looking to squeeze every fraction of a dB out of a 10m array.  I just
> want something that 'works', is directional and has some modest amount of
> gain.
>
> (I have built several K1WA/K8UR arrays and am not totally happy with them)
>
> My SO2R contest station uses a single horizontal antenna on the 2nd radio
> and a bunch of vertical 4-squares on the primary radio.
>
> Any ideas on the Comtek Mod fellas?
>
> Tnx
>
> Mike VE9Antenna Antenna
>
> Mike, Coreen & Corey
> Keswick Ridge, NB
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk