Seven SOTA antennas compared using WSPR on a summit

Equipment Antennas
63

I believe that the 44 ft doublet as a system may have come from the work of LB Cebik W4RNL. He did a lot of work on this. A summary is here. http://www.n5dux.com/ham/files/pdf/W4RNL%20-%20Top%20Five%20Backyard%20Multi-Band%20Wire%20HF%20Antennas.pdf

More here: The All-Band Doublet

And here: Only One Wire

The NORCAL doublet was suggested by Doug Hendricks - KI6DS

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64

The red and green number display is in column C, not column D. I believe it’s the column C numbers that must avoid multiples of 0.5, correct?

For CAT5e velocity factor of 0.64, feedline lengths of 7.6-7.8m are favorable.

Thanks & 73,
Barry N1EU

65

Hey Barry

of course you are right. I have corrected it.
The total length of the system (radiator and feeder) should not be a multiple of 0.5 lambda.

73 Armin

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66

Armin,

thanks for finding the original spreadsheet and the translation, that’s excellent. Hopefully it will help people find a good feedline length for their doublet.

73 Gavin
GM0GAV

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