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80 mtr Antenna question


#1

Does anyone out there use a helical antenna for SOTA activations? I’m looking to use one for 80mtrs. Compared to a 1/4 wave wire dipole I know I’ll have less performance. Perhaps just a base load with a short whip? Any ideas or comments? Or perhaps a stop it James, it’s a silly idea!!

James
G7MLO


#2

In reply to G7MLO:

Hi James,

For the effort involved in setting up a vertical you really would be better using a simple half wave dipole. While it is possible to use a short whip, you will struggle to get an adequate ground radial system which would be essential to take the place of the bodywork of a vehicle for which mobile antennas are designed. You would also have a very narrow bandwidth at which the whip would give a resonable SWR, thereby limiting yourself still further.

Not a silly idea, but there are much better & easier options.

73,

Mark G0VOF


#3

In reply to G7MLO:

Not quite what you were asking, but it might be worth your while to take a look at the Rybakov 806 antenna. I’ve got one built but have not had a chance to try it out yet, having had an attack of the porkine lurgy. I imagine that it will not be best suited to NVIS work but mght bring in some decent DX, and its an all-band antenna.

73

Brian G8ADD


#4

In reply to G8ADD:
That Rybakov antenna looks very much like the Comet CHA250B several people have reversed engineered the Comet CHA250B, I have tried one and not impressed with using one with QRP, Full size dipoles are pretty hard to beat and dirt cheap to build. Sean M0GIA


#5

In reply to M0GIA:

In reply to G8ADD:
That Rybakov antenna looks very much like the Comet CHA250B several
people have reversed engineered the Comet CHA250B, I have tried one
and not impressed with using one with QRP, Full size dipoles are
pretty hard to beat and dirt cheap to build. Sean M0GIA

True, Sean, but vertical polarisation has its attractions for DX and it isn’t that easy to manage below say 21 mHz without a kite or balloon, the Rybakov 806 is one way of playing with it. I have a couple of friends that have achieved great results with the CHA250B, by the way, they think it is the best thing since sliced bread, I’m not so sure but am willing to try.

73

Brian G8ADD


#6

In reply to G8ADD:

True, Sean, but vertical polarisation has its attractions for DX

Brian

Is there much DX to be had during the middle of the day on 80m?

73

Richard
G3CWI


#7

In reply to G3CWI:

Not often, Richard! :wink:

You will remember that I am trying it out as an all-band antenna, and whilst in the Spring on 80 I have heard ZLs as late as 0800, plus 60 is often still performing at that time too, which might possibly warrant an early start - but really I am thinking of its DX potential on the HF bands and a less traumatic start time!

I suppose my thinking is that it would be nice to have an all-band antenna with reasonable DX potential now that SOTA is intercontinental, but without covering popular summits with trip-wires!

73

Brian G8ADD