HF Antenna

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HF Antenna

Postby 742-xx » Fri Dec 30, 2016 9:24 pm

I'm new to HF and I'm currently 'experimenting' with wire aerials. I'm only interested in recieving.
I've got a G5RV Antenna in the loft, but I'm desperately short of space, so I've ended up with the wire being zig-zagged all over the place. I'm sure that this isn't exactly efficient.
While I can often get Shannon quite clearly, I rarely get to hear both sides of the conversation. I have recieved Gander VOLMET, but it wasn't ideal.
So I bought some speaker wire and started experimenting further.....
My garden isn't massive so I started with 33 feet from an upstairs window going to the end of the garden. The results were impressive, compared to the loft set-up. Still only getting one side of conversations generally, but much clearer. Then I tried 66 feet under similair conditions, although I had to do a 90 degree bend across the garden. This wasn't at all good. But was it the weather conditions ?
I then replaced the two 52 feet wire 'legs' on the G5RV Antenna with just one 33 feet speaker wire one and it was much better than the manufacturers set-up.
I relsih a challenge, but I do feel that I'm perhaps going around in circles to some degree.
Would a balun or unun have any effect ?

So to my real question ..... Discone offer a HF verison of their scanner antennas. It appears too good to be true - is it ?
If I was to stick it on a 10 foot pole on my roof would it be effective ? Could I get rid of all of this wire ?!?!

I'm going for a lie down ........
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Re: HF Antenna

Postby m0lsx » Fri Dec 30, 2016 10:11 pm

I have a short off centre fed dipole (Windom) zig zagged around my loft & it is not ideal, but they do work.
A discone will work at HF, but so do 2 feet of less of telescopic antenna on a portable radio. But neither works at all well.
A balun may improve things on one frequency, but not others as it will always change by the 4:1, 9:1 etc ratio. So good bad or indifferent it will change it. Some frequencies will be better, some will be worse.
A 9:1 is a traditional SWL balun. And if it's a Balun that has an earthing capability, then thats an advantage, as it will reduce some background noise.
G5RV's are notoriously deaf. So there are better options.
A dipole that is cut for around 6mhz, may be a good option??
I use to have a 48 meter (6.2 mhz) dipole in my loft back in my broadcasting days.
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Re: HF Antenna

Postby 742-xx » Fri Dec 30, 2016 10:52 pm

I think my next move will probably to make a di-pole that will fit in the space I have outside. Probably an inverted V utilising the two 33 feet wires that I have already used to good effect. Then to tweak it for interference.

I knew when I got into this that it would involve a lot of trial and error so I suppose I only have myself to blame !

Thanks for the reply.
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