Short HF antenna for 10m or 11m

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Re: Short HF antenna for 10m or 11m

Post by n0th1n6 on Wed Jan 10, 2018 12:53 pm

Hi Harry,

Again, thank You for answering. A lot to choose from but I am interested in the loop antenna as well. I am worried though that the gimmick capacitor will not work for 10m. I am very interested in the compressed sponge capacitor. Can you give me an idea how to make it?

Best Regards,

Noli, 4G1ZYS

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Re: Short HF antenna for 10m or 11m

Post by Admin on Wed Jan 10, 2018 12:24 pm

Hi Noli,
Thank you very much for your NY greetings on Twitter. I received the e-mail notification but I was unable to open the notifications/message page with you in it!!

If you are looking for a light and smalkl HF antenna then there are several suggestions.

1 - Loop antenna. http://213.114.131.21/antennas/20m_ant_00.htm
This particular project was for 14MHz but the sizes can be scaled and you can make a mono-band very easily and in a very confined space. The 20m antenna is less than 1m diameter. no groundplane needed.

2 - Use a vertical whip antenna as long as you can (but 1/4-wave or shorter). You cn then put a tapped inductor in the feed to it to bring it to resonance. A 1m pole can give very good results on 10/11m. The coil needs to be something like 5cm Diameter and use mains cable to make the coil. For a 1m whip and 28MHz you will need about 5 - 10 turns.
This antenna does need a groundplane but you just need a connection to anything that has sufficient mass, such as balcony handrail, car roof, etc.

3 - Make a centre-fed 1/2-wave antenna on a pole but use wire coilled up on something like a 2m-long plastic conduit tube, but space the turns out a bit so the antenna occupies the full length of the tube.
This antenna does not need a ground connection.

4 - Google "slinky" and buy two of the metal versions. These you can stretch out to suit the space available. If the space is short (like on a balcony) then feed a clothes-line through them for support.
This antenna does not need a groundplane.
This antenna will need an ATU.

So there are a couple of suggestions for you.

I personally favour the loop antenna. I am presently making a 3D plastic screw-thread than can compress sponge to make a 10kV variable tuning capacitor for the loop antenna. It should be possible to have two or more loop antennas on the same frame using one common feed loop, or even a tapped loop?

Very best regards from harry - SM0VPO

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(Thanks to those who tried and couldn't make the QSO. Back on 14.200MHz Sundays from the 24th Sept.)
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Short HF antenna for 10m or 11m

Post by n0th1n6 on Tue Jan 09, 2018 1:02 am

Hi Harry,

I am constantly looking for ways to make a transmitting antenna that is light and not too long. The reason for this is that 1) I don't have a good tower where I can mount a heavy antenna. 2) not enough area to mount a wide antenna (only have 8 meters longest that I can use). That said, I am looking at the short HF antenna in your page as my main antenna for 40m. I also want to make one for 10 and 11m and this is what I want to clarify. With the current design, will it work up to 10m without modification or do I need to build one just for this band? Would a wire soldered to the roof enough as ground for this antenna?

Thanks and BR,

Noli, 4G1ZYS

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