I think you need a Balun at the feed point ? I think it may play better horizontally ? 🤔.....?

I love this video - simply because it shows a true amateur experiment that failed. Together with the comments this is a great learning experience. More of that!

The antenna is a helically wound linearly loaded dipole. There will be interactions with the enviroment. Trying to tune it to resonance indoors may not predict its performance outside. Hight above ground might be playing a factor. The idea of adding telescoping whips to either end and tuning the antenna using them may be a good suggetion. Just a few inches of straight wire or some wires in a fan configuration might improve its performance. The role of the coax feeder has to be considered. A current choke close to the feed point might make the performance more reproducible. Antennas of similar design are going to be be sharply tuned and you may have to decide what portion of 20m you intend to operate.

@mysteryham4065

2 ай бұрын

Good advice. Thanks.

Another thing you might consider doing is building a 49:1 balun and then using a noodletenna as an end-fed half-wave. That means you can feed it from the bottom, and also will work on some frequency multiples. I've seen some videos of people making end-fed slinky antennas that work well on 40 meters and 15 meters. You will need some short counterpoise wires but should be a lot easier to deal with than a traditional 1/4 wave vertical (which requires a bunch of 1/8 or a few 1/4 wave radials). Here's an example of a slinky in EFHW mode: kzread.info/dash/bejne/hJme3M-pmsu6p7g.html You can build a 49:1 balun cheaper than you can buy, fwiw. Basically you need some wire and a toroid ferrite.

Partner, what you made was a large loading coil. Add a stinger to each end and the performance will increase. Adjust the coil count for better tuning. A loading coil is only one part of the antenna system. Experimenting is the fun part of the hobby. Good luck.

@mysteryham4065

2 ай бұрын

Indeed. That makes sense. Thanks for stopping by!

The z of a heavily loaded dipole is less than 10ohms. Maybe 5 ohms. You could make it work but the z is one of 2 problems. The other is that, unless its on a tall mast, it needs to be horizontal so both sides are balanced to ground. Apart from that , it's perfect 😂

Your feedline may be coupling with your radiator. Make sure your feedline is perpendicular to radiating element. I use a vertical 20m OCFD antenna and had high swr when my feedline was was not at a 90 degree angle from the feedpoint. Good Luck Ross, K8RLB

@mysteryham4065

2 ай бұрын

That is an excellent point. I will try that!

@texasyojimbo

2 ай бұрын

@@mysteryham4065 the description on K7RAW's noodletenna video mentions using a Mix 31 ferrite choke (which is sometimes called a balun; when he says "no balun" he is sort of using the narrow definition of a balun). Years ago I played around with slinky dipoles and frequently had issues getting it to tune. I suspect this was largely because I didn't discover the importance of chokes. You can do an air-core choke (no ferrites required) if you have some extra coax. Somewhere in my junk drawer I have an air-core balun that I made wrapping coax around a plastic water bottle. For lower bands you'll want to use a larger form. For higher bands, probably fewer turns are needed. Ferrites just make the job easier because it means having to coil fewer feet of coax (which can get lossy, btw, when you have non-trivial SWR).

Love your little mcHF transceiver! I really like mine. Bought it 2nd hand but won’t sell it. I’ve tried the slinky dipoles. They work, not great but it was fun (to me) trying.

@mysteryham4065

2 ай бұрын

Thanks. Sometimes I like the RS-978 and sometimes not so much. But most recently I like it again. Some guy was selling it out of the back of his pickup truck at Hamvention 2023 and I went for it. Thanks for stopping by.

need more round😅

If you touch the outside of your coax connector and the SWR changes your getting RF on your coax (Common Mode Currents), and therefore false SWR readings. Your coax needs to be decoupled with a 1:1 balun or ferrite chokes, AKA Common Mode Choke, before your radio to stop this. Any loaded shortened antenna like this will be less efficient than a stretched out wire. Antennas are sensitive to their environments, especially metal in their environment, especially indoors, as your finding out. Antennas prefer wide open spaces, ABOVE things in their environment. The further away from your living area, the less QRM / man made noise from digital devices within your home will affect your reception. The odds were stacked against your setup working well. ALWAYS make wire antennas longer than you think you need (lower frequency) them trim them to increase resonance to your desired center frequency. Too high a resonant frequency, too short the antenna. 73 -mike

Your down too low in the 20 meter band. You were down below the frequencies they were using, unless you were shooting for the CW stations. You might try this on 10 meters. This might work better with your SWR