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Loop 40m


#21

Hi Mark,

This antenna does not work well with a Balun. I have tried it and went back to the Q-Section. I have been using a 40m Horizontal loop for over 3 years now and simple is best. No balun, no ladder line, just (in the case of my original version) garden, fasten-up wire and 75 ohm satellite dish or normal TV coax, cut to the correct length for 40m based on its Velocity factor and then the standard Rg58AU or RG-213 50 ohm feed to the shack. Handles up to a KW no problems. After moving the antenna to Germany from Australia, the wire got upgraded to the light thin wire with teflon fibres in it for strength. Actually didn’t improve performance but it looks better as it doesn’t kink so easily.

The 40m full wavelength horizontal loop antenna at anything over 5m off the ground (ideally 7-10m) works well on 40m and even better on 20m. Without the Q-section, you won’t get the SWR down below 3:1. With the Q-section for me it’s between 1.5:1 and 2:1. Karl has managed to get his even better, before he has even set the exact wire length of the loop!

Heard Karl today from DM/BW-088 and it was a better signal than from his G5RV and this with the Solar radiation hit that we apparently had this morning.

73 Ed DD5LP.


#22

Tell you what all folks
First antenna made was a 11m inverted V tuned wire via calculation feed straight into RG213 coax worked very well SWR damn nr perfect.

Next home brew I did was with a help of an Italian gent via the internet was a 4 El beam short boom and when fired that one up the SWR was nigh on spot on again 11mb using gamma loading.

Now again with this loop perhaps am just lucky in getting it nigh on right first time LOL. But will get hold of a analyser and tune it better still.

Did try you for this morning Ed on 40m but no joy hearing you return and yes bands certainly been little naughty of late. Surprised you even heard me calling in .

But here’s the strangest of all. This evening been using the Astatic mike again and its working fine even when chatting to MI0JLC/p on his Ireland Sota tour was not cutting out mind you conditions lot better this evening as he was cracking in compared to yesterday could barely barely hear him.

Anyway,s its about 7m off the ground, the RG6 feeder goes straight into the ATU no 50 ohm required as moved the feed point closer to the shack in fact its above me just away from house nicely above it. Yet seems to be working OK so far. And the triangle hoz loop has a lot of air around it also.

This evening the coax is out window for this antenna has no grounding and static electric will quickly build up in it. Need to make system so one can switch it away from rig to ground so it can easily discharge.

Thanks again for one and all on your comments and good discussions on this matter.

Long live Sota :smile:

Karl


#23

Know nothing about this.
But sounds interesting.

And thanks Mark was using the Astatic mike then also and not the standard mike.

Yet can quite see the kick of making that contact live on air if you see what I mean. Do like riding the ionosphere, Ok we have the internet, hmmm boring simple done no challenge at all. Being a ionospheric jockey that,s another matter.

Any ways back to the Loop discussion.

Next antenna challenge will be an 8m fibre glass telescopic pole vertical with wire inserted and 9:1 unan can be used at home or portable. But as extra on the portable side make an Inverted V half wave at 7m height off the pole & ladder fed of course.

Karl


#24

Weak Signal Propagation Reporter Network. http://wsprnet.org/drupal/

You have to register to allow the spots to come through. You can use a huge array of hardware to send and receive signals. For testing and viewing propagation cycles and antennas its very useful. You can see openings and the chance of success on any band typically have 200Hz allocations.

I use a compiled C library on the Raspberry Pi which works very well.

Jonathan.


#25

@2E0FEH

If you were using the 40m delta loop on 12.06.2015, the signal was almost buried in the noise here in YO. Still, I’m happy I’ve managed to work you from YO/EC-008 summit.

73,
Petronel
YO8SEP