Testing a 20M Vertical Delta Loop Antenna While Activating Holmes Educational State Forest! 

qrper.com/2023/09/pota-with-a-20-meter-vertical-delta-loop-and-the-elecraft-kx2/?swcfpc=1 Click the link above to read full details about this activation, including all equipment links, at QRPer.com.

Keep filming the whole deployment. Seeing you struggle with an antenna shows it’s not just me!

Loops either horizontal or vertical will load on even harmonics. the matching unit on antenna matches 125 ohms approx. to your 50 ohm rig. Your are a great operator and I like that paddle. 73 AF5U Dave

At its fundamental frequency, a close-to-ground, bottom-CENTER-fed HORIZONTAL or VERTICAL Delta loop will have a radiation pattern similar to a close-to-ground dipole; i.e., max radiation toward the clouds. While not optimal, its reduced radiation at lower azimuthal angles will accommodate radio communications. Additionally, for receiving, a Delta loop is a relatively quiet antenna. A close-to-ground, bottom-CORNER-fed VERTICAL Delta loop will have a radiation pattern similar to a ground-mounted vertical antenna; and similar to a ground-mounted vertical, it will incur greater ground losses than a horizontal antenna. I always find it amazing that substantial radio communications can be achieved with the combination of a sub-optimal antenna system and QRP.

Really appreciated the site assessments! Love the videos. Thanks for bringing us along on your radio therapy.

Enjoyed the activation! Prayers sent for your parents.

Congratulações pw8gts

Good call on showing the setup. It helps to see the reality of setting up a delta loop in the field like this.

Enjoyed. Hope your mom gets better. Thanks

Hi Tom! I just wanted to say thank you. You were basically the only POTA youtuber I've ever watched. Through your videos I learned CW, even before my Tech license :) I got my General license (It's called "B" in Israel) recently and just passed 400 CW contacts, mostly at 25WPM. I will forever continue watching and enjoying your videos! 73 es 72 de 4X5AU@KM72kb

A loop a full wave circumference on 20 m like the one you have will be a half wave circumference on 40 m and the impedance at the feedpoint will be very high (like a shorted quarter wave line). Losses in the coax will be enormous, even after the balun at the feedpoint (probably 4:1) does its thing. So if you want to use it on 40 m, remove the balun and switch to open wire or ladder line, preferably of electrical length 1/4 wave on 40 m. If you use typical 450 ohm ladder line with a velocity factor of around 0.91 that would be about 31 ft or 32 ft long. This will produce a relatively low impedance at the transmitter end of the ladder line. Then put a 1:1 current balun at the transmitter end of the ladder line and your KX2's tuner will take care of the rest. If you need more feedline length, go the rest of the way to the transmitter with coax, on the transmitter side of the ladder line and balun. On 20 m and 10 m the ladder line will be an even number of quarter waves long and the relatively low impedance the loop will have at its feedpoint on those frequencies will simply get repeated at the other end of the ladder line. However on 15 m where the loop has a high impedance as it does on 40 m, once again the ladder line being 3/4 wave long will invert the impedance, like it does on 40 m, which is again what you want. So for 40 m, 20 m, 15 m, and 10 m, this would appear to be a very nice solution. Let's hope the wonderful KX2 tuner can make it all work on the WARC bands too! As a retired mathematician, I can't help saying this: The solution for 80 m is left to the reader. Another thing you might try is to connect your feedline at the apex rather than at the midpoint of the low horizontal section of the delta loop. There shouldn't be much difference on 20 m or 10 m but it will behave very differently on 40 m and 15 m because now you will have high voltage low current points high in the air instead of down near the ground. So while the impedances at the lower end of the ladder line won't be all that different from what they would be on those two bands if fed down low with ladder line, the radiation pattern will be very different (probably worse?). Yet another thing you could do would be to put a removable jumper at the middle of the low horizontal section and feed the loop at the top. The jumper being down near the ground is readily accesible so you can open it up for 40 m or 15 m and close it for 20 m or 10 m. When you open the jumper, you've got a highly bent up half wave dipole on 40 m, and a 3/2 wave doublet on 15 m. Then you can go back to using the balun and coax feed on all bands. I had such an arrangment in my back yard for a while some years ago. My KX3's tuner found a match on any band. The antenna got out about as badly on 40 m as you'd expect for such a bent-up thing! Try these ideas and let us know how they work. Of course you'll have to keep the parallel conductor feedline off the ground and not curl it up. David VE7EZM and AF7BZ

For broadband matching with minor loss, place a small remotely controlled ATU (e.g.; elecraft T1 with remote tune switch) at the feed point. This will allow you to efficiently use the antenna from 40 thru 10. Alternatively, feed it with low loss 450 ohm open line attached to the transmitter via an ATU.

The ants ,flies, & mosquitoes make me send some of the wildest CW code you ever heard!

Very nice😮

Loops work on all harmonics. They are better than dipoles in this respect, which only work on odd harmonics. Loops are typically around 200 ohms, so the balun is probably 4:1.

It's directional broadside to the loop. KE6VG

Great video. Thanks for showing the whole setup. Loops like that are usually fed with a 4:1 or maybe a 5:1 as their impedance is typically in the 200s range.

Aha... I can hear myself right there, that was so laud. Sorry for the confusion, I can see the problem on your the log, I miskeyed additional dit for my call suffix toward the end of the QSO, from AF5D become AF5B. My bad!! Still re-learning cw. Thank you, Thomas for being so patient with me. Hope to catch you again next time. 73, Bayu - AF5D

A Delta Loop fed at the bottom has horizontal polarity

And I hope you got a good price for your IC-703, I had been looking gor an IC-703 for a ling while, but the ones on eBay looked scratched & rough at original MSRP, lol. So i bought the TR-45L Skinny instead. Other than FedEx losing it for a few days, the TR-45K Skinny has been wonderful!!!

Interesting antenna, only thing I see that might help is some type of high color wire 🤷‍♂️, but being out where folks shouldn’t be running around black is ok

More than likely it is a 4:1 transformer. I believe loops are about 200 ohm. Tim - K5DEZ

my 40m delta loop will tune up 10-80m.

Was I mistaken or did WA2JMG send an 'XX' before signing off with 'EE'? If so, what is the 'XX'?

How high was the baseline off the ground? Looks like 4-5 feet. Impressive results!

How much did that loop help out with all the noise that seems to be there at Holmes? both times I was there its was bad. My wife loves walking around there while I ham, so if that loop helped alot I know I want one of these.

Hola Thomas, no hay nada en el link...

Don't sell your IC-703+....I prefer my 703 plus over my far more expensive KX3 !!!!! I could get rid of my KX3 and not miss it, but I would dearly miss my 703 +

I bet you only had a short time to do this today

I noticed how much quieter the noise is on this antenna. Now you have me wanting to string one up during an activation. Haha! de WK4DS

Great Antenna Tom. I built many a Delta look for VHF. (6,2m) single and in beam form. worked well. And I did not get to work you on this one but think it was the next one maybe it was on the 5th of the month. Anyway nice antenna and activation. thanks for sharing es CUDTL OM! de Ellis WA1RKS