#388

This "part 2" video summarizes the build, tune and test of a trapped EFHW antenna for the 20, 30 and 40m amateur radio bands. My previous video:
• #387: How to build an...
...shows the process of building and tuning the low power / QRP traps that I purchased in kit form from N7KOM. See additional links in the previous video for details. My resulting wire lengths were:
UNUN to 20m trap: 30'-2.5" (about 9.21m)
20m to 30m trap: 4'-7.5" (about 1.41m)
30m trap to end: 8'-6" (about 2.59m)

[@LordVoidFury]

I have basically no familiarity with RF outside of your videos--you communicating with something 1000 miles away made me smile; that is so cool

[@AnanasGuy]

Why not get your license and join us? There is always room on the air for someone new

[@Wheel_Horse]

Hi Alan! Another great video! 73 OM!

[@N7KOM]

Well done! I like that you show that the resonance doesn't need to be "perfect". For QRP, under 1:1.5 is gonna be great. No need to fret about getting exactly 1:1. Hope to QSO with you on this antenna soon! 73!

[@Swamp-Fox]

Your trapped EFHW turned out great! Nice compact, lightweight package. Thanks for the detailed tuning process explanation. 73, Patrick KF4LMZ

[@Wheel_Horse]

That's the biggest spool of wire wrap wire I've ever seen!

[@w2aew]

It’s not wirewrap wire. It is 26 gauge stranded.

[@Wheel_Horse]

@@w2aew Looks just like my spool of 26 ga WW wire! Only bigger!

[@BalticLab]

Great video, Alan. As usual!

[@sasines]

Thanks for the part 2 of your antenna! As well as being a ham I’m a bit of a bird nerd and that sounded like some very vocal Northern Cardinals. Thanks again.

[@w2aew]

Yeah, lots of them around here.

[@Alex-M0OOV]

That was great, would love to see more hand-on and dyi build videos from you!

[@VE6LK]

Great video (as always) Alan. Your style of tuning matches mine - cut the wire long and tune it up.

[@iblesbosuok]

Great QRP on a beautiful summer, sir.

[@HALEdigitalARTS]

Nice video, thanks!

[@SuperSuperGenius]

1 word Alan... Waygos. The twisty connectors are so 70s.

[@N5PJ]

I like this.

[@ornithopterindia]

👍Thank you sir.

[@MattHeere]

Curious what you have for counterpoise with this setup? I get away with 25' of coax for my full size EFHW, but I can easily see needing a better "ground" with the higher radiation resistances you get from a loaded antenna, especially on the lower frequencies.

[@w2aew]

Just the shield of the 25’ coax feeder. Counterpoises aren’t as critical for EFHW antennas due to their high feedpoint impedance.

[@MattHeere]

​@@w2aew Not critical, but you can't skip them entirely either. Every circuit needs a ground reference, and you do have different radiation resistances with all those traps. It would be worth trying a 50' piece of coax. $5 says your match improves by more than the difference in coax loss would account for on 40M.

[@anullhandle]

1st couple of mins until you panned away from the table it looked like you might be at the beach but the birds didn't sound right :) I keep telling myself I'm gonna learn code I need to just get on with it. Maybe with the grand kid if I can get her out of the pool long enough. Your video catalog makes a nice reference library.

[@ae5au]

Alan, these videos are very timely for me as I ordered N7KOM's trap kit last week while on vacation and it will be delivered today. I also intend to make a 40/30/20 EFHW. I was wondering if you happened to test it on 10 meters. I've been using the Par 40/20/10 that was trapped on 20 and worked well on 10. After I trimmed it down to 30 meters instead of 40, I haven't been able to get the SWR low on 10 and the curve is strange, not just off frequency.

[@w2aew]

I haven’t tested it on 10.

[@jampskan5690]

Is it possible to have even more traps? Say, one for 17, 15, 12, and even 10? Or will that not work for some reason?

[@w2aew]

It's possible, but the interactions in tuning would likely be complex, and the added weight of the traps might not be worth it.

[@davidryeburn6446]

I noticed two things. (1) When you made the traps, the 20 m trap was resonant just a bit below the lower end of that band, not right in the CW portion where I would have expected. (2) When you tuned the antenna, the 20 m portion of it was a bit shorter than the usual half wave length. I wonder if these two things are related? David VE7EZM

[@w2aew]

All interrelated I’m sure.

[@franklinsanchez7984]

I wanted to see the traps being built, according to the desired frequency

[@w2aew]

Watch the previous video, #387, on my channel. kzbin.info/www/bejne/gXqoi6Ctd510ftksi=N9ZylVF16Ad2Kl3c

[@user-ou4dp1ps4r]

Sir, Make videos on RF analyser

[@w2aew]

I have already done a complete review of the RigExpert AA-55 Zoom. kzbin.info/www/bejne/h2OrdaisbZmgodk

[@bobby9568]

I dont know why Im still subscribed to your channel

[@BobGarrett66]

@bobby9568 Probably because like the rest of us, you realize that Allen puts out some great, educational content! Have a great day! 73

[@bobby9568]

@@BobGarrett66 its because i thought it had great content ten years ago but now its not that great anymore, sorry

[@tcarney57]

@@bobby9568 And you're so incompetent that you can't properly unsubscribe?

[@w2aew]

Please, let me know the type of content that you’d like to see more of!

[@maximus6884]

if you want to criticize, criticize with a purpose. Otherwise, your words are just not worth typing and reading.

[@jomckarth4836]

any problem with your ears? turn back the volume!

[@w2aew]

It really wasn’t that loud, it is just that the camera’s microphone is heavily biased to sound in front of the camera.