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QRP Guys adding another new antenna product


#1

The guys over at QRP guys are really pumping out new products as of late.

I noticed when perusing their site the other day a new antenna, currently listed as under development. Its a trapped 20-30-40 meter end fed antenna with a built in N7VE LED circuit.

I’ll probably be purchasing this guy as well. The kits are fun to build and the more recent ones are very functionally designed. It would be nice if they diverged from the 20-30-40 meter bands every now and then though!

Link: https://qrpguys.com/qrpguys-multi-band-end-fed-antenna


#2

They’re also selling the trap kits by themselves. I grabbed a few kits and plan on building a trapped 40/30/20 dipole and also modifying a linked end fed I have.

–Jay W8ES


#3

Their trap instructions say nothing about adjusting the traps for resonance. I find this puzzling.

Sotabeams, on the other hand, gives very detailed resonating instructions.

You can’t just wind X number of turns on the toroid, add a capacitor, and expect the resonance to be close without measurement and adjustment and then making sure the turns stay fixed in place.

Barry N1EU


#4

Also, I must say that I find the design with a tuned circuit inferior to a broadband transformer as in @HB9BCB 's EFHW (Trap EFHW and Coupler and https://hb9sota.ch/wp-content/uploads/2018/01/Slim-EFHW-Koppler.pdf) and the 40-20-10m design described by VK3YY at https://vk3yy.wordpress.com/2014/08/31/end-fed-for-40m20m10m/ (3D-printable parts at https://www.thingiverse.com/thing:1948711).

Heinz’ design does not require any adjustments for a decent SWR in a wide range of configurations and over varying types of ground. I really do not see how the new proposal is in any way superior over these existing designs.

If you don’t want to build it yourself, hamshop.cz (@OK1CDJ) has a similar antenna readily made for ca. 25 EUR:
https://www.hamshop.cz/antennas-c9/trapped-efhw-antenna-40-30-20m-qrp-i344/

73 de Martin, DK3IT


#5

… although the total length of 20m seems a bit untypical despite the traps … but the most important are the promised SWR values (…), regardless of the arrangement (Inv-V, Inv-L, stretched, vertical, …) and height above ground, hi.


#6

Barry, I also noticed the instructions left a bit to be desired and had already dropped an email to the QRPguys about it. I personally have no problem building and resonating traps, but I agree it should be addressed in their directions.

–Jay W8ES


#7

I assume they use a little lower inductances (same as the tiny traps from SOTABeams), so the pure radiator will be ca. 18.x m long (as compared to the ca. 16m in your design), and the specified length of 20m might include a piece of rope at the end.

73 de Martin, DK3IT


#8

That well may be… some installation hints are given here:


The length of my 40/30/20 trapped EFHW (POLYS-26 wire) is 16.80m…