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Author Topic: Had success with EARCI antenna  (Read 1025 times)

Offline W2LJ

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Had success with EARCI antenna
« on: July 03, 2014, 16:19:20 UTC »
This past weekend was Field day here in the US.  We set up our club station NJ2SP as all QRP, all battery/solar power.  The CW transmitter made 270 contacts all together on the 80/40/20 and 15 Meter bands.  The antenna we used was the EARCHI end fed, which is basically a 53 foot (16 Meters) radiator to a 9:1 UNUN.  I used a 25 ft (7.5 Meter) piece of coax between the UNUN and the transceiver to act as a counterpoise.

The whole antenna project is described at:
www.earchi.org/92011endfedfiles/Endfed6_40.pdf

And a list of wire lengths vs SWR is available at:
http://www.balundesigns.com/servlet/the-102/QRP-9-cln-1-Unun-1.5/Detail

The antenna was used as a sloper, the high end being about 35 ft (10 Meters) up in a tree. Our best DX from New Jersey was Hawaii, Puerto Rico, the Cayman Islands, and the US Virgin Islands, as well as working most of the US West Coast and British Columbia in Canada - all on 5 Watts.

There's no perfect antenna solution for portable QRP operations, but this configuration is fast becoming a favorite!

Larry W2LJ

Offline PA1FJ

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Re: Had success with EARCI antenna
« Reply #1 on: July 03, 2014, 23:09:40 UTC »
I have this same antenna made but with a wire of 9 meters, and works great on the bands of 40-6 meters, with 5 watts QRP.  :)
73 Fred PA1FJ

Offline WH7TT

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Re: Had success with EARCI antenna
« Reply #2 on: July 12, 2014, 01:10:25 UTC »
I have the same EARCHI UNUN and since reading about the 53 Feet on W2LJ's blog I have been using it with my FT-817. It works great. I have an outboard tuner and SWR Meter and this thing tunes easily on every band I have tried. Also, the highest I have had it is maybe 15 feet. Being in Hawaii I have only talked Hawaii so far but I am continuing to try to work more dx contacts.
Edward,
WH7TT

Offline sm5mek

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Re: Had success with EARCI antenna
« Reply #3 on: July 12, 2014, 08:25:24 UTC »
I recently did me an antenna like  EARCHI end fed, but with wire 9,9 m and balun 9:1 on an ring T50. Small and light. Did it worked with that small toroide? Yes, i can use my FT817 with full power and tuner T1 to get good result, also usable on 80 m. At 10 W things happens, the SWR starts to jump upp and down, mostly up, so the ring surely will be overloaded at this power. See pics at my blog http://sm5mekqrpeng.wordpress.com or my new Swedish homepage http://sm5mek.eu
CU :-)
Best regards, 72 de SM5MEK, Jenny.