Saturday, 25 October 2014

QTH updates: LDG RT-100 & G7FEK nested Marconi antenna

I have replaced my doublet in my back garden with a G7FEK nested Marconi antenna and a LDG RT-100 / RC-100 remote antenna tuner at my QTH.

G11 SDR QRP - EMU 0204 - RC-100 -MyDel  MP-30SW IV

Details of the G7FEK antenna can be found here

Courtesy of G7FEK

My implementation is as follows. The far end is supported by a Tecadi mast at 7.2m. The shack end is at 5.5m held by a pulley at bathroom window. The wire is oriented NE/E - SW/W.
The bottom of the vertical section is located at the base of the mast.
Tecadi mast at the west side of the garden
 I have so far only used two elevated radials of approx. 20m and 10m. They run along the garden fence at 40cm and 140cm above the ground. The antenna wire and radials are connected to a 1:1 choke balun which is connected to the LDG RT-100 via a short RG-214 jumper.
I also implemented the optional 20m radiating element which climbs along the mast.
23m of RG213 reach the shack.
The vertical elements are made with Sotabeams antenna wire and their open wire line spacers.
The horizontal wire is the mid duty antenna wire from Westlake Electronics.

I used the recently finished VK5JST aerial analyser to tune the wires for resonance on 80 & 40m before connecting it to the tuner. It took some pacience and attempts but after a couple of iterations I got in the box.

LDG RT-100 & Better QRP - balun - waterproof with liquid tape

Side view - the white wires are the elevated radials

I have earthed the RT-100 using 2x 4ft - 3/8'' earthing rods. Photo below.

3/8'' earthing rods & jubilee clamps - screwfix
 I am pleased with the new aerial system - 80,40,30,20,17,15m tune without a problem. The others I have not tried yet. I worked some DX this week P40MW, EX2F, UN3M with 10Watts of CW - which I could not hear before with the doublet.

 I left running WSPR whislt typing the post - 20-21 UTC
WSPR - 30 & 40m

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