Glad to Have the Sky Loop "Pentabus" Up
Dimensions
This time, a five-sided rhombus sort-of-shaped thing. A Pentabus? Total wire this time about 470 feet, just shy of the 500' spool. If I added more wire it would droop a bit. The wire here is taunt between trees. Plain 14 AWG insulated wire. Green to hide among the trees.
Anchored in each corner with a guy-line and PVC insulator. I can bring each corner down as needed for servicing the antenna.
Fed at the N-W Corner with 450 window line to a (legacy 2010) Palstar AT-AUTO (the version pre-Palstar split. So this would be the Kessler design).
Cost of antenna
$40 worth of guy line.
$60 worth of wire
$2 worth of zip-tie.
Surplus Window Line (I've had it for 10+ years, probably 120 feet involved here)
$8 worth of SCH-40 PVC
Performance
It tunes the following bands quite easily:
10 m
12 m
15 m
30 m
40 m
80 m
Issues
I cannot get a 1:1 VSWR on 17 or 20 m. As close as I can get is about 1.2 VSWR on 20m and 1.8 on 17 meters.
I'm not sure why yet. I did make some coax changes in the shack between radio and amplifier and antenna switches and so on, so the add-up of coax between Rig/Tuner/Amp has changed some since the last time I had the Loop running. I will be experimenting with a quick fix with different lengths of coax in the shack before I look further.
Loading
No balun/unun at all. The AT-AUTO (for lack of a better case) is the tuner and the pi-network in the tuner does what it needs to do.
It's brilliant on 40m and 30m. I can drive 35W on the Elecraft K3 and deliver 700W via the homebrew linear amplifier (4kV Plate voltage, Class AB-2, Grounded Grid, Pair 3-500ZG -- new valves just got 'em!)
Anyway, this is a vast improvement over the 43 foot vertical I was running. Although the vertical was fine for 80, 40, 30, and 10, it also could not load for 20/17 either via AT-AUTO.
But the Loop is back in action.
I will making use of it to reach 40m contacts as before, DX and W's. When I get the 20 meter load figured out better, I will reach out on 20 meters also.
Just glad it's back.
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