Topband: Low frequency RX antenna

[Tim Duffy]

The transformer and the resister are very close together. The bottom is 40 feet long - split to feed.
I tie to two ground rods.

I have no experience with the other questions.

73
Tim K3LR

-----Original Message-----
From: Topband [mailto:topband-bounces+k3lr=k3lr.com at contesting.com] On Behalf Of Mark Connelly via Topband
Sent: Friday, October 4, 2024 6:09 PM
To: topband at contesting.com
Subject: Re: Topband: Low frequency RX antenna

I have a few questions about the VE3DO loop as described at:http://www.k3lr.com/engineering/VE3DO/OptimizedDOLoop.pdf

With reference to Figure 1, are the 9:1 transformer and termination resistor located close to each other, i.e. pretty much within a foot or two of each other and the center of the antenna, or is there more separation? I was guessing that for a 40 ft. top horizontal length, each of the bottom horizontals would be somewhere between 18 and 20 ft. even though not explicitly stated.
Can the ground of the transformer just be tied over to the ground of the termination resistor without any connections to ground rods, mesh, radials etc. and, if so, can the whole assembly be elevated to at least 8 ft. base height in situations where people, animals, vehicles, yard/farm maintenance machines etc. may need to pass under? I know that Flag antennas can be deployed this way without the ground connection but could the VE3DO be also?
Has anyone looked into Vactrol remote adjustment of termination?
Another scheme would be 4:1 transformers at both sides, two 100 ohm balanced lines (twisted pairs) to the operating position, a 4 pole 2 throw switch to send one side to a 2:1 balun to receiver/amp coax. for the forward side and the other side to a 0-250 ohm pot for in-shack termination control (would be transformed to 0 to 1K at the antenna). That set-up would provide pattern reversal via the switch.
The above set-up has been successfully done with Flags of reasonable size with short (under 200 ft.) feedline distances.
Mark Connelly, WA1ION | South Yarmouth, MA, USA | FN41vq
<<Hello Wes;
The VE3DO loop has a much better front to back ratio compared to a K9AY.
The K9AY is easier to erect
73Tim K3LR
From: Wes Stewart [mailto:n7ws at yahoo.com]Sent: Wednesday, October 2, 2024 6:28 PMTo: topband at contesting.com; Tim DuffySubject: Re: Topband: Low frequency RX antenna
Tim,
Why is this preferred over a K9AY?
Wes  N7WS
On Sunday, September 29, 2024 at 08:10:12 PM MST, Tim Duffy <k3lr at k3lr.com> wrote:
Greg, W8WWV has done some new work on the VE3DO loop.
I use 3 of them here at K3LR.
Greg's latest paper is here:
http://www.k3lr.com/engineering/VE3DO/OptimizedDOLoop.pdf
73Tim K3LR>>
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