I recently built a two-wire switchable-direction beverage based on the
description in ON4UN's Low-Band DXing (4th edition). The beverage is 375'
long and an average of 6' high. I am using WD1-A wire and the transformers
use 2873000202 cores and have isolated windings as described on W8JI's
website (http://w8ji.com/beverages.htm). Turn ratios are based on Table
7-35 on page 7-73 in ON4UN's book. Currently, I am using two coax runs to
the shack but will eventually use a single coax that is switched between the
low impedance sides of the two transformers. The beverage appears to be
working properly (F/B, S/N, gain).
I followed the schematic in ON4UN's book except for two grounds which I
omitted:
1) Figure 7-98A on page 7-70 shows two grounds on the far end of the
beverage. One is the ground on winding n2 of the transformer, which I
included in my beverage. However, the schematic shows a second ground (to
the left of T5n1), which is connected to one of the two beverage conductors.
What is the purpose of this ground? Can I use the same ground rod that I
used for T5n2 or must it be separated by some distance? If it should be
separated, what is the optimal distance?
2) Figure 7-98A also shows a grounded connection between coax J2 and coax
J1. What is the purpose of this ground? Since I am using separate windings
on my transformer, I don't think it makes sense to connect these coax
grounds to the ground rod for T1n1. How far from the feedpoint should this
second ground rod be placed? If I have a common mode choke at the
feedpoint, where should the ground rod be placed relative to the choke?
Since I have two coax runs, can I simply connect the two shields in the
shack?
Any help would be greatly appreciated.
73, Barry K4CZ
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