Topband: Two-wire switchable-direction beverage

[Barry Baker, K4CZ]

On Fri, 1/30/09, Barry Baker, K4CZ wrote:
> I recently built a two-wire switchable-direction beverage based on the
> description in ON4UN's Low-Band DXing (4th edition)
> 
> 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?  ...
> 
> 2)  Figure 7-98A also shows a grounded connection between coax J2 and
> coax J1.  What is the purpose of this ground?  ...



I received a half dozen responses to my questions about the two-wire
beverage, including an email from ON4UN.

1)  In Figure 7-98A on page 7-70 the second ground shown on the far end of
the beverage (to the left of T5n1) is a graphics editing error and should
not be included.   

2)  Also in Figure 7-98A, the grounded connection between coax J2 and coax
J1 is intended as a ground for eliminating common mode currents.  If this
ground is used, it should not be connected to the same ground rod used by
the T1 transformer.  Any common mode grounding should follow the guidelines
elsewhere in the book including Section 2.8.3 (page 7-61) and Figure 7-88
(page 7-60).

Thanks to everyone who responded.

73, Barry K4CZ