Seems to me that what is being recommended is taking place already, to
some extent, with no added effort:
1. When a rig is connected to the Astron, the negative power supply lead
almost always is connected to the rig chassis which in turn is connected
to the rest of the station equipment chasses through various coax lines,
shielded cables, etc.
2. The green wire in the a-c power cord of the Astron and the same in
the power cords of the rest of the station equipment all come together
at the a-c service common ground (not neutral).
Now this situation may promote ground loop problems so the suggestion to
directly connect the negative terminal with a short conductor to the
Astron chassis and to the "station ground" is probably good advice and
worth doing.
72/73, George W5YR - the Yellow Rose of Texas
Fairview, TX 30 mi NE Dallas in Collin county QRP-L 1373
Amateur Radio W5YR, in the 54th year and it just keeps getting better!
R/C since 1964 - AMA 98452 RVing since 1972 Kachina #91900556
(12/99)
"Michael O. Hyder" wrote:
>
> Well, the RF sensitivity of some of those supplies comes about when RF can
> get into the negative post. The chassis and the common ground bus of the
> supply are not one in the same -- enabling the supply to be used in
> laboratory and other applications where a floating negative might be needed.
> In amateur service, however, that asks for trouble. An example: we ran two
> meter repeaters from Astron supplies. Nearby (or even distant) lightning
> strokes could come in the transmission line, get into the negative post and
> destroy the voltage regulator circuitry. Once the negative post was
> grounded to the cabinet, we had no more trouble.
>
> In the ham environment, powering a rig from such a supply would not normally
> be a problem so long as everything was bonded together. But on the other
> hand, ground loops within the station could create a problem. I am glad,
> Bob, that you have had no problem but stand by my suggestion that the
> negative post of the Astron supplies be grounded to the cabinet of the
> supply. Perhaps you can think of a reason not to do so??
>
> Regards, Mike N4NT@chartertn.net
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