[Elecraft] What Guage Wire for PS?

[Lyle Johnson]

Hi!

> ... The earth ground would typically not be needed in many
> portable operations, unless you were dealing with
> a long and high antenna that develops static charge.

In 1984 I was installing some low-power transmitters at a mine on the island
of Bougainville.  We were having serious problems with the output
transistors in these units - they kept burning out.  Since they were running
at about 10 mW, power dissipation wasn't the cause.

One day while driving in the area, one of our engineers happened to have a
9" quarter-wave mag-mount whip antenna on the roof of the pickup truck he
was driving.  The other end of the coax was terminated to a BNC connector,
but not connected to a radio.  Hearing a mysterious "pop...pop...pop" noise,
he looked at the BNC connector and was surprised to see a repetitive spark
jumping across the tip of the BNC connector to its shell!

We then studied the transmitter schematics and noticed that there was no DC
path to drain static buildup from our 9" whip antenna.

We installed a high value resistance across the antenna to the transmitter
ground, and all the transmitters worked fine for years after that.

Moral: 9" qualifies as a long and high antenna (at least in Papua New
Guinea)!  Use a ground! :-)

Lyle KK7P