CaveDweller wrote:

I'm expecting a brown truck to pull up today and deliver me a brand
new NRD-545. As you know, Mr. Franklin and about 17 of his friends
have departed this locale, never to return. Due to their absence, I
have a great interest in proper equipment grounding.

Here is my situation. I have two SWL antennae-a 200 foot inverted L,
fed through a transformer which is grounded; and an Alpha Delta sloper
which has it's "down leg" grounded at the same point. Both coaxial
feedlines are fed through a switch with an arc-plug protector, which
is also grounded, but to a different ground rod about 40' from the
first one. FWIW all ground conductors are flat-braid.

My current radio is grounded to the house wiring, which has been
checked and is done properly. I plan to run the 545 from batteries,
though, so this should not be an issue.

Should I tie these grounds together? And then ground the 545 to the
same point? This would result in some rather long ground connections,
but I'm thinking that would protect the radio the most.

Of course, I'm interested in the lowest noise possible, but my main
concern is protecting my new baby.


A ground won't protect your radio. Someone once said that your radio is
just a very very expensive fuse serving to protect the three dollar
ground wire.

The main purpose of a signal ground to your radio is enhanced
performance. The tuning circuitry performs a lot better with a signal
ground.

Now, a safety, or electrical ground, is there to protect YOU. Should a
component inside the radio short to the case, the ground will assure a
tripped breaker or blown fuse so that the case isn't unknowingly
energized. This ground doesn't do much to protect the radio either.


Your best protection is a completely separate lighting arrester with
it's OWN ground setup. Disconnecting the antenna during thunderstorm
activity is most likely the most important single thing you can do. a
diode or two aimed from the antenna to ground will protect against
static zapping your radio's front end.

An old bit of advice consists of tying a knot in the power cord going
into the set. The theory being that any huge sudden influx of current
will automatically choke itself off due to a Lenz's law effect...

http://www.physics.ncsu.edu:8380/cou.../lenzslaw.html

I've never had the good fortune of being hit directly by lightning, so I
can't vouch for the efficacy (ten dollar word) of the proposal. It can't
hurt, though...



mike