On 16/03/2005 12:02 PM, Jack Painter wrote:
"clvrmnky" wrote

[...]

I get a bit of a boost in signal running off the wall-wart, but it is
actually more convenient for me to run off batteries. I end up moving
the receiver around quite a bit. I can pick the big blowtorches and the
relays from Sackville quite nicely off the whip, so I often listen to
them in the kitchen or when doing chores around the house. For "DXing"
I settle in near the door where I've got my antenna experiments going.

That's interesting OM, as it implies you are seeing a counterpoise effect of
rf-coupling across the windings of the dc transformer, or perhaps just the
secondary side? If a wal-wart helps complete an antenna, it would seem
there may be a design component missing from the antenna somewhere ;-)

I realized that my nomenclature was wrong. I should have said "bit of a
boost in amplitude" because this is what I'm /really/ hearing. I'm
guessing here that when running of the wall-wart we just have more
available current to draw on for RF and AF amplification, heterodyning
&etc. I have no proof that the signal coming into the set is any
better/stronger or that my antenna is more sensitive or selective.

That is, I don't recall the signal meter changing much when I switch
back and forth between battery and wall-wart. Although, quieter signals
will be uniformly attenuated (along with the noise) slightly when I
switch to battery.

Currently (with a random-wire antenna) the radio seems to not care what
is on the "ground" side. This is hardly scientific, but when I attach a
good number of feet (i.e., more than the length of the antenna) of
copper wire to the ground side of the antenna input (or touch it with my
hand) I get no noticeable change to tuned stations or between-station
noise. I may hear the slightest bit "tick" of noise when my finger
makes first contact with the case of the plug that goes to chassis
ground. Nothing obvious, however.