On 8-May-2004, "Jack Painter" wrote:

experiment) from keeping all of that available voltage (0v felt on neutral)
as long as the current did not exceed 15a or whatever your breaker allows.
Obviously a 100w light bulb shorted to ground would blow instantly, before
the breaker could protect it..

Uhhhh, No! The most voltage from either wire of a 117 Volt household circuit to any other wire or
to any made ground is 117 Volts. The light bulb would be quite happy to glow at something up to its
normal brightness for as long as you wanted. Now if the grounded conductor was somewhere out in a
field instead of being the local house ground, then the light bulb would not receive the full 117
Volts, because of the resistance of the intervening earth, and would be unhappily dim.

As for the Original Poster's question about the 117N7 transmitter, they were inherently unsafe
unless built on a chassis insulated from the antenna and ground. The usual method was to use a
floating negative (not connected to the metal chassis) inside the transmitter. The antenna was
isolated from the 117 VAC circuit by the DC blocking capacitor to the pi network. The external
antenna ground connected to the chassis. The cathode of the tube and the negative side of the DC
Power Supply had to be bypassed to the chassis through a large capacitor for an RF ground. In no
case should the neutral conductor be left unconnected, even if a water pipe ground could carry the
neutral current. That would leave 117 VAC on the chassis (and the metal shafts of tuning
capacitors.. and the ON/OFF toggle switch) if the ground wire came loose.

I grew up in that era too and got many shocks from AC-DC radios.

Ken Fowler

Thanks Ken, you're right. I was thinking that without current-sensing
abilities on the neutral side of the circuit that it might allow the full
available current, but of course a light bulb would just work as a light
bulb, drawing no more power than it was designed for! I feel a little dim
myself right now ;-(

Jack

"Ken Fowler" wrote in message
...

On 8-May-2004, "Jack Painter" wrote:

experiment) from keeping all of that available voltage (0v felt on
neutral)
as long as the current did not exceed 15a or whatever your breaker
allows.
Obviously a 100w light bulb shorted to ground would blow instantly,
before
the breaker could protect it..

Uhhhh, No! The most voltage from either wire of a 117 Volt household
circuit to any other wire or
to any made ground is 117 Volts. The light bulb would be quite happy to
glow at something up to its
normal brightness for as long as you wanted. Now if the grounded
conductor was somewhere out in a
field instead of being the local house ground, then the light bulb would
not receive the full 117
Volts, because of the resistance of the intervening earth, and would be
unhappily dim.

On 9-May-2004, "Jack Painter" wrote:

Thanks Ken, you're right. I was thinking that without current-sensing
abilities on the neutral side of the circuit that it might allow the full
available current, but of course a light bulb would just work as a light
bulb, drawing no more power than it was designed for! I feel a little dim
myself right now ;-(

Jack

No Problem. It's a good thing to point out that a light bulb with short leads can be used as a good
test device for the effectiveness of a circuit ground or to identify the hot (ungrounded conductor)
from the neutral (grounded conductor).
-ken-

Maybe it is time for the experiment.


Bill

Ken Fowler wrote:

On 9-May-2004, "Jack Painter" wrote:

Thanks Ken, you're right. I was thinking that without current-sensing
abilities on the neutral side of the circuit that it might allow the full
available current, but of course a light bulb would just work as a light
bulb, drawing no more power than it was designed for! I feel a little dim
myself right now ;-(

Jack

No Problem. It's a good thing to point out that a light bulb with short leads can be used as a good
test device for the effectiveness of a circuit ground or to identify the hot (ungrounded conductor)
from the neutral (grounded conductor).
-ken-