As to you lamp dimming, I do not know what the wiring capacity of
your
house was but the transmitter was being fed by the same mains drop
from
the street as the lamp. That is, IMO, the most likely cause of the
dimming. Just my guess.

Dave WD9BDZ

=======================================
Dave,

The mains supply from the road was capable of 50 kilowatts without
excessive volts drop. For a few years it was used for electric
cookers, several 3-bar central heating radiators, etc., without
problems. Far more than the TS-520 with an RF power output of 100
watts.

There may been something very peculiar with the 60-watt bedroom
filament lamp which caused it to cool off when both RF plus 50Hz power
currents flowed through it. I didn't try another bulb.

There may have been incorrect house wiring such that the only power
point in the bedroom, used for the transmitter, was connected, by
mistake, to the lighting circuit. But even then, the lighting circuit
should have been capable of withstanding the load of the transmitter
without much of a voltage drop. Shortly afterwards I moved the shack
downstairs into the garage. At the time I never checked house wiring
and later on the family sold the house and moved. The new owner was
not a radio amateur.
----
Reg, G4FGQ.

In article ,
Reg Edwards g4fgq,regp@ZZZbtinternet,com wrote:

There may have been incorrect house wiring such that the only power
point in the bedroom, used for the transmitter, was connected, by
mistake, to the lighting circuit.

That would be my guess. Here in the US, at least, it's quite common
for a single 15- or 20-ampere circuit to be used for both wall
outlets, and lighting circuits, in one or more rooms. There's nothing
in the electrical code which requires separation of these sorts of
loads... and in fact I seem to recall a clause which actually forbids
"one outlet per circuit" branches, for some reason.

But even then, the lighting circuit
should have been capable of withstanding the load of the transmitter
without much of a voltage drop.

It doesn't take all that much of a drop in voltage to result in a
visible change in the brightness of an incandescent-filament light.
According to one site I've found, light output is roughly proportional
to the voltage raised to a power between 3.1 and 3.4. A 5% drop in
voltage would thus result in a decrease in light level of more than
15%, which would be pretty easy to notice.

If you were transmitting 100 watts CW key-down, I'd guess that your
transmitter was probably drawing at least 300 watts from the
mains, and perhaps rather more depending on its design.

Add a few more likely or possible elements e.g. a linear power supply
which tends to draw most of its current from the mains during the
voltage peaks (and thus causes a disproportionate amount of voltage
sag on the lines during those peaks), insufficiently-thick house
wiring in the walls, and perhaps a slightly loose or corroded
connection to one of the outlets or switches or breakers, and I can
well believe that keying a 100-watt CW transmitter could cause enough
voltage drop to result in visible dimming of the lamp bulb.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Dave Platt wrote:

It doesn't take all that much of a drop in voltage to result in a
visible change in the brightness of an incandescent-filament light.
According to one site I've found, light output is roughly proportional
to the voltage raised to a power between 3.1 and 3.4. A 5% drop in
voltage would thus result in a decrease in light level of more than
15%, which would be pretty easy to notice.

If you were transmitting 100 watts CW key-down, I'd guess that your
transmitter was probably drawing at least 300 watts from the
mains, and perhaps rather more depending on its design.

Add a few more likely or possible elements e.g. a linear power supply
which tends to draw most of its current from the mains during the
voltage peaks (and thus causes a disproportionate amount of voltage
sag on the lines during those peaks), insufficiently-thick house
wiring in the walls, and perhaps a slightly loose or corroded
connection to one of the outlets or switches or breakers, and I can
well believe that keying a 100-watt CW transmitter could cause enough
voltage drop to result in visible dimming of the lamp bulb.

A friend of mine back in the 70's had me come over to listen to his new
stereo. It was a Phase Linear system as I recall. The speaker cabinets
had 9 components each in them. We put "Hall of the Mountain King" on
the turntable and turned up the level to the point just before it began
to distort. The power amp was pretty substantial and I noticed the
lights were dimming to the music. I went outside and could see the
power meter change speed in time to the music. And this was in an
industrial building. That was the loudest home stereo system I ever
heard. Probably the best sounding as well.

ac6xg

Reg;

As I said it was my guess. That's what you get for guessing. It would
seem that your house has sufficient capacity to carry a 60 watt light
bulb and a 100 watt transmitter.

If you ever find out what happened let the group know.

Maybe I'll meet you on the air some day.

Dave WD9BDZ


Reg Edwards wrote:

As to you lamp dimming, I do not know what the wiring capacity of

your

house was but the transmitter was being fed by the same mains drop

from

the street as the lamp. That is, IMO, the most likely cause of the
dimming. Just my guess.

Dave WD9BDZ


=======================================
Dave,

The mains supply from the road was capable of 50 kilowatts without
excessive volts drop. For a few years it was used for electric
cookers, several 3-bar central heating radiators, etc., without
problems. Far more than the TS-520 with an RF power output of 100
watts.

There may been something very peculiar with the 60-watt bedroom
filament lamp which caused it to cool off when both RF plus 50Hz power
currents flowed through it. I didn't try another bulb.

There may have been incorrect house wiring such that the only power
point in the bedroom, used for the transmitter, was connected, by
mistake, to the lighting circuit. But even then, the lighting circuit
should have been capable of withstanding the load of the transmitter
without much of a voltage drop. Shortly afterwards I moved the shack
downstairs into the garage. At the time I never checked house wiring
and later on the family sold the house and moved. The new owner was
not a radio amateur.
----
Reg, G4FGQ.