[CQ-Contest] LINE VOLTAGE & YOUR AMP??

[James W. Fisher, Jr.]

W5AJ wrote about communicating with his power company about line voltages. 
I have had an experience which may be of interest to other amplifier
owners.

My amplifier monitors line voltage  and other stuff and shuts itself off if
certain  limits are exceeded.  I found there was excessive voltage in the
middle of the night, and only in the middle of the night.  My power
company's nominal voltage is 240, and I had verified this voltage at the
socket before I first plugged in the amp  However,  my apmplifier  would
shut itself off during warmup periods around 3-4 am, and my admittedly
uncalibrated multimeter indicated voltages slightly in excess of 255 when
this had just occurred.  This problem never occurred during more normal
peoples' working hours--say, 7 am to 7 pm.  It did not always occur even in
the middle of the night.

My frequent and increasingly strident calls to the power company got
varying responses, including one customer rep who said in essence that
having no electricity constituted an emergency meriting after-hours service
but having excessive voltage did not.  I stated that having  no electricity
represented no threat to my amplifier, but too much was a threat not
covered by warranty. They then sent out a repair crew to check it about
midday and naturally the voltage was OK.

The power company eventually fiddled with the regulator several miles down
the line, saying they thought it might be sticking when it should be
adjusting downward  for lighter loads.  They then also kindly installed a
freshly calibrated line voltage chart recorder and left it with me for some
time.  The fix apparently did the job; the chart recorder showed
appropriate voltages and my amp (which had turned itself off 10 times) has
not had anything further to say on the matter.

One other customer on the line had been complaining about apparent
variations in voltage.

My comments to the power company:
o I was lucky my device had an internal monitoring system.  Otherwise, I
could have had shortened tube life or other problems and never known why.
o I was a number of miles from the regulator.  If the voltage was, say, 257
at my place, what was it next door to the regulator?

Since the voltage during the day was always OK, the only other way I might
have detected this problem would have been to monitor voltage continuously.
 I don't know how widespread this problem might be.

Jim Fisher
74237.2073 at compuserve.com








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