[Johnson] Modifications

[David Harmon]

Sherrill......I had this problem for awhile so I called the Edison folks
and they moved a tap on a transformer somewhere and now the voltage
varies from 115 to 118.
I just checked it and it is 118 right now. Usually, it is about 117.

I called them and complained that the 125 volts was overheating my
appliances and I was worried about fire etc. etc.
Make sure to mention that some of your appliances are rated for 115 max.

Regards

Dave Harmon
NSRCA 586
K6XYZ[at]comcast[dot]net
Torrance, Ca.

-----Original Message-----
From: johnson-bounces at mailman.qth.net
[mailto:johnson-bounces at mailman.qth.net] On Behalf Of Sherrill E.
Watkins
Sent: Thursday, July 22, 2004 8:44 AM
To: johnson at mailman.qth.net
Subject: [Johnson] Modifications

While we are discussing the pro and con of modifying classic equipment,
I
would like to state that some of the worst mods to do to classic
equipment is
to "solid state" the rectifier in the power supply. Unfortunately, this
is
easy to perform and the owner thinks he has "improved" the equipment
because
he has eliminated the rectifier tube. As explained previously in
articles
both in ER Magazine and the Old Timers Bulletin, the instantaneous
application of high voltage to the plate of a cold tube is a sure way to
destroy the tube. Also the solid state rectifiers increase the voltage
level
over the tube rectifier thereby causing the equipment to run hotter and
additional stress is placed on all of the components. Classic equipment
will
be damaged by the simple addition of solid state rectifiers and this
must
NEVER be performed. Also, classic equipment should be operated at a low
AC
line voltage and never at the high (120-125 levels) that is common
today. My
AC line voltage is 125 VAC and I understand this is quite common. For
older
equipment, 110 to 115 maximum would be better.-73- Sherrill W. k4own.   
Johnson mailing list
Home: http://mailman.qth.net/mailman/listinfo/johnson
Help: http://mailman.qth.net/mmfaq.html
Post: mailto:Johnson at mailman.qth.net