[R-390] Variacs

[rbethman]

John,

	The power companies are sort of caught in a Catch-22.  The days when these old boatanchors were made and originally used, the cost of producing power was a LOT cheaper.  Remember the gas prices in the '60s?

	The problem they face is the increased cost of production AND the LOSSES caused by transmission and distribution.  One method of reducing the losses caused by transmission and distribution is to increase the voltage, thereby lowering current.  Remember that power losses are based on the power formula P=I**2 x R.  By reducing the current they reduce their loss in transmission and distribution.  They waste less power in the transmission lines.  This is NOT a trivial loss.

	I was involved in power line transmission and distribution preventative maintenance.  The best way to find problems is to perform infrared scans of the lines, connections, and transformers.  For the best results these scans are performed during the summer months when loads are at the highest, and are also done at night.

	You would be amazed what can be seen.  Our scanners were originally manufactured by either Motorola or Magnavox (my memory doesn't recall like it used to.)  In any event, these devices could spot  a bird at over a quarter mile.  We would find some spring loaded in-line splice connectors that had developed a poor connection from quite a distance.  We photographed the bad spot through the scanner, and return during daylight hours and photograph the bad spot during the day so they could easily locate the problem.  Copious notes and logging are made during the entire process, to ensure the repair crew can locate the problem.

	I've unlocked the cover to the enclosed pad mounted transformers  to scan them, only to find there was NO need to scan it.  The connections were glowing a medium red in the dark.  I remember one in particular.  Not only was it glowing, it had been installed when the use of aluminum power lines was at its peak.  This one had a puddle of molten aluminum lying on the concrete pad.  Obviously this one was marked urgent!  It was repaired the very next morning.

	The whole purpose of the infrared scans is to reduce the expense of just waiting until it fails.  Once they have a failure, there is loss of equipment and labor costs.  

	As part of this progression to harness these expenses, our line voltages have risen over the decades.  I have a dedicated AC voltmeter plugged into my ham shack.  During the course of a 24 hour period, it has read as low as 122VAC and as high as 127VAC.

	Our old equipment was designed for anywhere from 100VAC to perhaps 115VAC.  My BC-610s transformers were designed for 100VAC input.  So with a 20%+ over voltage condition, I would expect their lifetime to be reduced.  This is why there is so much discussion over methods to reduce the voltage applied to this equipment.

	First, the components are already aged.  Second, they are being subjected to voltages from 10% to 20+% over their original ratings.

	Roy Morgan, K1LKY, has given several great treatises regarding proper variac connection, and fused plugs, not to mention providing us with the color code equivalents of the Asian power cords to American standard color codes for wiring.

	There is NOTHING wrong with the use of an ADEQUATELY rated variac to protect our treasures.  Neither is there anything wrong with adding a "bucking" transformer.  These devices allow us to run this aged pieces in a modern world, and extend their life spans.

Bob Bethman - N0DGN

+-------------------------------+----------------------------------+
| N0DGN AMRadio Manassas, VA    |          Home Builder            |   
+-------------------------------+----------------------------------+
| Bob Bethman                \\\|///     " The absence of a danger |
| rbethman@comcast.net      \\ ~ ~ //      signal does *NOT* mean  |
|                           (/ @ @ /)      that everything is OK " |
+-------------------------oOOo-(_)-oOOo----------------------------+
|                                                                  |
|        2 BC-610s w/BC-614s, 2 R-390As - 1 Collins 1 Eac          |
|         Heathkit DX-60, Apache, Mohawk, SX-101, HT-32A           |
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jlap1939@yahoo.com wrote:

>My Friends,
>
>Have got a lot of "no no no" from many...who pointed
>out your variac is probably not right anyway...
>
>So,, What is the correct voltage to be applied to the
>390 series??? What are they supposed to run on..Seems
>I read it, but can't find it right now...
>
>Why is control ever needed, and (subject to everyone
>getting mad at this old man again), why is it that
>way? How much variation is there, and how does it vary
>throughout our fair land..Why can't the power cos. get
>it right, or do they even want to, and how much
>additional (we don't know about) does it cost you and
>me,, and...do they care if the power is "right"..? Wht
>is "right" and how can the average person ever know??
>(Maybe its' like the pharms...we don't "understand"
>the cost of R&D, and the expense of operating, which
>is why some pills cost $40 bucks each..)(Give me a
>break...)
>
>If all is not as it should be, why do they get all
>those hugh tax breaks, and raised rates, when they
>claim they have to "build" again...
>
>Does Europe or the East run any better, (or different)
>
>Put another way, can I take my R-390 with me to
>Mongolia??
>
>Or Iraq?
>
>My Regards,   John  (JLAP)
>  
>