[Amps] Clipperton-L question

[Jim Thomson]

Date: Thu, 12 Sep 2013 18:55:57 -0400 (EDT)
From: Louis Parascondola <gudguyham at aol.com>
To: gudguyham at aol.com, ka4inm at gmail.com, amps at contesting.com
Subject: Re: [Amps] Clipperton-L question

I meant to qualify my statement that using an inferior switch for the job is a bad idea as we can now see.  I've changed switches in Clippertons that were arcing a few times before they broke down bad enough to blow fuses.  Swan and Dentron in the 2000L used 12v relays to switch secondary HV and eventually the contacts pit badly.  Just about the only company that did a similar switching arraignment  that did it with proper equipment was Henry amps.

##  The henry radio 8 k ulta and also 3 k ultra  both used a spdt  vac relay.    Problem is they are not latching types.   They have to be wired so the default, with no coil current, is LOW V position.  Another issue when
using vac relays is you can only toggle between two  taps.   Now with more vac relays, no big deal.   A single wafer model 85 or 88-90-92 switch  wont break down,  succumb to corona or any other fubar.
You can also get corona shields for any of the switchs..provided they are single rotors.    RF switchs usually use multiple pole rotors....  IE..shorting switch. 

##  In actual usage,  I havent see corona effects..sans corona shields, on any 85-88-90-92  switch..whether  RF  or  B+  across the contacts. 

##  Either way... depending on the amount of C  used in the B+  supply,  you will  still get a big sec surge when switching from  a low tap to a higher tap.   Bad enough switching from a 4800 tap to a 5200 tap...
and even worse when toggling from a 2300 tap to a 5200 tap.   No big deal... just shut off the 240AC, switch taps, turn it back on..and let the step start  do its thing. 

##  sure, you can also change primary taps...provided  you have an appropriate sized primary tap switch.   I bought some surplus ohmite, double wafer, 100A per wafer, tap switchs..and paralleled the wafers.
They actually still make em.... in 1-2-3  wafer configs.   My 240 is all over the map, varying from night to night..and also  during the same night.  Seen it as high as 247.2  and low as 233.   No big deal, as I have primary taps
at  198-208-218-230-240-250. 

later... Jim   VE7RF