[AMRadio] 220 vac line

[manualman at juno.com]

I believe they did the same thing with the Johnson Thunderbolt and KW
amplifiers.

Pete, wa2cwa

On Wed, 27 Jul 2011 07:55:19 -0400 "Paul Christensen" <w9ac at arrl.net>
writes:
> > Electric kitchen ranges with 3-wire plug run on 240V, with the 
> neutral and
> > ground bonded together.  So does the BC1-T broadcast transmitter 
> in 
> > original
> > configuration.
> 
> And, so does the Alpha 70 and 77 series of HF amps -- along with 
> some of the 
> big Henry models.  In the case of each amp, neutral is used to run a 
> 120VAC 
> blower.  In the Alpha 70/77 they made it easy to separate neutral 
> from 
> chassis ground by cutting a jumper on the Cinch-Jones power plug.  
> The 
> change doesn't even occur inside the amp.  I ran 4-wire, #8 AWG 
> between the 
> panel and the shack, terminating into a 30-amp twist-lock 
> receptacle.  My 
> only dilemma is that I have one receptacle and four amps, requiring 
> a 
> physical change of the power plug when changing between amps.  No 
> really 
> good solution comes to mind, mostly for convenience reasons.
> 
> At the time these devices were manufactured, it was acceptable to 
> join the 
> chassis to the neutral connection.  40+ years ago, the NEC may have 
> strictly 
> forbidden this practice, but the NEC is a premise wiring standard -- 
> not a 
> products wiring standard.  So, perhaps the root of this really goes 
> back to 
> what was allowed  under UL guidelines at the time.  Well after 1970, 
> the 
> manufacturers seem to have gotten the idea and had found a means to 
> better 
> utilize the blower between 120VAC and 240VAC service.
> 
> Paul, W9AC