[Boatanchors] AC inputs?

[rrkrr]

Eugene,
You did say there was a military connector for the power.  Perhaps this 
was for a military system where neither side of the power line was 
grounded, so you could have a fault on either side as Glen said.

Standard US house wiring has the neutral wire connected to ground at the 
circuit breaker / fusebox, so ordinarily the neutral wire at the service 
outlet is only off from ground by the voltage drop caused the the 
current flowing through the resistance of the wire between the outlet 
and the circuit breaker.  If there's nothing unusual in the primary 
circuit that would make the neutral line fuse necessary, I think I would 
bypass it.  That said, I don't know anything specific about your antenna 
coupler, so caveat emptor.

Here's a guess - since this unit is intimately connected with the 
antenna, is it designed to run from a balanced isolation transformer 
that would block differential mode noise on the power line?  Maybe the 
balanced input is part of a power line noise canceling scheme....

Bob K4ERR

eugene at hertzmail.com wrote:
> Hi Bob. Transformer primaries say 115 which is where its connected.  I
> think its right because the secondary says "0, 26v, 27v, 28v, 29v" for
> each tap and my ac voltmeter reads that when I connect it. 
>
> This unit is probably 80s TMC equipment. All solid state. For photos,
> see:
> http://www.hertzmail.com/tmc/
>
> Would you suggest I bypass the neutral fuse? 
> Eugene
>
>
> -----Original Message-----
> From: rrkrr [mailto:rrkrr at comcast.net] 
> Sent: Sunday, April 29, 2007 12:04 AM
> To: eugene at hertzmail.com
> Cc: boatanchors at mailman.qth.net
> Subject: Re: [Boatanchors] AC inputs?
>
> Eugene,
> How old is this piece of equipment?  Are you sure it is wired for 
> 115-125V where one side is "hot" and the other "neutral" and is not a 
> balanced 230-250V system where two sides are "hot"?
>
> In any case the present standard is that the neutral line should not be 
> fused, especially in a system where there is no ground wire.  This is so
>
> that a fault will always cause the hot side fuse to blow leaving the 
> other connected external wires at ground potential (or very nearly).
>
> Bob K4ERR
>
>
>
> eugene at hertzmail.com wrote:
>   
>> Hi All,
>>
>> Picked up a TMC antenna multi-coupler.  It has a 3-pin mil connector
>> that thanks to folks here, I have ordered the mating connector to make
>>     
> a
>   
>> cable. Question has to do with hot/neutral.
>>
>> So I was investigating how to wire this up and was trying to figure
>>     
> out
>   
>> which pin is hot and which is neutral.  Ground was easy to figure out.
>> Far as I can tell, it shouldn't matter on this which is which, but I
>> wanted to check with the experts. 
>>
>> The two wires (hot and neutral) come in from the connector. Each
>>     
> passes
>   
>> through a fuse (the neat kind that light up when the fuse has blown!)
>>     
> so
>   
>> far, since both sides are fused, I think I'm ok. Then the fused sides
>>     
> go
>   
>> to a DPST on/off switch. So far so good.
>>
>> Then these switched wires go directly to the primary of the power
>> transformer...So it seems to me that there is no specific hot and no
>> specific neutral.
>>
>> Can anyone confirm that some equipment is build this way and that it
>> might not matter?
>>
>> Thanks
>> Eugene
>> _______________________________________________
>> Boatanchors mailing list
>> Boatanchors at mailman.qth.net
>> http://mailman.qth.net/mailman/listinfo/boatanchors
>> ** List Administrator - Duane Fischer, W8DBF/W9WZE **   
>> ** For Assistance: dfischer at usol.com **         
>> $$ For vintage radio info, see the HCI web site $$      
>> http://www.w9wze.org    
>>
>>
>>   
>>     
>
> _______________________________________________
> Boatanchors mailing list
> Boatanchors at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/boatanchors
> ** List Administrator - Duane Fischer, W8DBF/W9WZE **   
> ** For Assistance: dfischer at usol.com **         
> $$ For vintage radio info, see the HCI web site $$      
> http://www.w9wze.org    
>
>
>