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Re: [Amps] 234v - to convert or not?

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Subject: Re: [Amps] 234v - to convert or not?
From: "Gary Hinson" <>
Date: Mon, 15 Sep 2008 19:07:56 +1200
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> A 'stiff' HV is a very good thing for dynamic loads such as 
> SSB.  It starts with the AC mains.  

Agreed ... So why not measure the input mains voltage at or near the same
socket and see how if performs when keying the amp?  In my last house, I
found I'd lose about 10V from 240V when the amp was just on/idle, and a
further 10V or so while transmitting at about 500W.  The problem there was

1) A rural mains supply from an (inadequate or faulty?) 10kV pole
transformer and about 2 hundred yards of 240V 3-phase wiring to the house,
hence all the house lights dimmed/flickered annoyingly when I transmitted.  

2) Poor quality wiring - ZL mains sockets are wired as fused spurs rather
than ring-mains, with strict limits on the number of sockets per spur (that
some idiot had ignored!).

I found a nice 250V AC meter on TradeMe, our local ZL equivalent of eBay,
mounted it in a wooden box and put it in the shack to monitor things.  It's
worth it for the feel-good factor.

Running the station on a nice 3kVA inverter genny gave no appreciable sag at
all.  Needless to say, I discovered that when the rural mains failed
altogether one evening during CQ WW CW 2007 ....

If a saggy 120V supply is your problem, the 240V circuit should at least
halve the sag and may cure it if the 240V circuit is otherwise unloaded and
uses better wire.

Thanks though for the tips about testing individual HV caps by warmth and
charge current.  I'm not rich but have previously taken the conservative
view that a duff cap is a sign that the others will probably fail before
long, so change the lot while the cover's off and iron's hot.  Those of us
familiar with Sod's Law *know* that if another fails, it will produce a
spectacular bang and release the smoke just as you're chasing an exotic
double mult while doing rather well in a contest ...

Gary ZL2!FB

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