Hi Paul et al:
We have been down this track on this reflector before.
50Hz at 230 or thereabout volts is the common mains supply in the UK,
Australia, New Zealand and quite a lot of other places.
It is very rare to have significant problems with transformers rated for
60Hz and rated less then 2kVA or so when used on 50Hz.
To my knowledge Henry 2Ks, SB220s etc perforrm on 50Hz with the greatest of
ease. The Drake L series power supplies get hot, but I believe they do so on
60Hz, too, being a pathetic design and out of character with the Drake
tradition.
Stuff about needing 30% more iron is not based on fact.
If one has equipment where there is a key component eg a tuned choke which
is specific to 60Hz then of course there will be problems unless the system
is retuned.
To run a tuned choke supply on a different frequency means that the power
supply voltage will soar and regulation will be lost.
Operating the amp at the then available max will quite likely result in
overload of the entire system and the weakest link will probably fail.
In the case cited the part that failed was the power transformer, but the
fault was not the 50hz supply but the high vacuum between the ears of the
appliance operator who just plugged it in and blasted away without checking
to see what the plate voltage was doing.
We all make mistakes, but the serious mistakes are the ones we do not learn
from.
73
end
Barry Kirkwood PhD ZL1DD
Signal Hill Homestay
66 Cory Road
Palm Beach
Waiheke Island 1240
NEW ZEALAND
www.waiheke.co.nz/signal.htm
----- Original Message -----
From: Paul Christensen <paulc@mediaone.net>
To: Barry Kirkwood <bjk@ihug.co.nz>
Sent: Monday, 04 June, 2001 7:46 AM
Subject: Re: [AMPS] 50~ vs 60~ ???
> I agree Barry. I believe someone on this refelctor indicated that an
> approximately 33% increase in iron was required for for an equal VA rating
> from 60 ro 50 Hz. I wonder if Hypersil steel tape designs require the
same
> degree of added mass as does the traditional E-I core design? Neverthess,
> it would seem that the prudent amplifier manufacturer would foresee the 50
> Hz condition and factor it into his power supply calculations and
> design...if for no other reason than to establish a bit more reserve at 60
> Hz.
>
> 73,
>
> -Paul, W9AC
>
> ----- Original Message -----
> From: "Barry Kirkwood" <bjk@ihug.co.nz>
> To: "Vic Rosenthal" <rakefet@rakefet.com>
> Cc: <amps@contesting.com>
> Sent: Sunday, June 03, 2001 3:36 PM
> Subject: Re: [AMPS] 50~ vs 60~ ???
>
>
> >
> > It is most unusual for transformers of a size commonly used in the
amateur
> > service and rated 60Hz to "burn up" when used on 50Hz.
> > Worst case is usually poor regulation. If the 60Hz device "burns up" on
> 50hz
> > it was proably a very poor transfromer when used at 60Hz.
> > BTW if there are problems, they are usually with tiny transformers in
> > accessories, not linear amp power supplies.
> > 73
> > end
> > Barry Kirkwood PhD ZL1DD
> > Signal Hill Homestay
> > 66 Cory Road
> > Palm Beach
> > Waiheke Island 1240
> > NEW ZEALAND
> > www.waiheke.co.nz/signal.htm
> > ----- Original Message -----
> > From: Vic Rosenthal <rakefet@rakefet.com>
> > To: AMPS REFLECTOR <amps@contesting.com>
> > Sent: Sunday, 03 June, 2001 4:56 AM
> > Subject: Re: [AMPS] 50~ vs 60~ ???
> >
> >
> > >
> > > "A.AIMETTE" wrote:
> > > >
> > > > What happens when you operate a USA 60~ hi power amp on 50~? Does
the
> > > > filament voltage change? B+ voltage changes?
> > >
> > > It depends. Some transformers in US-made equipment are rated for
50/60
> Hz
> > and
> > > others are not. I used an SB-200 in Israel with no problems.
However,
> if
> > the
> > > transformer is not explicitly rated for 50 Hz., it can definitely burn
> up.
> > I
> > > recommend checking with the equipment manufacturer.
> > >
> > > 73,
> > > Vic, K2VCO
> > > Fresno CA
> > >
> > > --
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> > > Problems: owner-amps@contesting.com
> > >
> > >
> >
> >
> >
> > --
> > FAQ on WWW: http://www.contesting.com/FAQ/amps
> > Submissions: amps@contesting.com
> > Administrative requests: amps-REQUEST@contesting.com
> > Problems: owner-amps@contesting.com
> >
>
>
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