I am no guru on transformers, but would be surprised if 50-60 Hz shift
needed anything like 30% more iron for equal performance.
Is there someone on the reflector who has transformer design tables/software
that has primary supply frequency as a variable and can give us an answer?
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: Barry Kirkwood <bjk@ihug.co.nz>
To: Paul Christensen <paulc@mediaone.net>
Cc: <amps@contesting.com>
Sent: Monday, 04 June, 2001 8:35 AM
Subject: Re: [AMPS] 50~ vs 60~ ???
> 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
> > > >
> > > > --
> > > > FAQ on WWW: http://www.contesting.com/FAQ/amps
> > > > Submissions: amps@contesting.com
> > > > Administrative requests: amps-REQUEST@contesting.com
> > > > 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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