[Heathkit] re off topic i think

Sun, 29 Feb 2004 14:09:58 -0500

I would like to mention,
I substituted the 5U4GB, in my Eico 720 and also my 723, the height of
the tub depends on the type of 5U4 you have available. They work great
no problems so far more than 5 years now.

Jim
WB2FCN
http://eshop1.chem.buffalo.edu 

Tom N�JMY - AAR7FV wrote:
> 
> The good ol' Eico 720 xmtr used the 5AR4 as well but for a different reason.
> The 5AR4 is high enough power, but still short enough to fit in the low
> profile cabinet.  5U4 wouldn't fit!
> 
> 73,
> Tom----- Original Message -----
> From: "Murray Grandy" <[email protected]>
> To: "heathkit list" <[email protected]>
> Sent: Sunday, February 29, 2004 10:31 AM
> Subject: [Heathkit] re off topic i think
> 
> > It's amazing what you miss when you're trying to go the cheep route. Of
> > course I am aware of these differences and they make sense. Just didn't
> > think. Guess that is why 5AR4's sell for several times the cost of 5U4's
> and
> > other similar rectifiers. I was going to use the 5AS4 in a Dynaco ST-70.
> > Guess I will look for the real thing. Thanks to all for the great info.
> > Murray
> >
> ****************************************************************************
> > ***********
> > The 5ar4 cathode is indirectly heated - meaning it takes 15-30 seconds to
> > start working - the 5as4 filament is the cathode - heating up in a few
> > seconds.  5ar4 is a good idea as the other tubes in the piece of equipment
> > have warmed up and will be ready to draw current when the rectifier warms
> > up.  The prevents the high voltage from attempting to rise to a much
> higher
> > value as it would with a directly heated rectifier or solid state diode -
> > therefore stressing the filter condencers until the other tubes have
> warmed
> > up sufficently to draw current.
> >
> > Regards,
> >
> > Bill Riches, WA2DVU
> > Cape May, NJ
> >
> >
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