[Hallicrafters] Hallicrafters HT-33A

[Glen Zook]

Glen, K9STH

Website:  http://k9sth.com


--- On Thu, 9/18/08, Roger (K8RI) <hallicraftersgroup at rogerhalstead.com> wrote:

> From: Roger (K8RI) <hallicraftersgroup at rogerhalstead.com>
> Subject: Re: [Hallicrafters] Hallicrafters HT-33A
> To: "Carl" <km1h at jeremy.mv.com>
> Cc: hallicrafters at mailman.qth.net, gzook at yahoo.com
> Date: Thursday, September 18, 2008, 11:09 PM
> Carl wrote:
> > There are several choices from the USA, China, and
> Svetlana depending 
> > on work involved and acceptable expense.
> >
> > 4CX1000A, 4CX1500A & B, 4CX1600B, 5CX1500A &
> B.
> >
> > There are also numerous Russian triodes as well as the
> USA 3CX1000A7 
> > and the 8877.
> >
> If you hunt there are PL-172s and 8295A out there, BUT it
> may take some 
> work to find a good one. Most, or many of the PL172s are
> gassy.  If the 
> guys would stick them in the amps and let them cook every
> few months 
> there'd be more good ones.  8295A tubes are the most
> desirable and 
> although the PL-172 has a "/8295A" on it a true
> 8295A is a ceramic and 
> metal Pentode while the PL172 is glass and metal. The 8295A
> is about a 
> 1/2" taller than the PL172 but there's plenty of
> room in the HT-33A and 
> B. If you can find either tube guaranteed it's worth a
> small fortune and 
> considerably more than the amps sell for with the 8295As
> going for about 
> twice the price of a PL172.  Most pull out 8295As
> aren't very expensive, 
> nor are the PL172s. The problem with those 172s is as I
> stated before, 
> so many of them are gassy.  I've picked up two HT-33Bs
> over the years 
> for about $300 to $350.
> 
> I don't know of any that are direct "plug-in
> replacements. The 8877 
> although rated at 50% more power is considerably smaller
> than the 
> PL172/8295A and takes a much better cooling arrangement
> than what the 
> HT33 A and B has. That was one of the nice things about the
> original 
> tubes. They only needed a fan blowing air up around the
> tube and 
> socket.  That fan didn't even have a shroud.
> 
> I don't know about the other tubes but converting to an
> 8877 takes some 
> physical mods with a bit of care to make it look good.  I
> think the 
> others are also smaller in diameter.
> 
> I don't know about the "A" model, but the
> "B" easily puts out the legal 
> limit with my voice characteristics even with that 110 volt
> primary.  It 
> does take a good hefty (short) run of #10 for the AC power
> if you don't 
> want to see excessive voltage drop.
> 
> 73
> 
> Roger (K8RI)
> > Carl
> > KM1H
> >
> >
> > ----- Original Message ----- From: "Glen
> Zook" <gzook at yahoo.com>
> > To: <hallicrafters at mailman.qth.net>
> > Sent: Thursday, September 18, 2008 8:31 PM
> > Subject: [Hallicrafters] Hallicrafters HT-33A
> >
> >
> >> I just obtained a Hallicrafters HT-33A linear with
> a bad final 
> >> (PL-172).  I believe that there have been some
> articles on changing 
> >> out the tube with a more readily available tube. 
> However, I have 
> >> been looking on the Internet and just cannot find
> any.  In this case 
> >> google is not my friend!
> >>
> >> Does anyone have a suggestion as to where I might
> locate this 
> >> information?
> >>
> >> Glen, K9STH
> >>
> >> Website:  http://k9sth.com
> >>
> >>
> >>
> >>
> ______________________________________________________________
> >>
> >
> >
> ______________________________________________________________
> >
> 
> ______________________________________________________________