[TenTec] Quieting fan

Tue Jan 20 14:52:16 EST 2004

Thanks for clarity on the Beryllium, Dave.  I couldn't remember
the details - just the poison bit.

The HA-14 didn't have a tuned input.  I think the SB-200 did.
It's been 30 years since I built one so I'm not sure.
I don't know if the SB-230 had a tuned input or not.  I had a
chance to buy one reasonably cheap recently and though tempted,
didn't follow through due to the cost of replacement tubes and
worse yet, the scarcity of the darn things.

I've been searching for an HA-14 for about 20 or 25 years.  Never
came across one over here.  In the meantime, with transistor
Amps, the need has gone away.  If I ever build another amp (like,
when I eventually retire), it will have 2x (or maybe 3x) 572B and
then a huge fan running at highly reduced voltage.  Should be
able to get it below the ambient noise level in the shack.

...73 Rick

-----Original Message-----
From: tentec-bounces at contesting.com
[mailto:tentec-bounces at contesting.com]On Behalf Of Dave Edwards
Sent: Tuesday, January 20, 2004 2:04 PM
To: tentec at contesting.com
Subject: Re: [TenTec] Quieting fan

Yikes!!!   A poison tube???
Spewing out toxic RF??
Actually, it was the heat sink conduit...a Beryllium block that
is toxic if
shaved, sanded, or otherwise "messed" with.
The HA14 (Compact Kilowatt) is an SB200 with an external power
supply. It is
small!!
Also quiet because of no fan. The difference between the HA14 and
the SB230
is that the 230
had a quiet system of cooling. The HA14 had no cooling.  It gets
pretty hot,
and should have a 8 or 9 watt fan on top of it. The HA14's
filaments are in
series vs parallel for the SB200.
Both amps work great. I wish the idea behind the SB230 could have
been
pursued. I don't think it is impossible to have silent operating
amps.
...Dave
----- Original Message -----
From: "Rick Westerman" <Rick at dj0ip.de>
To: <tentec at contesting.com>
Sent: Tuesday, January 20, 2004 12:46 AM
Subject: RE: [TenTec] Quieting fan

> It was the 70's and the mobile amp was (as I recall) the HA-14
> using 2x 572B's.
>
> The problem with the SB230, apart from the tube being highly
> poisenous, is simply the cost of a new tube and the extreme
> difficulty of locating one anyway.  Otherewise it was a good
amp.
>
> 73
> Rick
>
> -----Original Message-----
> From: tentec-bounces at contesting.com
> [mailto:tentec-bounces at contesting.com]On Behalf Of Ron Notarius
> WN3VAW
> Sent: Tuesday, January 20, 2004 5:28 AM
> To: tentec at contesting.com
> Subject: Re: [TenTec] Quieting fan
>
>
> Wasnt the SB-230 the allegedly mobile linear, or am I thinking
of
> a
> different one?  Also, I seem to recall it from the era of the
> late 60's
> and/or '70's, not the '80's.
>
> 73, ron wn3vaw
>
> "I'd give real money if he'd just shut up!"
> Dr. Leonard McCoy, "Start Trek VI:  The Hills Are Alive with
the
> Sounds of
> Klingons"
>
> ----- Original Message -----
> From: "Dave Edwards" <kd2e at comcast.net>
> To: <tentec at contesting.com>
> Sent: Monday, January 19, 2004 11:01 PM
> Subject: Re: [TenTec] Quieting fan
>
>
> Steve... My 1KW Heathkit SB230 from ...I guess the early '80s
> uses a heat
> sink cooled tube.
> A single 8873, it uses no fan...just a heat sink on the back
and
> does an
> easy 600 watts out.
> Totally quiet!!
> ...Dave
> ----- Original Message -----
> From: "Steve Weber" <kd9bo at mac.com>
> To: <tentec at contesting.com>
> Sent: Monday, January 19, 2004 8:17 PM
> Subject: Re: [TenTec] Quieting fan
>
>
> > Dear fellow cult-of-the-cosmic-orange-dot members,
> >
> > Would it be possible to surround the tube with a finned heat
> sink
> > similar to those used on some transistors?  What about
ducting
> that
> > discharges by the tubes or even surrounds the tubes?  Having
> never
> > seen the inside of this amp, I may be simply blowing hot air.
> (ouch)
> >
> > KD9BO Steve
> >
> > >Hi Gary,
> > >
> > >The original post was in regards to an amplifier which uses
a
> pair
> > >(maybe 4) 572B triodes. These are glass envelope tubes.
While
> it may
> > >be possible to precool the air using a chilled water system,
> there
> > >would still be a need for a fan to blow the air across the
> tube
> > >envelopes. Perhaps the air flow rate could be reduced and
the
> fan
> > >could be quieter using cooler air.
> > >
> > >There are water cooled tubes and conduction cooled tubes,
> which
> > >could reasonably incorporate a liquid heat transfer media.
In
> the
> > >case of glass envelope tubes I really see no reasonable way
> that
> > >water cooling could be applied.
> > >
> > >DE N6KB
> > >
> > >
> > >
> > >
> > >_______________________________________________
> > >TenTec mailing list
> > >TenTec at contesting.com
> > >http://lists.contesting.com/mailman/listinfo/tentec
> >
> >
> > --
> > Steve Weber
> >
> >
> > No trees were killed in the sending of this message. However
> > a large number of electrons were terribly inconvenienced.
> >
> > *******************************
> >
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