Re: 3-1000z tube coil survived 1st light.

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Randy by way of Terry Fritz <twftesla-at-uswest-dot-net>" <randy-at-gte-dot-net>

Well, from the pics, there certainly is forced-air to the tube-base, and it
appears a "chimney" is in place..... I'm betting if the plate is less than a
very
warm cherry-red in color, heat isn't a problem. I've seen ARRL amp designs
with NO forced-air or chimney, just a muffin fan across the envelope, for
tubes in this class. Again, visible heating of the plate is de riguer'<sp?>
for
these beasties, 24 X 7 X 365.

Randy

----- Original Message -----
From: Tesla list <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, January 16, 2001 8:12 PM
Subject: Re: 3-1000z tube coil survived 1st light.


> Original poster: "Dr. Duncan Cadd by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <dunckx-at-freeuk-dot-com>
>
> Hi Ross!
>
> Date: 16 January 2001 15:26
> Subject: 3-1000z tube coil survived 1st light.
>
>
> >Original poster: "Ross Overstreet by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <ross-o-at-mindspring-dot-com>
> >
> >Hi Guys,
> >
> >I managed to get the 3-1000z off to a reasonable start.
>
> What a beauty!
>
> I wouldn't be too concerned about not being able to keep
> your fingers on the glass!  An 833A has a glass temperature
> of around 145C between the seals at max power with forced
> air cooling, so you won't be able to touch the glass when
> the thing is working at full power.  Even a humble 6L6 will
> cook your fingertips just with the heater power alone.  I
> assume Eimac publish a recommended airflow - for the 833A
> it's 40cfm from a 2 inch diameter nozzle between the seals.
> An 8877 at 1,5kW output needs 54cfm, so this should give you
> a ballpark figure if the Eimac data isn't to hand.
>
> Neat coil!
>
> Dunckx
>
>
>