[Hallicrafters] HT-33A Fan Assembly Needed

[rbethman]

Regarding being "that close to RF".  Hooey!  Amp Supply made their amps 
using one of the high speed 4" muffins blowing across the 3-500Zs from 
the side, no enclosure to protect it, no chimneys on the tubes either!

They also used a resistor to switch in or out for "Lo / Hi" speed 
cooling.  The full legal limit output NEVER bothered the fan!

The SAME fan was used in an old Z-80 based Northstar Horizon Computer of 
OLD!

These are 120V fans.  AT&T used the same fans in some of their 
communications racks/equipment.  I've got a fan system from them that 
was headed for trash as upgrades were done.  That has been over ten 
years ago.

I put the whole frame in the window sometimes if we need to vent fumes 
from over zealous use of a cleaner.

They cool the finals VERY well! (In a commercially built amp.  I even 
run 25W AM in with about a 300W resting carrier out of the amp!)

Bob - N0DGN

On 4/16/2010 2:51 PM, Paul Kraemer wrote:
> Gary
> Kudos on the very nice find!
> WW Grainger has a nice selection of these shaded pole fan motors and high
> efficiency blades commonly used in small exhaust fans and range hoods. The
> old mounting centers were typically 2" which is now 1 7/8", other than that
> they are very close fit. I found one for an SB-200 linear. Motor plus blade
> were about $17. At the time I noticed that the same one also fit a Heathkit
> Warrior and CE 100V
> The 3.5" computer fans run off a couple diodes on the filament transformer
> do a nice job too but many of them don't like being that close to rf.
> Paul K0UYA
>
>
> ----- Original Message -----
> From: "garyislander"<gary at garyislander.com>
> To:<Hallicrafters at mailman.qth.net>
> Sent: Friday, April 16, 2010 10:37 AM
> Subject: Re: [Hallicrafters] HT-33A Fan Assembly Needed
>
>
>    
>> It is a bladed fan according to pictures I have seen of a HT-33A..
>>
>> I also found a SX-101A and a HT-32A in this same land fill.  Both units
>> were in rough shape, but after much work I got both to operate properly.
>> Both units were mice hotels, but they cleaned up pretty well.  Had to hand
>> make several adjustable coils in the HT32A, but thats the fun of restoring
>> these boatanchors.  Some rewiring, replaced some tubes and re-aligned as
>> close to spec. as possible.
>>
>> Have made about 300 contacts with this setup with very good reports using
>> a D-104.  Forgot what it is like to work a contest with a seperate
>> receiver and transmitter.   Maybe the amp can be saved and put into
>> operation.....this one could be a long shot!
>>
>> Gary K1MQ