Hi Bear,
I agree with Rich. Have a 220 myself, running almost full power after 30
years and original 3-500Z tubes - print NOT brown. If you want DIY chimneys
check
http://www.qsl.net/sdxa/homebrew.html Good luck!
73s Bert/VE3OBU
-----Original Message-----
From: amps-admin@contesting.com [mailto:amps-admin@contesting.com]On
Behalf Of Rich
Sent: Tuesday, December 03, 2002 3:41 PM
To: bearlabs@netzero.net; AMPS
Subject: Re: [Amps] Q: Chimneys for 3-500/4-400??
>Rich wrote:
>
>> >Rich wrote:
>> >
>> >> The work-around is to plagiarize the split-chassis transverse 6" fan
>> >> cooling system used in the Heath SB-220. The glass envelopes will run
>> >> way cooler, the amp will run quieter, and there will be no expensive
>> >> glass chimneys to buy.
>> >
>> >Nah nah... no thanks... I think the issue is the temperature of the
plate
>> >seal
>>
>> Would the fins on the anode/plate radiator work better with vertical
>> airflow or horizontal airflow?
>
>Depends upon the anode radiator design!
The fins extend horizontalally. If the fins extended vertically, they
could short against the top cover to the rf deck in many amplifiers.
>And the actual airflow and
>air temp before the air reaches the radiator/cap.
>
With an air-system socket + chimney, the air is preheated before it
reaches the anode's radiator cap. With the Heath method, the cap
receives cool air from the top of the horizontal fan in the same
direction as the cooling fins. Which seems better to you ?
>>
>>
>> >and the pins seals... I'd also prefer to have the same temp air on all
>> >sides of the tube.
>> >
>> >You should read the description of how HOT the Henry folks intend to run
>> >these
>> >tubes - *very*.
>> >
>> - Henry Radio, Co. uses glass chimneys with noisy centrifugal blowers.
>
>Right - I'm using a much quieter blower... the old one is long gone anyhow.
>
What does a manometer measure for the pressure drop across the socket?
>>
>>
>> >I've got a nice quiet "squirrel cage" fan for the bottom... expect it do
do
>> >way better than a muffin fan blowing across ... unless I'm missing
something
>> >about the Heathkit method?
>> >
>> I too scoffed at Heath's cooling method until I inspected the ink marking
>> on the glass envelopes after months of service. In a Henry 3K-A the ink
>> quickly turns brown, In my SB-220, I use Amperex 3-400Zs that were mfg
>> in 1967 and 1978, the ink is still green, the vacuum is good, and the
>> emission is still ok.
>
>You have to consider where the tube is being run... Henry, I suspect has
more
>*juice* to their supplies and probably a higher voltage - I think 3kv - as
>compared to the Heath.
>
The Henry 2K-4 and the Heath SB-220 both run c. 3kV. The 3K runs at c.
3.9kV. The latter puts out about 1.5db more suds.
>>
>> - To see the principle behind the Heath cooling system, light a candle,
>> hold a paper-towel roll's core-tube in front of the candle, and see if
>> you can blow out the candle.
>
>check the temperature on one side of the tube compared to the other...
>
If the ink gets toasted on the leeward side of the tube, there's a
cooling problem. It doesn 't.
>I'm sure you can blow air across the tubes, and have it work OK.
The color of the ink tells what's what.
>That's
>not the plan here and not how it's gonna get set up, so all that is rather
>moot... there's really no space for a transverse fan anyhow.
>
> Regards,
>
> _-_-bear WB2GCR
>
>>
>>
>> >I'm going PICKLE style! :- )
>> >
>> > _-_-bear WB2GCR
>> >
>> >>
>> >>
>> >> >
>> >> >Wondering if anyone can suggest an inexpensive source for chimneys
for
>> >> >the 3-400/4-400 type tubes? Especially cheap imports. :- )
>> >> >
>> >> >Or if anyone in the US has a pair they want to blow out...
>> >> >
>> >> >Or if anyone has a DIY solution...
>> >> >
>> >> > _-_-bear
>> >> >
>> >> >
>> >> >
>> >> >--
>> >> > _-_-bearlabs
>> >> >
>> >> > http://www.bearlabsUSA.com
>> >> > - Silver Lightning Interconnects & Custom Mods -
>> >> >
>> >> >
>> >> >_______________________________________________
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>> >> >Amps@contesting.com
>> >> >http://lists.contesting.com/mailman/listinfo/amps
>> >> >
>> >>
>> >> - Rich..., 805.386.3734, www.vcnet.com/measures.
>> >
>> >
>> >
>> >
>> >--
>> > _-_-bearlabs
>> >
>> > http://www.bearlabsUSA.com
>> > - Silver Lightning Interconnects & Custom Mods -
>> >
>> >
>> >_______________________________________________
>> >Amps mailing list
>> >Amps@contesting.com
>> >http://lists.contesting.com/mailman/listinfo/amps
>> >
>>
>> - Rich..., 805.386.3734, www.vcnet.com/measures.
>
>
>
>
>--
> _-_-bearlabs
>
> http://www.bearlabsUSA.com
> - Silver Lightning Interconnects & Custom Mods -
>
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
- Rich..., 805.386.3734, www.vcnet.com/measures.
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