[Amps] Quieting a Henry 2K Classic X

[AJ]

Hi Dennis

Why not use destructive interference, I did that back in school many
years ago.

I know so many people complain about fan noise etc when it can be
quelled.

Having said that you would need a small computer PI ?

Surprised none of the big amp / radio people have not done it as today,
with most of the equipment with computers on board.

Not so easy back in school . . .

AJ___ VE3HJ



On Fri, 1 Nov 2019 18:24:31 +0000 (UTC) Dennis W0JX via
Amps <amps at contesting.com> wrote:

> I have acquired a Henry 2K Classic X (domestic model) amplifier.  It
> uses a pair of 3-500Z's with chimneys. The very loud Dayton blower is
> driving me nuts. The Dayton blower is a model 2C915A, 3020 RPM, 230
> volts and 140 CFM. This same blower is used when the larger Plate
> transformer of the Export model is installed. I suspect that this
> blower is much larger than required when operating at 1500 watts on
> CW or SSB.
> 
> The standard blower in the 2K Classic was a Redmond 80239, 110vac
> unit. I cannot find the specs but I suspect it was around 90 CFM.
> 
> I have researched several articles on about using a pair of 3-500Z's
> and the reference material shows a need for about 13 cfm per tube or
> 26 cfm total. Likewise, a 3-1000Z requires 4 cfm. I am aware that
> back pressure requirements play into this also.
> 
> I read somewhere that it is possible to slow down a blower during
> standby periods by using a "split-capacitor" motor. Perhaps I have
> the phraseology wrong, but what I would like to do is have a blower
> slow down in speed significantly during listening periods and come up
> to speed during TX.  I operate mostly CW, little SSB, and do not use
> break-in/QSK so I could switch relays to do this.
> 
> My other alternative is to install a smaller blower and risk
> shortening tube life. I do not contest very much nor operate
> continuous modes such as RTTY and FT8 at full power.
> 
> Your ideas are welcome!
> 
> 73, Dennis W0JX
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps