I use German EBM blowers for my YC-156 amplifiers and they are very quiet
even before I add noise reduction Audio foam insulation to the cabinets and
Blower body itself.You can find Audio cabinet foam insulation on Ebay,etc..
one side has adhesive so it`s very easy to apply to your
cabinetry.Another thing is to be sure your blower wheel is balanced
for zero vibration and add filtering to the air input.Good luck and I hope
you find a solution for your noise issues...73 All,Jim..K7RDX..
On Fri, Nov 1, 2019 at 1:13 PM AJ <iamfromcanadaalso@gmail.com> wrote:
> 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@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@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
>
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