Quiet fan for my radio rack

If you elect to stay with fans, I had good luck with fans from acoustiProducts. (vendor

I used these for an OR application, trying to surgeons happy. They really were quieter that :Standard" fans.

Hear a few of the other manufacturers of reduced noise fans. IMHO, you really need to look carefully as the word quiet is very subjective.

Specifications for Panaflo and for Cormair Rotron Whispers are from

Specifications for NMB fans are from

Specifications for JMC fans are from

(good ANSI specs)

Noiseblocker fan specs from

but good luck finding the fans in North America.

Verax fan specs from shop.erfrier.net (German). I'm not sure if they are available in North America

Don

My experience is that ordinary fans run at reduced voltage are a great way to achieve quiet operation. The muffin fans in HP 264x CRT terminals ran virtually silent because HP operated them at 1/2 their nameplate voltage. I cool my old Heathkit boatanchor rig with a 12 V brushless DC muffin fan that is silent because I run it at 6 V. If your rack has 2 fans an easy solution is to simply wire them in series so they run at 1/2 voltage.

John

snipped-for-privacy@trail> I'm the new proud owner of a R-390A. (Some will say I'm a fool but

I'll agree with those some others. I used the mil equivalent of the R-390 when I was in the army in the late '60s in Germany, and I was stuck in a radio van on the back of a deuce-and-a-half. One consolation was that it didn't need much heating in the winter. I think the one I used was made by Motorola (or were they called Galvin?).

The radio site was right next to the 100kW diesel generators that ran

24/7, just to run all those toobs and air conditioning they needed to cool them. Nothing like a diesel generator to keep you awake all the time. The guy that bunked in my cubicle used to bring his (Dave Clark) earmuffs to bed with him, and sleep with them on. I never could figure out how he did that. ;-)

Use a filter to keep out the dust and reduce the noise.

Puff up your chest with pride and show off your R-390 boatanchor a couple times a year to your ham buddies, and the rest of the time use a Sony ICF whatever they are or similar general coverage receiver. ;-)

Mount a panel with a speaker in it in the rack, and connect the Sony to it, and your friends will never know. You'll have a lot lower electric bill this summer. :-))

So add a power resistor and drop the voltage until there is around 80V on the fan. It will move less air, but it will be very quiet.

--scott

--
"C'est un Nagra.  C'est suisse, et tres, tres precis."