Along the same lines (I think) I note that more and more desktop computers have gotten away from small fans (i.e. 80 mm) and are using large fans (120 mm) and running them at slower speeds, all in the name of reduced noise.
Hopefully, Carl, you will be able to come up with a way to mechanically isolate the fan from the radio (David's rubber feet should do the trick) so you don't have that vibration driving you nuts. Good luck. 73, Eric KA8FAN ________________________________ From: David & Chris Drake <dra...@psci.net> To: gypsym...@aol.com; Drakelist@zerobeat.net Sent: Wednesday, February 11, 2009 4:14:44 PM Subject: Re: [Drakelist] cooling fan noise Carl, I just installed a 24v EBM-Pabst fan on the back of my TR7. Getting 12v out of the radio to run at about half speed. I then put a 2w 80 ohm resistor in series to slow the fan down more yet. This is the third try at fans, and its now nearly undetectable, but moves enough air OUT of the radio for adequate cooling. On my TR4C, I have a 12v fan with 4 of the little screw on drake feet like was used on the rear of radios to cushion and elevate the fan slightly above the top. I position it above the final cage. You could do the same thing with a TR7 or any tube radio. I have a dual set in a frame I made sitting on top of my L4B and the L4PS. Works great. David Wd9cmd ----- Original Message ----- From: gypsym...@aol.com To: Drakelist@zerobeat.net Sent: Wednesday, February 11, 2009 12:11 PM Subject: [Drakelist] cooling fan noise Hello to the group, Am working with my TR 5. Initially used a R.S. fan but was way to noisy. Read the archives. Evan K9SQG said he used 220 V. ...soo A Boxer 230 V. with ball bearings "Pewee" starts and runs fine. Still to noisy. Made neoprene washers for the metal to metal mount...no help. I tried closed cell foam pads under the chassis feet...no help. NOTED that in open air on a dining room table that it was quiet when sitting on a bamboo placemat. I am using on a desk top, with a shelf for other equipment about 6 inchs up..... Echo chamber no..because if I lift it up... QUIET Anyone with any thoughts ? Carl Hibbard WD8NHK ________________________________ Nothing says I love you like flowers! Find a florist near you now. ________________________________ _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
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