Chemistry Electronics Services
ARCHIVE OF REPAIR TRICKS, USEFUL INFO, ETC.

INEXPENSIVE REPLACEMENT FANS "NMB" 3110NL-05W-B59
FOR BRUKER AVANCE NMR AMPS, BLAH, BLAX, BLAXH ETC.

The two or three fans in the rack inside various Bruker NMR amplifiers are no longer available from online suppliers or from the manufacturer NMB. They're 24Vdc, 3-wire 80mm size, w/locked rotor sensor (NOT "locked rotor protection.") If your web search ever finds an NMB 3110NL-05W-B59, it won't be any twelve bucks each!! Must we buy them only from Bruker?

Inspecting the NMB catalog, we find that "N" fans are gone, and are replaced by identical "K" fans which work just the same, but have a mirror-image rotor blade shape. The max DC drive current is also 6% higher. The closest match which is yet widely available is: NMB 3110KL-05W-B69-D00, on Digi-key as P13491-ND, $14 each. Works fine, it's what we've been using in all our amps. Note that the "B69" means: ballbearing, speed-6, and 3-wires. Don't buy "B60," it's 2-wires.

Also, the little rubber thingies break off when removing these fans. Search turns up nothing. Aha, they are called "rivets," or fan mounts. I found these on digi-key: RP1063-ND "FM-1" Fan Mount.