I found that a lot of the 1KHz noise on mine was caused by a bad ball bearing in the motor. I replaced it with a new bearing and the 1KHz was then only loud.
It isn't the motor, it is the 1KHz drive. Airplanes with 400Hz 3 phase motors in the instrumentation are similarly loud. -Chuck Harris Bill Hawkins wrote:
Had some interesting times with the HP-113B clock, but had to mount it in an insulated cabinet with an insulated door because it made so much 1 KHz mechanical noise. No wonder the housing for the assembly is so heavy. Did they find a quieter motor for the 115B? Bill Hawkins -----Original Message----- From: George Race Sent: Monday, October 15, 2012 2:57 PM To: 'Discussion of precise time and frequency measurement' Subject: [time-nuts] HP 115BR Clock Repaired and Ready to go I still have the HP 115BR Clock. It is fully repaired and fully functional.
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