Hi Have you looked into any actual data on small rf transformers under vibration at 10 MHz?
A change of a nH isn't the same thing at 10 MHz as at 6.3 GHz. An air core coil in the signal path at 6G would indeed be an issue. A circulator likely would not be. An RF transformer at 10 MHz has a lot more in common with the 6GHz circulator than with the 6GHz air core coil. The phase noise of your reference is going to head up by your +56 db. As long as the transformer's impact is well below the reference, it will not show up in the output signal. I would bet you an order of fries at the local MacDonald's that the single ended transmission of the signal will pick up far more noise than anything a properly constructed rf transformer will do at 10 MHz. Noise at the load is a problem, no matter how it gets there. Transmission may not be inside your scope -yet. It's still an issue that directly impacts what you are trying to do. Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of life speed Sent: Thursday, February 18, 2010 4:47 PM To: [email protected] Subject: Re: [time-nuts] Advice on 10 MHz isolation/distribution (Clay) Message: 5 Date: Thu, 18 Feb 2010 11:11:18 -0800 From: Hal Murray <[email protected]> Subject: Re: [time-nuts] Advice on 10 MHz isolation/distribution (Clay) > Thank you, but I require a circuit without transformers > for reasons of vibration susceptibility. Is the problem wires moving relative to eachother within the transformer or the whole transformer moving relative to the local magnetic field? Does it help to pot things in epoxy or varnish or ...? Years ago, when I took the lid off a small mini-circuits transformer it was just a few turns on a toroid. Something like varnish would be easy to apply. Hal, The problem is modulation of the reference signal via relative movement of the transformer guts. While I understand there are ways to 'harden' magnetic devices, my application is far too sensitive to even consider a magnetic approach given the availability of alternatives. Any spurious signals present on the 10 MHz reference will be increased by 56 dB by the phase-locked loop. Clay _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
