Another thought , I have done this with a pair of synth sig gens: The brik's designs are such that you can typically get them to phase lock at harmonics of 100 MHz around the nominal. So you should be able to get one to phase lock at 10.1 or 9.9 GHz, giving you a 100 MHz offset beat note from the mixer, suitable for analysis by most prosaic test equipment.
On simple way to examine the quality of 10 GHz multiplication is simply to listen to the 100 MHz beat with a SSB receiver. Another interesting tool is to put the 100 MHz into an oscope with the sweep synced to the original 100 MHz, or set up as a XY display. Lester B Veenstra MØYCM K1YCM [email protected] [email protected] [email protected] US Postal Address: PSC 45 Box 781 APO AE 09468 USA UK Postal Address: Dawn Cottage Norwood, Harrogate HG3 1SD, UK Telephones: Office: +44-(0)1423-846-385 Home: +44-(0)1943-880-963 Guam Cell: +1-671-788-5654 UK Cell: +44-(0)7716-298-224 US Cell: +1-240-425-7335 Jamaica: +1-876-352-7504 This e-mail and any documents attached hereto contain confidential or privileged information. The information is intended to be for use only by the individual or entity to whom they are addressed. If you are not the intended recipient or the person responsible for delivering the e-mail to the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this e-mail or any documents attached hereto is prohibited. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, January 27, 2011 12:21 AM To: [email protected] Subject: [time-nuts] Update -- Comparing 10 MHz Oscillators at 10 GHz Thanks to some help from Joe Ruggieri, I finally managed to get a pair of 10.000 GHz microwave "brick" oscillators phase-locked to 100 MHz inputs. These require an input of about 0 dBm at 100 MHz and have an output of about + 13 dBm at 10 GHz. To gauge whether or not loop noise would interfere with using these to compare 10 MHz oscillators, I assembled the following test setup as I have not yet constructed the required 10 MHz to 100 MHz multipliers. Both 10 GHz microwave bricks were driven through a splitter from an HP signal generator locked to 100 MHz. The 10 GHz output of one brick was routed through an HP X885A phase-shifter equipped with WG/coax adapters and on to one input of an Anaren hybrid combiner. The output of the other brick was routed through a 0-10 dB SMA attenuator then on to the combiner. The reject side of the combiner was terminated. The main combiner output was routed through a 10 dB attenuator to a Systron-Donner coaxial detector. The DC output of the detector was monitored with a digital voltmeter. First the phase shifter and attenuator were adjusted to cause the two sources to arrive at the combiner with equal amplitudes and 180 degrees out of phase and produce a null at the detector output. I measured as little as 0.01 millivolt on the DVM at the null point. Then the phase-shifter was adjusted to rotate the phase 180 degrees to place the combiner inputs in phase. The detector output was about 128 millivolts. This experiment seems to confirm the earlier results by Ulrich Bangert and his friend that noise does not appear to be a problem with this method for rapid frequency comparison. However it would be convenient to have an attenuator and phase shifter to null the sources. Bruce Hunter, KG6OJI. _______________________________________________ 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.
