EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: cncjerry on January 02, 2022, 08:23:50 pm
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I've been playing around with various PLL circuits to sync a 10Mhz Wenzel TC/VCXO to a Rubidium standard. I've tried several with somewhat good results.
I recently built Bill Riley's: http://www.wriley.com/A%2010%20MHz%20OCVCXO%20and%20PLL%20Module.pdf (http://www.wriley.com/A%2010%20MHz%20OCVCXO%20and%20PLL%20Module.pdf) [/url]
and the Wenzel (mid page with 4069 and 4016): https://wenzel.com/documents/tuning.html (https://wenzel.com/documents/tuning.html)
I also built another using dual output DACs that was more aligned with a GPSDO as it used 1PPS.
I'm wondering if there is a standard board/module that takes in two signals and produces a tuning voltage? This would be like a GPSDO without the GPS or DO, just a PLL or some other tuning circuit. I can just use the Wenzel circuit as it is cheap and works as well as Riley's, at least from initial testing but I have a couple of these and thought if there was a module I might go that route.
Thanks.
Jerry
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Something like this? It is more like a kit. Use only what you want:
- home for 10811A, MTI-260, Morion MV-89, 100 MHz ECOC 2522, CVHD-950 and others
with pos/neg regulation sense.
- Xilinx Coolrunner CPLD ($2.50) to create local 1pps
- 1pps CMOS 50 Ohms driver
- Can lock to external reference frequency. 2FF phase/frequency comparator in CPLD
- Not yet implemented: locking on incoming 1pps. Foil capacitor for large time constant
- OPA140 FET opamps for control loop without loading the foil capacitor
- 2 Linear Tech sine to square converters, for VCXO and reference
- 10 turn pot to adjust nominal frequency
- TL431 reference if the VCXO does not have one
- output amplifier to 20 dBm. Enough signal even after power dividers.
- output amplifier can be used as frequency doubler with only slightly less output power.
- notch filters with crystals or toroids to remove harmonics or sub-harmonics.
- power meter for level of incoming reference clock
- VHDL source for 1pps and phase detector (or standard JEDEC programming file)
- can be used as a test bed for a blob of logic with enough test points
- Gerber files available, tested at JLCPCB and others
- Minimum usage is just bare mechanical mounting. Some have done that. Low-cost enough.
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I know this is an ancient thread, but...
Gerhard - do you sell a board - either raw or assembled of your circuit? Or is there access to CAD files to modify it and get it built?
cncjerry - Did you produce CAD files for the Bill Riley design?
Any conclusions on a good circuit for this? In my case I'd like to lock an HP 80211 OCXO (good phase noise) to a Symmetricom X72 Rubidium standard (good long term accuracy, lousy spurs...)
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No, I don't sell them. but you can get a board or two for free.
They have been manufactured at JLCCB.
Sending empty boards to US in a simple letter was quite a disaster,
I got most back. :-(
Files are available in Altium format. The Xilinx Coolrunner CPLD
is EOL but seems still to be available at DK and Mouser.
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I'd love to get more information (design files and maybe even a board) - I sent a PM with my contact info.