On Sun, Apr 07, 2013 at 11:27:23AM +0100, Alexander Wright wrote: > On 07/04/13 05:01, WB6BNQ wrote: >> Hi Alec,
>> You may be in luck. However, I would need some additional pictures, >> particularly >> of the connector on the bottom, also some of the inside. > Bill, > Thanks for your reply! Here are some photos of the inside: > http://m0tei.co.uk/fe5650pics/ > You'll see that it comes with a custom machined plate screwed > onto the front - this was how it was mounted in the thing i > pulled it out of. It can be removed but i found it easier to > take the thing apart with it on. A thermostatic switch used to > bolt onto it to (presumably) act as a thermal cutout. The baseplate (2xLM2941, LP2952) basically is the power supply/regulation, so nothing interesting there. > You'll also notice that the boards we're probably interested > in are potted it some sort of white compound - it's hard but > crumbly - feels like some sort of polymer foam. I've started > to pick it off a bit but could you just confirm that this is > actually a sensible thing to do before I go all out scraping > it off? The purpose of the polymer foam is isolation to keep a stable temperature throughout the boards. http://www.qsl.net/z/zl1bpu/PROJ/FE5650-2.jpg The top layer in this image is the DDS board, and it is basically identical to the FE5680A, which means it can be adjusted in a wide range, but only does digital synthesis based on the reference frequency. But let's see what Bill says to the pictures ... :) best, Herbert > Thanks! >> The primary physics package is a stand alone analog Rubidium frequency >> standard >> that outputs 50.255* MHz frequency. That signal is used to drive various >> output >> board configurations, included inside the unit, to provide a customer >> required >> output frequency. The more recent revised units (they look the same) use >> a new >> digital scheme that is much more of a hassle. > This unit is probably from late 1996/1997 if that helps? >> The one that I and a number of people are familiar with is the >> 5650-option-58 >> model whose output was a 1pps. To get the 1pps the 50.255+ MHz signal was >> used >> to drive a Direct Digital Synthesizer (DDS) that produced 8.3+ MHz signal >> that >> was then divided down via normal TTL dividers to produce the 1pps. The >> DDS is >> capable of being changed to other frequencies up to about 20 MHz, however, >> the >> filter following the DDS needs to be changed or bypassed to properly >> filter the >> new frequency. Bypassing is the easiest method but would require using an >> external filter to get rid of aliasing and spurs. >> I put together a zip file of various information on FEI-5650-option 58 >> that will >> help you get familiar with the family line. If you have problems with the >> link >> let me know. Also, after you get a successful download let me know so I >> can >> reduce the FTP storage level, thank you. >> http://pages.suddenlink.net/stevewingate/cryptic1/for alec on >> 5650-option-58.zip >> Bill....WB6BNQ > Awesome, looks like there's some great info there! Unfortunately i'm not > sure hoe relevant it is to mine since my option doesn't seem to do RS232.... > On 07/04/13 04:17, Herbert Poetzl wrote: >> Open it up, take some nice pictures of the circuit boards >> and components and I can probably tell you what might be >> possible (after looking at them :). > Thanks Herbert! Pictures above^ >>> As far as i'm aware this model doesn't have serial control. >> best, >> Herbert > Best regards, > Alec > _______________________________________________ > 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.
