mistery oscillator - Page 1
Forum section: electronics / projects

author: geo999
author_rank: Contributor
timestamp: February 03, 2015, 08:41:31 pm
content: Hello community !I've just found the oscillator in the picture attached on a pile of junk.I think it's an oven controlled / temperature controlled oscillator at 26 MHz, not a particularly useful frequency, nonetheless would like to use it ...Tried to find the specs but looks like "Tele quarz group" doesn't exist anymore ...Does anyone happen to have some specs / application note / pinout / any info on this part ?Thanks,George

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 03, 2015, 09:36:24 pm
content: Nope, but I know which is the ground pin...(Yeah, I know, don't quit my day job, etc)

author: geo999
author_rank: Contributor
timestamp: February 03, 2015, 09:39:44 pm
content: good one !

author: wiss
author_rank: Frequent Contributor
timestamp: February 03, 2015, 09:42:07 pm
content: http://pt.aliexpress.com/store/product/Morion-MORION-constant-temperature-crystal-oscillator-OCXO-MV102-10-0MHZ-10MHZ/1385002_32214422180.html?or not...maybe this one is better?http://pt.aliexpress.com/store/product/TELEQUARZGROUP-OCXO-TQOC26-01-26-000MHZ-12V-import-OCXO-disassemble/1385002_32214100045.html

author: babysitter
author_rank: Frequent Contributor
timestamp: February 04, 2015, 06:05:23 am
content: What looks like a solder trace between the bottom part and the cap is a solder trace. You can take it apart, show pics here, learn about it and probably put it together working.

author: geo999
author_rank: Contributor
timestamp: February 06, 2015, 08:07:48 pm
content: Hello,after some digging I managed to get it running.The pinout is somehow similar to this one :http://www.euroquartz.co.uk/Portals/0/oc31t12a.pdfStill I do not know what is the purpose for the 3 remaining pins, do I really need to use them ?The output signal is somehow clipped sine ( please see attached picture )Does anyone have any idea how to get a clean sine out of this signal ?, use a band pass ( 26 MHz centered ) filter to cut the harmonics ?Thanks,George

author: amc184
author_rank: Regular Contributor
timestamp: February 06, 2015, 08:55:56 pm
content: Two of those pins are probably for frequency adjustment. You'd connect one of the 5V pins to one end of a trimmer, ground to the other end and the adjust pin (probably the 2.6V pin) to the wiper. Adjusting the trimmer will vary the output by a few PPM.The other 5V pin might be an enable pin with an internal pull up, and might shut off the oven if pulled low.Just guesses though, you'll have to experiment carefully to find out for sure.

author: jwm_
author_rank: Frequent Contributor
timestamp: February 07, 2015, 01:06:22 am
content: Quote from: geo999 on February 06, 2015, 08:07:48 pmDon't know if it is the best way but when I had to do something similar to get a clean 50 ohm sine from an OCXO I took the output and fed it into one gate of a 74AC14 then took the output of that gate and fed it to the other 5 in parallel, combining all the outputs through resistors to give a 50 ohm impedance on the output. This gave a very clean square wave which I fed through a bog standard LC band pass filter. Beautiful sine wave output.

author: dannyf
author_rank: Super Contributor
timestamp: February 07, 2015, 01:18:28 am
content: QuoteIt is easy to tell if they are output or input pins: load them with a small-ish load (from 100ohm - 1k).QuoteDo you really need "clean sine" output?It is going to be difficult. A "clean" way would be to use that to drive a DDS that generates a clean sine output.QuoteYeah, not exactly "clean" however.

author: Vgkid
author_rank: Super Contributor
timestamp: February 07, 2015, 03:36:20 am
content: I would monitor those 5v pins. One is probably an oven alarm, with the othèr a v-tune.looking through my c-mac catalog, see if the indented pin changes states after a while, oven alarm.