Oscilloquartz OCXO 8696 - Page 1
Forum section: electronics / testgear

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: August 22, 2019, 09:05:43 pm
content: Hi all,I try to find the datasheet for an OCXO made by Oscilloquartz.Google was not my friend for this searchThe model is: Oscilloquartz OCXO 8696-AS (please see the attachment)Thank you

author: radiolistener
author_rank: Super Contributor
timestamp: August 23, 2019, 12:31:16 pm
content: are you sure this is not fake OCXO?

author: PA0PBZ
author_rank: Super Contributor
timestamp: August 23, 2019, 12:49:05 pm
content: Quote from: radiolistener on August 23, 2019, 12:31:16 pmWhy?

author: radiolistener
author_rank: Super Contributor
timestamp: August 23, 2019, 02:10:46 pm
content: they remarking even cheap transistors, so why do you think this is original OCXO. As you can see, the label is very different...

author: Vgkid
author_rank: Super Contributor
timestamp: August 23, 2019, 03:59:37 pm
content: So SMH was part of the swatch(oscilloquartz) group until 1998, plus look at that serial number. This is an older unit, so it could be legit

author: radiolistener
author_rank: Super Contributor
timestamp: August 23, 2019, 04:23:16 pm
content: As I understand, this OCXO bought on ebay or aliexpress. It needs to be disassembled and inspected what is inside. Without it you cannot guarantee that this is genuine OCXOI have a lot of fake elements with fake marking on it. For example one says that this is Texas Instruments, but actually it is not... Also I know they produce fake reference voltage, fake TCXO, and other fake things...

author: jpb
author_rank: Super Contributor
timestamp: August 24, 2019, 11:36:46 am
content: Quote from: radiolistener on August 23, 2019, 12:31:16 pmIt would be very strange to fake a model that no one has heard of! Or were you joking?I can imagine someone might want to fake a BVA model which are worth thousands.I would just assume that the pin out is the same as for the 8663, the voltage and frequency are on the label. It is slightly annoying not to be able to find the general specs but given that it is old and second hand they probably couldn't be relied on. It would be nice to know if it is SC cut or not but measuring it should give an idea of performance (especially if there are two samples to measure against each other).

author: radiolistener
author_rank: Super Contributor
timestamp: August 24, 2019, 01:13:46 pm
content: Quote from: jpb on August 24, 2019, 11:36:46 amThere is a lot of fake things on this market: capacitors, resistors, crystal oscillators, diodes, transistors, IC, MCU, FPGA, etc. The main goal is to sell that fake stuff. If it can raise demand, they can place any brand/model name on the label. If it can helps to sell, they can make "old and second hand" from a new fake element.So, the question is how you know if this is genuine OCXO?

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: August 24, 2019, 09:25:57 pm
content: This OCXO is genuine for sure.It was from a telecom exchange from aprox. 1994 (from the datecodes on the chips)It is not a fake item from ebay or AliexpressThe 2 boards device is very complex with an with a 80C31 microprocesor, a LM399 voltage reference and 2 AD7541A 12-Bit, Monolithic Multiplying DAC.I attach a picture of the two boards in order to show you how huge the OCXO is

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: August 24, 2019, 09:27:15 pm
content: sorry, in my previous post the attachment is missing

author: edpalmer42
author_rank: Super Contributor
timestamp: August 24, 2019, 10:54:28 pm
content: I see date codes from 1993. Online info from that time is rather unlikely, particularly for something like this. The Wayback Machine didn't start until 1996, but it looks like Oscilloquartz didn't have a web site until the end of 1998.Are you looking for specifications or pinout? Pinout should be easy to figure out since you've got the board right there.About the only thing you can do is measure the case size and see if you can find anything from Oscilloquartz that used the same case. The 86XX line is all OCXOs. Some are single oven, some are double oven. Based on the size, yours could be double oven, but that's basically just a guess.Ed

author: radiolistener
author_rank: Super Contributor
timestamp: August 25, 2019, 01:17:04 am
content: wow, cool board, where you get it?

author: tomeo.gonzales
author_rank: Regular Contributor
timestamp: August 25, 2019, 07:50:56 am
content: The board is from a decommissioned exchange. It looks very elaborate and I think the OCXO is a high quality one. So I really want some help to find the data sheet. The pinout is very easy to find by looking at the board.

author: tkamiya
author_rank: Super Contributor
timestamp: August 25, 2019, 05:37:40 pm
content: I have some oscilloquartz units. I can take it apart but without having any reference unit, how do I tell it's a fake or genuine? Or is it obvious?What did you find when you took apart "Texas Instruments" version?

author: radiolistener
author_rank: Super Contributor
timestamp: August 26, 2019, 06:02:51 pm
content: Quote from: tkamiya on August 25, 2019, 05:37:40 pmit was usual TI marking. But it was completely out of specification and one pin doesn't works and internally disconnected (in original TI chip it is used). Also, there was some indication that previous marking scratched out.But I also have Chinese fake chips which has ideal Linear Technology marking. But actually it is fake and out of specification.So, it looks that the only way to check it is to test it's performance and compare with datasheet.

author: tkamiya
author_rank: Super Contributor
timestamp: August 26, 2019, 06:23:52 pm
content: Oh, I see. You have a fake IC chip.... I thought you had an ocxo with TI marking on it.

author: radiolistener
author_rank: Super Contributor
timestamp: August 26, 2019, 06:47:24 pm
content: yes, but if you bought it on ebay or aliexpress, there is high risk that you got fake or factory rejected item which is out of specification. And OCXO is not exception.

author: tkamiya
author_rank: Super Contributor
timestamp: August 26, 2019, 07:05:36 pm
content: Yes, I know. I don't think ANYTHING is an exception anymore.I have a few fake GPIB adapters here and some questionable stuff. I usually test parts individually first, before using them. With my OCXO, I brought them up and tested to make sure output are correct, and tested the reference voltage. If they are factory rejects, then that's little more difficult to test.I'll probably run a comparison test with known HP parts with similar spec and see how they fare. Out of spec rejects circulating is nothing new but this fake thing is something else. With eBay and all these markets are helping them spread much faster and wider.

author: tkamiya
author_rank: Super Contributor
timestamp: August 30, 2019, 11:33:19 pm
content: I rigged up my OCXO and took some measurements. Once warmed-up, calibration is pretty close per my 12 digit counter that is using GPSDO as clock. Adjustment range is good. Output is per spec. At this point, I have no reason to doubt what I have is not genuine.Phew....