Morion MV89 Ultra High Stability OCXO timebase - Page 1
Forum section: electronics / testgear

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: October 30, 2015, 08:22:16 pm
content: Just ordered via the usual online source. I have been reading they may fail before 30 days, otherwise ok. Thinking of burning-in before installing in Agilent 53230A, and Spectracom SecureSync. Anyone else try these yet?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: October 30, 2015, 08:39:07 pm
content: Some have problems.Here's a teardown...http://www.rbarrios.com/projects/MV89A/

author: DimitriP
author_rank: Super Contributor
timestamp: October 30, 2015, 08:50:07 pm
content: Usual online source is like saying you married a humanIs it coming to you from China, UK, or Poland ?

author: Melt-O-Tronic
author_rank: Frequent Contributor
timestamp: October 30, 2015, 09:53:53 pm
content: Some time back, I got one from the "usual online source". Its output was, at best, -8 dBm instead of the +7 dBm rating. Usually, after power-up, it would be less than -25 dBm. If I let it warm up, then pounded it on the bench, it would jump back up to -8 dBm.The seller was good enough to send me a replacement. It would power up to -27 dBm, then after warming up and a quick power cycle, it would jump to +5 dBm, but sometimes would drop down again hours later.No more MV89A's for me. When they work, I'm sure they're spectacular performers. But there are so many reports of issues with them, I wouldn't trust a used one and especially wouldn't design around one.

author: Matje
author_rank: Regular Contributor
timestamp: October 30, 2015, 11:56:10 pm
content: Quote from: SoundTech-LG on October 30, 2015, 08:22:16 pmFirst: remember these are used units, pulled from retired equipment by whoever, utilizing whatever methods, handled in unspecified ways, probably abused every which way, multiple times.I have 3 of these from China. One had a blown output coupling cap, after replacing that (there is a description on the web for it) it worked fine, but can't be trusted because of the things I had to do to open the can (a small propane blowtorch was involved) and the not quite airtight way it is sealed now ;-).These things are quite stable, provided the f-control input is at a defined potential. They are not exactly precise without being controlled by some better reference, however a primitive counter-based GPS setup can get you to within a few mHz of 10 MHz.I would suggest to try to get as many as resonably possible/affordable, check them out as well as you can, and then built a lab frequency reference from The Chosen One. Serious instruments have a reference frequency input and having one reference frequency in the lab makes some things easier, like having only one clock makes it easier to know which time it is.

author: edpalmer42
author_rank: Super Contributor
timestamp: October 31, 2015, 01:47:38 am
content: I don't have any experience with Morion oscillators. I've heard the kinds of stories discussed here and decided to pass on that brand.If I was looking for an oscillator for an ultra high stability timebase, I'd be looking at brands like Wenzel, Oscilloquartz, or HP. Even then, as Matje said, these things have been badly abused so it's pretty much blind luck whether you get a good one or not. That's why they're priced so low. You probably don't want to know what they would cost if they were new!Ed

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: November 01, 2015, 07:05:29 pm
content: Yeah, would be interesting to know the going price on a new one. Morion USA is a few miles from here in San Jose, CA shouldn't be hard to get. Will be interesting to see how it burns in. Failures should start in a few weeks (if any)I would think. Not going to replace the Agilent, or Spectracom standard time bases until I shake it down thoroughly.