Hi I probably should not rule out the MV89’s going through an exceptionally brutal salvage process. I’m sure there are a range of outfits doing this stuff and that some take more care than others. We may just have a lot of 10,000 MV-89’s that got nuked and now are forever floating around the world getting re-sold multiple times.
You could ask - why not test them fully? That’s not an easy task. The list I gave is far from a full test process on an OCXO. One would at least add aging and some more detailed limits here and there to a proper test profile. If you are looking for damaged parts, there would be even more testing required past a normal testing profile. I’ve always found that building in performance / reliability is a lot cheaper than testing it in ….. Bob > On Apr 12, 2015, at 10:03 PM, Peter Bell <[email protected]> wrote: > > I would personally consider those MV89s from Chinese sources as being extra > suspect - a few years back, one of the Chinese surplus vendors had a big > box of them (some removed from PCBs, and others apparently new) that were > identified to me as containing bad ceramic caps and suffering from various > problems ranging from poor phase noise performance to being completely > inoperative. > > The guy who had them (who I know quite well) volunteered this information > and said that as far as he was concerned they could only be sold as scrap - > but it's possible they have ended up in the hands of dealers that are not > so scrupulous. > > > On Mon, Apr 13, 2015 at 8:46 AM, Bob Camp <[email protected]> wrote: > >> Hi >> >> I don’t think there’s anything at all wrong with the MV-89A as an OCXO. In >> fact, I believe that properly >> handled they are a good part. The gotcha is the abuse they get in the >> “recycling” process. I’m >> willing to bet that any OCXO that sees the same sort of process will come >> out with issues. >> >> Bottom line - Don’t attack an OCXO with a torch, drop it down a flight of >> stairs, leave it out in the rain >> for a few years, and then really abuse it after that. They need to be >> treated with some care …. >> >> For what ever reason, parts like IC’s seem to be more tolerant of the >> scrap out process than OCXO’s. >> Rb’s seen to show up *with* PCB’s still attached, so they didn’t get the >> torch process. >> >> Because of all that, there’s not much way to pick a “good” OCXO model. The >> thing you need to find >> are parts that you are sure did not take a beating while being pulled off >> of boards. With zero view into >> that end of the sourcing process …. not much way to pick and choose. >> >> About the only thing to do is to buy parts that never went on to pc >> boards. That’s no guarantee, but >> it ups the odds a bit. You may be buying test rejects. They could still >> have been dropped down a >> flight of stairs. They might be counterfeit parts. >> >> Considering that you are buying a $250 to $400 OCXO for <$20, there *will* >> always be some risk …. >> >> Bob >> >>> On Apr 12, 2015, at 6:02 PM, Perry Sandeen via time-nuts < >> [email protected]> wrote: >>> >>> List, >>> >>> >>> >>> It appears from Bob Camp’sexperience (and others) that the Chicoms >> Morion oscillators are to be avoided. >>> >>> >>> >>> My question is: Could Bob Camp,Rick K. and other gurus with experience >> come up with a list of the Ebay 10 MHzsurplus oscillators that would be >> worth buying as well as what would be a fairprice? Also some good vendor >> names would be nice as well. >>> >>> >>> >>> I realize that surplus listvaries quite a bit and it still a bit of a >> crap shoot, but perhaps the odds arebetter from certain venders, makes, and >> models. >>> >>> >>> >>> Regards, >>> >>> >>> >>> Perrier >>> >>> >>> _______________________________________________ >>> 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. >> > _______________________________________________ > 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.
