[time-nuts] MTI 260-0624-D OCXO

Adrian Godwin artgodwin at gmail.com
Thu Feb 18 07:40:00 EST 2016


I have a small collection of 10811 and similar oscillators here, collected
from hamfests rather than china (and mostly pre-ebay).

What sort of testing regime would you put them through ? I don't have
anything as exotic as a timepod but I do have an HP53131A, the Tait Rb
source, and a KS-24361 set up. And always keen to get hints on the
acquisition of new toys !



On Thu, Feb 18, 2016 at 12:09 PM, Bob Camp <kb8tq at n1k.org> wrote:

> Hi
>
> It is *much* better to have an OCXO that you do not need to test to death.
> There is simply to much testing to do. A modern factory does not test the
> quality into the product (of any sort) they design in and build it in. The
> same
> is true of the normal customer for virtually any component. They make sure
> the parts come from somebody they can trust and save a lot of testing time.
>
> That said, yes, I have a pile of scrap parts sitting in front of me as I
> type this.
> It’s a hobby. Time does not count. It lets me play with all sorts of toys
> doing
> the testing. I occasionally learn things in the process. Mostly I learn
> that
> my hope of a 100% perfect batch is still a dream ….
>
> Bob
>
>
>
> > On Feb 17, 2016, at 9:56 PM, timenut at metachaos.net wrote:
> >
> > Bob,
> >
> > In this case, I know how it was taken off the board - it wasn't. They
> just cut
> > the board around it. I had to remove it myself. Nice thing about that,
> is that
> > I got a nice plastic, pre-formed part that fits between the board and the
> > OCXO, probably as an insulator.
> >
> > You are also right about the number of things that you need to test to
> make
> > sure that one of these is fully functional. However, this is a "starter"
> OCXO
> > for me and I don't yet have the equipment to perform the tests. The best
> that
> > I can do is to make sure that, when powered up
> >
> >   1. I see something that sort of looks like a sine wave at a reasonable
> >      magnitude.
> >
> >   2. My 2465B CT frequency counter thinks that it is somewhere near 5Mhz.
> >
> >   3. If I apply gnd, or VRef to the adjustment pin I see the frequency
> change
> >      at least a small amount.
> >
> > Without more equipment, there isn't much more that I can do to test.
> Unless
> > you have some suggestions?
> >
> >
> > Mike
> >
> >
> >> Hi
> >
> >> Best guess is these things get taken off the board with either a big
> torch or a charcoal fire.
> >> You can ask Mr Google to dig up pictures of the process. Depending on
> just how quick
> >> they are, the insides of the OCXO can easily be reflowed. The
> likelihood of it reflowing and
> >> cooling back to a reliable joint … not real good.
> >
> >> Bob
> >
> >>> On Feb 17, 2016, at 5:16 AM, Andrea Baldoni <erm1eaae7 at ermione.com>
> wrote:
> >>>
> >>> On Tue, Feb 16, 2016 at 07:58:21PM -0500, timenut at metachaos.net wrote:
> >>>
> >>>> I just received a 5Mhz OCXO from eBay (MTI 260-0624-D OCXO). After
> testing it,
> >>>> it is clear that it is defective.
> >>>>
> >>>>  1. It never heats up.
> >>>>  2. The reference voltage is zero.
> >>>>  3. Only noise is seen on the output pin.
> >>>
> >>> I had the same issue with some of them. It's very likely that the
> internal
> >>> solder connections from pins to PCB are broken, at least, the one for
> power.
> >>> It happens because the inner oven is heavy and there isn't any thermal
> >>> insulator (besides air) to keep it from moving.
> >>>
> >>> Wheter the crystal has been damaged or not, it's unknown. I had one
> where the
> >>> crystal actually fell off from its supports too.
> >>>
> >>> I posted a link to photos of the internals, time ago. The link is dead
> now
> >>> and I don't think to have the photos anymore but perhaps someone
> downloaded
> >>> them.
> >>>
> >>> Best regards,
> >>> Andrea Baldoni
> >>> _______________________________________________
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> >
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> >
> >
> >
> > --
> > Best regards,
> > Timenut                            mailto:timenut at metachaos.net
> >
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