[time-nuts] Electronic Research Co. Precision Crystal Oscillator.

Bob kb8tq kb8tq at n1k.org
Mon May 14 18:14:23 EDT 2018


Keep in mind that roughly 99.9% of all OCXO’s produced went into OEM specific applications
with spec sheets that reflected the OEM’s requirements. Both the OEM and the manufacturer 
had reasons to keep those documents private. In both cases it made it more difficult for 
competitors to “clone” the OCXO or end product. That protected the investment made in the
design (which was considerable). 

The first question on any surplus OCXO is - does the oven still work correctly? They can fail 
in several ways. When they do, repair involves tearing into the part. For maximum performance
one needs temperature test capability to “fine tune” the settings. (  = the circuitry has a residual 
temperature coefficient and the crystal is offset to null that out ). 

Next question generally is - can it be tuned on frequency? If so it has some use. 

Past that one would need to do ADEV and / or phase noise testing to work out what a specific 
example is still doing.

Yes this sounds like a lot of work. None of it is crazy hard in a basement setting. You do 
need to set up some gear to do it. Even that gear is not nutty to come up with ….


> On May 14, 2018, at 5:48 PM, Dave B via time-nuts <time-nuts at febo.com> wrote:
> Hi.
> A little while ago, I acquired an ERC EROS - 800-MIL-2  10MHz 24V
> powered OCXO, dated 95-23.
> Well, it seems to work, and comparing with the trusty Thunderbolt, once
> warmed up and viewed on a dual channel 'scope, where one channel is
> triggered from one source, the drift relative to each other is some 16
> seconds for a full cycle of drift.
> I've tried to lookup the spec of these things, and found surprisingly
> little, other than scan's of oriental data sheets, that of course
> neither I nor Google can translate.  But is that a reasonable sort of
> performance?
> I have no idea what it came out of, but it's surprisingly lightweight,
> the outer casing get's "gently warm" after it's been powered on for an
> hour or so, but otherwise appears fine.
> Is it worth keeping as a portable reference, or ???
> Regards to All.
> Dave B.  (G8KBV/G0WBX)
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