[time-nuts] OCXO Board

Gerhard Hoffmann dk4xp at arcor.de
Fri Oct 26 21:41:09 EDT 2018

I have made a similar board for Morion MV-89, MTI-260 and HP10811.

It has regulators for all voltages required (worst case for all types), 
can lock to an

external reference ( ring mixer from Macom/Pulse el cheapo transformers 
and and diode quartet),

LMH6702 buffers), power level indicator for ref, usual Wenzel style diff 
amp squarer

or Linear technology squarer depending on personal preference.

It can produce 1pps from the oscillator with either a $1.50 CPLD

or TVB's PICDIV.  1pps drives 3V into 50 Ohm. Should be enough for 

CMOS. The CPLD has enough resources to lock the OCXO to an external 1pps.

That has not been tested, I also have no PICDIV. But there isn't much to it.

There is also an SMA for external EFC.

The output amplifier can deliver 20 dBm and act optionally as a doubler, 
5 to 10 MHz

for example. There are 2 harmonic notches with either crystals or toroids.

I only had to click together some macros from my library, and since 
especially the 10811

needs so much space, there was free epoxy, so to say. The board could be 
sawed to

to pieces in principle, if someone should be interested in LMH6702 
buffers, mixer,

doubler... There is some "air" between the functions.  The subcircuits 
have I/Os on a 100 mil grid

so they can be easily arranged on Vector board. (with a ground plane, 

Circuits / Gerbers / Altium Designer files are available.

I wanted to lock 16 MTI-260s loosely to a common reference and Wilkinson

them together to see how far I could come wrt phase noise. I have them 
already here,

but I'll find no time for that in the foreseeable future.

That guy who sold the LUCENT KS24361 plug-ins had made me an offer I 
could not deny.

Ask me if you need Lucent spare parts! I was only after the oscillators.

My interest has kinda slipped into 1/f noise in baseband and chopper 

Bottom side.


Top side:


best regards,


While I'm at it, this is the phase noise of the FE405 that I got from 
the group buy

here, some time ago.


Is that uproar far out normal?   But over seconds to minutes it dives 
down nicely into E-13 land.

Am 26.10.18 um 20:25 schrieb ew via time-nuts:

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