[time-nuts] Trimble 65256 OCXO
tractorb at ihug.co.nz
Mon Nov 28 04:33:32 EST 2016
Thanks for confirming my suspicions, Bob. I'm using a 10k 10 turn pot across
the regulated 12v supply at present to feed the EFC but I'll change to using
----- Original Message -----
From: "Bob Camp" <kb8tq at n1k.org>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Monday, November 28, 2016 3:17 AM
Subject: Re: [time-nuts] Trimble 65256 OCXO
> Pin 5 is the EFC reference pin. It may (or may not) have a voltage on it.
> If there is a
> voltage on it, it’s a voltage that the original OEM customer found useful.
> It may (or may not)
> have a series resistor to match up with an OEM specified trim pot.
>> On Nov 27, 2016, at 2:04 AM, Dave Brown <tractorb at ihug.co.nz> wrote:
>> This 10 MHz unit has a 5th pin that I can't find any documentation about.
>> There have been posts in the past that have also indicated its use is
>> unknown. Looking at the base, the four connections in the corners are
>> known quantities. (ground, EFC, 10 MHz out and + supply) No. 5 is midway
>> along one side.
>> I thought it may be a reference supply for the EFC pin- with a 12.03 volt
>> supply the unknown pin measures at 2.803 volts-which is usefully above
>> the required EFC voltage ( ~2.4 volts) to bring it on frequency.
>> But does anyone have some hard data on this 'unknown' pin?
>> DaveB, NZ
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