[time-nuts] Racal 9420 OCXO

[Robert Atkinson]

Hi,
I've attached a copy of the catalogue specification for Racals OCXOs. They do have electronic trim as standard. They are used in the 9478 frequency standard. The 9478 service manual specfically states that no information on the OCXOs is provided and they must be returned to Racal or appointed agents for repair.

Robert G8RPI

--- On Wed, 24/8/11, GandalfG8 at aol.com <GandalfG8 at aol.com> wrote:

From: GandalfG8 at aol.com <GandalfG8 at aol.com>
Subject: Re: [time-nuts] Racal 9420 OCXO
To: time-nuts at febo.com
Date: Wednesday, 24 August, 2011, 16:03

In a message dated 24/08/2011 00:03:19 GMT Daylight Time,  
danrae at verizon.net writes:

I don't  think Racal released circuit diagrams of any of their ovens.  I 
have  traced out the circuit of the rapid warm up oven found in a lot of  
receivers, the 9442-12 and have fixed those, there is a ceramic cap that  
frequently goes wonky.  The two 9420s I have fixed were just broken  
wires; they seem to have used PVC insulated wire which degrades...  I  
haven't done the homework on those yet.

The 9420s I have do have an  EFC input as well as a stabilised Voltage 
out to feed it, and in the  receivers I have that use it [RA1795] the 
fine setting is done from that,  coarse setting from the top adjustment.
-------------------------
Hi Dan
 
I've taken a further look at the RA1794 manual and see now that it does  
confirm a fine tune pot being available when using the 9420.
Having opened up this oscillator I find there are  connections to every pin 
on the B7G connector so will assume until proven  otherwise that it does 
meet the interface spec shown in the 1794 manual.
I suspect the comments I've seen claiming most do not have the EFC  option 
is more a case that in many installations it isn't used, which  isn't quite 
the same thing.
 
Thanks again for your comments.
 
regards
 
Nigel
 
 
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Racal OCXOs.pdf
Type: application/pdf
Size: 59332 bytes
Desc: not available
URL: <http://www.febo.com/pipermail/time-nuts/attachments/20110824/0cb7d927/attachment-0001.pdf>