[time-nuts] 10811

SAIDJACK at aol.com SAIDJACK at aol.com
Mon Nov 17 20:32:47 EST 2014

On the PSTI message fields question, I am checking into it, will get back  
soon with an answer.
On the 10811, that OCXO can typically be mechanically tuned to have a  1.5V 
nominal EFC set voltage. The LTE-Lite can drive from 0V to 3.0V EFC, so  
that should be more than required on a good (well aged and good thermal  
stability) 10811. We have not tried driving a 10811 with it yet though, so can't  
say for sure. One requirement is that the OCXO has a positive EFC  slope.

In a message dated 11/17/2014 16:28:51 Pacific Standard Time,  
bill.riches at verizon.net writes:


Patiently waiting for my 10 mhz unit.  What are  your ideas on using it to
control a 10811 instead of the built in 10 mhz  osc?  Will there be enough
control voltage for the  10811?


Bill Riches
Cape May, NJ

-----Original  Message-----
From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf  Of S. Jackson
via time-nuts
Sent: Monday, November 17, 2014 6:40  PM
To: jim at jtmiller.com; time-nuts at febo.com
Subject: Re: [time-nuts] LTE  Lite Came!!

Hi Jim,

thanks for your question. The reason we put  that note in there is  

1) On these 20MHz units the TCXO  output in fact can drive 50 Ohms inputs as
we put a strong buffer on the  board, but the synthesized RF output and the
1PPS output cannot drive 50  Ohms. Those two are CMOS 1M Ohms input  only.

Using 50 Ohms  impedance on the TCXO output will however heavily tax  the
internal  power supply and CMOS buffer, and create heating on the board
right next to  the TCXO which will affect stability somewhat. So can it be
Yes.  Should it be done? That's up to the user to decide.

2) On the next  batch of 10MHz DIP-14 TCXO units the external TCXO itself
drives the output  directly without a buffer. That TCXO is not capable of
driving  50  Ohms inputs, only CMOS 1M Ohms inputs. So a buffer is required
on  these  10MHz units if 50 Ohms test equipment is to be used.

Hope  that explains it,

In a message dated 11/17/2014  15:27:21 Pacific Standard Time,
jim at jtmiller.com writes:

Hello  Said

I got a nice surprise in my mail today:  LTE-Lite!

There was a note with it that said (in effect) none of  the outputs are  
50ohm capable. So it looks like I should build up a  little board with the  
divide by two and incorporate on that a 50ohm  capable buffer for clock  
transmission to the rest of my  system?

BTW, you're welcome to answer via Timenuts as I'm sure  others will have  
the same  question.


Jim  AB3CV

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