[time-nuts] Ebay FE-5680A Rb I see the price has gone up for these

Bob Q quenbob5 at pacbell.net
Tue Dec 20 13:46:38 EST 2011

I also got an FE5680A, what a deal.  Thanks to earlier postings I had the 
correct pin out, info on the 1/16 hex key and the command set.  It needs 5V 
on pin 4 to operate.
After 24 hours mine ran 6 mHz low compared to my GPS-based 10 MHz.
I opened the case by removing the 2 flat head screws near the connector and 
the 2 pan head screws in recesses in the center of the base plate.  I 
noticed what looked like smoke residue from a blown part, as have others, 
but no sign of a bad part.
The LPRO-101 has a flat surface and a thermal pad for heat transfer over the 
whole base.  The FE-5680A injects heat into the base plate in the center and 
sinks it around the edges.  Good magnetic shielding and thermal transfer may 
require using most of the 16 mounting holes.
I found "Termite 2.7" from CompuPhase worked to communicate with the 
FE-5680A in Windows.  I set the COM port, 9600 baud, local echo, append 
nothing and hex view.  I sent 0x2D040029 to get the offset.  The "0x" lets 
the program know the number is in hex.  My offset was 0, same as others have 
mentioned.  Possibly the FE-5680 was controlled externally to sync up the 
1pps output to GPS using the "set temporary offset" command.
I wonder if there's a status command, analogous to the lamp voltage test 
point on the LPRO-101.

-----Original Message----- 
From: Chuck Forsberg WA7KGX N2469R
Sent: Monday, December 19, 2011 2:25 PM
To: lists at lazygranch.com ; Discussion of precise time and frequency 
Subject: Re: [time-nuts] Ebay FE-5680A Rb I see the price has gone up for 

My 5680A arrived today.  Mailman demanded a signature.

This thing requires plenty of current to get started.
My Tek CPS250 1.2 amp output (A+B parallel) only gets 7.5 volts.
Now to scrounge something a bit bigger.

Chuck Forsberg WA7KGX N2469R     caf at omen.com   www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
   Omen Technology Inc      "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231   503-614-0430

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