[time-nuts] What does PCB with 10811 oscillator do?

Marco Bruno IK1ODO at spin-it.com
Sat May 21 15:33:50 EDT 2005

At 19.01 21/05/2005, David Kirkby wrote:
>I bought a 10811-60111 which was attached to the PCB shown in this photograph:
>Can anyone tell me what it is? It seems to have some logic on it (74LS90N, 
>74LS158N) a pot for the fine adjustment of frequency, a couple of trimmer 
>capacitors, a Motorola 1820-1052  and another chip that looks like 
>1820-n439, but I may be wrong.


There is a PLL to lock an external frequency reference in the 1-5-10 MHz 
range, some buffers/multiplexers for the oscillators, power supply 
stabilization for the oscillator, and the EFC circuit. This is definitively 
the oscillator board of HP 5328A/H99 or /H98 or /E22 or AN/USM-459.
The schematic is online (for a couple of days) at 
www.spin-it.com/download/5328A.pdf . It comes from LOGSA, so HP should be 
happy ;-)
Look around page 175.

73 de Marco IK1ODO

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