[time-nuts] Spectracom 8140 distribution amplifier and the Taps- some application info

[John Ackermann N8UR]

I'm not sure if there's been other data posted, but a few years ago I 
did phase noise measurements of the 8140T as well as HP 5087A and 
TADD-1.  That info is at

http://www.febo.com/pages/amplifier_phase_noise/

I got my hands on a tub full of 8140Ts but don't have the 8140 driver. 
However, all you really need to drive the taps is 10 MHz at ~10 dBm (not 
sure the exact spec) riding on 12VDC.

I built a power injector to put 12V on a 10 MHz sine wave tapped off the 
10811A output in a 5065A Rb and used that to drive a string of about 10 
8140Ts in my old lab.  I terminated the string with a blocking capacitor 
and 50 ohm load; you need the capacitor to keep the DC off the load.

As has been pointed out, the 8140T isn't the lowest noise distribution 
system you can get, but it sure is a convenient way to put a bunch of 10 
MHz spigots around the basement and the performance is adequate for 
anything but the most critical applications.

John