[time-nuts] HP5370A vs B version

[Frank Stellmach]

Hi Mr. Taka Kamiya,

the B version has a 500MHz front end, copied from the HP5345A, with a 
matched pair of amplifier / Schmitt trigger hybrids.
The A version has separate amplifier and Schmitt trigger ICs.

There were also changes on the trigger circuit.

Then the B version has a simplified µP board, has the OCXO 
(10811-60111), which is a must for absolute T.I. and frequency measurements.

Maybe the firmware was also improved a bit, I think mainly concerning 
the GPIB steering of the trigger circuit.

This T.I. counter is supposed to be superior over others of that era, 
because this special time interpolator was more linear.

I really love mine, so I don't want to sell it.

Frank