[time-nuts] External Frequency Standard Inputs on Counters

[Ed Palmer]

I see that on many counters (e.g. SR620, HP 5370, HP 5372) the external 
frequency standard input has an impedance of 1Kohm.  Why such a high 
value?  Are they implying that it's acceptable to daisy-chain a single 
reference to multiple devices like an old 10Base2 ethernet network?  
Should such a link be terminated in 50 ohms like a 10Base2 network?

Ed