[time-nuts] Equipment question: OCXO versus GPSDO + XTAL

[Wolfgang]

Hi,

I'm new on this list. 

Right now, I'm planning to buy a brand new Agilent 53230A frequency 
counter (350 MHz, 20 ps, 12 digits/s, 2500 EUR). 

I'm wondering whether it is worth investing into a built-in OXCO timebase 
option when ordering the 53230A since that adds 950 EUR. 

The alternative would be to go with the standard timebase and connect 
a GPSDO like the TBolt or a Rb-based oscillator to the 10MHz reference 
clock input. Or, to use the both OCXO option AND the GPSDO/Rb clock. 

Opinions needed based on experience with other devices: Would you think 
buying the 53230A with a built-in OXCO timebase gives better performance 
for any measurement than using the standard clock with an accurate external 
reference?
Or, how would "OCXO option + GPDSO" compare to "standard osc + GPDSO"?
(Especially for usual gate times 10ms to 10s.)

Regards,
Wolfgang, DL1SKY



Known specs are: 

Standard oscillator: 
  ??? / day
  0.2 ppm / month
  1 ppm / year

OCXO option:
  0.3 ppb / day
  10 ppb / month
  50 ppb / year