[time-nuts] LPRO testing

[iovane at inwind.it]

lists at rtty.us wrote:

>The main questions on the lockup sweep is going to be:
>
>1) does it make it to / past the right frequency? 
>2) how soon after it does get there, does it lock up?

It crosses the right frequency a few times until lockup, in both directions.
According to my experience, typical lockup time for a healthy unit is 3.5min.

>3) if it doesn't lock up, does it do something odd as it sweeps past the 
right frequency?

It may get stuck at either end of the sweep span. Normally the sweept voltage 
(as available at the voltage monitor output) should vary between about 0.5V and 
12.5V and vice-versa. If it reaches 0V or about 14V then one of the voltage 
comparator circuits failed, and the unit gets stuck. 0.5V and 12.5V are preset 
thresholds for the voltage comparators. I happened to come across both cases, 
and the failing components were 100K resistors.

Antonio I8IOV