[time-nuts] EFRATOM FRK Lamp Voltage

[Joe McElvenney]

Hi,

   A few years back I obtained a Racal-Dana rubidium standard with
a EFRATOM FRK-L fitted. I was concerned that the indicated lamp
voltage was about 5.5V where the book says it should be between 6
and 12V. Subsequently I obtained another lamp from a surplus
source hoping that the voltage would move upscale when changed.
Unfortunately it didn't and has stayed around 5V, slightly lower
than the original. I can't put the old one back because I cracked
the glass when prizing it out of the sealing compound.

   So, was I seen off or is this typical of the voltage spread
likely to be encountered? I must say that the unit locks up
quickly enough and works fine as far as I can see. I realise that
the lamp voltage is only the output voltage of the first op-amp
after the photo-diode and may not be a reliable indication of its
true health.

   Anyone know of a cheap source of spare lamps?


   TIA - Joe