I made a silly ebay "make an offer" on a 1992 and the dude accepted it. Didn't expect that
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
After replacing all the switches I noticed the reference was surprisingly good. Turns out it's a "04E High-Stability" oven. Cool.
Option 04E High Stability Ovened Oscillator
Frequency: 10 MHz
Aging Rate: ≤ 5 x 10^-10/day at shipment averaged over 10 days
Temperature Stability: ≤ 7 x 10^-9 over the range 0°C to 50°C
Line Voltage Stability: ≤ 5 x 10^-10 two minutes after a 10% line voltage change
How good is that relative to modern references?