[Elecraft] K3 dumb Q about PPM

[Art K6XT]

Gents
Lots of confusion about oscillator specs. Allow me to add more.

Specs on TXCO's are given at specific conditions. Deviate from those 
conditions and the spec does not apply. In deviating conditions one must 
review the manufacturer's spec sheet to discover how the TXCO will respond.

The PPM spec only refers to long term drift, as defined in the 
manufacturer's specifications. It has no bearing to short-term changes 
in room temperature as suggested in some of the posts. Again, see the 
manufacturer's specifications. This is exactly why the (for example) K3 
has a TXCO alignment procedure. So that a picky user can adjust the TXCO 
exactly on frequency under a specific set of operating conditions. 
Deviate from the alignment condition, the TXCO will respond by deviating 
from "perfect" alignment. The need to control temperature change and 
remove heat is exactly why industrial and military electronics are often 
in cold climate controlled spaces where the temperature never varies and 
the carbon units wear sweaters.

Lastly, for the newer folks, be happy. We hams used to be in the 
business of chasing each other up and down the bands as our oscillators 
wandered randomly about. Receiving station wanders one way, transmitting 
station wanders the other. Many newer folks may not even know what 
"youp" means. These days just about any rig worthy of the name newer 
than 20 years old is "rock solid" from turn on +1 minute. And quite a 
number, "rock solid" from turn on plus 10 seconds. Try that with the old 
Hallicrafters with the valve handwheel knobs where a sharp rap on the 
desk sent the rig five kHz up the band!

-- 
73 Art
Allison, Colorado
"Whether you believe you can do a thing or
not, you are right."  --Henry Ford.