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. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
