EMRFD Message Archive 9919

Message Date From Subject
9919 2014-04-18 04:38:27 petervk3ye VXOs - pulling crystals up
Just wondering if anyone's experimented with pulling crystals up in frequency and what sort of range can be achieved. 

I have a 16 MHz HC49 crystal.  With a Colpitts circuit I can go up to 16.010 (which is approx 144.090 when multipled by 9).  I would like to go up to 16.023 (to cover 144.2, or at least 16.017 MHz for 144.150 MHz).  

Wondering if anyone can comment whether this is feasible, or whether it's too high. 

The circuit below loads the crystal with low capacitance and has some good results but not as high as I would like. 
9920 2014-04-18 09:49:02 kb1gmx Re: VXOs - pulling crystals up

I've not had much success in getting crystals to go higher.  At 16mhz 16.010 was about the best I could do.
Going down was far easier and 15.975 from 16.000mhz was easy and likely further was possible.


9921 2014-04-18 09:58:09 Alberto I2PHD Re: VXOs - pulling crystals up