G'day, Time flies, I didn't realise it was so long since this was posted.
Regards, Mike VP8NO ----- Original Message ----- From: "KEN BROWN" <[EMAIL PROTECTED]> To: <[email protected]> | From: "John, KI6WX" <[EMAIL PROTECTED]> | Date: Sun, 24 Aug 2003 20:51:50 -0700 | Subject: [Elecraft] 4 MHz Oscillator Mod for Easier Adjustment | The reflector traffic seems to indicate that some folks are having | trouble | setting their 4 MHz oscillator to the desired frequency. I added the | following changes to my K2 4 MHz oscillator about 2 years ago to improve | both its settability and its frequency stability. The mod increases the | bandspread of C22 and significantly reduces the drift in the oscillator. | The drift reduction will only effect the K2 frequency accuracy if you do | a | CAL PLL at a different temperature than when you first set the 4 MHz | oscillator frequency. I haven't tested this change on any other K2 so I | don't know if it will work for all 4 MHz Xtals. | | The change requires two 10pF N750 capacitors. Replace C21 with one of | the | 10pF capacitors. Solder the other 10pF capacitor across X2, the 4 MHz | Xtal. | With this change, the correct frequency is obtained with C22 in about the | middle of its range. If you don't need the frequency stability | improvement, | you can use 10pF NPO capacitors. | | If this change doesn't work in your K2, it can easily be backed out by | removing both capacitors and re-installing the original C21. | | -John | KI6WX _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
