Crystal Control for the Knight Wireless Broadcaster
Posted on May 11, 2007
I have a vintage Knight Wireless Broadcaster, as I mentioned in an earlier post. It has been the subject of fairly extensive modifications, entirely in the audio department to date. I use it with an isolation transformer so that I can directly ground the chassis to earth ground. 🙂 It will deliver 100V p-p of RF directly to a 10′ wire antenna without any attempt at matching.
Where it falls down in comparison to today’s LPAM equipment is in the use of an unstabilized carrier frequency. It’s hard to enjoy listening to your station when there’s always a whistle or hum in the background. In the past, I’ve seen some circuits for modifying the Knight to use crystal control, but haven’t run across any lately. If you modified your unit to use a crystal, I’d like to hear what you did, and how it worked out.
My SSTRAN is just fantastic in this regard. There’s no carrier frequency adjustment, yet the unit is right on frequency and drift is imperceptible. I’m never going back to using a free-running oscillator…