Re: A simple 60 meter CW transmitter
Hi Dennis,toggle quoted messageShow quoted text
This is useful information but will not help a project like mine. Xtals directly on the operating frequency will be usable in a CW transmitter with a keyed xtal and straight though amplifier chain. It could work in a phasing type SSB transmitter. My project involves a 9 mc xtal filter and thus a ~9 mc carrier oscillator in the SSB generator and either ~4 mc or ~14 mc heterodyne xtals to arrive at an operating frequency on any of the five (actually ten) channels in the 60 meter band.
Xtal oscillators with temperature compensation or outright ovens can provide some of the best frequency stability and phase noise performance. Free running L-C VFOs can also be very good in regard to phase noise performance but will fall behind the xtal oscillators in holding a channelized specification as in the 60 meter band. It can be done. I would prefer xtal control of the five channels since I also anticipate field operation when we are working with those government agencies in emergency situations (if that ever happens). It seems to be the cleanest, most stable way to keep a radio on the button in adverse environments.
For a club project, the CW transmitter with keyed xtal oscillator directly on the operating frequency (center of channel) will be much less complicated and less expensive. Never mind about smaller, too.
Now to look at the ~5 mc xtals for use in my antique (more than 25 years old) heterodyne radios in the xtal socket substitute for the VFO.
On 06/16/2015 06:17 AM, firstname.lastname@example.org [4sqrp] wrote: