Lee. I would be very leery of using this as a VFO. You are going to have to do a ton on technical work work regarding birdie and spur analysis and you will need some good test equipment including a spectrum analyzer. It is not just a matter of thinking about harmonics. DDS generators can be pretty dirty of not well engineered and implemented.
Regarding the "mute function" during receive. I doubt that it has provisions for this and you are going to have to do some real analysis of the guts of the thing to see if this can be implemented either in a mute or shift manner. 're the doubling and tripling to get up to 20 and above, yes you could do this. This kind of approach - regardless of signal source, depends upon distortion of the waveform in the doubler or tripler - etc. - in order to generate harmonics. If you look at the oscillator waveform of a crystal calibrator, you may not like what you see. The waveform is intentionally distorted in order to generate harmonics all the way across all bands up through 10 meters. It all could work, but you have a nice engineering job in front of you. Some may even say they have "done it" but without the engineering, be careful. Bill N7OTQ -----Original Message----- From: Boatanchors [mailto:[email protected]] On Behalf Of Lee Sent: Sunday, April 09, 2017 8:42 PM To: boatanchor <[email protected]> Subject: [Boatanchors] Possible VFO??? Could you use this generator as a VFO? Would you need a low pass filter for it? For 40 meters and above, would you use a 40 meter signal for all bands 40 thru 10 meters? I suspect so as most old boat anchor rigs used 40 meter crystals for 40 meters and above. Then the next question is how do you mute it while receiving. I'm wondering if there would be a way to move the output frequency while receiving. Possibly a fast acting relay could switch in the generator while transmitting and switch it out while receiving. I'm not sure how much radiation would come out of the plastic box while receiving if it was still on the operating frequency. (This is assuming we are operating on 40 meters and the generator was on 40 meters.) It certainly has enough output power to drive a boat anchor. Anyone on here experimenting with this concept? Lee, w0vt http://www.ebay.com/itm/351825634342?_trksid=p2057872.m2749.l2649&ssPageName =STRK%3AMEBIDX%3AIT _______________________________________________ Boatanchors mailing list [email protected] https://puck.nether.net/mailman/listinfo/boatanchors _______________________________________________ Boatanchors mailing list [email protected] https://puck.nether.net/mailman/listinfo/boatanchors
