Someone build this for us all to use in SDR! I want to mention an idea I once had in the 80's I told someone about and they said someone had done it but I never did run across an example of anyone doing it anywheres since then. Maybe it is out there somewheres. Its a PLL idea. A logical circuit evolution of sorts.
You can take a frequency counter and sample its latter digits and then use that data as a PLL control where the frequency counter loops to the vfo with a vco signal to a Varicap diode. This means you have to unlock it then tune the vfo and then relock it. I did see an idea not long ago close to this idea somewheres on the net, but it was not exactly as I see it here. This will make sine wave vfo's popular again. But you can keep your square wave detector circuits in the i.f. so don't get me wrong here. The vco control signal is a matter of sampling an up or down count movement in the frequency counter in the finer resolution ranges of the circuits dividable counters. A simple chip or two and a transistor and perhaps a diode are required in the sampling circuit to create a vco voltage. I suspect that a high resolution frequency counter that runs in real time terms; and not at a slow gate period, will be best. Sampling the digits in the 10 to 1 Hz range. The idea can then become standard in most frequency counters sold for amateur radio use. And work with any vfo idea one has. Which means that it is a universal application for all vfo's. I feel that the vco signal must have a good amount of current so that one can use two or three Varicap diodes parallel or merely one depending on the frequency of the vfo. VLF range vfo's might require two or three parallel Varicap diodes to do the trick in obtaining enough capacitance change. Hence this is for VLF to HF use. A parallel resitor to the Varicap diode circuit will match the current load when only one Varicap diode is required in a vfo. If anyone runs across an idea along these lines or even developes a circuit for this then let us know. This really is a logical idea and a most usefull idea. And its about time it was made. Finally, a simple circuit board can be made that can be added to any frequency counter; will also do the trick. I hope it seems simple enough an idea and hopefully will be simple once someone with fast designing abilities gets ahold of an idea for it. Dan _____________________________________________________________________ Call Anyone, Anytime, Anywhere in the World - FREE! Free Internet calling from NetZero Voice Visit http://www.netzerovoice.com today! Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/soft_radio/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
