Hi If you run a filter with a shunt capacitor input (as opposed to the series L proposed by Charles, the current in the driving gate goes way up. It’s driving a short at the harmonic frequencies and it does not like this. If you want more power with a simple T, just run the T. No resistor at the input or output. You can get > 18 dbm this way. A single gate providing 18 dbm probably will not last very long. A gate in a “3.3V only” family may not be happy with the ringing on the filter input. This of course begs the question - do you *need* more than 18 dbm?
Bob > On Jul 16, 2015, at 11:10 PM, D W <[email protected]> wrote: > > Hi, > > A while back I ordered an item of equipment from a very excellent eBay > seller, johnkw40. He may be a member of the list, I'm not sure. He included a > schematic for a low pass filter circuit to filter a 10 MHz square wave to a > sine wave. > > A quick analysis shows that it is a 5th order chebyshev filter with a cutoff > frequency of about 14MHz. You could do better, but this filter can be built > with only five standard value passives, which is quite convenient. > > I made a little SMT version of it and ordered the boards on OshPark. It seems > to work pretty well. The circuit schematic and a screen shot of the response > is attached. Any comments from the list on how that looks would be welcome. > > Dan > > <image2.png> > >> On Jul 16, 2015, at 10:49 AM, skipp Isaham via time-nuts >> <[email protected]> wrote: >> >> re: 10MHz Square to Sine Wave Conversion >> >> The GPSDO I recently acquired outputs a 10 MHz square wave. I'd like >> to convert it to a sine wave and I am looking for suggestions and info re >> any reasonable pre-made circuits and/or boards. No sense reinventing the >> wheel if I can avoid it. >> >> Otherwise I will start Sent from my iPhone >> >> Thank you in advance for your replies. >> >> Regards, >> >> skipp >> >> skipp025 at yahoo dot com >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
