some years ago i spent an obscene amount of time trying to build some
xtal 27 mhz radio control transmitters which i think are still legal in the uk http://www.ukrcc.org/27mhz.html i say some, because although pretty basic i could never get the output stage to tune, this was usually a pi type arrangement with one or two variable caps,which i think was high pass filter,ariel matching. i would have thought a band pass filter would have been better.
found a brilliant site for designing filters http://www.aade.com/
i had no equipment for checking frequency etc
now ive a bit more time and a bit more cash im having another go,
so any suggestions regarding equipment and getting these things to work, particularly anyone whose been down this road would be most welcome.
the statement on your forum that commercialy available stuff is a far better bet than building your own is perhaps never more true than with this... but its not the same,also if you buy something and it goes wrong its usually scrap but if you build it yourself you can usually fix it.
regards
dougal
xtal 27 mhz radio control transmitters which i think are still legal in the uk http://www.ukrcc.org/27mhz.html i say some, because although pretty basic i could never get the output stage to tune, this was usually a pi type arrangement with one or two variable caps,which i think was high pass filter,ariel matching. i would have thought a band pass filter would have been better.
found a brilliant site for designing filters http://www.aade.com/
i had no equipment for checking frequency etc
now ive a bit more time and a bit more cash im having another go,
so any suggestions regarding equipment and getting these things to work, particularly anyone whose been down this road would be most welcome.
the statement on your forum that commercialy available stuff is a far better bet than building your own is perhaps never more true than with this... but its not the same,also if you buy something and it goes wrong its usually scrap but if you build it yourself you can usually fix it.
regards
dougal