Hello all,
I am trying to muliply a 72MHz crystal oscillator to 1296 MHz. My
first approach was to just make a series of X2 or X3 transistor
mulipliers to get the require X18 multiplication fact. However, I have
found two pieces of equipment in the junk box which just use diode
multipliers. One is an old Electrophone UHF CB radio which multiplies
the crystal oscillator by 17 (I think, from memory)then uses helical
resonators to filter the desired harmonic. The same approach is used in
an old King aircraft transponder where the 138 MHz crystal is multiplied
to 960 MHz with just a diode and uses the first two stages of an
interdigital mixer to get rid of unwanted harmonics.
So, the question is, which is the better approach? I just want a
reasonably clean signal source to test a 1296 MHz down-converter.
The diode approach seems simpler but is it likely to contain more
spurious signals than a transistor multiplier chain?
Alan
VK2ADB