i'm doing my mini project of jamming the vhf band of 3 specific frequencies.Its a low power vhf band jammer.
the suggested frequencies will be
a. 97.6MHz,
b. 191.25Mhz
c. 197.25Mhz
i'm thinking of using a relay to switch between these sub-circuits.
QUESTION
a. is't possible of using a relay to switch between the sub circuit of the frequency
b. what will be the range of value for the capasitor/inductor and it's parameter
c. other suggestion regarding the project
The frequencies are so high that a few pF of stray capacitance will change the frequency that is calculated. You must make it on a pcb then try it.
Don't use a breadboard that has very high stray capacitance and stray inductance.
TV tuners use PIN diodes to switch inductors and use varactor diodes (variable capacitance diodes) for tuning. They don't use relays.
curious,,,do a pll work for all type of frequencies...i was thinking of using separate vco for the different frequencies integrated together before pumping the signal into 'a' pll and a rf power amplifier....
if you use a single PLL you would need an adjustable divider and or multiplier for the 3 frequencies, i dont see a way to harmonically relate them but that was just looking, i didnt do any math YMMV