Need Help On This Circuit

[Ayne]

i found on the net.
this is a data transmitter circuit.
opreating frequency = 418Mhz

what will the value of resistors, capacitors and coils.

can any one explain for me

 

[RadioRon]

This circuit is not useful without the component information and I doubt that someone will post the values for the components. You should ignore this example and go find one that has complete information.

 

[Nigel Goodwin]

I would further suggest you buy a pair of ready made licence free radio modules - these are legal to use, making your own probably isn't. You should also be aware that building UHF radio gear requires VERY, VERY careful construction.

 

[Dr.EM]

Just while were here, about construction of VHF/UHF circuits. Is point to point wiring good? If the circuit is simple like this, it would be an option so long as it didn't need to be very compact. Either using tag boards or joining component leads together.

 

[Nigel Goodwin]

Just while were here, about construction of VHF/UHF circuits. Is point to point wiring good? If the circuit is simple like this, it would be an option so long as it didn't need to be very compact. Either using tag boards or joining component leads together.

NO!!! - construction is critical, VERY short wires and good layout are essential, as is STRONG construction, half on inch of wire is a considerable inductor at these frequencies. Use either normal PCB construction (with the board designed specifically for UHF use), or solder short leaded components directly to 'islands' cut in the copper surface (a very old amatrue radio technique).

If doing it on veroboard (which is seriously pushing things!), remove all unused tracks and portions of tracks - AudioGuru's 'bug' layout is a good example, but bear in mind that's only VHF and about 1/4 the frequency!.