duffy
Well-Known Member
Glad to hear you got an increase in range already.
Bypassing the RC network can cause mismatch, that's why I suggest making the resistor smaller.
Yes, the circuit ground, case, shield, etc. should all be common - I suspect if you check the copper "pours" they will all lead back to ground. (otherwise, they would all just be a load of parasitic capacitances...)
Yes, a dipole will add gain - but you are already part way to that. Your case is the other half of the dipole, whether you like it or not. Sorry! That's just how these kinds of FM transmitters are usually designed. Tank and a transistor, nothing fancy, L7 is probably the coil on the tank and if it doesn't already have a lead grounded it will have a path to ground through the transistor that drives it.
I'm thinking you probably want to add the radials to the case itself for the lower half of the dipole. If that hole's so small it could touch you definitely want to drill it out bigger.
Bypassing the RC network can cause mismatch, that's why I suggest making the resistor smaller.
Yes, the circuit ground, case, shield, etc. should all be common - I suspect if you check the copper "pours" they will all lead back to ground. (otherwise, they would all just be a load of parasitic capacitances...)
Yes, a dipole will add gain - but you are already part way to that. Your case is the other half of the dipole, whether you like it or not. Sorry! That's just how these kinds of FM transmitters are usually designed. Tank and a transistor, nothing fancy, L7 is probably the coil on the tank and if it doesn't already have a lead grounded it will have a path to ground through the transistor that drives it.
I'm thinking you probably want to add the radials to the case itself for the lower half of the dipole. If that hole's so small it could touch you definitely want to drill it out bigger.
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