i guess, i didn't explain the nature of the problem clearly. i CAN
tune my current transmitter easily. I just don't think that many will
be able to do so as i am building this as a club project.

The reason is that .. it is easy to mistune your transmitter to
another harmonic. this is especially true of VHF where the preset
capacitors can swing a wide frequency range within their 22pf range.

i was thinking that, instead, it might be a better idea to depend upon
generating the signal directly at 144MHz.

that said, as of now, i am continuing to use the a crystal at 18MHz
fundamental and multiplying it through three balanced doublers to
144MHz. In my second version, i have replaced variable capacitors in
the doubler outputs with fixed capacitors and tunable inductors. that
way, i hope to be able to restrict the tuning range of each doubler
output centered around the required second harmonic. it is tough work,
but that is what differentiates homebrewing for yourself from
homebrewing for a group project.

- farhan