tuned circuit for FSK LNA amplifier

hi for all

i make LNA at range between 45&49MHZ for FSK receiver

i want to make two tuned circuits at input of LNA for desired frequncies

the qustion now can i find coil in this range with high quality factor?

Selfmade coil in most case.. you can incrase Q-value if you winding with flat copper strip from copper sheet compare to circular copper wire. - circular geometry is best shape to make most possibly skin-effect... flat shape or Litz-wire give lot lower skin effect compare to massive circular wire.

with circular massive copper wire you can make around Q = 200 , possible 300 in best case , but with flat copper strip I succesfully make near Q=450 in my try to make band reject filters in 70 MHz range (reject deep is _very_ depend of Q-value... and one of methodes to measure Q-value).

How can I make that flat copper coil? do you mean copper on board?

Thanks in advance,
Ahmad,

simular

I use buyed copper-sheet around 0.1 - 0.2 mm thickness (Im in vacation, cannot check thickness on my work just now)

copper on FR4-board is litte for thin and more or less hydrogenium hardened (from plastic/glue over long time and/or electroplating process, its not same 'plastic' as copper wire/sheet or new glown small copper oil-pipe) and often brittle and easy to broken/cut itself in very hard bend (for example moment to draw off from FR4-board).

but, you can try, easiest way is using hot air-fan to soften glue between board and copper sheet and start lift copper from corner.

Thank you xxargs,
But, sorry, i'm still unable to imagine the process you described above, can you give simple illustration drawing for the process of that coil!?

Thanks alot..
ahmad,