19-04-2012, 09:29 PM
(19-04-2012, 12:34 AM)Skywave Wrote: Hi Lawrence,
I've been sitting here with pencil and paper trying to produce a block diagram to figure out the overall idea: and I'm sorry, I'm stuck!One thing does cross in my mind: since your detector has a tunable bandwidth of 500 kHz, surely this means that your 3 MHz I.F. must have a bandwidth of from 2.75 MHz to 3.25 MHz, i.e. centred on 3 MHz ? Therefore, irrespective of your method of deriving the local osc. freq., surely that means, in turn, that the necessary pre-selection before the mixer needs to have a selection of tuned circuits similarly tuning in 500 kHz segments. And that is a lot of L/C ccts. to cover the whole S/W spectrum !
It's obvious I've misunderstood thingsSo if you could send an attachment with a block diag. explaining your idea, I would be much obliged; thank you.
Cheers,
Al.
Hi Al, when tuning the tunable IF the RF tuning can be set for max signal for any point on the RF range selected, none of the tunable circuits are ganged. Any help/comments welcome.
Have also replied with better description etc and preli. block diagram.
Lawrence
