02-11-2012, 09:32 PM
Thanks Guys, OK, I set it up again as outlined by Gary and to my joy, one of the IFT's resonates at pretty much exactly 470KHz. The other one was still off and unlike the good one, each side of the dodgy one resonates at a different frequency.
So, following the guidance from Lawrence I decided to see first of all if I could find fixed caps that would get me closer to the right spot. After much faffing around I found that one side would resonate at 468KHz with a 110pF and the other side would also resonate at 468KHz with 105pF (100+5 in parallel). It's not perfect by any means but I think I'll leave it like that for now and revisit once I get to the set going and can assess it's sensitivity, selectivity, etc. I'd be looking at fractions of pF to get it any closer.
I had the camcorder going while I was messing with it so I'll post a clip and you can see a newbie in action
Major thanks guys. As usual this forum proves to be the best !
Cheers, John
So, following the guidance from Lawrence I decided to see first of all if I could find fixed caps that would get me closer to the right spot. After much faffing around I found that one side would resonate at 468KHz with a 110pF and the other side would also resonate at 468KHz with 105pF (100+5 in parallel). It's not perfect by any means but I think I'll leave it like that for now and revisit once I get to the set going and can assess it's sensitivity, selectivity, etc. I'd be looking at fractions of pF to get it any closer.
I had the camcorder going while I was messing with it so I'll post a clip and you can see a newbie in action
Major thanks guys. As usual this forum proves to be the best !
Cheers, John
Time flies like an arrow, fruitflies like a banana!
