perbedaan wfm dengan nfm
Well, Thanks again, you really helped me a lot!
As I'm talking about a transmitter (It's NFM now), and as I need it to be as WFM as it can be, I understand that I have to amplify the Audio or change the Varicap.
What I'm trying to do is to change both frequency and modulation mode of a small transmitter working on the 123MHz band. It uses a 24.700MHz crystal, so it works on the 5th overtone. I'm trying to use a 16MHz crystal - but it's pushed to the 9th overtone (about 176MHz).
I haven't tried to do reverse engineering on this particular circuit, but from what I could see, it has 2 multiplying stages, but here is something that I cannot understand as well: supposing that the first stage is a "tripler" and the second stage a "doubler" I was supposed to get 23.7 x 6 = 142.2MHz, not 123MHz - and I'm almost sure it uses 2 stages... may you have any explanation on this?
By the way, placing the 16MHz crystal on the same circuit, the Audio is now VERY low.
Thank you for be so helping