Thanks for the extra info.
I want to try this out (to see the maximum distance I can get in real life).
Is this pulse amplitude modulation? No.
What parameters do I need for the IF transformer? Searching online, I found a few IF transformers and they have things like turns ratio, impedance prim, Sec, etc. I'm not sure what these things mean exactly and how to figure out the required IF transformer from the schematic.
The transformers are standard Radio IF 455-465KHz, you could buy [once] 135KHz transformers, specially for this type of application
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