Golborne Vintage Radio

Full Version: MC1496 Mixed technologies Pantry TX.
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Hi Jeffery.
One of the programs available for the SdrPlay is a spectrum analyser, very useful it is indeed. The output off the MC1496 is rich in harmonics, fortunately the output is very low indeed with a maximum range of 10 odd metres, once into the 1J18B there is a rudimentary tuned circuit that filters out harmonics very well indeed. A Pi tank circuit would be even better TBH. I do intend once I'm fully happy with the project to do another video showing harmonics and all the waveforms on the spectrum analyser and scope. Once I'm happy with it all and yes I may go back to fully solid state with this I'll consider getting a PCB made or even a few done as well.
Low power shortwave signals can sometimes go a very long way. http://www.gqrp.com/tech.htm
I don't know the world records but I think that milliwatts have gone halfway round the globe. As a pantry TX you will obviously be using an inefficient antenna which should help avoid accidentally being heard in Paris or Peking.
Oh yes I'm well aware of what and how far a low power shortwave transmission can go.
There is a very good resource you can use online and it's SDR receivers that are controllable from your pc, they are dotted around the globe. One I was told about is Kiwi SDR, which I've used in the past. I can tell you that 100mw can be seen, not necessarily heard many hundreds or even thousands of miles away, a blip on the waterfall can be made out, so beware that you use only a very short antenna that is not cut to the fundamental wavelength or a division of it. In the right conditions I'm certain that the signal level would be strong enough to be heard.
I'm hoping to pass the foundation and intermediate next year as I'm interested in QRP operation, with home built gear.
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