Basic FM transmitter modulator part 2
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- Опубликовано: 19 окт 2024
- WARNING please check with your local EMI regulations and everything done in this video uses a passive dummy load.
The FM transmitter modulators is now built on a proper PCB with drilled holes which makes the circuit more stable.
I'm so into this, salutes from Spain!
In the Netherlands we (as pirates) used to use this oscilator too!
It can be found as: Josty Kit HF 65 - Google is your friend on this one!
unfortunately the builder had forgotten an LF amplifier,
This ensures (A bit more) that the oscillator remains more stable!
(the wiring from the sound source to the oscillator can cause instability!)
There are more mistakes made but we will forget to discuss them in this case!
Healthy and Friendly Greetings from the Rotterdam area!
Rob
Thanks Rob
@@ReedSwitchTube Just be careful with that 2N3866, unfortunately I can't buy them anywhere here in the Netherlands anymore!
Even decent good trimmers are rare!
Have you made a transistor LF amplifier for the oscillator? it shields the oscillator and provides more stability
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On KorteGolf you can also create nice transmitters,
AM modulated at 6300KHz with an inverted V antenna you can go terribly far!
Greetings from the Rotterdam area!
Rob
@@hobbyrob313thanks Rob, one good things is that I’ve kept dozens of genuine 2n3866 and 2n4427 made by centrisemi USA. Trimmer capacitors are getting rarer to find now days. You can still buy tiny trimmer capacitors cheaply which is good up to 15 watts before rf heating becomes a significant issue. Ceramic trimmer shown in this video can handle up to 30 watts where as plastic polymer insulated trimmer is good up to 50w with good cooling. The rarest type are mica compression trimmer, which I’ve seen handle up to 150w.
To increase oscillator stability you could add a phase lock loop system, which is very simple to do.
Magyarországon a kalózadók ideje 10 éve már hogy lejárt, de azért vannak páran akik időnként a rövidhullámú sávokban szoktak adásokat adni. A kvarc oszcilátorok elég "kényelmes" megoldás. A középhullámot "elfoglalták" a Szerb és Orosz "elvtársak" a OIRT (keleti URH) viszont majdhogynem üres.