7 ways to cut chirp in a simple QRP transmitter

[@davkdavk]

Excellent information. I'm venturing into QRP CW as we speak. Cheers VK5DR

[@tomgeorge3726]

Good video Peter, I was getting worried that you took towards the end to point out a well regulated power supply. It would possibly be the most important criteria for stable operation.

[@raafatalheety826]

Yi1hxh rafat 73 from baghdad iraq

[@TheArtofEngineering]

Thanks Peter, I'm finding this all out! Presently I have a 40m transmit stage that isn't too chirpy but the power drops as I transmit for a longer time? Think it might be the driver for the BD139 transistor. The driver is a 2n3053 in a TO-39 metal case. Might try a heat sink on it? Great video 73 de VK2AOE

[@vk3ye]

Yes, definitely have heatsinks on both transistors.

[@Paul_VK3HN]

Send faster?

[@TheArtofEngineering]

@@Paul_VK3HNif only I could!!! 😂😂

[@TheArtofEngineering]

@@vk3yethanks peter

[@tim46767]

Why not key the buffer?

[@FarleyHillBilly]

Inter electrode capacitance changes with applied voltage. Keying the buffer will alter the VFO frequency causing chirp.

[@tim46767]

​@@FarleyHillBilly What kind of electrode? We're not talking about tubes. Anyway. That makes no sense at all, since the power amplifier needs much more. That's why I suggested keying the buffer and not the final stage.

[@FarleyHillBilly]

@@tim46767 Collector to base capacitance. Google ' W1FB Solid State Design for the Radio Amateur ' for a free PDF.

[@thomasvandevelde8157]

@@tim46767 Transistors are actually a LOT worse with inter-electrode capacities than most tubes. Excluding VHF-to-SHF FETs ofcourse. But generally, bipolar transistors have parasitic capacitances much worse than any vacuum tube. Especially the Emitter-Base capacitance can be very large (and works as a varicap basically)

[@tim46767]

@@thomasvandevelde8157 Why are you talking about tubes? Neither vk3ye's video nor I mention tubes. Again, it's about where to switch. Watch the video and read my answer. What you're saying is pointless.

[@TridentMissileTech]

I like the chirpy sound. Not all the time but it’s not that common in US. And when I hear it I think, wow a cheap unit getting out and sounding different enough that it draws you in.

[@vk3ye]

Agree. Only a little chirp though. Too much is hard to copy under weak signal conditions.