Greetings from Dublin Ireland. Really wished you could get some kind of crowdfunding and upgrade to 2.5 or 5kW transmit power, and the daily cost of electricity for that. No hope of getting you from my distance if you are 100 and 200W. I will be in North Luzon in the Philippines in a month and will try from there on my Sihuadon D808. Regards

That was really interesting, thanks for sharing Peter! de vk2moe

Cool! I love QSL cards

Thanks for this. Unfortunately, my issue isn't addressed. Mine transmits, but the receive circuit has a constant audio tone oscillating much like a digital signal would sound

Thanks I was never really sure how the bureau worked. I was told I could come and dig through the huge pile to see if I had any or I could get them shipped to a club. I just live too far away from any clubs or the bureau to make it worth it. Anyway Thanks for the video.

It doesn't look like you are any more interested in QSLing than I am. I've never felt any desire to trade cards. When I'm DXing on HF I just like to find out about people and their locations.

Have these cards been sitting around in buros for 10 to 15 years? Blimey! What if you QSL back and it takes as long, half these guys would be SK by the time the exchange was done!! 😢 Do they offer posthumous DXCC?

Saudações !!! Fiquei nostálgico das trocas de Cartões QSL. TKS & 73 !!!

A real sense of romance in these cards. I might get some? I was thinking about getting my Easter Island one but they wanted 5 pounds....bit rich for this miser 73 de George VK2AOE

Any way to use crytals for a notch filter instead of a band pass?

If your address being public was an issue, get a PO Box or use your club's PO Box.

That is a clever idea.

Could you be more specific about the type of piezo transducer?

Some years ago I built a single FET regenerative radio. This too called for some high impedance headphones. At first I used a crystal earpiece, but a pair of 600-ohm headphones, about 80 years old, which, in the 1950s, my uncle had given to my brother and I, together with a home-made crystal set, also worked pretty well. A supplier on e-bay suggested using an Eagle products LT 700 transformer, together with a modern 32+32-ohm headset, with the earpieces in series, making 64-ohms. This transformer was a driver transformer for a transistor radio push-pull audio output stage, using germanium transistors. They were common in the '50s and '60s, but were no longer needed when silicon transistors became the order of the day. This also worked well, using the centre-tapped secondary as the primary winding and connecting the tip and ring of the stereo plug to the primary. This isn't a very accurate impedance match, but modern magnetic materials produce much stronger magnets than the old 'phones, making modern headsets, even cheap ones like I used, very sensitive. There's also an Eagle Products output transformer, type LT44, which was used to drive a 3 to 8-ohm speaker. This didn't work very well. These two transformers are often supplied as a pair, and , rather surprisingly, are still available.

Thanks Peter! Great tip for the youngsters!

Thanks Peter. Very innovative and very clever...

Wow, amazing!

Thanks... If you have time to send me a link to a regenerative receiver schematic that is reasonable, but not over the top in complexity I would really appreciate the effort. I found a schematic in 2009 that I followed and the result was excellent. I moved and lost my receiver in the process. I tried to build off two schematics found on line several years ago and either I or the schematic was lacking because each was a failed attempt. I don't want to give up & surely wish I had kept the schematic from 2009. I am aware of ARRL's Kitchin design that's linked at their site. I'd use it, but I am a retired mathematician and the symbolic representation indicating antenna coupling is unfamiliar to me. If I were to guess I'd say the antenna circuit was loose coupled to the LC circuit that can be thought of as the tuner in the system. I am aware not every regenerative receiver uses such a scheme and my first sucessful receiver did not, but it did use a tickler coil. I'd really hate to try the ARRl design having guessed wrong, thus I am avoiding it & it seems other designs I've tried are insufficient thus any good, but not overly complex design would as indicated be greatly appreciated.

I know these: 2.15 dB = 1.64 3 dB = 2 6 dB = 4 10 dB = 10 20 dB = 100 and so on...

Dr Peter Crystal! 😂

Hi Peter, where can I get a transducer and what do you actually mean by it?

Hi Peter, That's an unusual way of using a piezo transducer to solve a needed problem. 73 WJ3U

i would be weary of transmitting that close to the SDR as it can fry the front end of it, if not careful..