Видео

Yes

Yes. AustinMics.com

@@AustinMics it’s just what I have been looking for

The mat in this video is a smooth, self-healing cutting mat. The suction base of The Hot Holder is not intended to stick permanently to a vertical surface. It is designed to reduce slipping when pressed onto a smooth surface.

I think they are almost all 1N5711s really. There may be some attempts at making real ones that didn't work. I did a comparison in a video on my channel. ruclips.net/video/5y7I7G_a3Qo/видео.html If you find a better option, you may want to tell others who are doing xtal radio stuff.

It's not technically "impossible", but it's WAAAAAAY more complicated than that. You can't just insert a reverb pan into a circuit. You need a driver amp and a recovery amp that the GA5 doesn't have, and you need to match electrical impedances and signal levels. Get a Summer Reverb Pedal from www.AustinMics.com/reverb

@@AustinMics but a guitar pedal can be made from these springs. It’s not necessary to use lamps!

@@iBorsch You are correct. No Tubes, Valves, or Lamps are required, but real spring reverb requires two additional amplifier stages that are not in a GA5. Transistors or op-amps must excite the springs, and a recovery amplifier must increase the output level and impedance to guitar level. You cannot simply connect a spring pan to an existing amplifier by soldering wires to part of the GA5 circuit. You need to design and add TWO additional amplifier stages.

Actually the fake 1N34A schottky diodes work better in crystal radios, they give much better selectivity.

@@shahid3520 If the fake one is something like the 1N5711 then it seemed to me that the selectivity was about the same. What makes you think it comes out better? Remember that I am adding a 2K loading resistor to make up for the lack of leakage. If you have a good explanation, I would like to know it. More selectivity is a good thing if we can get it.

@@kensmith5694 5 years ago I made a magnetic loop crystal radio antenna and tried all kind of diodes, germanium diodes gave better sound quality but the selectivity was poor, I posted a comment on a video ' How to discern Germanium-Diodes from Schottky-Diodes' by KainkLabs, here is the comment : @shahid3520 5 years ago I used a fake Germanium diode sold as 1N34 which in reality is a Schottky diode, it gave excellent selectivity much better than true germanium diodes OA90, OA81 and a diode with two black rings. I tested them on a magnetic loop which is based on your design but made it 12% larger. Also tested 18 SWG and 175X46AWG litz wire, satisfied with both but the later much more expensive. There is a powerful local signal which was strongly interfering with two close weak AM radio signals. With germanium diodes I was unable to stop the interference but with the fake schottky diode the problem has been solved, stations tune very sharply. There is some loss of sound quality but still satisfactory.

@@kensmith5694 For a good selective crystal radio we would need a high Q LC tank and a diode that does not over loads the tank circuit.

​@@kensmith5694 Please find and watch the video by KainkaLabs You can read my comment there and also this explanation by KainkaLabs ' How to discern Germanium-Diodes from Schottky-Diodes' @KainkaLabs 6 years ago Germanium diodes have a dynamic resistance of only a few kOhms. Thereby they load the tank-circuit much too much so that the voltage breaks down. The remedy in the old days was that the voltage and (high) impedance of the tank-circuit was transformed down to match the dynamic impedance of the crystal-/germanium.diode and of the typically 2x2kOhm headphones behind them. Disadvantage: When transforming down the reception voltage you loose weak stations because every semiconductor-material needs at least a voltage of around 25mV to rectify at room-temperaure! (This is governed by the laws of physics and can´t be changed except by cooling down the diode down to sub-zero temperatures.) Schottky-diodes have a much higher dynamic impedance and are matched much better to the high impedance of a tank-circuit (in resonance). Thereby you don´t need to transform down the tank-circuit and have much a better result in receiving low-level stations. So Schottky-diodes make a much better use of the reception-voltage of the tank-circuit. I will explain this in great detail in a future video series which will be named "Mythbusting Crystal-Radios" or something like that. 99% of the information you find on the internet concerning crystal-radios is totally wrong. And the first myth is that germanium diodes are better than Schottky or Silicon diodes because they have a lower "turn-on" or "knee" voltage...

I do not do repairs on the 820. I hope you find someone. Good luck!

Yep!

Allparts, through Thomann.

It's an intermediate-level kit, not recommended for beginners. Beginners should check out my AUSTINDRIVE pedal at: www.AustinMics.com/austindrive-kits

Yes. 99% IPA is hygroscopic, quickly absorbing water from the air. Over days or weeks of use, it will stabilize to around 65% - far less effective than 99%, and only marginally better than water alone. This method is used to precipitate and separate the plastic from the solution so it can be cured and disposed-of properly.

Because germanium diodes are outdated and arent sold from professional distributors, but they are still used in some audio applications

Not for a guitar pedal.

Schottkys are also around 0.2V - that's the point.

That wasn't my goal here. I had a broken winding, and i just wanted to see if I could fix it with stuff on-hand and some creative engineering.

I would assume it would have somewhat less capacitance when scatter wound. It would be interesting to compare them. I would guess it wouldn't be a dramatic difference when most reverb circuits roll off some highs.

Page 12: c.searspartsdirect.com/mmh/lis_pdf/OWNM/L0908450.pdf

@@AustinMics thank you so much!! Your awesome sir👍👍

I tried testing using the battery test and 200 ma test ADC and i get 00.0 guess i have a fake germanium diode… but it is reading at 279 when switch to diode test

So the stripe side is the positive or the negative side?? Some diode may have stripe on both side?

Current flows in the direction of the stripe. Stripes on each end? You'll need to measure with your meter to determine polarity.

Are they valuable? I have lots of OA81 etc salvaged decades ago

See www.AustinMics.com/reverb

Ghost Riders in the Sky

@@AustinMics thanks !

We're working on it. August, 2023

www.AustinMics.com/reverb

It's at the end of the video, but www.AustinMics.com/reverb