I thought RF detection performance was what made a good diode. Your test setup is high audio range. Details on test setup, scope settings, amplitude, etc. would be helpful to evaluate the results. I believe the “wave stability” is an artifact of the scope sync settings rather than diode characteristics. Looks like you are using AC coupling on the scope, making it hard to see reverse current flow, if any.
@df9999999999 In a crystal radio, you don't have to worry about the carrier the RF is way outside of human hearing. The diode is there to take half the AF signal to allow the earphone to work.
@@tsbrownie The tank circuit must develop sufficient RF voltage to forward bias the diode and create a DC voltage that is completely independent of any AM modulation, and in the case of a simple half-wave diode circuit, pulses at the RF frequency of the carrier. Audio may be reconstructed from the positive RF pulses because the RF output level of the detector diode is proportional to the modulation envelope. The capacitor at the output of the detector acts as a low-pass filter on the rectified RF, allowing only the audio rate signal to pass to the headphones. But, the diode performance is based on its RF rectifying ability, not audio. I think you need a load resistor matched to the output impedance of the diode to get meaningful readings.
I don't know the bat85. Funny you should ask about 2 Schottkey diodes. I just tried multiple Schottkey diodes 2 days ago. I also tried adding a resistor for reverse leakage. Didn't work.
@@tsbrownie How here is something I just wondered and was blown away. AM radio is vertically polarlarized. So therorically, a vertical antenna is best for crystal radio for AM!!!!!!! FM is circular polarization so it does not matter; you get 1/sqrt(2} on matter which way you place your antenna!!!!!! Sounds right, most people have a vertical antenna on their car, sa vertical broadcast would be best. But perhaps many people had radios in cars, maybe the broad cast horizontally, as people would string up long wires, since in the 1920s most radio were crystar radios!!!!!
Superb video
I thought RF detection performance was what made a good diode. Your test setup is high audio range. Details on test setup, scope settings, amplitude, etc. would be helpful to evaluate the results. I believe the “wave stability” is an artifact of the scope sync settings rather than diode characteristics. Looks like you are using AC coupling on the scope, making it hard to see reverse current flow, if any.
@df9999999999 In a crystal radio, you don't have to worry about the carrier the RF is way outside of human hearing. The diode is there to take half the AF signal to allow the earphone to work.
@@tsbrownie The tank circuit must develop sufficient RF voltage to forward bias the diode and create a DC voltage that is completely independent of any AM modulation, and in the case of a simple half-wave diode circuit, pulses at the RF frequency of the carrier. Audio may be reconstructed from the positive RF pulses because the RF output level of the detector diode is proportional to the modulation envelope. The capacitor at the output of the detector acts as a low-pass filter on the rectified RF, allowing only the audio rate signal to pass to the headphones. But, the diode performance is based on its RF rectifying ability, not audio. I think you need a load resistor matched to the output impedance of the diode to get meaningful readings.
1SS86, the performance of ultrashort wave band is much better than 1N34A, welcome to see my 1SS86 as my main-page.
Does things change if you use 2 x Schottkey in parallel? How about a BAT-85 Didode?
I don't know the bat85. Funny you should ask about 2 Schottkey diodes. I just tried multiple Schottkey diodes 2 days ago. I also tried adding a resistor for reverse leakage. Didn't work.
No, diodes in parallel do nothing extra.
Is an input of 1.3 volts is a bit high for a crystal radio?
I've gotten almost 3 volts out of them. Enough to power a digital clock.
th-cam.com/video/0WvZC3-mR6Q/w-d-xo.html
@@tsbrownie Be interesting to know what your antenna set-up is.
@@franzliszt3195 9 meters, center tap. Under the house eves. One of my videos shows it.
@@tsbrownie wow, 3 volts from nine meters.
@@tsbrownie How here is something I just wondered and was blown away. AM radio is vertically polarlarized. So therorically, a vertical antenna is best for crystal radio for AM!!!!!!! FM is circular polarization so it does not matter; you get 1/sqrt(2} on matter which way you place your antenna!!!!!! Sounds right, most people have a vertical antenna on their car, sa vertical broadcast would be best. But perhaps many people had radios in cars, maybe the broad cast horizontally, as people would string up long wires, since in the 1920s most radio were crystar radios!!!!!
👍👍👍