18-08-2020, 11:42 AM
I have still some 1N60 I bought about 15 years ago. They have a green band and no other marking. Iv'e not many left so I ordered some 1N60P from a UK eBay seller not too much more expensive than China, hoping he really was in the UK. They came today via Royal Mail and An Post, so "epartbox" does seem to be shipping from the UK.
They are Vf = 266 mV +/- 9mV and about 18 pF +/- 1pF (precision LC meter that does down to 0.5 pF +/- 0.2pF), but 0 pF on Chinese tester. At least 50V PIV (56 to 65V).
They look like 1N4148, except marked 1N60P in the tiny black print.
They are about Vf =341 mV, +/- 2mV and zero voltage capacitance is about 7.8 pF +/- 0.2pF, less with any reverse voltage, about 6pF on a Chinese tester. PIV is better than 60V (measured parts were 68 to 80V).
Conclusion:
The old green band ones are best for a crystal set or very low level peak detector. They might not be great without selection for a ring diode mixer. Capacitance might be an issue on higher RF frequencies and detectors above 10.7 MHz. The marked 1N60P part is better for anything other than a crystal set or a very low level peak detector at lower frequencies. In practice there might not be much difference on a crystal set or low level detector (about 80mV difference).
The recent purchase with 1N60P on the body that look identical to 1N4148 with body print seem to have a smaller spread of Vf, so may be fine in a ring diode mixer without selection. There is less varicap action, i.e. the capacitor isolated capacitance is only 2pF more than the Chinese tester capacitance (18pF more with green band part) and is a fairly low 8pF with no voltage to less than 6pF reverse biased. There is no measurable spread on capacitance as +/- 0.2pF is less than the repeatable measurements without a jig. With a PIV over 60V and low capacitance they should be fine for an FM Ratio detector. I'll try them on my 21.5 MHz IF.
I'll trace curves sometime and measure reverse leakage. The PIV is too high for that Vf for a Schottky diode. The low Vf types are only 15V to 20V PIV.
They are Vf = 266 mV +/- 9mV and about 18 pF +/- 1pF (precision LC meter that does down to 0.5 pF +/- 0.2pF), but 0 pF on Chinese tester. At least 50V PIV (56 to 65V).
They look like 1N4148, except marked 1N60P in the tiny black print.
They are about Vf =341 mV, +/- 2mV and zero voltage capacitance is about 7.8 pF +/- 0.2pF, less with any reverse voltage, about 6pF on a Chinese tester. PIV is better than 60V (measured parts were 68 to 80V).
Conclusion:
The old green band ones are best for a crystal set or very low level peak detector. They might not be great without selection for a ring diode mixer. Capacitance might be an issue on higher RF frequencies and detectors above 10.7 MHz. The marked 1N60P part is better for anything other than a crystal set or a very low level peak detector at lower frequencies. In practice there might not be much difference on a crystal set or low level detector (about 80mV difference).
The recent purchase with 1N60P on the body that look identical to 1N4148 with body print seem to have a smaller spread of Vf, so may be fine in a ring diode mixer without selection. There is less varicap action, i.e. the capacitor isolated capacitance is only 2pF more than the Chinese tester capacitance (18pF more with green band part) and is a fairly low 8pF with no voltage to less than 6pF reverse biased. There is no measurable spread on capacitance as +/- 0.2pF is less than the repeatable measurements without a jig. With a PIV over 60V and low capacitance they should be fine for an FM Ratio detector. I'll try them on my 21.5 MHz IF.
I'll trace curves sometime and measure reverse leakage. The PIV is too high for that Vf for a Schottky diode. The low Vf types are only 15V to 20V PIV.
