22-12-2023, 05:28 PM
(This post was last modified: 22-12-2023, 05:32 PM by Mike Watterson.)
The 1N4148, OA81 or BAW62 should make no difference. The BAW62 are good.
You sure on anode / cathode orientation vs the EB91 pin out? They should work better!
Did you solder on tag side or simply fold leads and poke into socket holes on top?
They only used EB91 because it was cheaper than a pair of 1N60 / OA81 etc. All the battery valve sets with VHF-FM used the 1N60 / OA81 type diodes, though the 1N4148 less likely to be damaged by a big signal (75 V PIV) than 1N60 (40 V PIV). The BAW62 is about 25% faster than the 1N4148, low capacitance (about same as 1N4148 @ 1pf) and also 75V PIV.
The OA81 is marginally better for weak AM and 1N60 a good bit better for weak AM. Both are inferior to BAW62 or 1N4148 for an FM detector. The Germanium diodes are generally lower PIV and higher leakage. I bought a big load of 1N60 as they are good for AM or even SWR bridge detectors.
The BAW62 should be just the same as EB91 or better if it's low emission or leaking to heater or something. Double check the connections and the diodes are OK!
You sure on anode / cathode orientation vs the EB91 pin out? They should work better!
Did you solder on tag side or simply fold leads and poke into socket holes on top?
They only used EB91 because it was cheaper than a pair of 1N60 / OA81 etc. All the battery valve sets with VHF-FM used the 1N60 / OA81 type diodes, though the 1N4148 less likely to be damaged by a big signal (75 V PIV) than 1N60 (40 V PIV). The BAW62 is about 25% faster than the 1N4148, low capacitance (about same as 1N4148 @ 1pf) and also 75V PIV.
The OA81 is marginally better for weak AM and 1N60 a good bit better for weak AM. Both are inferior to BAW62 or 1N4148 for an FM detector. The Germanium diodes are generally lower PIV and higher leakage. I bought a big load of 1N60 as they are good for AM or even SWR bridge detectors.
The BAW62 should be just the same as EB91 or better if it's low emission or leaking to heater or something. Double check the connections and the diodes are OK!
