02-19-2023, 10:25 PM
Hi Ron,
Totally love W3LNB's redraw. They are much clearer than A-Ks drawings.
One possible source of the distortion is that you are using a UX200 or 200A as an amplifier. They make horrid amplifiers, as the tube has gas. It is meant solely for use as a grid leak detector. Its claim to fame is that it is more sensitive as a detector than a 201A. However, 201s and 112s can be subbed as a detector without mod.
Per the RCA Receiving tube Manual RC13 (1937?), both the diode and grid leak triode detectors load down the previous RF Amp, thereby changing its sensitivity. I dunno if there is a difference on loading with the diode vs grid leak circuits and if that difference changes the resonant frequency of the tubed circuit. That has to be taken into consideration. Otherwise, the circuit looks great. Guess maybe it is better to try this on a 3 dial radio. Maybe restore the wiring and finish restoring your 35 (U r almost there) and wire up the 37 chassis as your test bead, using a 201 in the detector, biased as an amp, using 67V on the plate as well as using 67V on the RF Amp plates.
One thing that drives my interest in this experiment is that there are articles on the internet extolling the crystal or diode detector as a high fidelity detector. There are experimenters that discuss the biased detector (not so easy to do in a battery radio) as a higher fideity detector because of its supposed infinite input impedance.
Totally love W3LNB's redraw. They are much clearer than A-Ks drawings.
One possible source of the distortion is that you are using a UX200 or 200A as an amplifier. They make horrid amplifiers, as the tube has gas. It is meant solely for use as a grid leak detector. Its claim to fame is that it is more sensitive as a detector than a 201A. However, 201s and 112s can be subbed as a detector without mod.
Per the RCA Receiving tube Manual RC13 (1937?), both the diode and grid leak triode detectors load down the previous RF Amp, thereby changing its sensitivity. I dunno if there is a difference on loading with the diode vs grid leak circuits and if that difference changes the resonant frequency of the tubed circuit. That has to be taken into consideration. Otherwise, the circuit looks great. Guess maybe it is better to try this on a 3 dial radio. Maybe restore the wiring and finish restoring your 35 (U r almost there) and wire up the 37 chassis as your test bead, using a 201 in the detector, biased as an amp, using 67V on the plate as well as using 67V on the RF Amp plates.
One thing that drives my interest in this experiment is that there are articles on the internet extolling the crystal or diode detector as a high fidelity detector. There are experimenters that discuss the biased detector (not so easy to do in a battery radio) as a higher fideity detector because of its supposed infinite input impedance.
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
Best Regards,
MrFixr55
