Sir Mike e Cee . . . . .

I tell you whut . . . . I don't know if the "tuning capacitor" aspect is related to its being totally missing, or possibly so dinged up as to be just irrrepairable ?

But at least, this info on correcting its specs, might make its actual acquisition a bit more realistically possible.

Now I am used to seeing the RF section of common two section tuning condensers being a 365 pf value.

Additionally, one then can see a variance up to ~ 420 pf on some units

BUT . . that high of a 515 pf spec, for a unit, completely blew my mind

As per Sir Carl Tee's:

Sam's photofact lists the tuning cap as 2 gang, 30-515mmf and 24-190mmf

I am finding no fault with any given numbers except that 515 pf figure.

Particularly, I was in total agreement with that 24-190 for the oscillator section.

Sooooooo . . . I just plugged those numbers into a resonance formula with the 24 pf in conjunction with its companion trimmer capacitor, to be taking care of the 1740 Khz end of the BCB.

(With it actually needing to be oscillating up at ~2195 Khz.)

Then the same situation with the fully meshed capacitor and the same shunting capacitance form the trimmer to be taking care of the extreme 540Khz low end of the BCB.

(With it actually needing to be oscillating at ~995 Khz.)

That all works out fine with an oscilator coil resonating with the osc tuning condernser section, if using a
135 uh inductive value. . . . . and having to use its companion trimmer for paralleling in an extra 18 pf

That confirms NOOOOOO problem with the osc section of the tuning condensers values.

AND NOW:

Moving on to computing the RF section of the tuning condenser results, with the unmeshed 30 pf value working out just fine for the high end of the BCB band, if one is using an inductive value of 240 uh for the loop antenna / antenna transformer/ ferri-loop antenna . . . . . whichever happens to be the choice used.

That only leaves the figures for the capacitor when fully meshed to tune in the low limit of the BCB.

Wel l l l l l . . . . it just so happens

THAT

point of resonance is 450 Khz, which would actually be placed even BELOW the blooming IF operating frequency of the receiver.

If one then crunches the numbers for receiving the low end of the BCB at 540 khz, that then computes out,
right at the 365 pf value.

Soooo . . . . looks like you are now needing the most common value of dual tuning condenser.

A unit with an ~ 30-365 pf RF section on it, and the mentioned osc sections values. Which is just about any unit commonly used in an old "parts" chassis.

Just the matter of the mechanical aspects and direction of travel, remains.

Looks Samuels ended up end printing an end error on that high capacitance figure.

Thassit . . . .

73's de Edd