07-28-2009, 03:50 PM
Well Ron, you nailed it! I guess that's why they call you Mr. Philco! I temporarily swapped the leads/components on the feedback coil terminals. Broadcast band worked as before, but short wave/police sprang to life!
I was prepared to rewind the coil if backward, but was fooled into thinking it was correct since the broadcast band worked fine even with the tickler/feedback winding backward. Just guessing, I suppose the 110pf capacitor between the bottom of the tuned winding and the feedback winding provided enough feedback on the broadcast band for the oscillator to work (and work well: -12.5 volts on the oscillator grid measured to ground). Could it be that the feedback winding is only there for the short wave band? I'm not exactly sure how the circuit works.
Anyway, if you can let me know the number of turns that are supposed to be on the coil, I'll rewind it. It now has 10 turns, and everything works fine.
Thanks again
I was prepared to rewind the coil if backward, but was fooled into thinking it was correct since the broadcast band worked fine even with the tickler/feedback winding backward. Just guessing, I suppose the 110pf capacitor between the bottom of the tuned winding and the feedback winding provided enough feedback on the broadcast band for the oscillator to work (and work well: -12.5 volts on the oscillator grid measured to ground). Could it be that the feedback winding is only there for the short wave band? I'm not exactly sure how the circuit works.
Anyway, if you can let me know the number of turns that are supposed to be on the coil, I'll rewind it. It now has 10 turns, and everything works fine.
Thanks again
