HW-101 The Saga Continues

[K7SZ]

OK, gang, time to get real:

I tried subbing out the two resistors that Mark advised me to change. About the only thing that happened was that we lost the calibrator signal for a while...still don't know what caused that...possibly a cold solder connection, since we reheated several joints and things "normaled up". 

We subbed out the 20mF electrolytic with a brand new cap that we tested on our "octopus" to insure that it was not leaky or shorted. Not much difference was noted. I am mplanning on going up to 47mF tomorrow, just to see what happens...

When we changed out the two resistors the one major difference we noted was that the oscillation would start out immediately, drift lower in frequency, bottom out then begin increasing in frequency again. Weird. This is independent upong where the main tuning dial is set or whether or not we have the cal signal present.

At this point, we are going to take a .33mF mylar and run it across the grid resistor of V14 (I think...that may be wrong as I don't have the schematic in front of me...this is the tube that we changed the grid resistor from 470 ohms to 75 ohms, per Mark's mods). According to our calculations, this will have enuff Xc (around 84 ohms at 6kc, which is what the howl oscillates at) to hopefully swamp the oscillation and eliminate it. 


73  Rich K7SZ

Editor, "QRP POWER" (QST)
Editor, "Homeland Security"  (Popular Communications)

QRP ARCI #2388  NorCal # 483, G-QRP-Club # 622, EPA-QRP # 21,
NW QRP #24, Zombie # 664, Ten-10 # 39647, FISTS# 2793
Flying Pigs #169, Shoes: 13 W, Jock: XXL, Grid: FN21bf
Aficionado of all things Drake and Heathkit

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