The AM Forum

I have developed a strange issue with my Valiant.  I had been working a lot of CW until last week, my plate wouldn't come on for unknown reasons on CW, and the grid had dropped to 25% of it's normal value.  Come to find out, the Low Voltage rectifier had wrong value filter caps, and so I fixed those while I was there, and voltages are normal now on the LV supply side of the house.

Now here is the strange deal.   In Zero mode on the xtal, VFO, and Zero switch, I have normal grid current and power in AM or CW mode.

If I go to VFO mode, I have that same super low grid current in both AM and CW.     What exactly happens when it is switched into ZERO mode?  It still uses the VFO and keys the oscillator, right?

If that is the case, then I suspect the only difference is that the keyer tube/circuit is added to the VFO tube grid I think if I read the schematic correctly.

If that is true, I'd guess something is wrong in that circuit?   

What do you guys think?   This one has me stumped, and I need someone with more experience!

Thanks in advance.

Joe

Turns out I needed brand new filter caps that arrived today, and everything went back to normal!  These were 15 ufd caps on the Low Voltage supply on both the input and output of the 5V4G rectifier.   Went ahead and put a new one of those in too, but that wasn't necessarily needed.