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marconi 157
#76

I only got it to work on rf and I got the loudest motor boating sound on pin3 of tube 6f6 and one of the speaker plug pins going to the output transformer
#77

OK. Now check the grids on the other tubes.

"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/
#78

if you look back to my other comment on page 5 I checked all the tubes and there was no motor boating sound until I got to tube 6f6 starting from antenna back to tube 6f6
#79

OK, but to be clear, is the motorboating present at the grid of the 6F6?

"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/
#80

motor boating very loud on pin 3 of 6f6 and not has loud on pin 5 and another question what should be connected to pin 8 of tube 6f6 has it looks like a wire has been cut off it
#81

the more I look I think there is a miss wire on tube 6f6 so if I could get some help on what should be connected to each pin that would be great thanks
#82

Pin 8 should have R9 & C27
Pin 1 '' '' '' '''' '' No connection. but probably used as a tie point.
Pin 2 & 7 "" "" Filaments
Pin 3 "" "" C26, C29, & one side of output trans. R10 maybe ?
Pin 4 Other side of C26 & other end of output trans.
pin 5 " " " R8 & C25 & one side of field coil.
pin 6 " " No connection but probably used as tie point.
Some of the parts might not be connected close to the tube socket and you might have to follow a wire to find them.
I hope I got this right, eyes getting dizzy trying to follow and write it down.Icon_smile
#83

here is my connections pin 3 .005 c-26 and it goes to one side of output trans pin 4 positive end of 20 mfd cap-29 and the other side of output trans pin5 .05 cap-24 and it goes to pin 4 of 6k7 also .01 cap-25 and it goes to pin 4 of 5y4 tube pin 8 has positive side of 25 mfd cap-27 and the resistors are right
#84

Is your C 29 a multi section cap? I'm seeing two C29s One at bottom of schematic from field coil to ground and one at the pin 3 connection which is the plate of 6F6G that looks like it goes to R10.
#85

(11-27-2016, 11:02 AM)KCMike Wrote:  Is your C 29 a multi section cap? I'm seeing two C29s One at bottom of schematic from field coil to ground and one at the pin 3 connection which is the plate of 6F6G that looks like it goes to R10.

I thought that but I looked everywhere for c-24 on the schematic and I think the one at the top next to the speaker is c-24 not c-29
#86

r10 could be tone control if you have one. If not, maybe that's why you don't have c29 at the plate of 6f6g. if c29 was multi section it would be one can or big paper capacitor with two caps in it and two wires coming out of it and the can could be grounded or have ground wire coming out also.
#87

(11-27-2016, 11:35 AM)KCMike Wrote:  r10 could be tone control if you have one. If not, maybe that's why you don't have c29 at the plate of 6f6g. if c29 was multi section it would be one can or big paper capacitor with two caps in it and two wires coming out of it and the can could be grounded or have  ground wire coming out also.
so do I make the changes you said or is what I wrote earlier right
#88

So far I haven't said make any changes just trying to figure out where everything is and if it's right.
Far as I can tell what you wrote earlier is correct, but I don't follow this, you wrote.. the pin 5 -.05 cap-24 and it goes to pin 4 of 6K7. I'm maybe just missing it but don't see it connecting to pin 4 of 6K7 on schematic.
#89

my mistake it goes to pin 3 of 6q7
#90

Just to get back to you. Everything based on what you wrote sounds like its hooked up correctly.
So, I don't know what could be causing the motor boating or what you should change.




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