[ARC5] C-30 missing...

[Kenneth G. Gordon]

On 29 Oct 2012 at 20:22, Geoff wrote:

> > output tube is missing. Apparently the original hacker removed it
> > but never put it back.
> 
> If its working that good why call the poor guy a hacker? Aint you got
> no respect for someone probably long departed (-;

Oh, gee! Ye're right. I apologize to his ghost.

> Geez, get some
> single malt.......

Hey! Good idea. I need it today. :-)

> > Even so, the audio output from this receiver is very loud. Plenty
> > loud enough for a loudspeaker. I am using a 600 ohm to 8 ohm
> > transformer feeding a Radio Shack small 4" square CB speaker. If I
> > turn the RF gain all the way up, it will literally drive me out of
> > the shack.
> >
> > So, is that capacitor really needed?
> 
> Not really

Kewel! Then I'll leave it out. No sense cluttering up the landscape.

> > I thought that if one removed that capacitor, some negative feedback
> > would result, and the audio distortion would be reduced, but that
> > the volume would be reduced also.
> 
> Correct. The capacitor is there to smooth and stabilize  voltage
> variations across the cathode resistor. OTOH in a pure class A amp the
> variations are minimal but manufacturers needed bragging rights for
> Watts output. In an AB class amp its beneficial.

OK. Neato! Thanks.

> If I need more volume I put an electrolytic across the audio driver
> cathode in sets that have a driver.

None in this one, of course. I suppose if I decided to drive a 15" Jensen, I 
might need one, but I sure don't with what I have.

> A large value if the output
> transformer can handle the lows. Ive brought distortion in some well
> known receivers from 10%+ down to 2-3% and still have plenty of big
> speaker volume even when dropping the B+ down to 220-230V which keeps
> the 6V6/6AQ5 sets happy.

Again, kewel! :-)

> > FYI, the B+ is 240 VDC under load.
> >
> > I am copying an NDB, call is MW, here even in the daytime.
> 
> I can log dozens during the day on the RAK, NC-240CS, and other
> vintage commercial or military sets....with Beverages of course.

Sigh....the only Beverage I have here is single-malt...you lucky dog.

Ken