[HBR] Source for older radio books

[Walter A. Hutchens]

Bill said:
> Try www.alibris.com. This is a consortium of used booksellers, with a good
> search facility.

I have bought from them in the past; thanks for the reminder.

> I'm using the other half of the 12AU7 as a phase splitter, hoping
> to drive the deflection plates of a 6JH8 as a product detector in
> push-pull. Anybody tried this?  

I haven't tried it but I think the phase inverter approach will work okay.  
It's only the difference that matters to the deflection plates, so if the two 
signals aren't quite equal or exactly 180 degrees out of phase, it'll still 
work fine.  

Hummm ... which signal are you applying at which input?   In a beam tube 
product detector I'd think it was natural to put the IF signal on the 
deflection plates, in which case balance is pretty easily achieved without a 
phase inverter by replacing the single cap tuning the final IFT with a pair 
of equal caps of double the size in series to creat an RF center tap.    Then 
you put the VFO signal on the control grid of the 6JH8.   

In fact you can use the 6JH8 control and screen grids as a triode to do the 
BFO job, thus saving a whole tube socket.   I think this circuit is in many of 
the usual references.

Rich said:
> It is postings like this that keep me fired up. I need all the
> inspiriation I can get to get working on my HBR-8. 

Me too!   Still diagramming and checking out mistakes in the 7-tube band 
imaging project: it never ceases to amaze me how often a radio works better 
when wired as you intended than when hooked up as connected.   

I average one wiring error per socket.   Well ... not counting routinely using 
pins 3-4 of a 9 pin socket for the filaments.    Since I always fix that 
before the filaments light up, I don't think it counts, do you?

Then there's the general coverage project.    That one's still in the thrashing 
about stage as I try to be sure I've got the best conversion scheme.   

> Keep up the postings!

Yes, definitely -- KEEP UP THE POSTINGS.

Walt
KJ4KV