If you are willing to use an IC you can get a whole synchronous detector circuit
in a single IC in the form of one of the old CQUAM AM Stereo decoder IC chips.
There are instructions on the web that describe how to do this.
What the
**** impedes your progress to your workshop and soldering iron?
Two things, first the fact that AM detectors are of academic interest only,
as
there has been no AM broadcasting around this area, that needs anything
better
than the crudest AM detector, for at least 15 years or so. *Second, I think
I am
more interested in putting my soldering iron to work on the John Stewart
inspired ³improved 25L6² amplifier. *There are three binary design
decisions to
be made before I purchase a chassis and begin punching it.
So it seems unlikely you'll ever listen to the benefits of my ideas.
Binary decisions eh. In a bind are you?
Me thinks you misinterpreted what I meant by the term "Binary decisions".
Here are the three decisions I have to make, perhaps I should flip a coin and be
done with it.
1. The output stage will be of the distributed load type with 50% of the load in
the cathode circuit, and 50% in the plate circuit. The decision yet to be taken
is should I use the McIntosh output circuit, or an Acoustical style of output
circuit? This decision will have some impact on the layout of the power supply.
2. I must settle on the output tubes to be used, a QUAD of 25L6GTs in push-pull
parallel, or a pair of 7695s. Actually this is a ternary choice, the KT55 is
another possible choice for the output tubes, while these are cool tubes,
finding some would probably not be easy. The output tube choice has a major
impact on the chassis size, and layout, so I have to settle it before I purchase
a chassis and begin drilling and punching it.
3. The driver tube must also be specified, the binary choice was between the
6211, and the 12AU7, yesterday I made it a ternary choice by adding the 12AT7 to
the list. These tubes all use the same socket, so they can all be tried with
only a change of cathode resistor.
http://fmamradios.com/stuff/E1.pdf
--
Regards,
John Byrns
Surf my web pages at,
http://fmamradios.com/[/quote]
Hey John, I just now checked at Antique Electronics. 7695s are cheap at $3.45. The 6.3 volt version is the 7754.
You & I had discussed this cct at length in Fall 2004. I would have thought you would have moved forward with it by now. I ended up suggesting the 17EW8 as the driver into your choke coupled interstage transformer scheme since it has lower rp than some other drivers you had considered.
The final schema with simulations is attached. The label on the OPTs should read 1:0.173, not as shown.
Cheers to all, John