TheRadioBoard

I agree. Too often in these discussions, people tend to be steered towards the same narrow group of receiver architectures.
To the point that (eg.) reflexing tends to be frowned upon.
I think the idea of this Board was to encourage all types of receiver construction and also innovation using those designs.

It's not all about Q, "furthest DX ever", minimal noise etc. - it's about maintaining an interest in your hobby, whatever form that may take.

....................................

While I probably wouldn't be bothered to do this with a regen, I am still considering it for a possible future triode autodyne superhet.

Meanwhile, here's another non-radiating idea based on a coil with assymmetrical coupling. It's a 6SN7 regen that I built several years ago.

Note the strange looking coil at the upper right. The primary (enameled magnet wire) is tightly wound around the ferrite toroid, and the secondary (purple insulated wire) is wound in big loops as shown. The result is that coupling is nearly 100% from primary to secondary, but from secondary back to primary, it is much less. As to how much less, I couldn't tell you, because I didn't do any accurate measurements at the time. I guess I should dig it out and see if I can get some measurements.

Now that's cool. (Can 65 yearolds use that word?)
Beats an ASIC hands down.

Those results would be interesting if you ever get around to it.

.......................................

It's impossible to miss! What a lovely coil. How did you physically manage to wind it? Is that transformer design your own, or have those sorts of coils been used in the past?

Thanks for sharing that.

!920's doughnut coils.
http://www.worthpoint.com/worthopedia/t ... ning-coils

http://i53.tinypic.com/5zr4o3.jpg

.......................

Guess you could wind a solenoid coil, slip it off the form, then form the toroid by bringing the ends together. Or wind on a donut (not glazed), then eat the form.

73,

_________________

http://kr1s.kearman.com/
http://qrp.kearman.com/

A slinky is a good example - it starts off as a solenoid.

Supposedly Hi-Q, as it is "semi-spacewound" and a greater proportion of the field is contained within the coil (as in a toroid). Downside is that due to the separation of the windings, the inductance value is less per length of wire used, than in a close wound coil.
http://upload.wikimedia.org/wikipedia/c ... spiral.jpg

............................

Quite easy to do. I just wound it as a solenoid on a broomstick, slid it off and then, essentially, screwed it onto the toroid. It was standard #22 PVC insulated hookup wire and was stiff enough to hold its shape.

Can't say that the receiver was a resounding success by any means, but the coil was pretty. Actually, it was one of the worst performing receivers I've ever built. Though, I wouldn't mind finding another project to use one of those coils.

Yes, and that is only one of its many drawbacks.

Looks like this thing came from a nuclear fusion physics lab .
Is there any reference explaining how the cancelling works with the asymmetric coupled inductors ?

http://www.g3ynh.info/zdocs/magnetics/i ... uction.pdf
Pages 36 & 37

There is an interesting thread at qrp-tech about improving the sensitivity of the WBR. You have to join the group to see the thread, but here it is:

http://groups.yahoo.com/group/qrp-tech/message/3874