The AM Forum

Couldn't seem to draw any interest in my peanut can load but perhaps a combination of eating peanuts and drinking wine might do the trick.  Here's what looks like a fun project - first you have to drink a bottle of wine (peanuts are optional).  Then you are ready to build this xmtr

http://timelesson.blogspot.com/2009/01/straight-key-night-mopa_01.html#more

This has the makings of a interesting project for one of those nor-easters we have up here.  Well, at least the first step

Al

OK: I can't resist this.  Here's another article.  I wound one of these coils on my second transmitter -- used an 807 osc powered by a PS made from rugged AM rx components.

http://members.shaw.ca/ve7sl/tnt.html

Now that was Coool. Nice work by that ham! 

That fella has the real Homebrewer spirit...

Sri guys, couldn't resist...

The last project left me a little dry, but this one wets my whistle!

Al,
Boy the underneath side of the wooden chassis shows a cap that looks like it has seen better days.  Maybe it has a new one installed inside the one that has seen better days!
Regards,
Joe, W3GMS

Check out his Xmas transmitter using an eye tube for the oscillator!

http://timelesson.blogspot.com/2009/12/evergreen-exciter-for-special-night.html

Hej !

Some time ago I made a nice little cw transmitter with a 813 in the final using a wine bottle in the tank circuit.
However it did not work well at all, after emptying the bottle it was difficult to tune the final... and that was not the only problem.

But, it worked much better next day...   ;D

Could get better efficiency by gluing some plastic strips to support the coil, then breaking the wine bottle and letting the pieces fall out (wrap the bottle with wax paper first).  I have  made several air-core coils that way.  Wine bottles are about the only option these days.  About everything else sold at the grocery store comes in plastic bottles. More of a novelty with the bottle still in place, though.

Use a wine bottle for  the plate coil and a beer bottle for the grid coil.  :)

All of those coils look better than the ones I wind.  I'm especially impressed by the ones wound out of tubing.   I need to take my game up a notch.

Metal coffee cans are slowly disappearing of the shelves,too. At least we still have large pickle jars to make chimneys from!

everything has to be cheap to sell now. Folks have to cut costs to stay in business.  Sad but true.

IMHO glass does a lot better job with food stuff, just too heavy to ship all that weight, with breakage and the extra cost. Plus, I bet some folks just plain don't like a heavy jar in there groceries.

Always were useful for radio and other things though.  A stout champagne bottle could make a base insulator, pickle jars for chimneys, salt water caps, and electrolytic interrupters and rectifiers.
You can do a lot with an old jar. 

My OM used to nail the lids to the joists in the basement, then fill the jars with hardware and screw them into the lid.  easy storage and out of the way, and you could see what you had.

 " A stout champagne bottle could make a base insulator"

I'm going to have to try this.....  much better than the old  7oz. green Coke   botll

klc

Yes, make sure you use a good champagne bottle, they are thicker walled than other bottles.

Trivia -- Supposedly Mr. Tesla used a certain brand's bottle for his salt water capacitors in his million+volt machines because they had superior RF loss characteristics...

I'm wondering if the following technique would work for cutting off the neck of the bottle leaving just the part that holds the coil - probably should wear safety goggles for this exercise:

• Score the bottle where the separation is desired.  Probably use some sort of jig to do that so the score line would not drift
• Wrap some sort of bare wire, possibly bus - around the score.  Hook this up to a high current fil transformer capable of some decent amps.
• Hook the primary of the fil xfmr to a variac and run it up so that the wire gets real hot.  The bottle should break off at the score.
• Then carefully smooth out the edge with emery cloth to reduce chipping and cutting.
  

Wonder if that would work?

Al

Probably would Al,  the old handbooks show a similar technique but use a string soaked in gasoline for the heat source. Your idea would probably be a lot safer!!

Some of these breadboard rigs can be works of art, nice craftsmanship etc.  I've been thinking about building a small AM rig in this manner. 

It does seem a shame to have all the "guts" of a rig enclosed in a metal chassis, I think you could build a safe and great looking Inside-Out rig that would be a work of art.

Yep, works good. No need to smooth anything if the score is even. I used nichrome from an old headlight dimmer switch, stretched it between two bolts on a wooden jig, and hooked up a battery charger. I did this to a large pickle jar on top and bottom. Made a nice chimney for a 4-1000.

so if one to were breadboard an AM rig say in the 100w catagory give or take 50w what would your tube line up be? considering old buzzard type tubes onlyl.

100 Watts? The old Editors and Engineers Handbook would suggest an 814 modulated by a pair of 811A's as ideal. A neutralized 812 final would also be a good tube but it is a triode.

Mike WU2D

Al,

My method http://www.bearlabsusa.com/ARCH/HENRYWEB/HENRY4.html

not shown is the nichrome wire jig, which consisted of a nichrome wire wrapped once around the score, it goes "tink" pretty fast... I used a filament transformer and a variac at the AC input end to control the heat.

Someone said something about tempering the glass by putting in an oven very hot and then letting it cool slowly... dunno, but it sounds good to me.

I used AlOxide paper to clean up the cuts.

                    _-_-bear

What's wrong with triodes?

I love triodes - esp. in push-pull. Here is a little Jones Oscillator that I rolled up last weekend.

Mike

Nice little lash-up.  That circuit is supposed to be able to work with almost any frequency. 
I should build one for 80 meters to go with my little two tube regen.