Home-brew Radio Circuits

Greetings!

I'm posting this request to see if any of you basement radio wizards have a favorite one- or two-tube AM radio circuit, of the Boy Scout sort that one would build on a block of wood, "breadboard" fashion? Tuned RF, regenerative, or whatever you like best is fine, whether earphone or speaker output - I'd like to put something together for fun, and use up some of those odd parts that I've had laying around for a few decades now.

Many thanks!


Win Kindel
answers:
You might want to try this site. Has some good circuits plus a lot of helpful information.


B



answers:
Hi Win,
I enjoy building loose coupled crystal sets from time to time.
Each one gets a little better. These are great fun and can be pretty amazing.Adding a trap will aid greatly to knock out unwanted adjacent stations and compensate for it's limitaions.
Here is the one i made during the winter:


The 1 watt IC kit amps can be directly connected with good results.
(because 1 watt is all you need!)

I like these because they are cheap to make and use common materials.
I am not much of a purist and just enjoy cobbing up a new one every now and then.
How well it works is whats important to me, plus just for relaxation or diversion.
My basic philosphy is not to spend anything and use recycled or scrap material as much as possible.

Reproductions or *well done* radios call for some prior experience and can be expensive.
I have the parts for Doerle 2 tube but have not assembled it yet.

The book "100 radio Hookups" by M Muhleman has many easy tube hookups. Available as a reproduction.

This website is facinating and a gold mine:

Thanks for the link,boilerhoosier.

Good luck Win,first and most difficult step will be deciding which one to build!



answers:
There was a 1-tube set in a Cub Scout handbook that I looked at in the early 1950s but I couldn't make much sense of it and there was no one in the family who knew anything about radio. Looking at it now I realize there isn't nearly enough info there to build it. I wonder why they even put it in the book, for all the good it did anyone.



answers:
Hi Alan

That was in the Bear Cub Scout book, blue cover. The radio used a 1S5 tube. I only had a good 1U5 which was able to rewire and make a working radio. The book had more of a picture diagram than schematic. Good thing as I couldn't read schematics.

In those days didn't even have tube sockets. Marked a board and drilled holes to fit the tube pins. Put connecting wire in the holes and inserted the tube over these wires. Solderless...

The Lion Book has a 2 tube radio..


answers:
I don't think this is what you are looking for but it is an interesting hombuild project anyway. If anyone has the reprint of the "Official 1934 Shortwave Manual" there is a 2 tube regenerative circuit in the back that I believe was first published in CQ in the 1960s. It is a design using a 6AV6 and a 6BA6 IIRC, one as the regenerative detector and the other as an audio amp/buffer. If nothing else the article makes some interesting reading about how a Japanese ham went about designing this circuit to be as stable as possible. I built the design which is on 2 chassis. One chassis is for the regulated B+ and DC filament supply and the other chassis is the receiver. It uses plug in coils wound on 6 pin forms and two vernier drives, one for main tuning and one for bandspread. It's sitting in a box in the closet. I should dig it out and fire it up again. I don't remember getting that great of performance out of it although it is a pretty neat set.


Sean

If it ain't broke, take it apart and see how it works.
answers:
Hey Norm, I remember that set in the Cub Scout book. Yeah, the instructions were about as vague as assembling some modern day Chinese made microwave oven cabinet! I also recall the two tube regenerative set that Sean was mentioning.
If a person wanted to see some real interesting sets, the ones built by Bob Don, W2HBE and Bruce Vaughn, NR5Q, would be ones to consider. Both those guys have written many articles for Electric Radio Magazine over the past half dozen years or so. Still trying to figure out what one to build next. But I sure have fond thoughts of a 24A regenerative detector impedance coupled to a 27 audio stage that was built on a wooden chassis. Even had a DeJur dial drive on the constant-frequency line variable capacitor.
answers:
Hi Curt

I remember using 27 & 24A tubes. At the time, didn't understand why filament batteries wouldn't last.


answers:
Ha, I used a 26 for my first code-practice oscillator and ran that on batteries. Meshna used to sell outdated mercury-cell packs that I disassembled.

I still have the three Cub Scout manuals upstairs.

My first two-tube regen was made from plans in a 1932 ARRL Handbook that a local ham gave me. I used 215A peanut tubes, but had to make my own sockets to fit them. Still have that too.



answers:
I liked to use 6.3 volt tubes because they lit up so nice and you could see the glow. I used 37's and 76's from the big stash of stuff I had gotten from my uncle in the early '50's, and used a lantern battery and a 45-volt Burgess. (I wonder how many 45's, 80's, 2A3's, UX-199's, and other gold bricks got trashed out of that stock...) Then I decided I needed a "modern" tube so looked in the RCA manual and crossed over the 76 to a 6P5-GT and went down and bought one with my hard-earned money. Regenerative sets are magic and lots of fun.

Reece



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Here's my circuit and set:

Fun set....


Chuck Schwark
The Philco Repair Bench at


answers:
Well, I see that Norm, Alan, and myself must have crawled out of under the same rock a long time ago. Why did we use those tubes? I used a 26 in my first homebrew one tube set when I was eight years old simply because I had one and the tube manual that the neighbor had said it had a 1.5 volt filament, so I thought it would work perfectly well with the #6 dry cell, which also put out 1.5 volts. How was I to know anything about current consumption at that age?
Yes, Norm, a 24A and 27 would tend to shorten the lives of filament batteries a bit. The set I had used a power pack mounted on a board which had the 80 and one of those combination transformer/ filter choke things by (if I remember correctly) Thordarson. The plate transformer was in the same steel case as the filter chokes. It also provided the 2.5 VAC filament power.
Regeneration was controlled by varying the screen voltage on the 24A and the coupling choke was the largest item in the entire set, about 4 inches cube. The set worked fine, but it suffered from hand capacity issues.
answers:
The first one tube radio I built was a neat little regenerative receiver using a type 30 tube and circuit drawn by my radio repairman mentor (Yeah, the same guy who said I needed to find some cats whisker wax for my galena crystal set).

My buddy and I wound our own coils using #22 green double cotton covered wire. We scronged most of our components from old TRF sets our "mentor" had stashed in the loft of his barn. The hardest part was to fabricate the tickler coil onto a coil form and make a turnable shaft that mounted near the top of the main coil, so that with the tickler coil inside of the main coil, we could rotate the shaft without breaking the tickler coil wires. Our solution was to form a coil of wire in the shape of a watch movement spring for each coil lead, around the shaft, between the tickler coil and the main coil. This allowed us to obtain a full 360 of rotation without breaking the wires.

These were great little sets. I used to listen for hours to far distant stations, such as WWL in New Orleans from our home in Michigan, which of course came through loud and clear at night. It was not unusual to log in 30 or 40 stations in an evening with it.

One of these days, I am going to re-create this little radio and re-live some really fun times.



answers:
Hi

You guys were ahead of me. My first tickler coil slid in and out of the antenna coil. That was the only adjustment. Tooth picks were used to hold it in place after I found the best adjustment.


answers:
Hi Guys...
My first was out of Morgans 1st Book...That regenerative receiver...I think it was a 1G3GT tube in the plan. I wound two coils made with toilet paper tubes...one for BC and the other was SW, but who knows where it was in the spectrum...I was only nine when I built it!...But it worked!

...Jim



answers:
<BLOCKQUOTE><font>quote:</font><HR>Originally posted by Jim Koehler:
Hi Guys...
My first was out of Morgans 1st Book...That regenerative receiver...I think it was a 1G3GT tube in the plan. I wound two coils made with toilet paper tubes...one for BC and the other was SW, but who knows where it was in the spectrum...I was only nine when I built it!...But it worked!

...Jim

<HR></BLOCKQUOTE>

My hero; Morgan. He ran that circuit in his books starting with the Boy Electrician! Used a 1H4... I remember having my dad chasing all over Hartford in the late '50s as we tried to find all of the parts! Darn tube was scarce then...

The guy at the counter at Hatry's gave me a 14-mmf variable instead of 140 mmfd, thanks to Morgan using a confusing .00014 mfd for the value. Parts clerk slipped a decimal. It received one station, wouldn't much off of it. Ah, the good old days.

Build a newer version using 30 tubes a few years back, put a few photos in the photo forum.

Pete



answers:
Yeah - I built my Alfred Morgan Boy Electrician regen in the early '50's - no problem getting parts but it didn't work because I couldn't solder and a wiring error. My local TV man helped me with it and told me to learn to solder.

Vicky



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Take a look at this web site from a guy here in Houston.TX

jimmie



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I built the regen out of one of Morgan's editions that used a 6BF6. I came across that book when I first got into electronics in the mid 1990s. I made a wooden frame and screwed a piece of sheet metal on top for my chassis and included a built in transformer power supply. I made plug in coils using some plastic pill bottles and glued tube bases to the bottom. I even curved some thin plywood and built a bullet cabinet for it. It was a good performer.


Sean

If it ain't broke, take it apart and see how it works.
answers:
Chuck,
There is an interesting version of the Doerl regen appearing in the 1935 Shortwave Craft. It uses a 19 for amplification. Plate 1 is coupled with a .1 to grid 2, and out plate 2 to phones.
I assume this was changed as it appeared in 1937 Hammarlund because as Norm pointed out, people got tired of dead batteries?

There is also an "electrified" version in the back using 57 and 56 and is resistance coupled but calls for a power tranformer(B+ 250)