The AM Forum

OK I admit it - I have Regen Fever...

First I did up a pair of 76's, than a pair of 6SK7's then restored one of those old Meissner two tubers and now I went kiddie - yes I built up the one tube receiver featured in Morgan's Boys First Book of Radio and Electronics. It was sort of for his 120th birthday party.

Anyway there is a nice link to the article for you regenerative nuts out there:

http://www.4shared.com/file/132692359/ad2319c6/Morgan.html

I have been having a ball with this receiver. Last night I was copying 10 Watt Fish Net beacons in the Atlantic between 1750 and 1850 KHz, heard a loud VP9 DX station on 1812 kHz, plugged in the lowfer coil and easily copied the 505 kHz Experimental guys, and then plugged in the 80M coil and listened to the 75M crowd.

As an experiment I hooked it up to my 120 ft longwire at high noon on Saturday September 12, 2009 with ordinary Consolidated 2000-Ohm Headphones. 36 stations were easily identified on the BCB at my QTH in Manchester NH. I have 2 strong local stations within 10 miles and there are several strong Boston stations to contend with. I then attached the same antenna system to my R-390A set in the 8 KHz position and was able to pull out 69 stations. This gives you an idea of what the little radio can do.

One tube...

Mike WU2D

 

Nice looking old school regen Mike. I have to admit I'm starting to get the same germ. I'm looking forward to having just as much fun some day. Thanks for the post and have fun.

Mike

My first receiver was a regen built out of the book of knowlage encyclopidia.
It used a 6SN7, and an interstage transformer, and worked ok.
I rebuilt it many times, putting it in different boxes and cabinets, which was great fun.

But its not much harder to build a good superhet, think old table top radio on short wave frequencies, add a filter and an S meter and away you go....


Brett

Regens are so cool.  That such a simple set can do so much has always facinated me.  You can argue their faults, but as a simple project that can really get you fired up they are hard to beat. (A SS regen using a FET or two beats the pants of of some QRPp Altoids Tin xmitter any day).

Nice job OM, keep it up.

now build a nice one tube xmitter to go with that 'genny.

Makes me want to go ahead and restore my National SW-3.

I  remember listening to 75 about 20 years ago on that receiver before the previous owner died and his survivors let it deteriorate in a damp basement.  Just below the point of self-oscillation, it would pull an AM signal right out of the QRM in the crowded 75m band almost as well as the R-390A or HRO, and the tuning was velvet smooth, too.

http://amfone.net/Amforum/index.php?action=dlattach;topic=21254.0;attach=14031

I built that 1936 Frank Jones xmtr.  Built on a Poplar board.  Works great and have had a ball working many contacts with a grand 5 watts output.  Used 30's vintage components and even the old round holder xtals.  See pics on my QRZ listing.

73,  Jack, W9GT

yep!  Jones 10 watter. Works with just about any dual triode you've got from 6s7s to 12AX7s have been used with success. Lends itself well to slat board construction too.

I gave a friend a gassy 100TH triode. He made a regen receiver out of it. He said gassy tubes are great for building regens. My question is why are gassy tubes good candidates?

A 100th as a regen receiver tube?
That has to be the strangest thing I ever heard of!

How about a 4-1000 regen or a pair of 833's?

I have a bunch of new old stock micro tubes, little triodes the size of lightbulbs, they might be fun to make a regen and little transmitter with.

I think they were used in early walkie talkies, you know, those shoe box sized ones....

Brett

Yes, my friend said the same thing. A bit over kill but that is beside the point.

I'll give him a gassy 833 and see if he can make one out of it. Maybe he can drive a speaker directly with it ;D ;D

When he makes the VHF version of the regen using a 100TH I will send him a copy of a construction article for the perfect preamp to go with it.  The preamp uses a pair of forced air cooled triodes in grounded grid and in the preamp they do require air cooling. 

I can hear it now, "my transmitter is p__s weak with a 6AQ5 final but my receiver really straps".

Ok, I don't want to hi jack the thread, my original question is Why Gassy Tubes?


 

Yes, that was a fact that was used back in the really old days.  I'll start looking for articles from my OLD QSTs for using gassy tubes in RX's

Mike:  isn't there some way to remove the B+ from the headphones?  Sounds dangerous even tho' I know they used to use that approach in the old days.  Sort of rules out the newer headphones.

Al

Put an little single ended  output transformer 5K -  10K to 8 ohms or so to match the modern phones. They won't be as sensitive though.

Boy, mentioning "Meissner" suddenly brought back memories!

When I was about ten years old, our Boy Scout troop leader showed several of us how to build a three tube Meissner regen from a kit.

I spent hours and hours in the basement listening to the one I built.  I was hooked on SWLing!  My parents had to drag me out of the basement when it was time to go to bed.

This all happened in about 1946.  We learned to send and receive Morse code in the Boy Scouts, too.

73, Barrie, W7ALW

How about using a vacuum display panel? you get as many triodes as there are digits, and each digit is a triode with multiple plates. The filament would use a single 1.5 V battery and the plate supply is a trio of 9 V batteries. IF I get a chance I will run some curves on one to see how much gain. As I recall, a couple of grid volts controls several mA of segment current. tying segments together could add up the plate current quickly. and the triodes could easily be paralleled.

     I built a Regen for a homebrew contest a couple years ago and out of 5 entries, it didn't even place. I don't think half the judges even knew what it was! That's O.K. though; I had a lot of fun building it. I used the Morgan schizmztic, but I cheated and used a 6C5. I also used a metal panel to help reduce hand capacity effect.
     The next year, I built a built an old school PW rack style TX based on an article by Lew McCoy. I don't think he intended for it to be modulated, but I thought "Why not?". It is a MOPA design that I set up initially on 10M for lack of crystals at the time. On 10m, it doubles in the osc. and doubles again in the P.A. On top of that, I cathode modulated it! Put that in front of a 'strappin leenyar' and say "Excuse me, mover over there slopbucketeers!". I don't think the judges liked that one either, but since they only had two entries, they had no other choice but to give me second place!
  BTW Mike, I had to put the Hartly experiments to the side for now, even though I have a working breadboard model. I'm presently working to get a BC-342 going that I picked up at Shelby a couple weeks ago. Man, what a PITA! It's hard to get at anything to take measurements with all those shields and front end tube mounting!

 Phil

    My next regen project is this:

Folks interested in building regen sets should contact Bill Hurni, W3HWT.   He has developed a real passion in developing these sets and has been amazed in the performance of these sets when applying some of the early articles dealing with minimizing circuit losses.  Going to lower loss coil designs, has made a large difference in performance of these sets.  Joe, N3IBX may have Bill's current email address. 
Joe, W3GMS

How can you not like a vintage regen set?
Here is my Crosley 51.

My Crosley 51 tunes up to 160!

Sigh...both of my regens never work well. I tried all sorts of things, but they both have been dead as a hammer. Pick up the broadcasters on 41M fine, but never can hear anything else. Not even the local AM hotshot at 930kHz.

WOW, a Super Wasp. Awesome! Thanks for the pictures, Have fun.

Mike

Ok I'll take a stab at this.  I think gassy tubes were prefered for regens because a regenerative circuit has a very high gain, and using high gain tubes (like a 12ax7 or 12at7) could cause no end of problems.  A lot of regen circuits use very low plate voltage for this reason, (like 12v on a 6SN7 circuit!!) and they work very well and are easier to control the regeneration on.
Since back in the '30 most radio types were pretty broke, using a gassy, and therefor poor performing tube meant you didn't have to buy a tube, but could 'recycle' one into your receiver.

Phil,
Nice repro.

& Great cloth covered wire, neat colors.  You cut the leads off a power transformer, huh?  ;D

Yup, I got hard up for some decent wire. The plastic/vinyl stuff just doesn't look right, and what I have of that is pretty cheap stuff and it either shrinks up or melts at the solder joints. Im working on this BC-342 now and all the cloth covered wire has started to deteriorate. I guess I'll have to break down and buy several colors in 50' spools and a lot of solder wick. Mike did a great wrtie up in ER on the Command set transmitters, now I'm really starting to get hooked on this antique military stuff. I can't wait to get the ART-13 going!
73, Phil

Here you go Barrie!

Mike WU2D

Wow! I've had this for nearly 20 years and just about forgot about it! I think I had bought it at the Charlotte hamfest kinda figuring it was a regen, but not sure. I had thought of stripping it and rebuilding another circuit on it. Thank goodness I had enough insight at the time to put it away for a while.

Hey, that looks just like the little regen in my barn!
In fact, it even has an blue ribbon attached to it.  ;)

How far did you go on the originality Bruce? Did you restuff the wax/paper caps? I think I may have a couple of 76's and a rectifier. No plug in coils though. Does anyone have the coil data? This would be a great little "take a break" project.

Actually I was kidding, I have Mike's wonderful little regen back at the house.
I bought it back from the AWA Conference, where Mike won a blue or red ribbon - he's a bit too humble to share that.  ;)
I can tell you that he did a wonderful job with the set, looks great, I've been tempted to try it out, but won't think of doing so without permission.


(http://gallery.me.com/brucehowes/100218/DSC02936/web.jpg?ver=12512078530001)

I'd like to learn a little more about these regans. I did a search online and found some information on the battery powered version. I'd like to get a skizmatic for the AC version. This may be a good father/daughter project.
Phil

Pretty but cranky!!! regen - Gross Eagle - circa 1934

Video of set on CHU -->>http://gallery.me.com/brucehowes#100297/MOV02236&bgcolor=black

(http://gallery.me.com/brucehowes/100297/DSC02229/web.jpg?ver=12533020170001) (http://gallery.me.com/brucehowes/100297/DSC02230.jpg?derivative=medium&source=web.jpg&type=medium&ver=12533020260001)
(http://gallery.me.com/brucehowes/100297/DSC02202/web.jpg?ver=12533019940001) (http://gallery.me.com/brucehowes/100297/DSC02206.jpg?derivative=medium&source=web.jpg&type=medium&ver=12533020050001)

There are some nice circuits for regens in the old 30's era Frank Jones Radio Handbooks.  I'm planning to build a matching receiver to use with the 6A6 push pull xtal osc xmtr that I already built.  This stuff is really easy to put together and recaptures the thrill of building your own station and actually making contacts with something that you built yourself.  Certainly easier than building a big AM rig, but still a lot of fun.  30's vintage components for these projects are plentiful, but you may also want to make some substitutions using more recent vintage parts.  You can purchase the boards and hardware at your local Home Despot or Lowes or Menard's and even dress them up with some nice stain or varnish of some sort.  These rigs also make wonderful Father/Son or Father/ Daughter (or Grandpa/ Grandchild) projects.  

Maybe old technology...but requires a little simple manual craftmanship and produces very satisfying results.

73,  Jack, W9GT

I have an Allied Knight kit Span Master. This kit is 1958 vintage and it works well. The manual is on BAMA.  It would be very easy to duplicate the coils if anyone has interest I’ll post a picture. It’s not quite as classy as the older stuff but it’s still fun. I’m surprised no one has mentioned any TRF receivers’. I myself have way too many Radiolas, Breadboards and crystal sets. I am a sucker for anything old with tubes.
73 Johnathan N8QPC

The set came from WA1HUD's cellar! It apparently was a kit that Meissner sold until they simply ran out of type 76 tubes. It had a curtain burner dropping cord that I was nervous about so I put an ordinary three prong cord on it (I did at least pick a brown one) and I grounded the chassis. No I did not go crazy and put period parts back in like paper caps. I did however have to add a voltage dropping resistor that gets plenty hot. It is AC /DC, hums more than I would like and tunes fast. This is no top performer!

Here is the schematic.

Mike WU2D

May not sound good, but it sure looks pretty, and like women, that's 50% of the equation!  ;)

Mike:  That's it!  That's the exact set!  Do you own that radio?  Wanna sell it?

Barrie, W7ALW

Hey, its in my barn, I've got first dibs!  ;)

Bruce that Gross Eagle is NNice.

73
Jack.

Thanks Jack, the Gross Eagle is a pretty rig and original, but unfortunately not very stable, very cranky, not at all like the National SW-3. I thought it was just my rig, that something was not right, Larry and I had been all over it, could not find a thing out of order. Then I spoke with Harold KB0ROB who has a Eagle as well, he had the same experience.

I've a bit of a dilemma, if it were rough, I'd tear it apart and rebuild it to be more stable, but it is 100% original and I can't bring myself to do that. I had a hard time just feeling ok unsoldering connections for testing components. :-) I suspect the unit is so nice as the original owner bought it, found out how cranky it was, and it sat on a shelf for the last 75 years!

I console myself with the thought that this winter I'll take some time to see if I can implement some fix which stabilizes the Gross rig, yet keeps it original.

Speaking of regens, here is a photo of the wonderful regen Larry kindly built me last year for Christmas.
It took a blue ribbon at this year's AWA Equipment Contest, a comment on Larry's building skills.
Loosely based on the Pilot Wasp, he calls it the "NE1S Quasi Wasp" and it works as sweet as it looks.
Complete story at -->> http://www.w1ujr.net/gift_from_ne1s.htm


(http://www.w1ujr.net/NE1S%20Quasi-Wasp/DSC02312.jpg) (http://www.w1ujr.net/NE1S%20Quasi-Wasp/DSC02305.jpg)

(http://www.w1ujr.net/NE1S%20Quasi-Wasp/DSC02302.jpg) (http://www.w1ujr.net/NE1S%20Quasi-Wasp/DSC02295.jpg)

That is absolutely beautiful work OM.

Very Humbling Construction, Awesum....Thanks for bringing them in. :D


73
Jack.

Regenerative sets ARE fun to build! I love them!!

I posted this before. I build this set last winter, complete with battery eliminator (underneath).

(http://99.239.154.87/Projects/Miniloop_radio/Miniloop_V3/Miniloop_V3_1.jpg)