Morgan One Tube Regen Part 2

The Morgan One Tube Regen gets improvements in this second video on the popular children's regenerative project receiver.

[@SteveHacker]

Very much enjoying binge-watching all your videos!

[@MIKROWAVE1]

Woops. There goes the weekend.

[@howardrollinsiii45]

I think that you have done an exceptional job at your presentation of the Morgan Regenerative Receiver. love the modifications you developed. I too enjoy experimenting with receiver designs to improve performance. Armstrong, Hertz, Faraday and Marconi would be very proud of you just to name a few. Very clear & practical. If you are not an instructor, you would certainly be a great one. I like the Clip board Front panel. Great Job. Thanks for sharing this with us electronic minded folks.

[@jerrykovacs3782]

Thanks for the great series Mike. You provide a lot of needed basic understanding and what effects circuits for regens. I'm learning!

[@aa1ww]

Beautiful job on both videos. Very clear and thoughtful presentation. Thanks!

[@rsantiqueshop]

Thanks Mike.I will let you know how everything turns up when is all finished.Keep up the good work my friend.Love your videos.

[@laphant1]

very enjoyable delivery and i like the upgrade analysis and improvements KA 9 EMP ..melvin

[@eugenepohjola258]

Howdy. Nice. I would suggest using a pentode. The tube gain may be done adjusting the screen grid voltage. My experience is a smooth onset of oscillation and no avalanche effect at max regeneration. Regards.

[@stationvictormike3415]

Just built a Morgan Receiver. I purchased coils and wound them. The specs U give also work on my 2 3S4 SW CW/SSB AM Receiver as well.

[@stationvictormike3415]

I JUST FINISHED MINE AND ADDED PANEL TRIMMERS FOR BOTH ANTENNA AND FINE TUNING AND WORKS AWESOME.

[@KarlsLabReport]

Thank you VERY MUCHh for your 6AU6 schematic on your Facebook site!! Copied that; I have a 6AU6 tube along with the rest of the stuff to build this.

[@easyeagle2]

Beautiful work. Morgan`s `First radio book for boys` was my bible in grade school. I built his regen. design using a 12a7 tube, (which I still have!). I have a comment and suggestion for your improved design. Morgan used that 50k instead of a 5k regen pot to reduce loading on the tickler coli, which of course is coupled into the antenna coil. This spoils the Q of the circuit. The best way to avoid this is simply to remove the 50k pot(or 5k) from across the tickler coil and connect it in

[@davidduley1029]

Thanks for the series. I am rebuilding the Morgan that I built when I was in junior high or high school incorporating some of the changes you suggested. I liked the clipboard suggestion so well that I am making a raised base plate and short rear panel out of clipboards, too. One advantage to this is I can do most of the wiring underneath. True, I can't use the ground plate underneath but I think the front metal plate is more important from what I have read. One error in the book I have not seen mentioned is of the pictorial drawing guide showing a top view of all the wiring (page 173 in my edition). The tube socket is rotated 180 degrees from where it should be to match the tube pin numbers. Nevertheless it is a great book.

[@davidduley1029]

Reply to myself. I finished building the set and it works well. I believe I found another mistake in the book: the schematic has an error. The "T" and "C" label for the tickler coil should be switched. The 2 drawings of the circuit show it correctly. Also, I used a 10K pot instead of the suggested 5K. I found it to be very touchy and eventually reduced it to 2.2K but it was still very difficult to adjust. I measured the resistance where regen occurred and found it to be in the 600 ohm range. After reinstalling the 10K pot the way the original circuit shows it I found the regeneration to much, much easier to adjust. It may have something with having a 10K resistance across the tickler coil versus almost shorted the suggested way. Yes, I have some wiper noise but it is worth it to get the improved regen adjustment. I realize some of my experience may be due to how I wound the coils though I did experiment a bit with that. I tried to use an output matching transformer to drive a modern low impedance headphone. The sound was muddy no matter what I tried. I fiddled with the grid leak resistor/capacitor all to no avail. I believe a good part of the blame is a cheap head phone but not all of it as a mixer amp also showed the output had too much low frequency audio. I discarded the idea and installed a resistance/capacitance output and ran it to a guitar amp which is high impedance and was very satisfied with the result. At any rate, it's been a lot of fun.

[@incognito-yj4gu]

Some of the updates needed may be due to a different tube than Morgan used. It would be interesting to hear the receiver exactly as Morgan built it.

[@chrismosley409]

Ok. I see it. I will have to glue a screw in there. Thanks, Mike. Love the videos.

[@mylowproject]

very good videos I learned so much.

[@TheSteelyD]

I would like to see a video of you putting your Paraset on the air for Straight Key Night. Thanks for the nice tube projects , 73..de SteelyD

[@robertpendergast2620]

Really well done tutorial. Thanks And, would you share your amplifier schematic?

[@stormshadow5555]

You're final comment sparked my curiosity... about improving this Regen to be on par with some of the best Regens out there. What are some of the best Regen's out there and what would you do to this one to get it up to that level? Thanks

[@JohnSmith-eo5sp]

8:10 The One Tube Regen Set I mentioned earlier is a much simpler design - - quite juvenile! I built it many years ago from a kit I ordered by mail. Just a little drilling, soldering, and screws were required. I wound the coil(s) by hand - - it is not a plug in, and the aerial connects directly to it thru a small capacitor. The potentiometer has a Ohm value that is too high for effective use at full plate voltage of 45V

[@davidduley1029]

A couple of other changes made to the receiver. I changed the output to a Bogen T725 line matching transformer. Using the primary as an autotransformer I was able to make an impedance match for crystal earphones. These tend to sound tinny but my ears hear better with them. I was also able to use the secondary (8 ohm) output for low impedance earphones. No switch needed; just two output jacks. I also switched to a 6C4 tube (some minor rewiring required). I think it goes into regeneration easier and I think I have a little more volume at the output. My set is battery powered and when I found out the 6C4 filament current is 150 ma vs the 300 ma for the 6BF6 I was sold. I also added a filament voltmeter to help prevent operating it with low filament voltage. I have been reading that low filament voltage can degrade indirectly heated cathodes. I also added a B+ switch to prevent low voltage operation during start up and shut down.

[@TheGearhead222]

I've built or worked on more than one Regen. and you have a very sensitive set, especially for the era produced!-John in Texas

[@MIKROWAVE1]

They are amazing in any generation!

[@rsantiqueshop]

Hi Mike.For some reason I just can't get to the lower frequencies.Even with another coil.Not sure if it is something I did wrong or is it just the set itself.So at least it does work.On short wave I can only get a couple of stations.I have a long outside antenna of about 100".Thanks for all your help.

[@stationvictormike3415]

Hi again, I built the 1H4G 1 tube set which is close to that circuit and one issue. Nothing came out, so I touched around the circuit and accidentally touched across the headphone jack and the Stations came in... So I thought "Resistance". I place a 200k pot across it temporarily and it sounds good.. The headset is a 2k headset that I use on my other set and works great on them.. This is the first time I have seen where I have to place resistance across this type of headset. I think there is something more to the circuit that needs adjusting. Also, I had an issue with the 2.5mH choke where it came apart and I re-fixed it by tac soldering it. I was curious about how it would work without it so I shorted it and the stations came in louder by 20-30%.

[@pp5cw]

what I have noticed is that there are variations on regen controls capacitor that go across.. in different circuits.

[@MauriatOttolink]

Hi Mike Thanks again for the A1 video. Enjoy them both frequently. Despite my having a shelf full of needlessly-expensive stuff, you take me back to the (my) days when school boys were building stuff which had been recently in service, Ham & WW2. I just obtained an identical friction reduction drive and would like to ask you about it. 1) How do you fix, the black 4" disc, against the front panel? 2) What is the significance of the two additional dial windows? IS THERE ANY? 3) Silky smooth, it is NOT! The drag varies from point to point... Any adjustment or lubrication likely to help. 4) Can't find a type or maker's name... Made in USA? 73 de G3NBY...Keep up the good work...You're held in high regard.

[@chadcastagana9181]

That 500K Ohm potentiometer for the regen control was probably meant for crkt using 90V B-batteries

[@UKBB]

Where do you find your knobs and the vernier knob?

[@friesofwisdom4399]

I've been building a few different regen radios recently, my favorite so far is www.qsl.net/pa2ohh/02reg.htm I've changed it up a bit: I'm using a tickler coil with a center tap that is grounded, and the regen pot's ends are connected to the ends of the tickler coil, it's wiper connected to the collector. This allows you to blend between negative and positive feedback which seems to give smoother control in my experience. I've added resistors and capacitors in series with the antenna coupling coil on both ends, to reduce the coupling and capacitance to ground. I'm also using a TL431 as an audio amplifier. With a single coil and tuning capacitor that I pulled out of an old radio (dual ganged, both gangs in parallel), I can tune from about 500khz, up to about 2.8mhz I'm in Cape Town, and at night I can hear Asian, and South American stations.

[@pp5cw]

good job... It takes tinkering

[@easyeagle2]

a separate b+ connection to the plate. Then place a 100pf capacitor in series with the tickler coil to remove all dc from it.

[@pp5cw]

Back in time like a twilight zone movie

[@LZ2SM]

How did you connect the amplifier to it?

[@MIKROWAVE1]

The antenna coupling variable or trimmer capacitors need to be insulated from the grounded plate. The turns ratio in the Morgan book is way overkill. For a broadcast band coil you need say 90 turns with a 15 turn tickler on a plug in coil form. I used a 2K to 5K Ohm transformer to connect to an external amplifier but it is not critical.

[@davem6492]

Do you have the schematic and parts list for this radio?

[@tubeDude48]

How about supplying number of turns and wire size for each tickler coil.

[@KarlsLabReport]

One other question: I have a Multi Elmac PMR-7 receiver with a 262 KHz IF section. I want to make a Q-multiplier for this radio. Can you suggest a simple circuit made from available parts to do this with? Thanks in advance. -Karl

[@chrismosley409]

Thanks Mike. The only thing I see is a little set screw that keeps the shaft of the variable snug with the vernier. Is this what you're referring to?

[@MIKROWAVE1]

Turn the vernier over so the brass is showing. You will see an oval recessed feature located just above the little pinch drive. That is sometimes outfitted with a screw, a threaded nut and sometimes it's just a plastic hole that sits over a screw head on the panel that keeps the thing from rotating. Glue an upside down screw into the hole if you have to.

[@8Ugri8]

Any idea, how to connect frequency meter to regenerative receiver?

[@rick601a]

Hey, I'm currently building on this radio. Collecting parts at moment. One question I have is how is the best way to approach getting rid of the DC in the phones audio. I have thought of using an audio transformer here. So I could use any audio amp here. Or maybe a simple resistor for the plate supply and cap to pass audio for the phones. Would appreciate any input you may have on this Thanks. Keep up the great videos lots of fun.

[@joesitter20101]

The circuit has a severe, potential safety hazard. If a perspiring barefoot child in a warm, humid location such as Los Angeles were to have the receiver well grounded, the moment she applies B+ to the radio, she could receive a painful and dangerous shock with current flowing from head to toe. Apparently beside not realizing that girls too can learn to love electronics, Morgan didn't think about electrical safety. Perhaps a 20K resistor from B+ to the plate and the 2.5mH choke tied to the headphones in series with a 10uF DC blocking capacitor.

[@chrismosley409]

Hi Mike, How did you attach that vernier dial to the face plate. I have one like it but it seems that it would only slide over the shaft of the variable capacitor

[@MIKROWAVE1]

There will be one small recessed feature with a hole just below or above the shaft. This will take a single 4-40. That is it! It basically keeps it from rotating. So you need to support and recess the variable so the shaft just pokes through. Then the vernier flush mounts.

[@colofagu86]

Nice video! Can you tell me what type of antenna do you use with the regen receiver? Can I replace the 6BF6 for the 6SR7?

[@MIKROWAVE1]

I have used a variety of antennas from a 120 ft long wire, to a 80M dipole, to a very quiet large vertical loop antenna, with these simple radios. The 6SR7 is an excellent perhaps even a better tube if it is the metal type. Ground the diodes or tie them to the cathode.

[@colofagu86]

@@MIKROWAVE1 I thank you very much for your quick response and the tips for using the replacement valve, I really enjoy your videos and the simple explanations of each topic, I got my radio ham license very recently and radio is a topic that I really enjoy, a greeting from Uruguay, CX1IT 73!

[@SpinStar1956]

Mike, enjoyed the video. I had bad luck when I was a kid trying to get regens going so I played more with DC and superhets as a result. Question: You moved the plate connection to include the whole coil @2:40. Since we are looking for "AC/RF" feedback, would it be appropriate to place a capacitor in series with the wiper to the plate; this would allow the 'rheostat' to NOT change the DC level on the plate (i.e. the DC would always be going through the whole coil and not be bypassed when the wiper is at the 'top' seemingly bypassing or shorting the coil altogether)? Thanks & 73...

[@MIKROWAVE1]

I have not tried this. Sounds interesting. I have seen the plate choke fed, and the throttle cap in series with the tickler to ground, which also breaks the circuit for RF.

[@stelian95]

Nice work ! Why does it work properly in SSB ? I thought it would be impossible to pick up SSB without a BFO.

[@KarlsLabReport]

When the receiver is oscillating, it reinsert the carrier into the SSB signal so you can render it intelligible.

[@chadcastagana9181]

3:04 That high resistance potentiometer maybe to limit plate voltage, if it were in series with the feedback coil?

[@MIKROWAVE1]

Any time you want to try and influence regeneration with a change in voltage to the detector stage, you have to consider the interaction of the detected audio on the voltage source's impedance - causing undesired effects like popping suddenly into regeneration. So we like to keep the voltage source at a very low impedance, rather than adjusting it with a series resistor. A variable DC regulator into a low resistance audio choke would work very nicely.

[@yeodakyum]

can i use a ecc83 tube

[@stationvictormike3415]

Second Morgan set. Take a look at the one that I built. kzbin.info/www/bejne/gqCokHeVZbCapJI. Yes, about 9 months ago, I had that very round dial that Ur using but sold that one. At that time, I wasn't planning on doing a second set until now but came close to it. I'm using the coils from my 2-3S4 Receiver and they seem to work on this one 6BF6 receiver.

[@cristianosar]

Very good, I built a similar one using a type 30 tube. One doubt, to plug it into the amp, I need the audio transformer first or can I plug it directly to the amp ? thanks

[@MIKROWAVE1]

Check out Part 4 of Morgan Revealed. Yes I did use an interstage transformer to isolate the input.

[@cristianosar]

@@MIKROWAVE1 thanks

[@rsantiqueshop]

Hi Mike Have built the radio and works ok but I can only get frequencies from 800 Kc to 1600 Kc.Have used a 1 1/4" coil with 25 wingdings on the tickler and 100 turns on the rest of the coil.Wire is 26 awg gauge.Any suggestions? Thanks.

[@MIKROWAVE1]

So that is why Morgan had the second coil with more turns on it. To handle the bottom part of the band. The 150T coil with say 25T tickler should get you down to 450 KHz to 1000 or so. You may need to use thinner wire to fit it. Say 28 enameled...

[@rsantiqueshop]

So if I use 30AWG wire,do you think I still should wind 150 turns and 25 turns on the coil or can I get away with less turns? Thanks Mike. Ray.That's my name by the way.

[@MIKROWAVE1]

If you have a second plug in coil, by all means wind at least 130 T on it to catch the bottom of the band.

[@allanegleston13]

i have that book. :)

[@edwardneuman6061]

I used to borrow this book, and others in the series from the local library when I was a boy. Wish someone would make it available as a pdf or e-book

[@michaelsimpson5417]

They're here: www.americanradiohistory.com/Archive-Bookshelf/Bookshelf_Hobbyist.htm

[@edwardneuman6061]

@@michaelsimpson5417 , Thank you!

[@mgraemem]

Is the audio amplifier also from the Morgan series?

[@MIKROWAVE1]

+Mgraemem The audio amplifier is basically the amp circuit lifted from an AC/DC All American 5 Receiver! The amplifiers in the book are simpler and safer!

[@mgraemem]

Ah. I found an example of just such a thing. Do you think that the amplifier you build for your crystal set using the 1U5 and 3V4 would be suitable in place of this amplifier?

[@mheermance]

MIKROWAVE1 My grandmother had one of those old tube AM radios. It sounded much better than a mono AM radio had a right to.

[@bobbiggley6992]

I have an old 6au6 tube would that work for a regen?

[@MIKROWAVE1]

You Betcha. I will publish a schematic on my FB page if you are interested: facebook.com/Mikrowave1/?modal=admin_todo_tour

[@rsantiqueshop]

hi what size coil (diameter) is used? also what wire gauge for sw and am bands? thank you.

[@MIKROWAVE1]

Coil Data is always needed. But it is never correct in the real world in my experience because there are simply too many variables. will the kid find a plug in coil with exactly the 1.25" Diameter you might require? Morgan cleverly solves this by suggesting two coils. One with 70 turns and one with 120 Turns. Between the two you probably will hit the BCB! Fooling with coils is part of the fun. As a general guideline, I like #26 AWG enamel for the BCB and up to 3 MHz.

[@MIKROWAVE1]

So for the BCB, maybe 100T and 20T tickler - and for 80M and 40M or 3 to 8 MHz, it pays to use a bit thicker wire like # 22 and you may only need 25T and just 5 turns for a tickler. Space them 1/2" apart for both bands.

[@rsantiqueshop]

@@MIKROWAVE1 Thanks Mike.I wonder If I can get away without the RF choke if I use an amplifier.?

[@MIKROWAVE1]

@@rsantiqueshop The choke acts to isolate the RF bypass cap from the headphones or the output transformer. So if you want to skip it, use a 4.7K resistor in place of the choke, a. 001uF cap to ground as a filter and a 47K down to the power supply B supply. You take the audio off the top of the 47K through a 0.1 uF cap to the Amp.

[@rsantiqueshop]

so if I wind some 30 awg magnet wire on a sewing bobbin would I be close enough on the required value of the RF choke for my Morgan receiver? I just don't have one of those meters to measure the inductance.Thanks again for all your help.

[@DAVIDGREGORYKERR]

What about hairpin inductors for 432-900mhz

[@MIKROWAVE1]

Nobody uses hairpins anymore. Curlers? I have to admit that I have not made an oscillator or superregen receiver above 170 MHz with tubes or transistors.

[@DAVIDGREGORYKERR]

@@MIKROWAVE1 they can be used for frequencies from 432MHZ-600MHZ and are shown in the RSGB VHF/UHF Handbook as well as stripline tuning circuits.

[@pp5cw]

thanks , I tried changing out the 270pf to 300 and some PF... Bingo... SSB intelligible. on my circuit... please check out Pedrazza's Radio shack on Facebook... and see... I'm still modifying radio...thanks

[@TheGearhead222]

Puffed? You mean Picofarads? Trying to stay politically correct here;)-John in Texas

[@MIKROWAVE1]

I knew an old time Radio TV guy who only said Triple OT caps. Then you have the micro micro farad guys...

[@garraper]

plastic screw driver