Regen Broadcast Plug In Coil Questions

[@johnwest7993]

I'm not quite reliving my childhood. I'm updating it from a position of knowledge and with the added convenience of useful test equipment. :)

[@иванепифан-к8ж]

Glad to see you again! Although I partially understand technical English, but nevertheless it is very interesting!

[@AirwolfBadarse]

Love your project mikrowave well done. I want to build a project but don't know where to connect plug in coils

[@migsvensurfing6310]

Nice work thank you.

[@JCWise-sf9ww]

Mike, thank you for explaining why Mogan had two coils in his design and your absolutely correct on the primary coil having about 260 uh, to cover just the BCB. I have modeled several tuning circuits for the AM broadcast band on LTsice for tuning range of 530 to 1710 khz or 540 to 1600 khz. There are other capacitances to consider like the input capacitance of the tube's grid, that effect tuning range, any trimmers & connecting wires, plus the coil's micro henrys value. I researched other regen radio's schematics (like the "1-Tube All-Bander" 1967 Electronics Illustrated) and they use the full 365 pf variable cap with one BCB coil and for the SW coils they would use a capacitor in series with the 365 pf tuning cap to limit the tuning range on the sw bands. Seen some of the Knight kits did that too.

[@sinisatrlin840]

I have stock of old coils, some factory made in 30s. But i have also made my own from polycarbonate tubing and octal tube bases. They look nice.

[@MIKROWAVE1]

Making your own coils is a very worthwhile part of radio construction!

[@sinisatrlin840]

@@MIKROWAVE1 Making coils is part of the "fun", important part. I live in Europe and LW is still active to some extent. Making good LW coil is to me most difficult. Nos German litz wire with 24 strands works great in my opinion, but winding it is painfull. Traditionally we had 500pF variable caps in our radios, US tradition is 365pF.

[@jerryuhte1284]

Mike,great explanation, tks !

[@alevans51]

Nice!

[@donholdaway2819]

How do I ask you a question? KB2NFQ. I have a question on plug-in coils, and how to properly connect the coils wound in the same direction.

[@MIKROWAVE1]

just look up my email on QRZ - WU2D

[@NoMoreFossil]

where you buy this coil form, 73

[@p1nesap]

Can you transmit with these lower AM frequencies and make contact?

[@MIKROWAVE1]

Because of the worldwide use of these frequencies for broadcasting, the power level and antenna length for unlicensed experimenters is limited on the actual Broadcast Band. Typical range is limited to around your property. But for licenced amateurs at higher power, the 630m Band and 160m bands can support long ranges to 2000 km during favorable conditions.

[@p1nesap]

@@MIKROWAVE1 Yes thanks I'm familiar with that, having transmitted AM across my apt. with 1 MHz crystal, 8:1300 ohm transformer & 3 meter antenna. I was wondering have you transmitted LF or VLF?

[@MIKROWAVE1]

@p1nesap I have done a full 1750m beacon at 1W input power in the 90s and lately I have done CW on 630m. Both very much fun. I could copy my 1W beacon with a "50 ft cage vertical " with 10 ft tophat, in my car with an active whip driving on interstate 495 at 55 mph 35 miles away in broad daylight. It's magic.

[@p1nesap]

@@MIKROWAVE1 Holy smokes 1750m wavelength from your car with active whip antenna? That's amazing, nearly the height of Mt. Washington. A low frequency rig/QSO video would be awesome, 620 or 1750m. I imagine you hear interesting things on those lower freq's.

[@MIKROWAVE1]

@@p1nesap I have a good video that shows what an active whip can do. This is a FET input amplifier with a low pass filter on the output in a small project box with a CB mag mount and whip last year on 630m. The mobile setup beats my home station because you drive away from the noise sources.kzbin.info/www/bejne/hGbbi6SPqth9bcU

[@Chris_Grossman]

Clearly built by Acme.

[@MIKROWAVE1]

All parts from Acme, shipped in well marked boxes.

[@Capecodham]

Puff? that was the name of my cat. You were probably too busy to be clear and say picofarad. Also too busy to say regenerative? Is Alfred Morgan related Morgan Freeman?

[@richardfranklin9313]

In the repair industry we nearly always used the term "puff" is quicker to say I suppose.

[@MIKROWAVE1]

I'm too busy to get the cat hair off my sweatshirt!

[@W1RMD]

I've got a Shih Tzu. That's kind of like a cat (in dog form). His whiskers don't make good detectors though. I was thinking......I could make a Shihtty regen. Don't be offended. Scotties are good dogs too! Puff was a magic dragon.

[@Capecodham]

@@richardfranklin9313 What do you do with the time you save? Do you say rec for receiver? Ant for antenna? Di for dipole? Be for beam? Piss for power supply?

[@sebastian19745]

​@@richardfranklin9313 I do not believe that 16k6 subscribers are all used with the repair industry jargon. Also, for many, english is not theirs native language. Wanting to watch a quality content, that this channel provide, do not mean to have to learn some esoteric jargon. Also, the standardization was made for something, especially in the industry. That is why, when I say "pico farad", I am understand by an electronist in India, USA, France, Brasil, Nigeria and...all over the world. And when I talk about a capacitor and I say "pico" is also clearly understand that is its value in picofarads. Puff, here is a "Soft armchair that usually doesn't have a backrest".

[@andrewandrosow4797]

Hello! Good work! Two coupled LC resonant circuits allows receive two different stations that is each next other without "mixing". It is from my experience. In my opinion - it is also actual for regenerative receiver. I made simplest transistor regenerative receiver - but with one selective circuit selectivity was bad in AM band. I`d like to ask - what is the sensitivity of this receiver? Can you measure it?

[@MIKROWAVE1]

Perhaps a comparison to a modern high performance receiver would show the sensitivity in a dramatic fashion.

[@andrewandrosow4797]

@@MIKROWAVE1 I read about transistor regenerator - that it has a sensetivity 2uV. It would be interesting - what is the sensetivity of tube regen. When you have MSI-SDR USB dongle and PC it isn`t difficult to measure the sensitivity. I did it - this device measures level of a signal quite good until 60MHz. But the input impedance of regen is quite big - it is , a quality multiplier.There must be a couple loop - for matching 50Ohm impedance. The technique may be the following: a signal from signal-generator (fabric or homemade) goes through 50Ohm cable to a small coil (couple of Inch in diameter , 2 turns) through 50Ohm resistor. The same coil connecting to a splitter: that consists of two 50Ohm resistors. One outputs goes to MSI-SDR, another to the regenerative receiver. To set input power - change distance between coils.