TRF Receiver

This brings back memories of how I started out in electronics as a kid. I couldn't afford transistors, but I did have vacuum tubes, so I designed simple radios, in which to use them. With a HT of a mere 9 volts, I was rather pleased with their performance :) .

Thx for all your great videos! All the best from Germany - H.

Best sound from TRF circuit - without superhet "birdies" and other noises.

excellent series Mike... much appreciated

Thanks for the video. Is a superhet in the works??

Mike I like your series on simple radios. When you add a 5th tube to a 4 tube superheterodyne, its usually a RF stage and performs so much better, or AA5 vers AA6. To me a 4 tube battery or AA5 radio with just a mixer/osc, IF, det/1st AF and AF output are what I would call minimalist radios.

Q-multiplier might be easiest addition to that schematic i guess.

Thank you Mike for a very nice video. My National SW3 has a tuned RF stage, tuned regenerative stage and one stage of audio amplification. It uses plug in coils and it is very sensitive . I have band spread coils for the ham bands and it receives SSB and CW very well. Thanks, Ellis.

Quick thought ... I have one of those Precision (920) tube testers too. It might be interesting to talk about use and getting updated/expanded scrolls, and how to maintain the units - even the test equipment needs help from time to time. Greatly enjoy your channel ... I remember the first Morgan book from early elementary school ... I was already into electronics, but it was a really great find in the school library. Thanks. Cheers

I am enjoying this series & trying to wrap my head around it! Off to watch it again!

👍I always thought I had a keen sense for the obvious, but never thought of connecting 9V batt's that way.

Love your videos, man. :) Inspiring!

When you mentioned the TRF regen, the first thing that popped into my head was the Doerle Signal Gripper which is a regen with a tuned RF amp before it. I considered building one but it would require me to make a set of two plugin coils per band. May try an untuned RF stage instead before a regen and see how that works.

Hats-Off Mike! Really great series and appreciate the deep-dives into all the subtleties of each topology--well done! I may have posted this before, but I now use Lithium 9V rechargeable batteries for everything from radios, DMM's, testers and even smoke and CO detectors. The rechargeable lithiums do have lower voltage but I have found that even when used with a device that shows a 'low-battery" warning, that the device functions just fine--plus they don't leak!!! I buy mine off of Amazon as either the EBL-brand (btw: I buy the set that has 4-batteries plus a 4-position charger; or the HiQuick brand; none have failed! Make sure that you get the 600mA version, they cost slightly more but last a bunch longer! Also, I charge to 8.2V, not 8.4V for cell longevity. I have excellent results, and next to no self-discharge; and yes they cost more up front but I have saved hundreds over alkaline DuraLeaks! 73...

TRF still works very well for a WWVB receiver. A few cheap transistors and LC's and you're in business. And of course, you don't want to change the WWVB carrier frequency, and a superhet will do just that.

Superheterodyne has been build with 4 tubes they simply remove the IF tube. It was intend for local station only.

❤😮Poland

Very nice series Mike! Any chance of a comparison between a FET vs. tube regen of the same architecture? 73.

I'm very interested in that little two tube amplifier. Has that been covered in a video? I looked through your channel but couldn't find a video on it. Perhaps it is a part of some other vid that doesn't have amplifier in the title, or maybe I'm just blind. If you haven't covered it, would you consider making a vid about it, and if you have, could you point me to the right vid? I'm interested because I'm making a two tube audio amp now, attempting anyway, and I've not been successful on audio amps in the past. (I'm looking at you, Morgan!) My current project is a 1950 Popular Mechanics circuit. I would love any insights into how it could or should be done.

Homebrew coils are invariably solenoid wound. It seems to me scramble wound is actually a better approach.