A new adaptation of a VERY old design. They are sold for use on ham bands and I've heard great things about them, especially for temporary and limited space setups. The directivity is amazing for something that's so small! I'll have to give one a try sometime. Thanks for sharing.
You can also try a double tuned setup: a variable capacitor on the frame antenna and set parallel to the ferrite rod connected to the radio. It might work better, might not, I'd love to see how well it does!
Using the ferrite rod purely as a high Q resonator like an air coil and putting an input link on it and coax to a remote big frame loop OR simply nesting the two for coupling are both viable ideas.
In my plans to play around with these. I'm an apartment dweller and AM is on its last leg here, allegedly 4 stations in town but have only been able to reliably pick up 2 on a modern radio.
Hi Mike! You can recommend to the makers to use the wire inside mobile phones headsets cable. Wich have at least 4 length of a multiple strands of very thin enameled copper wire. This wire should make good coils in MW band. Best wishes my friend!
Nice video! I'm not surprised to see the loop performing so well. I bought one of those cheap eBay/Amazon external tuned loops and was amazed by how well it improved the reception of cheap transistor radio receivers with a ferrite stick just by bringing it near the radio. Now I'm wondering how well tuned loops would perform on the HF bands. -- John N0BUP
Untuned loops with high dynamic range preamps are seen more at the higher frequencies (for reception only). Tuned loops are being used fairly commonly now on the ham bands for TX and RX.
I've had it, I'm going to play myself using solid state. I like tube tx for a bit, but come on... let's play at least partially where people want to play. With some transistors 🤣
So the bigger open air loop antenna does perform quite well! Did you say the big loop was about as good as a 75 ft long wire? I made a loop antenna on a 2 ft diameter cardboard strap spool with 14 ga house wire and tuned it with a paralleled 4 section 460 pf (per section) tuning cap to tune to the BCB. Man did it work good!
Hello. The video is top notch as always. Did you make a similar receiver with an external antenna. and use the heptode as a radio tube? I found in the literature of old issues a diagram of a device based on the CO-242 heptode. This is an old Soviet lamp. the difference in the circuit in the ultra-low anode voltage is only 4.5 volts.
You can use these in pentode mode with the screen tied to B+, or with the screen and plate tied together to form a triode. The gain will be less with the triode connection, which sometimes is an advantage in regens, but the pentode connection make the most sense here.
I want to know if instead of headphones can I place the 3V4 tube with T725 Boegen audio output onto the plate I think that winding in the transformer measures 3K ohms with many rainbow colored taps
A new adaptation of a VERY old design. They are sold for use on ham bands and I've heard great things about them, especially for temporary and limited space setups. The directivity is amazing for something that's so small! I'll have to give one a try sometime. Thanks for sharing.
Loops of all kinds are very much back in Ham Radio and SWL.
Great vid as usual. Also, if you put the loop closer to the ground, it gets more sensitive. Give it a try! like magic.
I will have to try that!
Great video & nice shorts!
I'm gonna make a 3' frame 👍
A true one day start to finish project!
Nice demonstration. Now to prefect an underground antenna for your basement
🎉
You can also try a double tuned setup: a variable capacitor on the frame antenna and set parallel to the ferrite rod connected to the radio. It might work better, might not, I'd love to see how well it does!
Using the ferrite rod purely as a high Q resonator like an air coil and putting an input link on it and coax to a remote big frame loop OR simply nesting the two for coupling are both viable ideas.
In my plans to play around with these. I'm an apartment dweller and AM is on its last leg here, allegedly 4 stations in town but have only been able to reliably pick up 2 on a modern radio.
I can get 9 or10 stations during the day on my car radio. That kind of sets the expectations.
Hi Mike! You can recommend to the makers to use the wire inside mobile phones headsets cable. Wich have at least 4 length of a multiple strands of very thin enameled copper wire. This wire should make good coils in MW band. Best wishes my friend!
Wow sort of a 4 Wire Litz!
@@MIKROWAVE1 yes, each of the 4 is a 7 wires litz of course without the silk coat.
They probably aren't insulated. I think Litz wire individual stands are insulated. Possibly it makes little or no perceptible difference?
👍
Nice video! I'm not surprised to see the loop performing so well. I bought one of those cheap eBay/Amazon external tuned loops and was amazed by how well it improved the reception of cheap transistor radio receivers with a ferrite stick just by bringing it near the radio. Now I'm wondering how well tuned loops would perform on the HF bands. -- John N0BUP
Untuned loops with high dynamic range preamps are seen more at the higher frequencies (for reception only). Tuned loops are being used fairly commonly now on the ham bands for TX and RX.
Very interesting
I've had it, I'm going to play myself using solid state. I like tube tx for a bit, but come on... let's play at least partially where people want to play. With some transistors 🤣
OK OK I've gone off lately way into planet valve.
tks for video..aslo the denotes are great...73
The notes usually get put in while editing and thinking about what questions might come.
Great Video !
Thanks for watching me play with some radios stuff.
So the bigger open air loop antenna does perform quite well! Did you say the big loop was about as good as a 75 ft long wire? I made a loop antenna on a 2 ft diameter cardboard strap spool with 14 ga house wire and tuned it with a paralleled 4 section 460 pf (per section) tuning cap to tune to the BCB. Man did it work good!
They work very well, and are very forgiving on the build style.
73,
9A5OS
Hello. The video is top notch as always. Did you make a similar receiver with an external antenna. and use the heptode as a radio tube? I found in the literature of old issues a diagram of a device based on the CO-242 heptode. This is an old Soviet lamp. the difference in the circuit in the ultra-low anode voltage is only 4.5 volts.
reception is carried out on an external antenna + grounding. and high-impedance headphones.
You can use these in pentode mode with the screen tied to B+, or with the screen and plate tied together to form a triode. The gain will be less with the triode connection, which sometimes is an advantage in regens, but the pentode connection make the most sense here.
@@MIKROWAVE1 Thank you very much for the answer. And by the way, thanks for answering. This is very supportive for beginner radio amateurs!
@@MIKROWAVE1 And I apologize that I communicate with you through Google translator. Forgive me, it turns out clumsily.
Did I miss a video on how to build that audio amplifier with the two tubes? Where can I find instructions...
My FB page Mikrowave1 Radio Resource page has the schematics and Parts List.
facebook.com/media/set?vanity=Mikrowave1&set=a.745667360893089
Cheers, got it. As a newbie your knowledge is invaluable.
I want to know if instead of headphones can I place the 3V4 tube with T725 Boegen audio output onto the plate I think that winding in the transformer measures 3K ohms with many rainbow colored taps
That transformer will work - no problem.