Two tube spy transceiver in field setup and Power supply design.

[@eb3bnj]

Nice project and amazing success. 73.

[@MilanCekic]

Fantastic design and functionality! ❤️ Thank you very much for sharing!

[@manolinija]

Nice and well organised internal box layout.

[@RadioProyectos]

You always surprise me Helge, the power supply has enchanted me. I've always had the problem of RF noise with step up converters, and the solution is brilliant, build a 50 Hertz converter. Simple and brilliant. And 400 km with a watt.. Wow 73 de EA1FLL 😊

[@STUDIOONTHERECORD]

50Khz…

[@WA8QFE]

I enjoy you videos. I actively us a CIA RS- 1 set and have a great time with it .

[@maestherc]

Enjoy watching your videos very much! Thank you for sharing.

[@drjet666]

Very good Helge, thank you for sharing your exciting prospects with us... keep up the good work! 73'de LA1DSA Jan Erik

[@danamarcy5414]

Wow what a great little radio! Very Nice. VE6KBI Dana in Canada.

[@Steve-GM0HUU]

Very good Helge, thanks for video. I still cannot believe that you fitted that Tx/Rx in the little tin 😂. Power supply is very interesting. I saw in another reply that you got the transformer core from a power supply.

[@PaddyOReilly_co_uk]

Superb ideas and enthusiasm. Mni tnx de G4MAD!

[@peterhausamann5923]

Awesome! Straight away I was interested in knowing how you would make an inverter for the 250VDC. Very interesting simple design. I like your antenna design too. The two tube transmitter is very well put together. Thank you for showing us. I always look forward to your next project.

[@LA6NCA]

I always use this power design. 90% of my powers are made like this. The big powers run at 400 - 1000 Hz, while this runs at 50 kHz.

[@sheep1ewe]

Thank You for making those vieos!

[@johnrayfield11]

Watched you tx/rx build. Good to see it running in the field.

[@larspregge6420]

Great. Especially the power supply.

[@youtubeaccount931]

Good success!

[@TomKristiansen]

Er litt stilig å se absolutt alt er hjemmlaget. har bygde en strømforskyner selv gleder med til å begyne på antenner snart.

[@electrifyingvids3545]

Thank you very much for the power supply design. I tried to design my own but to no avail and ended up using mains as the HV. Excellent video. Field day! Edit: I didn't see the voltage multipier at the output so if you wind a transformer for 300v, you'll get ~600v DC on the output. But hey, more voltage fot meeeee. Edit 2: completed it. But, I miscalculated the transformer and now get 730v preregulated from the transformer. This killed and smoked the 10k resistor on the regulator.

[@snoopy266ZB]

Many thanks for sharing this very nice Project.❤ Could you please also provide the 3D files for the Morse key?

[@electrifyingvids3545]

What kind of transformer did you use in your PSU design? Was it a commercially bought unit or a custom wound transformer you made by yourself?

[@LA6NCA]

I took a ferrite core intended for power supply. I designed and 3D printed a bobbin. I then wound a primary and secondary winding. The primary winding is 2 x 19 turns.

[@electrifyingvids3545]

@@LA6NCA Thanks!

[@p1nesap]

Awesome

[@jamesttk488]

I was about to ask you how do you obtain the anode high voltage until you let the cat out of the tin can. Very surprised and definitely enjoyed your innovation. Two thumbs up for you. Thanks for sharing this very interesting video with KZbin.....James VA7VB

[@joeblow8593]

Thanks

[@mohinderkaur6671]

Very nice work! I may try to build this! The cd4047 250v inverter can be made more efficient using a chip like 3525 smps controller. It has deadtime and can use feedback to control pwm + short circuit protection.

[@LA6NCA]

Thanks for the info on 3525. Looks very good. Maybe I'll order some of these. However, I do not understand how the regulation takes place. After all, I operate with a transformer that cannot regulate the voltage with the width of the pulse, but the turnover ratio in the transformer.

[@mohinderkaur6671]

@@LA6NCA There is an inductor after the rectifier . smaller the pulse width, lower the output voltage. You are correct, wont work correctly with capacitor input filter,

[@mohinderkaur6671]

@@LA6NCA There is an inductor after the rectifier. That makes PWM work.

[@jagmarc]

@@LA6NCA your 250 V DC regulated supply looks OK and robust to me as is. I can see it already has the 'dead-time' of a few % of dutycycle (the gate series resistor) and also the resistor make FET soft switch-on. The linear series regulation is about the only place would gain efficiency, but 'burning off power' here is doing a good job as an active filter, being a source-follower , expect it filters better than a capacitor.

[@dvlm8471]

Замечательно получилось

[@marcusf.6722]

Compact design so far but a 12 volt battery in a knapsack would be a bit heavy. But overall, impressive. A lightweight, compact battery would be an advantage. Tx and Rx was at the forefront.

[@LA6NCA]

Yes you are right. I made a small battery pack with lithium batteries, but unfortunately it was not finished for the trip to Jøssingfjorden.

[@EC5ABG]

Buen trabajo, 73.👍👏👏

[@Tamlin73]

Genial radio, hvordan fungerer Koss Porta Pro med radio?

[@jerryuhte1284]

Ammazing work , 73Jerry k9ut

[@psnpacific]

👍

[@jagmarc]

I was just about to recommend increasing the EL90's gridleak from 100K towards 1 meg to get more power, but you've already increased it to 330K. There's a Grundig TK ?? tape recorder that used a EL90 for bias oscillator / erase head. And another for class A speaker driver with anode at 6 W

[@LA6NCA]

Thanks for the nice suggestion. I have certainly not done everything to maximize it. But it worked fine. I have so many new ideas to design, so not everything will be 100%, but maybe 95%? But I am very interested in such comments for future projects.

[@jagmarc]

@@LA6NCA it's often said that "the last 10% takes 90% of the effort" :)

[@mt8385]

Thanks fo new video, one remark..the earlier captions were easier to read

[@LA6NCA]

Thanks, I'll go back to the regular font next time.

[@mt8385]

@@LA6NCA Thanks, the youtube embedded subtitles are also not bad, so if anybody doesnt understand english it could automatically translated

[@jean-jacquesdelalain]

Hello dear OM interested in the assembly of your 2 tubes transceiver can you give me the number of turns for the coil of the EK90 tube and the 6AQ5 a big thank you 73 QRO jean-jacques F6ggz

[@yle5788]

Ikke ofte jeg finner norsktalende video på hackaday =)

[@asbjrnursin8912]

Som alltid - en utmerket video Helge. Et spørsmål: hva slags toroidkjerne bruker du i dipolantenna? 73 de LA5MT.

[@LA6NCA]

Jeg vet ikke. Ukjent type. Men jeg målte at induktiviteten var stor slik at den fungerer som en balun.

[@joseneves2822]

Many thanks for sharing / 73

[@bergkongs]

73 de LB7MJ

[@TheArtofEngineering]

Awesome video tu fer sharing 73 de VK2AOE