KW7T Two Tube Transmitter Receiver - Intro

Can a Two Tube Transmitter Receiver be a practical rig for QRP Ham Radio?

[@olafelsberry420]

I used to live in La Junta Colorado, I was amazed at the broadcast am radio I would receive.

[@MIKROWAVE1]

Nice lower noise environment for AM!

[@olafelsberry420]

@@MIKROWAVE1 you hit the nail on the head kind sir, definitely little to mechanical whine simply because there was little electrical interference.

[@radiotec76]

Nice appearance! I love the combination of wood base and legacy vacuum tube components!

[@MIKROWAVE1]

He did a great job at balancing the retro look with practical components - at the price of some some performance limits, as we will see in the next video.

[@matthiaswilhelm9813]

Very good Performance mister😂❤

[@MIKROWAVE1]

It works but you do have to be patient.

[@ribeiroflyby9766]

Nice gear Bro, RF its one of best part this cience called Eletronic. Like from Brazil 👏👏👏...

[@MIKROWAVE1]

Obrigado por assistir meus vídeos de rádio.

[@ahchu3256]

Very cool! I think I will attempt this project - DE K1TB

[@MIKROWAVE1]

This will be a great project. Start collecting parts!

[@awaismushtaq5719]

For home-grown product, design is fairly sober

[@barrymontgomery9860]

Very cool!!

[@MIKROWAVE1]

We shall see how cool soon!

[@Chris_Grossman]

This was an interesting since I had never looked at the one tube transceiver circuits. The transistors in the schematic with the step-up supply will degrade over time due to McDonald effect from the reverse base-emitter bias on the off transistor.

[@MIKROWAVE1]

That is quite a primitive circuit, and I will take a closer look when we get there with the series.

[@luisagonzales1442]

❤

[@DAVIDGREGORYKERR]

Should that Solid State high voltage generator not have had a feedback winding and just one 10K resistor not 2 10K resistors and a 50Pf capacitor across the two collectors of the transistors to get a nice clean signe wave instead of a raspy sound square wave.

[@maciekbal5924]

Great as usual. ❤ Is your tuning knob old stock or did you found a place to buy it this time?

[@MIKROWAVE1]

I do not know how Dwight supplies these rigs with that Vintage Hardware. It seems unbelievable that he has access to such stock in quantity.

[@acestudioscouk-Ace-G0ACE]

Interesting and thanks for showing it to us. Is the 250V DC supply easily found today please?

[@acestudioscouk-Ace-G0ACE]

@@tripplefives1402 Thanks for the information, I appreciate it. As my handle suggests, I'm in the UK where the voltage is 230v but I take the principle for what you say. A varaic is a good option and is on my shopping list. Thanks again and best 73, G0ACE

[@MIKROWAVE1]

The unit has onboard 250V that is converted up from 12V. So the unit only requires 12V and, of course, a 9V battery.

[@acestudioscouk-Ace-G0ACE]

@@MIKROWAVE1 Thanks for the information Mike. That clears things for me.

[@JCWise-sf9ww]

Very nice 2 tube transceiver with vintage tubes, etc.. Why did he not use the 250 vdc source divided by 2 resistors for the regen tube? That way you would not need a 9v battery and it could all be powered by one 12vdc power source.

[@MIKROWAVE1]

There are many ways, but component count, perhaps by the time you clean it up enough? We shall see.

[@DAVIDGREGORYKERR]

Was it Shango066 if not who?

[@kenchilton]

Do you have a link for order info? Do we just contact Ike at his QTH mailing address?

[@MIKROWAVE1]

He seems to have an EBay and Esty store, but yes, email for queries.

[@DAVIDGREGORYKERR]

Anyone built this unit into an Altoids Tin using Pencil stub vacuum tubes.

[@MIKROWAVE1]

I have a few of these. My buddy keep stealing them for fuzzboxes.

[@DAVIDGREGORYKERR]

@@MIKROWAVE1 There are Russian Germanium Transistors that should work also.

[@scottmorgan5370]

I've never been the first viewer. No big deal at all. Good grief, 200 - 500 Volts in a set of headphones ???

[@MIKROWAVE1]

Ha the good old first days of radio.

[@jennyjansen754]

I guess using an audio transformer would be cheating.

[@MIKROWAVE1]

@@jennyjansen754 Folks are experimenting with ordinary small power transformers. For instance a 120VAC to 6.3 VAC 1 Amp job has a 19:1 voltage ratio which squares to a 362:1 Impedance transformer. So if you had a tube with 4500 Ohms of plate impedance, the output impedance would be 12 Ohms to drive ear buds.