KW7T 2 Tube TX RX - Operation

The KW7T CW QRP TX RX is put through its paces. This is Retro QRP folks!

[@AJMjazz]

A nice way to introduce the real "radio art" of amateur radio. Thanks for posting this. I enjoy your channel as well.

[@MIKROWAVE1]

It is always fun to go back and play with these primitive circuits!

[@jackhreha4907]

Yes! hand received trimming is a feature. Yes! this is art. The KW7T is a labor of love. Perfect for a slow fist. Morgan is looking down with a smile. And don't ever clean the tarnish off that key. It would be like cleaning your usual coffe cup. Best Regards Jack

[@MIKROWAVE1]

Thanks for watching Jack! Ah yes the patina of age. I've got this body that is getting collectible as well.

[@RadioProyectos]

I like a lot this type of QRP 😀👍👍👍👍 Thanks for sharing 😊

[@MIKROWAVE1]

Playing with such simple sets that can be understood easily is a lot of fun.

[@blevinsmusic]

Thanks for doing the video! Great job and I fully agree 100% with your analysis. It was fun working with you to resolve the interaction with the send/receive coil functions. Of course, I have added the fix to the schematic. I lucked out on that one. Wish all problems in life were that easy to fix :) KW7T

[@towerman75]

Dear Mike -- Watching all your videos, it makes me believe that you are on another planet. Every received (even as simple as a 1N34A diode), you are able to pick up stations with tremendious sensitivity and selectvity. It's just not fair. Over the years I have built all kinds of receivers, and it has always been a struggle to receive anything. I know it has to do with location, but it still doesn't seem fair.

[@MIKROWAVE1]

I could explain but "It's magic" sounds much cooler.

[@MIKROWAVE1]

Oh and don't watch my video for this Wednesday. I set up a schedule for several attempts to work Steve VE7SL over the weekend on the one tube Hartley. It was doing 1.5W into a dipole with a 3:1 SWR and 150 ft of coax. Our first try was 8 PM Saturday evening on 7057 kHz. It was still daylight on his island off British Columbia. The problem was, he heard me on the first call and it was all over in 5 minutes!

[@Derrick6162]

Nice little rig. This is one of the things that is missing in today's amateur radio hobby. I'm glad that I saw this. Thanks for sharing 👍.

[@MIKROWAVE1]

First principles radio stuff is fun in the world of SDR slices.

[@jamescrofutt8767]

Thanks Mike, great video series. , appreciate you doing this, 73 Jim N0XE

[@MIKROWAVE1]

You are a class act Jim!

[@Tom-W7TMD]

Sooooo Coool!! A great addition to a qrp collection!

[@Swamp-Fox]

What a great little retro QRP TX RX. You made some nice mods. I really enjoyed the tube substitutions.

[@MIKROWAVE1]

Just about any power pentode will behave well in these simple circuits.

[@alainmichaud8992]

Good video!

[@MIKROWAVE1]

Thanks for watching!

[@DAVIDGREGORYKERR]

Anyone tried using Pencil Stub Vacuum tubes so you can make that small enough to fit an Altoids Tin and use a bicycle headlight battery for the heaters and 4xPP3 batteries for the B+.

[@marknesselhaus4376]

Yup, that is a nice rig there. I have been working on a crude DC receiver that is a basic crystal radio circuit for 40M with a single transistor vfo that is very loose coupled and filtered audio with a old RS amp. It tunes from 7.029 to 7.045 because my crystals for my one transistor transmitter are in that range as well. Perhaps we will cross paths on 40M someday. My channel shows the receiver in op, 73 WA4JAT😀

[@MIKROWAVE1]

Wow Mark! Now that is a simple setup all right and ir sounds like a ball of fun. It's nice to have 40M back after a long time where we had so much Shortwave QRM on the band.

[@marknesselhaus4376]

@@MIKROWAVE1 Thanks, yeah it is fun to see how well simple and basic circuits will work and still remain fairly stable even if hay-wired. Kind of how Spock used "Stone knives and bear skins" hihi . I used this circuit years ago using toroids and it was better at keeping the SW broadcasters at bay but I am a sucker for good old cardboard coils so I added a trap filter to the antenna lead for this lash-up and it takes care of Radio Cuba at night. I have copied over 50 hams on 40M from Canada to Brazil just this month alone using a basic end end fed wire so it has proven itself to me ;-) I have been a ham for 49 years now and it never gets old even if I do hihi. Take care and 73, WA4JAT

[@zhivko1946]

Евала на този маистор

[@MIKROWAVE1]

Благодаря, че гледахте видеоклиповете ми!

[@ferrumignis]

Looks like a fun little QRP set! As you say, the seller must be working almost for free at that price, but I guess he enjoys doing it. Quick question, probably showing my ignorance, but doesn't shorting out the coil not being used degrade the Q of the tuned circuit in use?

[@MIKROWAVE1]

No doubt some effect on tuning range and Q, but not severe enough that you can not regain performance with feedback. And that goes for TX too.

[@nemonikUTube]

@MIKROWAVE1 your tube amplifier, did you build that? Was it a kit? Where did you get it? Or did you build it? Can you share the plans and parts list for?

[@MIKROWAVE1]

The little 2 tube battery amplifier is all on my FB support page. (people are building it too). facebook.com/media/set/?vanity=Mikrowave1&set=a.745667360893089

[@JCWise-sf9ww]

So it's some type of digital transmission I been hearing on the ham bands. It sounds like some kind of weird sci-fi alien howling. Do know where I could find out more information about how that works? Is there a way to decode the transmissions?

[@MIKROWAVE1]

Psk31 is easy to decode with free software for the PC.

[@JCWise-sf9ww]

@@MIKROWAVE1 What I have heard is not PSK31 which is narrow band.The sounds I hear here at my place on SW HF ham bands, is somewhat wide band and sounds like a varying moaning or howling. I can't seem to find any web sites or info on what it really is.

[@K1OIK]

Can an Eimac 4-400 tube be substituted for the 12L6? Where is the panadapter?

[@MIKROWAVE1]

That is slight overkill.

[@K1OIK]

@@MIKROWAVE1 Maybe Amperex 4-150?

[@MIKROWAVE1]

@@K1OIK I can't afford the socket.

[@georgeetherege8347]

You’re going to need a bigger filament transformer.

[@luzookiipcbway]

Hey. We found your videos so rewarding, and were wondering if any prototype services may help? Such as custom PCBs, 3DP, CNC etc. If so, would love to supply freely and reach any YT collab together! (PCBWay luz)

[@MIKROWAVE1]

Lets talk!

[@G7VFY]

How about some of your favourite aluminium flashing as grounding underneath. I have a quite a few 20v Lenovo laptop PSU's that might be Ok for a receiver. G7VFY

[@MIKROWAVE1]

Absolutely! Now that's stinkin thinkin! A labor of love for sure, but doable?

[@G7VFY]

@@MIKROWAVE1 If you look inside an IBM/Lenovo laptop power supply you will see that some effort has been made to keep RFI to a minimum. However, very modern PSU's have extra logic in the PSU and the laptop to check that the PSU is 'authentic'.Very annoying.

[@awaismushtaq5719]

Unfortunately for someone like me it's too expensive

[@MIKROWAVE1]

Yes still a few more Dinar than many of us can part with. So we scrounge parts from old radios and build simple sets.

[@declercqmichel2990]

Tk for nice videos I build too the trx with tube Exemple tube el 84power 4 watts and 6l6 I transmit between 6 and 7 hour gmt to 7003,5 mhz wirh my home made transmitter tube 6l6 power 5w my call sign is ON4KMC/QRP best 73 and tk again for videos