A quick note about the resistor at TIP31C B-C. If you do a bootstrap by splitting that resistor into two in series and feeding the mid point from your amplifier's output, you can get a better positive swing. I like the design. I would have used TIP35 and TIP36 for my output but only because I have some.
I love the world according to Charlie! Brilliant job as always. I'm certainly going to play around with an infinite impedance detector and maybe even a Franklin oscillator (if I can prize the Si5351 from my hands!). So good to have you back on CZcams. 73, Nick M0NTV
Thanks David. I'll see what the next build will be. I'm conscious that my approach to things is not textbook, which opens myself up to criticism. To me these are just a video diary of what I have been playing with. All good fun.
@@CharlieMorrisZL2CTM I am an EE, and frankly, I think your approach, and designs, and methods follow a very good process, and you use most of the rules for transistor biasing and design that I learned. in school, and used through the years. Your results speak for themselves. You do great work, and follow a consistent, well thought out design process that yields good results. Kudos! The only thing that might be something else to add to your design toolbox for transistor biasing is a little stability analysis. I can't think of anything else you are really missing in the process.
Missed watching Charlie....took a break from things for some life stuff.....kicking off my resurgence into radio this weekend at Hamvention! Hopefully i will add many things to my junk box for future trials into the homebrew world.
@@CharlieMorrisZL2CTM Maybe not a masterpiece. However, it's designed beautify, and beautify built! And good enough to be (picture) framed. Perhaps you should change your channel name to Electronic Arts (EA™) 😆
I really like the way you make your circuits. They are very beautifuls and make me want to do the same thing. Also it works well and the sound is amazing, sorry for my basic english !
Hi Charlie, have you, or ever thought of building an updated version of the Tucker Tin ssb transmitter with commonly available parts? Anyway, keep up the excellent work! Best regards, Lance ZL3LAD.
Really nice Charlie. It sounds great. I like your constuction technique. I too make a lot of use of solder wick. And I like copper clad on wood. More room is better than not enough room. And there is a benefit in keeping all the circuitry visible. 73 and thanks, Bill N2CQR
I do love the engineers view on design, we will calculate what value we need then just pick a close preferred value. before PC's we would work out the affects of tolerances on the components, taking the min and max values to calculate what the tolerance spread would do in production and writing the test specification around it. PC's and lt-spice made that a much easer job. 🙂
@@CharlieMorrisZL2CTM it's not a short cut it's a design decision. In the same way we try to use a lot of the same values for components, reducing the amount of different parts in the BOM reduced costs. If you don't have any tolerances in your specification then you going to need exactly the right value which certainly puts the costs up.
BTW: You can use up to 3 .step commands in LTSpice. This way you can plug in all combinations of min and max for 3 components to see the spread of results. If you want more there is a trick where you step a "test number" and then make the resistor values with expressions.
@@kensmith5694 can you remember when you ran spice off a floppy on a 367. When I was doing it all by hand the only other option was on the mico-vax terminal. I don't think we had the spice program on the vax.
@@TheEmbeddedHobbyist My first PC was an 8088 based DOS box with two floppies. I am leaving out the ZX80 as a "PC" I still own my slide rule and can remember how to use it. The first simulation software I encountered range on an IBM360. Spice has made a lot of stuff easier. At one point I downloaded the source code for it and worked on fixing a few bugs. For a correct "deck" it was ok but some syntax errors would cause it to segfault without telling you what line caused it. My changes may even appear in versions today. I just made the uninitialized pointer lead to a syntax error. At least you would then know what line did it.
Another fantastic, scratch built, radio. I must have missed it, but I'm intrigued about the variable, vernier-drive tuning capacitor. Where did you get that from. Such things are now almost imposable to find! 73 de VK6AWK
@@CharlieMorrisZL2CTM Those air_gap variable capacitors, especially the vernier drive models, are impressive. More so, when considering the technology (manufacturing) of the time, compared to today's CNC laser cut, and robotic mass production, can't make equal quality for the price today. And I can't argue with having the circuit naked. But perhaps a clear Polycarbonate cover to deter dust?
If you just wanted to listen to the station up the road you could have just done it with a few transistors and an AF amplifier 😅 Nup not good enough says Charlie... but I won't worry about an AGC hahaha, might as well set up an AGC now anyway 😂
@@CharlieMorrisZL2CTM I want to try playing around with a "crystal set"... okay I'll call it a detector 😆 But the idea is to use a stage of RF amplification ahead of it. Then of course bias the detector a little. Then play with an AF amp using AGC that has a LOT of open loop gain... might as well make a single conversion superheterodyne radio. I'm with you Charlie, you're doing great 😆
@@Dazzwidd For "extra credit" you can make a reflex amplifier that does the RF and the audio. There is a bit of a trick. You make the polarity of the audio such that more RF into your detector makes less current in the amplifier transistor. This gives it some AGC without even trying.
@@kensmith5694 yeah, you could do that. Being serious here, I would make an AGC arrangement that provides you with an S meter indication if I was doing what Charlie is. Might be better to gain control the intermediate frequency stages rather than the audio and maybe have a little AGC on the front end 🤔
@@Dazzwidd Normally, AGC is done in the IF stages. You want to take some gain before it just to be sure you are above the device noise. The AGC signal is usually a low pass filtered version of the detected output. The IF stages are run with emitter resistors bypassed so that the gain depends on "little re". This lets you have a fair range of gains. A meter on the AGC voltage works as a signal meter. With a bit of cleverness, you can make it work in dB.
As always you explain things excellently and make it look very easy and simple.
A quick note about the resistor at TIP31C B-C. If you do a bootstrap by splitting that resistor into two in series and feeding the mid point from your amplifier's output, you can get a better positive swing.
I like the design.
I would have used TIP35 and TIP36 for my output but only because I have some.
A beautiful looking and sounding radio. Thank you for taking us through the design process. 73, ZL1SHP
Thanks for the feedback, much appreciated. I'm pleased it was useful.
I love the world according to Charlie! Brilliant job as always. I'm certainly going to play around with an infinite impedance detector and maybe even a Franklin oscillator (if I can prize the Si5351 from my hands!). So good to have you back on CZcams. 73, Nick M0NTV
I was thinking of a similar design with the Si5351,less organic but probably more repeatable
Cheers Nick. It's simple, but works well for my purposes.
Great job and sounds great. It's really good to see you make another series of videos. Always enjoy your content.
Thanks David. I'll see what the next build will be. I'm conscious that my approach to things is not textbook, which opens myself up to criticism. To me these are just a video diary of what I have been playing with. All good fun.
@@CharlieMorrisZL2CTM I am an EE, and frankly, I think your approach, and designs, and methods follow a very good process, and you use most of the rules for transistor biasing and design that I learned. in school, and used through the years. Your results speak for themselves. You do great work, and follow a consistent, well thought out design process that yields good results. Kudos! The only thing that might be something else to add to your design toolbox for transistor biasing is a little stability analysis. I can't think of anything else you are really missing in the process.
Missed watching Charlie....took a break from things for some life stuff.....kicking off my resurgence into radio this weekend at Hamvention! Hopefully i will add many things to my junk box for future trials into the homebrew world.
That sounds great. I'd like to go there someday. I'd have to take a second empty suitcase if I did!
Really enjoyed the run through ..It sounded good too...Keep it up Charlie!
Thanks. Just listening to it now as I work. Very happy.
Great video, as always!
Thanks for the feedback. Just me chatting away.
a masterpiece of discrete component design. if it isn't, i don't know what is.
I wouldn't say that Stephen. Each to their own. The method works well for the types of circuits I build.
@@CharlieMorrisZL2CTM
Maybe not a masterpiece. However, it's designed beautify, and beautify built! And good enough to be (picture) framed.
Perhaps you should change your channel name to Electronic Arts (EA™) 😆
I really like the way you make your circuits. They are very beautifuls and make me want to do the same thing.
Also it works well and the sound is amazing, sorry for my basic english !
Go for it Tony!
@@CharlieMorrisZL2CTM yes it is planned I am retiring in september I will have some free time
Hi Charlie, have you, or ever thought of building an updated version of the Tucker Tin ssb transmitter with commonly available parts?
Anyway, keep up the excellent work!
Best regards, Lance ZL3LAD.
Thanks for the update..enjoyed learning as always 73s
Do update your blog with actual photos as you did in the pass.
I'll make a note and put some up later.
Really nice Charlie. It sounds great. I like your constuction technique. I too make a lot of use of solder wick. And I like copper clad on wood. More room is better than not enough room. And there is a benefit in keeping all the circuitry visible. 73 and thanks, Bill N2CQR
Thanks Bill. It's just a simple little radio, but that was the aim.
I second everyone's comments here Charlie. Thank you, 73, VK7IAN
My pleasure. I'm pleased it was enjoyable.
Good result and circuit board :)
Thanks. I think it works well.
Charlie, can you explain the volume control shown on your breadboard, it's not shown on the schematic or video?
I do love the engineers view on design, we will calculate what value we need then just pick a close preferred value.
before PC's we would work out the affects of tolerances on the components, taking the min and max values to calculate what the tolerance spread would do in production and writing the test specification around it.
PC's and lt-spice made that a much easer job. 🙂
I know it's bit of a shortcut, but it works well for me for the types of circuits I play around with.
@@CharlieMorrisZL2CTM it's not a short cut it's a design decision. In the same way we try to use a lot of the same values for components, reducing the amount of different parts in the BOM reduced costs. If you don't have any tolerances in your specification then you going to need exactly the right value which certainly puts the costs up.
BTW: You can use up to 3 .step commands in LTSpice. This way you can plug in all combinations of min and max for 3 components to see the spread of results. If you want more there is a trick where you step a "test number" and then make the resistor values with expressions.
@@kensmith5694 can you remember when you ran spice off a floppy on a 367. When I was doing it all by hand the only other option was on the mico-vax terminal. I don't think we had the spice program on the vax.
@@TheEmbeddedHobbyist My first PC was an 8088 based DOS box with two floppies. I am leaving out the ZX80 as a "PC"
I still own my slide rule and can remember how to use it. The first simulation software I encountered range on an IBM360. Spice has made a lot of stuff easier. At one point I downloaded the source code for it and worked on fixing a few bugs. For a correct "deck" it was ok but some syntax errors would cause it to segfault without telling you what line caused it. My changes may even appear in versions today. I just made the uninitialized pointer lead to a syntax error. At least you would then know what line did it.
Another fantastic, scratch built, radio.
I must have missed it, but I'm intrigued about the variable, vernier-drive tuning capacitor. Where did you get that from. Such things are now almost imposable to find!
73 de VK6AWK
The capacitor came out of an old boat anchor radio that was as parts only. I scored a crystal filter out of that too, which was good,
@@CharlieMorrisZL2CTM
Those air_gap variable capacitors, especially the vernier drive models, are impressive. More so, when considering the technology (manufacturing) of the time, compared to today's CNC laser cut, and robotic mass production, can't make equal quality for the price today.
And I can't argue with having the circuit naked. But perhaps a clear Polycarbonate cover to deter dust?
Riveting as always Charlie. Which antenna did you end up using ? You were intending to try just a piece of wire across the shack.
I strung up a long wire in the roof. Works well.
Looks good. Sounds good.
Enjoy !
I did.
73 PE1LLA
Cheers. I'm very happy with how it turned out.
Hello, which machine is the mixer from?
It's a standard 7dBm DBM device. An SBL-1.
Very helpful and enjoyable. ZL1GH
Glad it was helpful. Again, not a tutorial, just a video diary.
If you just wanted to listen to the station up the road you could have just done it with a few transistors and an AF amplifier 😅 Nup not good enough says Charlie... but I won't worry about an AGC hahaha, might as well set up an AGC now anyway 😂
It was a scratch that I wanted to itch. Yes probably an overkill, but fun nonetheless.
@@CharlieMorrisZL2CTM I want to try playing around with a "crystal set"... okay I'll call it a detector 😆 But the idea is to use a stage of RF amplification ahead of it. Then of course bias the detector a little. Then play with an AF amp using AGC that has a LOT of open loop gain... might as well make a single conversion superheterodyne radio.
I'm with you Charlie, you're doing great 😆
@@Dazzwidd For "extra credit" you can make a reflex amplifier that does the RF and the audio. There is a bit of a trick. You make the polarity of the audio such that more RF into your detector makes less current in the amplifier transistor. This gives it some AGC without even trying.
@@kensmith5694 yeah, you could do that.
Being serious here, I would make an AGC arrangement that provides you with an S meter indication if I was doing what Charlie is. Might be better to gain control the intermediate frequency stages rather than the audio and maybe have a little AGC on the front end 🤔
@@Dazzwidd Normally, AGC is done in the IF stages. You want to take some gain before it just to be sure you are above the device noise. The AGC signal is usually a low pass filtered version of the detected output. The IF stages are run with emitter resistors bypassed so that the gain depends on "little re". This lets you have a fair range of gains. A meter on the AGC voltage works as a signal meter. With a bit of cleverness, you can make it work in dB.