A viewer pointed out an error. I had specified X1 capacitors to ground from Hot and Neutral. They should be Y Safety Caps. Y Caps Fail open. X Caps fail closed across the line to pop the fuse. I will update the schematics.
When I first watched "The New Yankee Workshop" with master carpenter Norm Abram in the 80's, I wished there was a similar program about electronics projects. Master Engineer Mike's New Hampshire Radio Shack is an equal.
Fantastic start Mike- another case of only hairy chested transformers need apply! That hand in the pocket is very good advice and I remember doing that for a trade test back in the eighties. David.
Regarding the #10 vs the copper tubing, I believe you say the tubing just insures more stability. What about the diameter of the copper tubing? -is a smaller diameter tubing OK to use? or are there other considerations to be aware of? Harry
At RF Frequencies, the skin effect favors the larger diameters with high RF Currents, so you get both stability and efficiency benefits as the coil diameter goes up. At this low power, it is unlikely that we see much of a difference in power out! But it looks good!
I'm going to have to learn CW. I'm one of those people that has to say what even though I heard you perfectly the first time. Just don't know that I can learn it. But I want to build one of these pretty bad, and I would love to use CW. Neat stuff
I have a question? When you look through the old manuals about this they show both a tx and rx antennas. Could you explain the separation needed between them and a simple way to calculate the separation between the two antennas. They did a lot of stuff back then that we don’t do now and it is fun playing with this old tech. Thanks for the info. kd0wih! 73
Really appreciate this intro Mike. I've never built a tx radio, let alone a tube rig. Only xtl radio years ago. I have ordered tubes off ebay and will find the other bits.
👍Thanks Mike. I had a rake through the junk box last night. No 227 (as expected). Thought I might have a 6J5 but no luck. I did find some 7C5s. Do you think one of these would work?
@@MIKROWAVE1 Thank you. Some Googling suggests Loctal and the 7C5 appeared around 1939. So, not BK compliant but good to know it will hopefully work. I might have some Loctal bases. Back to raking around in junk box 😆. What I did find was some car brake pipe. I think it is 3/16" diameter (yes, we still use Imperial for some things in the UK). It looks like it's is made out of brass rather than copper. So, maybe more rigid than copper tube and might make a stable tuning coil.
Well to be fair, not much tube dissipation and it's into a dummy load. And at 150V and a light current drain of less than 30 mA. The 330 uF cap and the big transformers help the regulation too. But it surprised me too.
Almost everything and anything you can think of electrically, thermally or mechanically can improve on the stability with these breadboards! A ground plane sheet above or below, or even a grounded front panel are both aids to stability. But honestly, these techniques although known, did not really show up for Ham Builds until the 1930's.
If you don't have access to a 6J5 tube, You can use one half of a 6SN7, it is two 6J5s in one envelope, for testing your 1929 transmitter. 6SN7 tubes are very plentiful (Used, NOS & New), for they are still manufacturing new 6SN7 tubes. The 9=pin 6CG7 or the 6FQ7 versions are also the same electrically.
80M worked pretty easily, even with the #10 wire inductor. 40M was a bit more challenging, so I went there. These both would benefit from a 365 pF variable capacitor in the output link, according to Steve VE7SL and I agree.
A viewer pointed out an error. I had specified X1 capacitors to ground from Hot and Neutral. They should be Y Safety Caps. Y Caps Fail open. X Caps fail closed across the line to pop the fuse. I will update the schematics.
When I first watched "The New Yankee Workshop" with master carpenter Norm Abram in the 80's, I wished there was a similar program about electronics projects. Master Engineer Mike's New Hampshire Radio Shack is an equal.
I used to watch New Yankee Workshop years ago. Fantastic. What we need is Norm to make us some breadboards 1920s style.
Now you went too far.
Nice old school radio 😊😊
Fantastic start Mike- another case of only hairy chested transformers need apply! That hand in the pocket is very good advice and I remember doing that for a trade test back in the eighties. David.
Both hands in pockets - even safer!
If only the professor on Gilligans Island had a 27 tube…
Regarding the #10 vs the copper tubing, I believe you say the tubing just insures more stability. What about the diameter of the copper tubing? -is a smaller diameter tubing OK to use? or are there other considerations to be aware of? Harry
At RF Frequencies, the skin effect favors the larger diameters with high RF Currents, so you get both stability and efficiency benefits as the coil diameter goes up. At this low power, it is unlikely that we see much of a difference in power out! But it looks good!
I'm going to have to learn CW. I'm one of those people that has to say what even though I heard you perfectly the first time. Just don't know that I can learn it. But I want to build one of these pretty bad, and I would love to use CW. Neat stuff
CW is fun and you can learn it. Start by listening to the slow CW on 40M around 7050 and 7100 kHz and Code Practice on W1AW.
facebook.com/media/set/?set=a.887987166661107&type=3
This is the drawing set on the FB Radio Resources Page
I have a question? When you look through the old manuals about this they show both a tx and rx antennas. Could you explain the separation needed between them and a simple way to calculate the separation between the two antennas. They did a lot of stuff back then that we don’t do now and it is fun playing with this old tech. Thanks for the info. kd0wih! 73
Great Video and Information. Looking Forward to rest of Series.
👍Thank you sir.
Really appreciate this intro Mike. I've never built a tx radio, let alone a tube rig. Only xtl radio years ago. I have ordered tubes off ebay and will find the other bits.
Keep us informed on your progress and ask for help!
Great Video and Information !!
Keys better than your Flex! Indeed it does Mike! 73, Jim W7RY... Dit.. Dit..
A bit of tongue in cheek there Jim...
👍Thanks Mike. I had a rake through the junk box last night. No 227 (as expected). Thought I might have a 6J5 but no luck. I did find some 7C5s. Do you think one of these would work?
7C5 local is fine if you have a socket!
@@MIKROWAVE1 Thank you. Some Googling suggests Loctal and the 7C5 appeared around 1939. So, not BK compliant but good to know it will hopefully work. I might have some Loctal bases. Back to raking around in junk box 😆. What I did find was some car brake pipe. I think it is 3/16" diameter (yes, we still use Imperial for some things in the UK). It looks like it's is made out of brass rather than copper. So, maybe more rigid than copper tube and might make a stable tuning coil.
Thanks 73""
Yi1hra
marhaban hasan yi1hra aliktrik! shukran lilmushahadati.
Maybe the Flex is superior but you didn't spend a gazillion $'s to have a transmitter to get on the air with. Great video !!
What, no chirp!!!
Steve
Well to be fair, not much tube dissipation and it's into a dummy load. And at 150V and a light current drain of less than 30 mA. The 330 uF cap and the big transformers help the regulation too. But it surprised me too.
Would putting a sheet of metal, grounded, improve stability? G7VFY
Almost everything and anything you can think of electrically, thermally or mechanically can improve on the stability with these breadboards! A ground plane sheet above or below, or even a grounded front panel are both aids to stability. But honestly, these techniques although known, did not really show up for Ham Builds until the 1930's.
If you don't have access to a 6J5 tube, You can use one half of a 6SN7, it is two 6J5s in one envelope, for testing your 1929 transmitter. 6SN7 tubes are very plentiful (Used, NOS & New), for they are still manufacturing new 6SN7 tubes. The 9=pin 6CG7 or the 6FQ7 versions are also the same electrically.
All good choices, as well as the 6C4 miniatures.
@@MIKROWAVE1 I would also add the 12AU7 tube, for it is two 6C4s in one 9-pin envelope.
Great Fun! Will get started on the power supply this weekend. What is the maximum B+ that you would recommend for this transmitter? 73 DE K1TB
They are actually rated for 275 VDC but you might get away with more !
Thanks, Mike!@@MIKROWAVE1
Or .... 80 band Mr
80M worked pretty easily, even with the #10 wire inductor. 40M was a bit more challenging, so I went there. These both would benefit from a 365 pF variable capacitor in the output link, according to Steve VE7SL and I agree.