Hi Mike, Bruce was my friend (as many others were) since the day I started helping renovate the old Museum in East Bloomfield. We tore out the old wiring, the lathe and plaster walls, the plumbing, and put new ceilings, walls, wiring, plumbing in while renovating the ham shack there. I was KA2HLW then, a young kid (just 19 then) with a novice license. Between W2ICE and WA2IYA, they both got me through my General class. Before my job sent me to NC, I donated three Collins R-390A's in a rack to the museum. Between Bruce and Burt, I couldn't have had two better "Elmers" in the world. I miss them both badly. I'm glad they named the 1929 QSO Party after Bruce, he deserved it! I'm in my 60's now, still a Ham after 40 some odd years, still enjoying the ham radio service ( I do not consider it to be "just a hobby" after all the storms and hurricanes we helped out on) over the many years. Now I go by W4FJF, and still operate my original novice station now and then even though I have many transceivers and amps, and an antenna farm that covers 5 acres. Glad to see the AWA still operating, too. Do they still have the spark gap transmitter I operated one Winter day (with FCC permission)? Still have all the QSL cards I got that day - great fun, that was. Take care and 73's.
Mikrowave, your tutorials rock! Thank you! I have viewed your Morgan Regen video hundreds of times. I find it particularly useful, and it helped me build my first working regenerative receiver. I'm goint to share some of the knowledge acquired in my 7th and 10th grade Science classes. They might as well get the passion for glowbugs. 73 and keep up the great work! Martin
love to see one of these transmitting on am!!!! thy used a carbon mike in line with the antenna!!!! no modulator needed!!! would like to see one on am!!!! I just love the sound of am. take care and good dx
The old ARC-5 transmitters were also MOPA types, with a Hartley oscillator, but with neutralized beam power tubes in the final. They also used CATHODE feedback, not plate. The 1920's rigs HAD to use plate feedback, because they used directly heated cathodes. (You could feed the filament voltage through another coil to get cathode feedback, and in fact the ARC-5 transmitter did that too for some reason).
Really interesting phenomenon. Would the drift eventually stabilize at some frequency (either direction)? Really nice drift fix; took a fair amount of time to tame it. Inasmuch as it can be controlled by the tuning the grid tap, is it known what the root cause of the the frequency drift is? Component drift with temperature (caps, copper resistance, tube)? Space charge in the tube?
Mike, with this type of transmitter would I have to use the old type caps? The tube I'm using is a 27 type which 250 volts. Could I use modern caps as long as they are within the plate voltage or do I need to go older and larger?
Dave, I hope you are able to build up a transmitter for the 1929 Bruce Kelly Memorial contest coming up soon in November. Any era parts can be used as long as the tube type was on manufacture in or before 1929 and the circuit was known to have been used. For instance a UX227 could be replaced by a a type 27, even if it were manufactured in 1947.
I'm trying to get it done. I'm having issues locating a power transformer I can use for the 2.5 volt filiment for the 27 tube. I want to build my own power supply. Hopefully I'll have it done. How precise can the tnt tune on a band? Do you have any good schematics for a vintage period powersupply?
Sometimes you can find a 230VAC 5V job that you simply run on 120. Also consider using half of AC a 5V Center tapped transformer. Finally 2 type 27s filaments can be connected in series for 5V.
Mike, I've heard there is no such thing as a dumb question. But, I'll ask one anyway. From where do you obtain the -90V bias shown in the circuit at 03:54 from the power supply shown at 11:10? I hope to enter this years contest using your MOPA design. I have all of the parts. Thank you. 73 Tim WA8LHB
+WA8LHB Hi Tim, The Bias supply is from a backwards 12V transformer connected to a 6.3V winding of the main power transformer in the power supply. That gives 60VAC which is run to a small bridge rectifier that feeds an electrolytic (positive side down to ground) and then a 100K potentiometer giving a 0 to -90V bias supply.
Very fun! Thanks for sharing!
Hi Mike,
Bruce was my friend (as many others were) since the day I started helping renovate the old Museum in East Bloomfield. We tore out the old wiring, the lathe and plaster walls, the plumbing, and put new ceilings, walls, wiring, plumbing in while renovating the ham shack there. I was KA2HLW then, a young kid (just 19 then) with a novice license. Between W2ICE and WA2IYA, they both got me through my General class. Before my job sent me to NC, I donated three Collins R-390A's in a rack to the museum. Between Bruce and Burt, I couldn't have had two better "Elmers" in the world. I miss them both badly. I'm glad they named the 1929 QSO Party after Bruce, he deserved it! I'm in my 60's now, still a Ham after 40 some odd years, still enjoying the ham radio service ( I do not consider it to be "just a hobby" after all the storms and hurricanes we helped out on) over the many years. Now I go by W4FJF, and still operate my original novice station now and then even though I have many transceivers and amps, and an antenna farm that covers 5 acres. Glad to see the AWA still operating, too. Do they still have the spark gap transmitter I operated one Winter day (with FCC permission)? Still have all the QSL cards I got that day - great fun, that was. Take care and 73's.
Excellent video...much enjoyed! Thanks for posting. 73 OM!
I will be starting research on a QRP video to handle the early commercial approaches in the 70's.
Mikrowave, your tutorials rock! Thank you! I have viewed your Morgan Regen video hundreds of times. I find it particularly useful, and it helped me build my first working regenerative receiver. I'm goint to share some of the knowledge acquired in my 7th and 10th grade Science classes. They might as well get the passion for glowbugs. 73 and keep up the great work! Martin
I started a TnT a couple years ago but never completed it. Think I'll give it another go! Thanks for the videos, awesome stuff. 73 Dave W6CPY
Easy circuit but a bit dirty, but it was popular and can be tamed!
I doubt that my Rotary Spark transmitter would have been well received in those contests. A single key press could cover an entire band ;-)
Very interesting, I have always been interested in making one for the heck of it. Thank You for all the tips. 73 Greg W7HRC
love to see one of these transmitting on am!!!! thy used a carbon mike in line with the antenna!!!! no modulator needed!!! would like to see one on am!!!! I just love the sound of am. take care and good dx
The old ARC-5 transmitters were also MOPA types, with a Hartley oscillator, but with neutralized beam power tubes in the final. They also used CATHODE feedback, not plate. The 1920's rigs HAD to use plate feedback, because they used directly heated cathodes. (You could feed the filament voltage through another coil to get cathode feedback, and in fact the ARC-5 transmitter did that too for some reason).
Great work
The introduction cw sounds like a lot of eastern European stations back in the 1980s
Excellent! Very interesting and entertaining! Keep up the good work.
Thank you this is great stuff.
Ha! I remember when lots of stations sounded like that. Half of all the DX would sound like that.
Are you the Bulgarian Buzzsaw?
@@MIKROWAVE1 HA, no, I am no one memorable. Just another CW lover, raised on old radios. WA2LKV.
lubie twoje cfilmy/pozdrawiam/
Really interesting phenomenon. Would the drift eventually stabilize at some frequency (either direction)? Really nice drift fix; took a fair amount of time to tame it.
Inasmuch as it can be controlled by the tuning the grid tap, is it known what the root cause of the the frequency drift is? Component drift with temperature (caps, copper resistance, tube)? Space charge in the tube?
Great stuff Mike thanks for sharing - 73 Kevin GW4WOV
Great video VE2PID been trying to get him a long time
Yes it is critical. Or the "00" send warning. keep em tight. De kv4li
Very cool!
Interesting !
Great video. You should have dressed in a shirt and tie and filmed in black & white for period authenticity. 😊
Mike, with this type of transmitter would I have to use the old type caps?
The tube I'm using is a 27 type which 250 volts. Could I use modern caps as long as they are within the plate voltage or do I need to go older and larger?
Dave, I hope you are able to build up a transmitter for the 1929 Bruce Kelly Memorial contest coming up soon in November. Any era parts can be used as long as the tube type was on manufacture in or before 1929 and the circuit was known to have been used. For instance a UX227 could be replaced by a a type 27, even if it were manufactured in 1947.
I'm trying to get it done. I'm having issues locating a power transformer I can use for the 2.5 volt filiment for the 27 tube.
I want to build my own power supply. Hopefully I'll have it done. How precise can the tnt tune on a band? Do you have any good schematics for a vintage period powersupply?
Sometimes you can find a 230VAC 5V job that you simply run on 120. Also consider using half of AC a 5V Center tapped transformer. Finally 2 type 27s filaments can be connected in series for 5V.
Fascinating-N5JYW
Mike, I've heard there is no such thing as a dumb question. But, I'll ask one anyway. From where do you obtain the -90V bias shown in the circuit at 03:54 from the power supply shown at 11:10? I hope to enter this years contest using your MOPA design. I have all of the parts. Thank you. 73 Tim WA8LHB
+WA8LHB Hi Tim, The Bias supply is from a backwards 12V transformer connected to a 6.3V winding of the main power transformer in the power supply. That gives 60VAC which is run to a small bridge rectifier that feeds an electrolytic (positive side down to ground) and then a 100K potentiometer giving a 0 to -90V bias supply.
Oscillator or theremin ?
Um. Oscillator with flavor?
Dont touch the +1000 DC on the PA tube
Bravo 73 milan yu1qg
I can't build but are you selling? VE2PID lives on 40 meters
Bravo best 73 su 1 Qg
thanks for sharing . de kf6uxj