By far, one of your very best videos ever. Really glad you went through the design with the math. When I was getting into electronics/ham-radio, everyone said to leave tubes behind (even the old-hats) so other than an a working knowledge to repair tube equipment, there was not much emphasis on actual detailed hows and whys. Funny how now with solid-state going to MOSFETs, we come back to design considerations and topologies like the old vacuum tube. So, I plan to do some tube-building--just can't beat hearing distant signals from a radio that glows in the dark! 73...
The 70's were an interesting time to be learning because tubes and transistors of several kinds and ICs were all being taught together in a unified way.
Excellent, great the time and work you put into explain this. Sometimes it is better to get it explained than to read it yourself. Personally I can make my own interpret faults about "the Miller effect". This was clear, thank you for the additional training. interesand what you do, 73
Wow, some very good information, you did a very nice job. I do have a small suggestion and that is when you are talking to a schematic being displayed that you somehow highlight the sections you are currently explaining and/or annotate it as you talk. I have an undergrad in Electrical Engineering and I was able to follow along but just barley, not your fault of course, rather my lack of tube knowledge and general cobwebs in my brain from lack of use. I look forward to the solid state video, I have experiment with BJTs in a cascode configuration and I should be able to follow along a little better. Anyhow, awesome job and thanks for sharing.
It is possible to build a two stage amplifier with a common cathode (emitter or source) stage driving a grounded grid (base or gate) stage where the DC feed for both stages are in parallel not series. Is this still a cascode amp or is now a cascade amp? On a tangent subject, in the early days of the BCB, the neutridyne circuit was popular, but was patented. To avoid patent violations, did any radio makers use either the grounded grid or cascode configurations in sets? There was an odd ball tube (WE717A) that had a mushroom shaped glass bulb atop an octal base shell. It was sorta a 6AK5 or 9001 with an octal base and was used in many WWII VHF receiver front ends.
I'm wondering what the purpose is of that small value resistor between the plate of the lower tube and the cathode of the higher tube in the Amico -and your final- circuit. Is it some kind of parasitic stopper resistor?
I saw several formulas where 'Gain' was defined, but it didn't say which gain. It could be the ratio of output voltage to input voltage, or output current to input current. I would assume voltage, but do others know that? Thanks for the informative video.
I love vacuum tube technology its so nostalgic. I have no tubes but i am looking for some from garage sales etc. i am mostly interested right now into the 12Ž1L tube which is soviet copy of german WW2 RV12P2000 Its only 12V anode voltage and 12V heater. then i have in plan to go to more high voltage stuff ( 60 ,90 , 180 etc. Volts ) aaand then maybe into some really HV stuff like GU81 which is big soviet HF transmitter Pentode with 450W of anode dissapation ( 600W max. for 3 minutes ) and well it need 3kV when operated on 6MHz ( maybe i will use it for some HF PA or radio transmitter on HF : ) ) I just love how those tubes glow and radiating heat ( when transmitting pirate radio glow of tubes is giving moderator most of the adrenaline ( my friend said ) ) and i believe i am not alone :D . See you next time. 73 from OK2???
have you tried the KORG Nu-tube 6P9 flat vacuum tube which can work of as low as 9V with a heater of 1.5V and I think it might be possible to build a balanced preamp with the said tube.
Thing is i live on the west coast. Cant get really ANY shortwave here. Im convinced many radio designs will work fine when signal is actually available
I am listening to the KFS WebSDR from Halfmoon Bay CA 6 PM West Coast and hear strong stations. WWV at 5 MHz, CFRX Toronto 6090, Radio Marti on 7305, China in English is blasting in on 7315. WBCQ on 9330, Radio Prague 9395. I suggest a 31 Meter Dipole.
@@MIKROWAVE1 many times when i tune to wwv i get a lot of interference i think its possible im getting both wwv stations at once (the one in colorado and the one in hawaii) I did pick up radio havana last night and ive picked up other stations as well before but they all tend to fade in and out. I was using a 25 foot long wire. Websdr is going to be much more sensitive than my TRF or a crystal though. So i dont think its a reliable indicator. I am able to get some shortwave but as i said they always fade because most are not aimed toward the west coast at all
@@researchandbuild1751 Agree on all and sure you can hear two WWVs since you are in the middle - and even some nights the same WWV coming at you delayed around the world mixing with the short skip! But 25 ft longwire is a possible weak point. Try a 50 ft dipole with coax coming into the radio and see if things quiet down.
This is where i have had some trouble. Thanks. Ps. Do you have some way for us to tip you? I have received so much help from your videos, and i think they are destined to become "classics" for other beginners.
To get these links to work, appears I have to split them up... (for those who want to read a bit more on the subject...) See pages 214 & 578 in the following www.tubebooks.org/Books/orr_radio.pdf
How does it compare (noise figure, dynamic range, immunity to overload etc) to more modern devices like for example mar preamps or preamps based on J310 transistor popular in ham radio world. Is it worth to try with tubes? I have some nuvistors lying around and I wonder if it's worth doing (besides educational aspect of ocurse).
I do not have equipment to properly test for these. However, when we are talking about BCB to Shortwave frequencies, IN GENERAL and with BASIC CIRCUITS, tubes will always outperform solid state solutions in regard to dynamic range, immunity and overload. And noise figure is moot at shortwave. We did not change to solid state for performance reasons, we changed for cost and power savings and miniaturization. It would be later that more exotic topologies would arrive to bring solid state up to the performance of tubes.
Greatly enjoy and have learned from your videos...! I always tell others to check out your videos... Thank you very much...! Regarding neutralization, a couple of questions... How to select the initial value? The value of Cn should be Cgk+Cgp (plus parasitic) and for the plate-to-cathode inductor value the conjugate of this value? How critical are the values, is it possible to estimate them, use a fixed value and get "good" (fair) performance, or should always use a variable value component? Thank you again..! 73, Greg (KC9ZEW)
Basically yes you can estimate, but that is based on a perfect phase and amplitude reversal method like a center tapped system to for feedback. So it is just very unlikely that you would achieve a null value because it really is a bridge circuit problem. So maybe CT the output primary and feed bypassed DC power in there. Then estimate the C neut value with a trimmer with a max of at least double that, and tune for the least feed through at the high end around 15 MHz (power off). This can be done in ether direction with Gen on one side and scope on the other.
Mechanical filters are by design, filters with very narrow bandwidths and sharp skirts. They are excellent filters. But they are also limited to frequencies below, perhaps 1000 kHz, and are generally lossy. So you only see them utilized in the last intermediate frequency of high end superheterodyne receivers, typically at 400 to 500 kHz.
When are you going to get out of the 50's???? You could buy ready made RF amps from China for $6.00. I made a 50 khz to 500 mhz preselector using toroids from Amazon and other parts from ebay. Total cost was $15 using some of my existing parts for my SDR receiver that covers 10 khz to 2 ghz and costed $120. (SDR Play)
Question: As the term of solid state is used strictly for any circuit that is on a printed circuit board and thus could be a microchip, transistor, or a tube, why is it in this more modern time that solid state refers only to semiconductor devices? There were tube radios where it was all mounted on a printed circuit board and were called "solid state". I do not recall when the switch was made in the reference but I see it more and more these days and from the original concept, the modern terminology is simply incorrect.
Interesting but I have never heard of this. I always thought that it was purely to do with devices that could operate with "solid" semiconductors which required no thermionic emission as valves do (with hot filaments).
![[ECHOSTASIS] - [SEVERED] - [TRILATERAL] - The Original Soundtracks](http://i.ytimg.com/vi/B-YGqZYzstM/mqdefault.jpg)
There is a lot of useful information here. I'll have to watch this several times and take notes.
By far, one of your very best videos ever. Really glad you went through the design with the math. When I was getting into electronics/ham-radio, everyone said to leave tubes behind (even the old-hats) so other than an a working knowledge to repair tube equipment, there was not much emphasis on actual detailed hows and whys. Funny how now with solid-state going to MOSFETs, we come back to design considerations and topologies like the old vacuum tube. So, I plan to do some tube-building--just can't beat hearing distant signals from a radio that glows in the dark! 73...
The 70's were an interesting time to be learning because tubes and transistors of several kinds and ICs were all being taught together in a unified way.
I like your videos very much, Thank you for the information!I wish I was educated in electronics like you and 50 years younger again.
Excellent, great the time and work you put into explain this. Sometimes it is better to get it explained than to read it yourself. Personally I can make my own interpret faults about "the Miller effect". This was clear, thank you for the additional training. interesand what you do, 73
Wow, some very good information, you did a very nice job. I do have a small suggestion and that is when you are talking to a schematic being displayed that you somehow highlight the sections you are currently explaining and/or annotate it as you talk. I have an undergrad in Electrical Engineering and I was able to follow along but just barley, not your fault of course, rather my lack of tube knowledge and general cobwebs in my brain from lack of use. I look forward to the solid state video, I have experiment with BJTs in a cascode configuration and I should be able to follow along a little better. Anyhow, awesome job and thanks for sharing.
Enjoyed your presentation.
It is possible to build a two stage amplifier with a common cathode (emitter or source) stage driving a grounded grid (base or gate) stage where the DC feed for both stages are in parallel not series. Is this still a cascode amp or is now a cascade amp?
On a tangent subject, in the early days of the BCB, the neutridyne circuit was popular, but was patented. To avoid patent violations, did any radio makers use either the grounded grid or cascode configurations in sets?
There was an odd ball tube (WE717A) that had a mushroom shaped glass bulb atop an octal base shell. It was sorta a 6AK5 or 9001 with an octal base and was used in many WWII VHF receiver front ends.
I think still a cascode since you are still talking two topologies, CE and CB. Cascade in my mind means a string of identical stages.
Well done ! Thanks.
I'm wondering what the purpose is of that small value resistor between the plate of the lower tube and the cathode of the higher tube in the Amico -and your final- circuit. Is it some kind of parasitic stopper resistor?
I saw several formulas where 'Gain' was defined, but it didn't say which gain. It could be the ratio of output voltage to input voltage, or output current to input current. I would assume voltage, but do others know that? Thanks for the informative video.
I love vacuum tube technology its so nostalgic.
I have no tubes but i am looking for some from garage sales etc.
i am mostly interested right now into the 12Ž1L tube which is soviet copy of german WW2 RV12P2000
Its only 12V anode voltage and 12V heater.
then i have in plan to go to more high voltage stuff ( 60 ,90 , 180 etc. Volts ) aaand then maybe into some really HV stuff like GU81 which is big soviet HF transmitter Pentode with 450W of anode dissapation ( 600W max. for 3 minutes )
and well it need 3kV when operated on 6MHz ( maybe i will use it for some HF PA or radio transmitter on HF : ) )
I just love how those tubes glow and radiating heat ( when transmitting pirate radio glow of tubes is giving moderator most of the adrenaline ( my friend said ) ) and i believe i am not alone :D .
See you next time. 73 from OK2???
Very cool tube!
have you tried the KORG Nu-tube 6P9 flat vacuum tube which can work of as low as 9V with a heater of 1.5V and I think it might be possible to build a balanced preamp with the said tube.
Thing is i live on the west coast. Cant get really ANY shortwave here. Im convinced many radio designs will work fine when signal is actually available
I am listening to the KFS WebSDR from Halfmoon Bay CA 6 PM West Coast and hear strong stations. WWV at 5 MHz, CFRX Toronto 6090, Radio Marti on 7305, China in English is blasting in on 7315. WBCQ on 9330, Radio Prague 9395. I suggest a 31 Meter Dipole.
@@MIKROWAVE1 many times when i tune to wwv i get a lot of interference i think its possible im getting both wwv stations at once (the one in colorado and the one in hawaii) I did pick up radio havana last night and ive picked up other stations as well before but they all tend to fade in and out. I was using a 25 foot long wire. Websdr is going to be much more sensitive than my TRF or a crystal though. So i dont think its a reliable indicator. I am able to get some shortwave but as i said they always fade because most are not aimed toward the west coast at all
@@researchandbuild1751 Agree on all and sure you can hear two WWVs since you are in the middle - and even some nights the same WWV coming at you delayed around the world mixing with the short skip! But 25 ft longwire is a possible weak point. Try a 50 ft dipole with coax coming into the radio and see if things quiet down.
This is where i have had some trouble.
Thanks.
Ps.
Do you have some way for us to tip you?
I have received so much help from your videos, and i think they are destined to become "classics" for other beginners.
To get these links to work, appears I have to split them up... (for those who want to read a bit more on the subject...) See pages 214 & 578 in the following www.tubebooks.org/Books/orr_radio.pdf
❤️❤️❤️❤️❤️❤️❤️👍
How does it compare (noise figure, dynamic range, immunity to overload etc) to more modern devices like for example mar preamps or preamps based on J310 transistor popular in ham radio world. Is it worth to try with tubes? I have some nuvistors lying around and I wonder if it's worth doing (besides educational aspect of ocurse).
I do not have equipment to properly test for these. However, when we are talking about BCB to Shortwave frequencies, IN GENERAL and with BASIC CIRCUITS, tubes will always outperform solid state solutions in regard to dynamic range, immunity and overload. And noise figure is moot at shortwave. We did not change to solid state for performance reasons, we changed for cost and power savings and miniaturization. It would be later that more exotic topologies would arrive to bring solid state up to the performance of tubes.
Greatly enjoy and have learned from your videos...! I always tell others to check out your videos... Thank you very much...! Regarding neutralization, a couple of questions... How to select the initial value? The value of Cn should be Cgk+Cgp (plus parasitic) and for the plate-to-cathode inductor value the conjugate of this value? How critical are the values, is it possible to estimate them, use a fixed value and get "good" (fair) performance, or should always use a variable value component? Thank you again..! 73, Greg (KC9ZEW)
Basically yes you can estimate, but that is based on a perfect phase and amplitude reversal method like a center tapped system to for feedback. So it is just very unlikely that you would achieve a null value because it really is a bridge circuit problem. So maybe CT the output primary and feed bypassed DC power in there. Then estimate the C neut value with a trimmer with a max of at least double that, and tune for the least feed through at the high end around 15 MHz (power off). This can be done in ether direction with Gen on one side and scope on the other.
Very good, Michael, I will make a note of this...!
Why not use a mechanacal bandpass filter? No tubes nor the power to run them?
Mechanical filters are by design, filters with very narrow bandwidths and sharp skirts. They are excellent filters. But they are also limited to frequencies below, perhaps 1000 kHz, and are generally lossy. So you only see them utilized in the last intermediate frequency of high end superheterodyne receivers, typically at 400 to 500 kHz.
When are you going to get out of the 50's???? You could buy ready made RF amps from China for $6.00. I made a 50 khz to 500 mhz preselector using toroids from Amazon and other parts from ebay. Total cost was $15 using some of my existing parts for my SDR receiver that covers 10 khz to 2 ghz and costed $120. (SDR Play)
Ha! I work in this field and purposely separate the channel from anything modern. RF principles are ageless.
If I paint my 6BA6 red will it increase the gain?
Now you're talking. Radium based for more emission I assume?
We want a low current battery operated antenna pre-amp trf.
Cool. Watch the next video on the Solid State version. th-cam.com/video/ZWEgjIG2yf4/w-d-xo.html
Question: As the term of solid state is used strictly for any circuit that is on a printed circuit board and thus could be a microchip, transistor, or a tube, why is it in this more modern time that solid state refers only to semiconductor devices? There were tube radios where it was all mounted on a printed circuit board and were called "solid state".
I do not recall when the switch was made in the reference but I see it more and more these days and from the original concept, the modern terminology is simply incorrect.
AC: Solid State refers to transistors, diodes etc that are not tube types. It has nothing to do with circuit boards.
Interesting but I have never heard of this. I always thought that it was purely to do with devices that could operate with "solid" semiconductors which required no thermionic emission as valves do (with hot filaments).
The valves /tubes have the electrons traveling through a vacuum, not solid semiconductor, so tubes / valves are called 'hollow state'. 👍👍👍😊