# Knowledge on Electron Tube Technology

#### Sajil1

Joined May 13, 2020
4
Hi Engineers! Want some consulting work? The catch is its vacuum tubes- tetrodes. I bet no one here plays with these anymore. If you do, please get in touch! Thanks.

Joined Jul 18, 2013
22,841
What do you need to know and what kind of project are you considering.
Max.

#### Sajil1

Joined May 13, 2020
4
What do you need to know and what kind of project are you considering.
Max.
The client intends to sponsor one project each 4-6 weeks with a budget between $500+$1000 with an additional bonus upon successful capital raising.

The projects will all be around high voltage circuits using 'tubes' such as tetrodes, pulse forming networks, thyratrons, and klystrons. Other projects will include analog heterodyne detection and mixing.

For those whose background is PCB design using solid state transistors, this is not a suitable match.

The client's working style is to be hands on and the expectation is to translate existing circuit topologies into hand-holding guidance.

The client is capable of respecting, honouring, and rewarding people that can zoom in past theory and focus on delivery.

An example first project could be:
1. Advise the client how to connect a beam power tetrode and operate it. You'd advise which transformers, capacitors, etc are required. After acquiring these, a series of video conferences to guide the client connecting the pieces together.
The GU series of pentodes will be used.

Is this something you have experience in and would be interested in discussing? Please let me know. Thanks.

#### Sajil1

Joined May 13, 2020
4
you might be surprised...
The client intends to sponsor one project each 4-6 weeks with a budget between $500+$1000 with an additional bonus upon successful capital raising.

The projects will all be around high voltage circuits using 'tubes' such as tetrodes, pulse forming networks, thyratrons, and klystrons. Other projects will include analog heterodyne detection and mixing.

For those whose background is PCB design using solid state transistors, this is not a suitable match.

The client's working style is to be hands on and the expectation is to translate existing circuit topologies into hand-holding guidance.

The client is capable of respecting, honouring, and rewarding people that can zoom in past theory and focus on delivery.

An example first project could be:
1. Advise the client how to connect a beam power tetrode and operate it. You'd advise which transformers, capacitors, etc are required. After acquiring these, a series of video conferences to guide the client connecting the pieces together.
The GU series of pentodes will be used.

Is this something you and experience in and would be interested in discussing further? Please let me know. Thanks!

#### cmartinez

Joined Jan 17, 2007
7,311
You don't need to answer to each of us independently in the thread. I'm personally not experienced with the expertice that you're requesting. But give it a couple of days, and maybe someone will chime in.

#### Sajil1

Joined May 13, 2020
4
You don't need to answer to each of us independently in the thread. I'm personally not experienced with the expertice that you're requesting. But give it a couple of days, and maybe someone will chime in.
Thanks, I am new to this forum so appreciate the help. If you know anybody who may have this expertise, please let me know! We would surely be interested in connecting and seeing whether we could collaborate with them. Thanks.

#### nsaspook

Joined Aug 27, 2009
8,259
Hi Engineers! Want some consulting work? The catch is its vacuum tubes- tetrodes. I bet no one here plays with these anymore. If you do, please get in touch! Thanks.
Many of us old guys have former expertise with vacuum tube power circuits. At what power level, frequency/pulse-rate, signal accuracy. GU (Russian) series power tubes generally mean VHF band linear operation or some strange audiophile application.

#### MisterBill2

Joined Jan 23, 2018
8,441
Hi Engineers! Want some consulting work? The catch is its vacuum tubes- tetrodes. I bet no one here plays with these anymore. If you do, please get in touch! Thanks.
The actual description of the work is very vague. There are a lot of tetrode tubes around, both as audio amplifiers and as RF amplifiers. But the when there is also mentioned Klystrons and thyratrons suddenly things get really broad.

There are hundreds of older texts and textbooks that describe operation and function in detail along with all of the associated formulas. And I hope that not one single word of that knowledge ever hits you-tube, presented as a 5 minute tutorial by some mumbling bozo. It is all there in the books. There is no royal road to expertise and insight.

#### col_panek

Joined Oct 30, 2015
12
Somebody is building a medium-high powered radar, and must have deep pockets. I'd like to know who, first of all.
Picture is me with an in-house made C band TWT transmitter.

#### MisterBill2

Joined Jan 23, 2018
8,441
Somebody is building a medium-high powered radar, and must have deep pockets. I'd like to know who, first of all.
Picture is me with an in-house made C band TWT transmitter.
They could also be wanting to build a GPS signal jammer or spoofer. I have concluded that the solution to jamming and spoofing is a small missile homing on the signal. And the missile should have perhaps a 25-yard kill circle. No need to be excessivly destructive.

#### Plamen

Joined Mar 29, 2015
101
Hi Engineers! Want some consulting work? The catch is its vacuum tubes- tetrodes. I bet no one here plays with these anymore. If you do, please get in touch! Thanks.
Petkan: I still remember them. If you have a specific question - please let me know. I have started with valves and may well finish with them

#### Papabravo

Joined Feb 24, 2006
15,750
The proposed budget of $500-$1000 for a 4 to 6 week project is insufficient for the level of risk by about a factor of 10. Ten grand for 6 weeks would provide about 41.00/hour for my time with nothing left for anything else. Sorry -- I'll pass on that. In fairness, I should mention that since I am retired I would need large inducements to get me to work again.

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#### OLD PHART

Joined May 19, 2020
4
I too am retired and remember the days of the vacuum tubes.
About the only way to get them now is to google them and try to find NOS.
A lot of the new tube replacements come from Russia.
They still used them in their MIGS in Vietnam.
The high power matched amplifier audio tubes are still used in hi-end audio amplifiers.
Radio and TV broadcasters no longer need an 1st Class FCC engineer on site to keep the frequency on band, and to fix things when they broke.
Everything is digital now.
The closest thing they have in solid state that behaves similar to a vacuum tube is a MOSFET,which is also a voltage device,as opposed to transistors that are current devices.
There is also work being done on Vacuum Transistors,kind of a hybrid of the two technologies that promises heretofor unreachable frequencies,into the terahertz..It uses a vacuum channel between source and drain instead of silicon.
These are nano scale devices at present,but very high output power is anticipated.
I was more or less forced to learn solid state devices and computer logic and programming due to the job market demands.
Vacuum tubes have the advantage of being immune to EMP,and the old HAM operators will be the backbone of civilian communications if such an event occurs.
The military has Faraday Shields on their equipment,so no problem for them.
Forgive me for preaching to the choir,I am sure you know all of this,this is mainly for the benefit of the solid state generation.
We put the first man on the moon with pencil,paper and slide rules and vacuum tubes.
Does anyone still have a slide rule?

#### MisterBill2

Joined Jan 23, 2018
8,441
Once again I will respond: There are hundreds of good texts on vacuum tube circuits and the advantage of learning from a book is that you can do it at your own pace, and review and restudy as much as needed.
A teaching deal seems far to much like it would turn into a much less comfortable design effort. So really, the whole thing has an unpleasant aroma about it.

#### Papabravo

Joined Feb 24, 2006
15,750
I too am retired and remember the days of the vacuum tubes.
About the only way to get them now is to google them and try to find NOS.
A lot of the new tube replacements come from Russia.
They still used them in their MIGS in Vietnam.
The high power matched amplifier audio tubes are still used in hi-end audio amplifiers.
Radio and TV broadcasters no longer need an 1st Class FCC engineer on site to keep the frequency on band, and to fix things when they broke.
Everything is digital now.
The closest thing they have in solid state that behaves similar to a vacuum tube is a MOSFET,which is also a voltage device,as opposed to transistors that are current devices.
There is also work being done on Vacuum Transistors,kind of a hybrid of the two technologies that promises heretofor unreachable frequencies,into the terahertz..It uses a vacuum channel between source and drain instead of silicon.
These are nano scale devices at present,but very high output power is anticipated.
I was more or less forced to learn solid state devices and computer logic and programming due to the job market demands.
Vacuum tubes have the advantage of being immune to EMP,and the old HAM operators will be the backbone of civilian communications if such an event occurs.
The military has Faraday Shields on their equipment,so no problem for them.
Forgive me for preaching to the choir,I am sure you know all of this,this is mainly for the benefit of the solid state generation.
We put the first man on the moon with pencil,paper and slide rules and vacuum tubes.
Does anyone still have a slide rule?
I have a collection of slide rules, both linear and circular

#### Papabravo

Joined Feb 24, 2006
15,750
Once again I will respond: There are hundreds of good texts on vacuum tube circuits and the advantage of learning from a book is that you can do it at your own pace, and review and restudy as much as needed.
A teaching deal seems far to much like it would turn into a much less comfortable design effort. So really, the whole thing has an unpleasant aroma about it.
Funny -- I was thinking the same thing, relative to great expectations for bargain basement prices. Sounds just like the reptiles I went to work for just out of school.

#### OLD PHART

Joined May 19, 2020
4

#### OLD PHART

Joined May 19, 2020
4
No batteries to run down,no unexpected reboot required,no updated versions to correct errors in programming.
Once you were familiar with your slide rule,it was actually faster than entering it on a keypad.
I still have an old Sling Psychrometer that I found at a yard sale.
Mercury thermometers are still intact,with a slide rule case to enter wet bulb dry bulb with output in Relative Humidity.
I know analog is now considered old fashioned,but the Panama Canal used pneumatic (analog) controllers from the beginning until recently without any problems;Not affected by EMP,nearby lightning strikes,power surges.
Analog was super reliable and much easier to explain to the inexperienced.
You could actually see the functions of each device in the real world.
Analog devices could perform some amazing thing,like square root,and square root extraction,multiply,divide, add,subtract,and totalization,integration.
And the functions could be programmed by changing pneumatic jumpers.
These analog computers were amazing to me.