Western Electric Vacuum Tubes

[oldtechie]

I know tubes are not a 'hot topic' on these forums but I do have a question that maybe someone can answer.

On Ebay some WE tubes are listed as "Small Punch" or "Large Punch". I am wondering what the term "punch" means. Is "small punch" the same as "fine mesh"? Or are they referring to something else?

I promise, I will come back and review this thread.

[CeaSaR]

Did a quick search and found a link ( https://tubeworldexpress.com/collection ... mall-punch ) to which there are both small and large punch on the same page. If you look at them side by side, the holes in the screen are just that - large or small as compared to the other.

Not much else on "punch" sizes.

[oldtechie]

@CeaSaR
OK - It does look like "small punch" is what others call "fine mesh". Best I can tell, anyway.

[CeaSaR]

If no other explanation comes back, there's a couple of other people I can query out there. Let's see what bubblers up.

[dacflyer]

So whats the difference in performance of large punch or small punch ? I never heard of this term before..

[dyarker]

I never heard the term "punch" used for tubes before either.

If it refers to the control grid, two things pop to mind. Frequency response (less likely), and gain. Small punch would block a greater percent of area between cathode and plate, electrons go through the open space (less current), but field between grid conductors could more easily cut-off electrons. Larger punch would let more electrons through because the space is a higher percentage.

Seems like that this should be another part number, or suffix letter on the part number.

Screen grid the same re space percentage, Reverse(?) re the effect of the field. (??)

Cheers,

[Janitor Tzap]

Yeah,

I've never heard the term "Punch" either.

I did a quick skim over the wikipedia page: Vacuum Tube.
https://en.wikipedia.org/wiki/Vacuum_Tubes
But didn't come up with that term on that page.
Though there are multiple links on the subject of Vacuum Tubes on the page.

Thou......
I seem to remember something about High Frequency, or Low Frequency response "Punch" of Audio Amplifiers.

Edit:
Oops,
I didn't look at that Link you posted to CeaSar.

Yeah, they do show Small & Large Holes in the Metal Anode Shield of the tubes.
Here's a PDF on the 328A Power Audio Tube.
https://static1.squarespace.com/static/ ... 7/328A.pdf
It refer's to that outer Anode as a "Suppressor Grid".
This makes me wonder if the hole size effects the gain output of the tube?


Signed: Janitor Tzap

[dyarker]

oooooh ... so far back..
suppressor grid keeps electrons from bouncing off the plate
of course those that strike the suppressor don't get to the plate at all
(like I said memory is very old on this. never heard it called outer anode though. good thing this thread is just for curiosity)

[CeaSaR]

I've got a few questions out to some who ought to know. We'll see what pops up.

[dacflyer]

I bet if EDD was still around, he'd tell you all about it... Anyone know where or what he's up to now days ?

[CeaSaR]

Wish I knew. Would like to hear from a few of the others who used to frequent the boards, just to let us know they are still kicking around after the past couple of years.

[CeaSaR]

So, I've been trying to find out what the deal is on these punched tubes. Just like the info on the web, there's not much to be found.
Terry at DLab was the first and he didn't know, but speculated about the cap.
Brad the Guitologist had never heard of them.
Mark at Blueglow Electronics has not responded.
I still need to try Paul - Mr. Carlson's Lab, Shango066, and Uncle Doug. I'll even try Gregg's Vintage Workshop for some of the guys that frequent his comments.

Might even just write to Western Electric directly.

Until then....

[Janitor Tzap]

Hmmm.........

I wonder if it is just some term that some of the younger Vacuum Tube enthusiasts use,
because they thought it was more appropriate?

My sister and her husband were in to Tube Audio Equipment, back in the 90's.
A lot were newer designs that were Pre-Amp, and even Main Amplifiers.

I'll see if they have heard of this term.


Signed: Janitor Tzap

[CeaSaR]

Hmmm.........

I wonder if it is just some term that some of the younger Vacuum Tube enthusiasts use,
because they thought it was more appropriate?

My sister and her husband were in to Tube Audio Equipment, back in the 90's.
A lot were newer designs that were Pre-Amp, and even Main Amplifiers.

I'll see if they have heard of this term.


Signed: Janitor Tzap

Using the link I first gave, I looked up the 2 tubes listed. These are from around the middle of last century, up into about he 80's. The pages really didn't give much of a clue as to the "punch", but one thing they did say was that they were designed to minimize microphonics. And if the punches were done right, I could see that as a possibility for them. You can read their datasheets here: https://www.westernelectric.com/library#technical

BTW, email sent to Western Electric. Now we wait.

[Janitor Tzap]

My sister and her husband were in to Tube Audio Equipment, back in the 90's.
A lot were newer designs that were Pre-Amp, and even Main Amplifiers.

I'll see if they have heard of this term.

They got back to me.
But they too have never heard that term as well.

Using the link I first gave, I looked up the 2 tubes listed. These are from around the middle of last century, up into about he 80's. The pages really didn't give much of a clue as to the "punch", but one thing they did say was that they were designed to minimize microphonics. And if the punches were done right, I could see that as a possibility for them.

Check out this PDF: "Getting the most out of Vacuum Tubes" By Robert B. Tomer.
Published Circa 1960.
http://www.tubebooks.org/Books/Atwood/T ... 0Tubes.pdf
There is a lot of Information in this, and on page 50.
It goes into great detail of the problem of microphonics.


Signed: Janitor Tzap