6BK4 substitute
 

While hunting through tubes last night, I came across a 6EA4. It's a compactron HV shunt regulator. Looking at the data sheet, it seems pretty close to a 6BK4. I'm tempted to build a socket adapter and try it, but the 6EA4 data I found on the internet doesn't have much about the regulated output of the tube. Anyone know if this would be a useable sub for a 6BK4?

-Ian

6BK4 sub
 

You can try and see if it regulates. (it should be just fine) You really can't hurt anything, would be the same as a defective 6BK4 if it doesn't. 40 years ago we used to talk about all of the similiar tubes and decided that it was one way to sell a distributor more tubes and stock more product.

Are you trying to get away from the X-Ray factor?

No, I'm just trying to substitute for a hard to find tube.

I haven't tried this yet, simply because I haven't had the time. But, I do plan to try it.

-Ian

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AES sells 6BK4C's new for $40. Granted, they do have the same tube used for $5. But, this is one of those tubes that is hard to test without simply putting it in a TV.

They're hard to find in the sense that I don't have any, and have't found any locally or at hamfests. I'm a little reluctant to buy parts if I don't have to, and while digging I found a new 6EA4.

So, I figured it was worth a shot.

-Ian

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If you haven't already, go to http://www.duncanamps.com/tdslpe/ and download their tube database. I'd look it up for you but I'm at work.

Although they probably do emit X rays, I wouldn't worry too much about that as they are in a cage and unless you stick your face in it for a period of time...

These are not hard to find tubes and always come across them at hamfests and they are on ebay at any given moment. Some nut case is currently asking $50 for only one now!! I wouldn't even pay the $5.50 shipping to get one for free. I know I have dozens of them in my 30,000+ tube stash now.

google tube substitution guide

Yeah, I have a whole box of a couple of dozen of them. Some of them have the neat beer bottle color caused by the X-Rays. I even saw on Google that you can build your X-Ray machine, using this tube with common work shop parts. I think Homer Simpson may be looking for these, if anone is looking for a sale.

Hi,

AES wants this much money for one! Your proposed substitute is the most commonly available of the sweep tubes. This model wasn't as heavily used due to being a late design sweep tube and not having been used in Amateur Radio Gear. Many Amateur Radio gear used sweep tubes in the 1960's and 1970's which has made some types expensive and hard to source.