Many people have told me this will never work...but I need to see for myself.





If it DOES work, I will build it nicer...but this should show once and for all if it will work.

Yes, that's a 6BK4 and a 6SN7...

Bill

It will work if you use the 6BK4 as a detector and 6SN7 as audio amplifier.

6BK4 was made for high voltage but it's a triode. Transconductance is only 200 with plate current less than 1 ma. The 6BK4 in your photo had a lot of use..

Bet you could do xrays with that tube

Right but think you would need 30KV?

That is exactly what I intend to do with it



True, and it's a 6BK4C / 6EL4A. I can't find it right at the moment but I have a NOS 6BK4A. Not an ideal tube for TV use, but I bet it would do as a detector.

More than a few people have told me it won't conduct with less than 20,000 volts on it - I say if the Audion worked, this should work too. I plan on running about 150 volts on the plate.

At 150v on the plate, it won't put out any more X-rays than a 5Y3...

Let me know if it works. I have a used one, and a new one to try if it works. Got to find em of course, there buried somwhere.......
I think it will work

Thanks
Jeremy

Been thinking I'd try one at about 1200v on the plate to see if it will actually amplify... I have a old scope transformer that used a 1V2 rect into a couple .2 caps... Just tried it and it's good, so one of these days I'll give it a shot...

If that doesn't do it, I have a bug zapper xfomer and some HV triplers for TVs...

Tom

There are far better tubes to use for this, I know that. The 6BK4 oly has a mu of about 2. The mission here is NOT to create the best 2-tube regen ever, it is to see if the 6BK4 will work at <200 volts on its plate. Some say it will not, I say it will.

Your scope power transformer...I think that will work, probably not a lot of tubes that can tolerate 1200v on the plate.

But - what would you do with it? Signal in shouldn't be a problem, but the rather high output voltage...you'd need a special cap just for coupling (the standard 630v cap wouldn't be adequate). An interstage transformer would have to have a very high impedance - here's an idea - perhaps using a flyback as an interstage transformer. Now that would get noticed!

My first regen radio I built when I was about 10 years old used an 01A. That worked well, despite the fact that I had no idea what I was doing.

No prob, I have some 1600/2000v caps for TVs and a few 1600v buffer caps for car radios... Values may be a bit small, but I should be able to test operation...

BTW, I'm not beyond sticking caps in series to increase voltage ratings...


Tom

6BK4 will conduct at lower voltage. Think of it this way, a lot of tube testers only use a couple hundred volts, some much less. You can test 6BK4's on tube testers.

Yes I confirmed that last night on a Precision 912 before I jumped into this post... Grid voltage set to max and load at minimum, nets approx 25% deflection on the meter, which is indicative of a good tube... Reducing grid signal lowers the reading, so it is apparently amplifying(if only a little)...

Since the tester uses 300v plate supply, I'm guessing it will take somewhat more voltage to achieve any real amplification...

Tom

Nice thing about a regen, it doesn't need a tube with high gain. As long as gain is over 1 feedback from tickler coil increases the signal.

Sure it would, but just kidding

Hey!

What happened to this?

here here what was the verdict how far were the ideas/trials taken?