Substitute for 5842/417A

[Peter Menting]

Am interested in Ralph Powers PP 6B4G amp, but the 5842 tube seems rare and expensive. Is there a good substitute for this?

Pete

 

[The-Planet]

5842/417A

Pete -

As long as you're not looking for Western Electric parts, the 5842 is easy enough to locate, $8-10 each.

http://www.the-planet.org

- Gary

 

[Peter Menting]

Gary;
Hane not seen anything for less than $30. Do you have a specific scource in mind?

Pete

 

[The-Planet]

5842/417A

Pete -

Electron Tube Enterprises (Dick Bergeron) has them for $8, Antique Electronic Supply has them for $10 and change. Links for both are on my website in the Links section.

http://www.the-planet.org

- Gary

 

[Peter Menting]

Gary:
Thanks so much for your help!
Pete

 

[Positron]

Brand

Guys, I don't know how concerned you are about microphonics, but over the years I have used them the Ratheon were the least microphonic. Some of the others, including WE were horrible.

 

[Peter Menting]

Steve;
I was not aware of that, but this would bring me back to my original question: is there a good substitute for this tube?

Pete

 

[Peter Menting]

Here is the schematic for the amp;

 

[Brett]

Steve;
I was not aware of that, but this would bring me back to my original question: is there a good substitute for this tube?

Pete

Some people use the 6C45, but it's not an exact sub. You'd only need to adjust the cathode R and C maybe. Last itme I looked they were about $US12.

Good amp design. Stigla had a thread or two on this amp about a year back.

 

[grataku]

I wish all tubes were this easy to locate and cheap!
I bought some NOS JAN 5842 raytheon from rfparts.com 8 bucks.

http://www.rfparts.com/tubereceive6.html

 

[Brett]

grataku, just an FYI, but some of the 5842's can be very microphonic, so be careful how you mount them.

 

[grataku]

Brett,
what would be the best way to reduce the problem? Little rings and stuff...do they really help?
I bought some JAN tungsol 76 from tubestore.com and upon light and controlled shaking I can hear something moving insight. that wasn't very inspiring.
GPimm seemed to think the 76 were pretty good from that standpoint.
What do u think?

 

[Brett]

Brett,
what would be the best way to reduce the problem? Little rings and stuff...do they really help?

Take a look at Steve Bench's thoughts on the subject. I do something similar-ish, but most of my gear isn't built into a "picture frame with a top plate type" chassis.

I bought some JAN tungsol 76 from tubestore.com and upon light and controlled shaking I can hear something moving insight. that wasn't very inspiring.

I don't have any 76, but maybe they have a very long filament and you can hear that rattling.

GPimm seemed to think the 76 were pretty good from that standpoint.
What do u think?

Not very experienced with the 76.

 

[Peter Menting]

Brett;
Thanks for the info and the steer to Stigla's thread. Will take some time to digest the proposed changes but I suspect in the end I will stay with the original schematic and then try to fine tune the results.
Pete

 

[45drive45]

raytheopn 5842's are plentiful and cheap. So far none that i have is microphonic
WE417A on the other hand are blardy expensive. I ahve a few and some are very microphonic.
BTW, Ralph PP amp is cool.
Using 6c45 is possible with inor change in values and will work well.