Marantz 4400 CRT Replacement Using RCA 2BP1

Kildare

New Member
A few years ago a member going by the name of 'Novanec' posted photos and instructions on how to replace the CRT for a Marantz 4400 using a RCA 2BP1 (instead of the Hitachi 50TB1). I've heard of this process before and supposedly it only requires some very minor changes to the connector pins.

The problem I'm having is that the web hosting site used at that time the posts were made is no longer valid and I can no longer retrieve the files. Anyone happen to have saved these uploads or have a working knowledge of the process?

Many thanks!
 
My Notes say the 2BP1 takes a different socket from the 50TB1 and I think the heater current is a little higher, you may have to install a slightly larger fuse in the filament power supply circuit.
My notes also say to swap Y+ and Y- or install the tube with the index up and swap X+ and X-.
These might help, too.
Tom



scope for 4400 2bp1.JPG 50TB1Specs.gif
2BP1.pdf
 

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It does take a different socket, i've done the conversion. The sockets are sold on ebay, ceramic jobs. I didn't touch the fuses and it worked no issue.
 
Bktheking, can you be more specific as to the socket I'm looking for? If you've actually done the conversion, you're just the person I need to talk to!
 
Found it, thanks. As someone who has actually done the conversion is it really as simple as catrafter states? No offense catrafter, I just wasn't clear if this was actually something you experienced or not!!! Appreciate both of your input.
 
I did the conversion but it was over 10 years ago. I don't remember it being difficult, I think I wired it up and then found the x axis was backwards, so I swapped the wires around and it worked fine.
It must not have been too difficult to figure out at the time, I used the two images and the PDF file I posted above, along with the 4400 schematic.
The 2BP1 has green phosphor.

Tom
 
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