This tube is the correct size and neck type (CR-7) as the monitor in the Space Invaders (Toei GM-140) and although the TV tube uses 11v on the heater and the monitor uses 12v it should be a close enough match.
The yoke on the other hand is not even close so I will have to do my first yoke swap, which will be interesting. I will try and document as much of the yoke swap as I can as I go along even if it doesn't all go to plan.
For anyone interested in more info on the TV it is a Boots Audio 14, with a Mullan A34-510W tube. There's also an isolanted transformer inside the case which might come in handy, I haven't had a change to check it yet but I am guessing it's a 100v-120v step down.
How did this repair go? :)
ReplyDeleteI'll let you know when I finish it, it's only been what four years or so. :)
ReplyDeleteI have started work on this again recently, recapped both chassis I have and I'm currently waiting on a part from China to fix the power supply. Once that arrives I'll be fitting this back in the cocktail cabinet and finally finishing it.
I've done this tube swap also. The Mullan tube is in lots of monochrome TVs, not just the Boots one, so is fairly easy to get hold of. I used a Ferguson TV. My opinion is that it's a none starter. The distortion on your tube, isn't adjustable & a deflection coil twist just won't work. The Mullan tube has a different deflection glass curvature and you'll find that with the Toei deflection coils, you end up with the beam scan going over the Anode cap. That's why you can see a disjointed side to the scanned area in white. If you pull the deflection coils back along the tube neck, you'll see the image if the anode appear more. Please correct me, but it needs a different tube. The heater is 1v difference too and that needs a circuit mod, or there will be an early death. Good luck, I still haven't got another tube type yet. I've fixed quite a few monitors and use a rejuvenator quite a bit, so I understand the circuits.
ReplyDeleteGood to know thanks for posting. I never got any further with it and will most likely sell it as a project as I don't have the room to have it set up anyway.
ReplyDelete