Cost of New CRT

[Tincanalley]

I have a Canon monochrome CRT from 1984 that wasn't working. After extensive troubleshooting, I have determined the CRT must be nearing the end of it's life. I had to turn up the sub bright control to max in order to get an image. It is bright and sharp, but I don't think it will last. I tried to rejuvenate it, but that had no affect. The G2 is getting 628V and the G1 starts at -130 with all brightness controls down and bottoms at -2V at full (internal and external brightness) in order for the image to appear. All other voltages to the tube are correct as well. So from what I can determine, the tube is tired.

I found a seller on ebay that has 3 of these CRTs for sale. They are new and exact replacements (same model number). However, I don't know if the price is high, low or average. They want 195 + 45 shipping. I really like this monitor, but I don't want to overpay for a replacement CRT.

Thanks

 

[GearTechWolf]

That matches what I've been finding price-wise while looking for a 13" monochrome tube for my Sinclair PC-MM (aka Amstrad PC-MM) monochrome monitor.
So the question is, what size is your monitor?

 

[Timo W.]

Monochrome picture tubes of the same size are mostly interchangable. Most important are the mounting tabs (they can face either to the front or backwards and are fixed to the tube). Try to find out which other monitors use the same or a compatible picture tube and buy a working one as a donor. That is way cheaper that paying 200 bucks for the tube alone.

 

[Hugo Holden]

I'm am a CRT enthusiast for over 50 years, so I'm pretty sure I can give you some sound advice with your dilemma.

I think, for an exact replacement for your CRT, where the CRT you are getting is NOS, that is a very good price.

It pays to remember that now, CRT's are a non renewable resource and to find some NOS, exact type for your beloved 1984 vintage VDU, is nothing short of a small miracle. And no company exists currently who can rebuild your worn out CRT. So those NOS CRT's are like the main jewel in the King's crown.

If I was in your position I would make the seller an offer for two, perhaps $150 to $190 each, then fit one to your VDU and put the other one into my CRT farm as a spare part.

Recently I bought a number of NOS CRT's for the 9" PET VDU, because these are also becoming very rare NOS and they were not cheap.

As noted, it is often possible to fit substitute CRT's to VDU's & TV sets and I have done this many times when the original part is not available (which is a common event these days), it does require physical compatibility of the tube bulb geometry, the mounting tabs (when present) and sometimes rewiring of the socket if the gun connections are different and of course the gun requires the same heater voltage, mostly for small CRT's this is 12V , but for larger ones it can be 6.3V.

Probably (only guessing here) the ebay seller you are dealing with is Newtubes ? They have always supplied me with very good CRT's including one which was a close equivalent to the one used in the IBM 5153 VDU.

 

[NeXT]

As noted, it is often possible to fit substitute CRT's to VDU's & TV sets and I have done this many times when the original part is not available (which is a common event these days), it does require physical compatibility of the tube bulb geometry, the mounting tabs (when present) and sometimes rewiring of the socket if the gun connections are different and of course the gun requires the same heater voltage, mostly for small CRT's this is 12V , but for larger ones it can be 6.3V.

Mounting tabs aside, the harder problem is verifying the pinout of the base. Most jugs out of Asia don't have a datasheet you can still find and quite a few other tubes reference back to radiomuseum.org who puts it behind a registration and paywall.

 

[Hugo Holden]

Mounting tabs aside, the harder problem is verifying the pinout of the base. Most jugs out of Asia don't have a datasheet you can still find and quite a few other tubes reference back to radiomuseum.org who puts it behind a registration and paywall.

Fortunately the CRT in the region of the base is transparent and it is usually very easy to see which gun electrode connects to which pin and where the heater connects. But it requires some familiarity with gun design.