Marantz Model 18 - Scope Tube

[Superfly10]

Hi all,
I'm sending my marantz Model 18 out for a complete refurb and am looking for anyone who has a line on the oscilloscope tube. My quote for the refurb is $450-$500. Any help will be greatly appreciated.

 

[bktheking]

Is your tube missing or bad?

 

[ausman1000]

email these guys for your scope, under $200 USD

https://www.die-wuestens.de/eindex.htm

 

[Superfly10]

The tube is Bad

 

[Superfly10]

ausman 1

email these guys for your scope, under $200 USD

https://www.die-wuestens.de/eindex.htm

I have emailed them and waiting reply.

 

[Superfly10]

Is your tube missing or bad?

Tube is bad but present. Stereo light comes on but no scope activity in any position or setting

 

[txturbo]

How do you know the tube is bad? I have several Marantz model receivers and tuners with scopes, many of them came with non functional scope sections. Never did I find the tube to be bad to the point that it wold not display. Some of them have burn marks but they all display something. That's not to say that a tube can't go bad but it's more likely the scope transistors or the HV section of the transformer.

 

[bktheking]

Agree with txturbo, these tubes rarely go bad-almost always something else. If you had a spare and plugged it in and it started to work that's one thing.

 

[Fhamre]

My bet is the scope transistors and circuit need attention. bk and tx can guide you through what to test. Very high voltages. There are some good posts worth reading. Every Marantz unit with a so called non working scope that has crossed my bench has just had a circuit issue that needed to be addressed.

 

[ausman1000]

Does the heater glow? I had one with an open filament/heater. If no glow then check for continuity across scope pins 1 and 2 while out of circuit.

 

[Chrisxo55441]

one just came up on ebay
https://www.ebay.com/itm/Telefunken...062122?hash=item5902436b2a:g:Y0gAAOSwHYpZ8DKI

 

[Superfly10]

How do you know the tube is bad? I have several Marantz model receivers and tuners with scopes, many of them came with non functional scope sections. Never did I find the tube to be bad to the point that it wold not display. Some of them have burn marks but they all display something. That's not to say that a tube can't go bad but it's more likely the scope transistors or the HV section of the transformer.

Ok thank you for the input. I will retract my statement that the tube is bad because I have not tested it or even know how. I had a guy tell me to check the power supply and it tested between 500 to 513 volts

 

[Superfly10]

one just came up on ebay
https://www.ebay.com/itm/Telefunken...062122?hash=item5902436b2a:g:Y0gAAOSwHYpZ8DKI

I bid on this one and lost at last second