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[email protected] tabbypurr@gmail.com is offline
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Default Marantz Model 19 Scope

On Friday, 26 April 2019 22:45:21 UTC+1, Dave Platt wrote:
In article ,
wrote:
Does anyone know anything about these ? I know the basics but there are details missing from the print,
LIKE THE PINOUT of the CRT !


The service manual is available at HiFiEngine.com (free registration
required to download). The scope-module schematic is on page 62 of
the original and the tube ponout is given.

The scope V901 is "CRT with 13-pin Nixie base", Marantz part number
337-1000. According to one article I read elsewhere, it's originally
a Siemens D3-II GJ.

After all of these years, I wouldn't be surprised if the cathode were
worn out (low emission) or the CRT has become gassy.

From what I hear you would need a SWAT team and a bunch of automatic weapons to get a replacement CRT.


From what I read, it's well beyond that now... you'd need the services
of at least four demigods, and several falling asteroids to blast one
loose. They're probably mostly in the hands of owners of Marantz
receivers in that series, being preserved against a Time Of Need.

Even people with experience on these things, how many receivers had built in scopes ? I saw one in another
brand once but can't remember what it was, maybe a Kenwood ? Other than that only Marantz and then even
very few models.


Some Macintosh tuners had scopes. Mac seems to have used a more
common/popular tube variety (a 3RP series), for which there are still
some used-but-good tubes available and even a few Chinese-build
clones.

Anyway, thanks in advance for anything useful on this matter. It makes a big difference in the value of the unit.


One guy who wrote, said that he'd sold a Model 19, and had also sold a
new-old-stock replacement CRT he had for it. He got more for the CRT
than for the receiver.

I've been dealing with a slightly similar problem myself... I bought a
CTS service monitor whose scope is working-but-dim. Fortunately it
has a 3RP CRT (like the Cushman and Macintosh systems do) and I have a
local source for a used tube (and there are online sources as well).

I was thinking of trying to cons up a solid-state replacement. I
think one could probably be made by using a Raspberry Pi or similar
processor as a core, hooked to a reasonably fast (audio-speed)
two-channel SPI-based ADC which would sample the horizontal and
vertical deflection voltages (suitably attenuated and centered of
course). The Pi would capture the data, and then draw it to a 2"
color LCD.


shango66 on youtube does some good explanations re CRT emission problem fixing. Though I don't remember him discussing EHT boosting.


NT