jFET's on oscillator board 1.066.110?

[b0190]

Hello ReVox Fan:

When I was trying to align oscillator I accidentally touched test point TP to ground; tuner section was dead. On the circuit diagram the oscillator board 1.066.110 has two jFET's (Q1 and Q3); marked as Motorola 0323 (or O323?) Also there was another FET marked as 0442 (Q6). Using web browser I can not find any information on these FET. Q1 and Q3 has four pin where one of them was case ground.
Can we replace Q1 and Q3 by any high frequency jFET's? What would be the most commonly available one?

Thank you!

[schori]

If you really expect answers, it would make sense to explain which machine you are talking about.
Maybe also write in the title of the post.

Is it an A720? OK, it's the Channel 720, but better write it in the title to invite people which see it in the overview...

[b0190]

Hello Schori:

Thank you for notifying my ignorance of including machine model number in the title. It was indeed a ReVox A720 tuner-preamp. Please also pardon me for using English in writing the context.

Best Regards,

Yeun-Jung Wu

[schori]

Hello Yeun-Jung Wu

Maybe this Posts helps you, also here in the Forum

https://revoxforum.ch/forum/forum/studer-revox-technik/revox-technik-im-detail/preceiver/a720/9935-a720-oszillator-defekt

[b0190]

Hello Schori:

Thank you so much for this link. It was exactly what I need! Yesterday I tracked a short diode on kHz board. The Nexie in kHz became normal.

I also disassembled one of the slide potentiometer with broken shaft. Maybe 3 D printing can save this unobtainable part.

Best Regards,

Yeun-Jung Wu

[b0190]

I also found 2N4119A has the same package with extra pin for case ground (TO72).