While looking for a replacement CRT for my TRS-80 4P (and only finding drop-in replacements for $200-400) I came into possession of a Sony SSM-930 9" B&W CCTV monitor.
The Sony monitor works, the neck pinout is the same as the M24-302 in the 4P except the heater voltage is expecting +12v instead of +11v. Not a problem considering the 4P actually sends it 12v. That goes through a 1N4002 diode which has a Vf of 1.1v, so I can probably bump that voltage if needed by using a diode with a lower Vf that still matches the volt/amp ratings.
Has anyone tried dropping one of these into a 4P? The only thing that concerns me is the SSM-930 schematics show a 1.1v peak-to-peak on the deflection yoke, and I can't find the same spec on the 4P or m24-302 tube. If necessary I can just hook up the oscillisocpe and watch the peak-to-peak going into the factory deflection yoke.
The Sony monitor works, the neck pinout is the same as the M24-302 in the 4P except the heater voltage is expecting +12v instead of +11v. Not a problem considering the 4P actually sends it 12v. That goes through a 1N4002 diode which has a Vf of 1.1v, so I can probably bump that voltage if needed by using a diode with a lower Vf that still matches the volt/amp ratings.
Has anyone tried dropping one of these into a 4P? The only thing that concerns me is the SSM-930 schematics show a 1.1v peak-to-peak on the deflection yoke, and I can't find the same spec on the 4P or m24-302 tube. If necessary I can just hook up the oscillisocpe and watch the peak-to-peak going into the factory deflection yoke.