Hatsune Mike
Champion
In my experience the Hitachi tube doesn’t benefit much from this
- Thread starter Hatsune Mike
- Start date
erdrick1980
Professional
I was about to do the enhancement mod on Hitachi after capkit...and when I compared it to the toshibas, I refrained myself since it looked sooo good already.
Now I'm glad I didn't do it. Thanks for mentioning it.
rememberizer
Student
I have some MS9 chassis that have different neckboards. Can't find a D506, r517, so I thought it might be an older revision, but I can't find a J404 on it either! It's marked 05a00675c1.
Is it possible to do these mods on this chassis?
Also does anyone have photos of what the edge curling looks like?
Is it possible to do these mods on this chassis?
Also does anyone have photos of what the edge curling looks like?
Hatsune Mike
Champion
You can do it on any of them fundamentally, but sure enough it's possible the jumper name is different or gone. Ultimately you just want to isolate that neck pin from ground and instead substitute the G1 voltage.
rememberizer
Student
Thanks. I guess I'll go and check the chassis that I've installed on cabs. maybe I'll find one that is similar to what you guys used. Just too much work to try and figure it out with these spares I have.
Ape Cosplay
Enthusiast
@Hatsune Mike, couldn't we make it a tri-sync by leaving the original R563 in place (22k) and wire a 47k resistor in parallel with a switch (for an equivalent resistance of 15k)?
That would leave the 24k mode untouched when the switch is open and give us 31k when closed.
That would leave the 24k mode untouched when the switch is open and give us 31k when closed.
Hatsune Mike
Champion
You could do that. The 31k is already a bit of a compromise though, and modifying the B+ voltage for the sake of 31k means that 24k might look a little off. However the theory of operation is fine to do something like you've described.
Thanks for this topic and with the help of a friend we did the sharpness mod. For me the end result is a very noticeable. Sharper and thicker scanlines. Only had to turn the screen pot a little bit to make the screen a bit brighter and that's it.
Before and after.
Before and after.
Attachments
GravitySandwich
Student
Did anyone perform the 31k mod on a MS9-29SU with a Hitachi tube? When i do it, i get massive rollover on the right side, even with a freshly recapped chassis.
Would love some help on how to fix this.
Would love some help on how to fix this.
rememberizer
Student
Hey guys. I attempted the 31k mod. G1/Sharpness worked. Replaced the resistor with a 15k, swapped the geometry caps, then swapped the connector to 24k. When I tested it, I heard an extremely loud squeal from the monitor so I shut it off. Restored the caps and I still get the same loud squeal. What did I do wrong? How do I fix it?
rememberizer
Student
rememberizer
Student
yes, it is.
You said you did the Sharpness Mod first and it tested ok?
rememberizer
Student
yes, it looked great, actually!
So I went ahead and tried the 31khz mod. I swapped the 22k resistor for a 15k, then replaced the geometry capacitors. Moved the connector to 24k and tested. Maybe I missed something? Did I need to set the HH24 pot before testing?
I have another Chassis that I'm willing to try this on. Just really want to get 31khz running on my other Net City.
It also might be worth double checking your work on the sharpness mod. I had a chassis I recapped last week that worked great on first test, then had sync issues later. Needed to fix some already re-worked areas and it’s all good
rememberizer
Student
The sharpness mod worked perfectly. It's something I did with the 31khz mod that messed up the board.
nem: I don't feel any static.
