Chassis swap (nanao ms9-29a for 29e31s)

[brad808]

Hey I'm looking to swap my chassis in my driving cabinet. Currently I'm using a dual res ms9-29a and am planning on swapping in a 29e31s tri res. The tube is a Hitachi a68ksa30x. Is this a direct replacement? Simply pull the old chassis out and put the new one in, or am I going to run into problems with this?

[grantspain]

sanwa 29es31s is a vga only chassis
sanwa pfx(pm1755) is a tri-sync
You can use a rodotron 666a or wei ya 3129a on the ms9 tube and will get reasonable to very good results-you may get some minor side compression on 15khz,24khz will look slight pastel concerning colours but 31khz should be very fine

[brad808]

sanwa 29es31s is a vga only chassis
sanwa pfx(pm1755) is a tri-sync
You can use a rodotron 666a or wei ya 3129a on the ms9 tube and will get reasonable to very good results-you may get some minor side compression on 15khz,24khz will look slight pastel concerning colours but 31khz should be very fine

Ok so the bottom line then is that the 29es31s won't work even in vga (which is what i need anyway)? Reason I ask about this specifically is there is someone close selling one.

Sent from my Desire HD

[apfelanni]

sanwa 29es31s is a crap chassis type .. 8/10 of my naomis with this chassis were dead within max 5 years. i wouldnt take it for free..
the hitachi tube deserves better ..

[grantspain]

sanwa 29es31s are vga chassis 640x480
not had any real issues with these,reasonably easy to repair-the tubes tended to be more of an issue tbh

[robotype]

people at rodotron says 666a does not match A68KSA30X.
the correct chassis would be CH-988-29.

[grantspain]

people at rodotron says 666a does not match A68KSA30X.
the correct chassis would be CH-988-29.

they are not taking into account the deflection yoke,the ch-988-29 is a 0.900 to 1.3mh chassis whereas the yoke of the ms9-29 is 0.300mh

[robotype]

I just measured the impedance of my hitachi tube A68KSA30X (DY 05F18712A1) H is 0.9 and V is 8.1.

[grantspain]

http://wiki.arcadeotaku.com/w/Yoke_Specifications

impedence is important but the inductance needs to match

I have swapped a few ms9 to rodotron 666a,did loads of research about 5 years ago on matching chassis to tubes

[robotype]

I have been trying to use ms9 chassis on the same hitachi tube but geometries were wrong so I gave up...maybe brad808 yoke is different.

about replacing ms9 with 666a I have done several myself and they all worked fine until recently; a friend of mine replaced his ms9 for a 666a to play vga games, changing resolution often killed two brand new 666a in a few days. one now randomly clicks to change resolution, the otherone is dead (consntant clicking, won't start).

I thought the tube or scan coil were defected (worked great with it's original ms9 chassis) but talking with jomac he told me to change resolution often would give this kind of issues, so these chassis work better in one resolution only.

so what would be the best solution to trisync an astro or egret II without replacing the crt?

[grantspain]

yeah switching res often would probably knock out the HOT,I have always fitted these to standard arcade machines so they stay at one res only

only sure fire way to match a chassis is to read the yoke windings with an inductance meter as well as an multimeter for impedence

if the yoke is way out you would get geometry issues,mainly size and in extreme the deflection circuit would fault

your only other option is to use a video converter board

[robotype]

yeah switching res often would probably knock out the HOT,I have always fitted these to standard arcade machines so they stay at one res only

only sure fire way to match a chassis is to read the yoke windings with an inductance meter as well as an multimeter for impedence

if the yoke is way out you would get geometry issues,mainly size and in extreme the deflection circuit would fault

your only other option is to use a video converter board

thank you for your help grantspain

what about nanao MS-2930 and MS-2931? do you know if I can use them on a A68KSM696X naomi tube? DY is 05F18745A1 99 1M (original chassis was MS-2934-S)

[grantspain]

yeah switching res often would probably knock out the HOT,I have always fitted these to standard arcade machines so they stay at one res only

only sure fire way to match a chassis is to read the yoke windings with an inductance meter as well as an multimeter for impedence

if the yoke is way out you would get geometry issues,mainly size and in extreme the deflection circuit would fault

your only other option is to use a video converter board

thank you for your help grantspain

what about nanao MS-2930 and MS-2931? do you know if I can use them on a A68KSM696X naomi tube? DY is 05F18745A1 99 1M (original chassis was MS-2934-S)

I am quite sure the nanao 2934 is same spec as 2932 which in turn should match both 2930/2931
2930 is manual switching res,the 2931 is auto switching digital chassis

[robotype]

great! thanks for the info.