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Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 3:30 am
by djcalle
Hi all,
I have a tube that seems like it could be a suitable donor for a Nanao MS2931 without a yoke swap.
It is a 68cm philips blackline tube with molded yoke and no rings: A68ESF002X43.
This tube comes out of a 100HZ tv which implies the yoke supports up to 31Khz.
I measured the yoke and the values don't seem too far off the measurements I took off my original yoke:
MS2930/31 tube
Lh 0.19 mh
Lv 16.3 mh
Rh 1.1 ohm
Rv 7.3 ohm
A68ESF002X43
Lh 0.30 mh
Lv 5.07 mh
Rh 1.1 ohm
Rv 6.1 ohm
My question is, would it be safe to plug it in as is or would the value differences present a risk of damaging the MS2931 chassis? I don't care about the tube.
Cheers.
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 10:31 am
by grantspain
the new tube is more for pfx or weiya 3129a
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 12:18 pm
by nem
You can apparently pair up one with a MS9 as well. I've been meaning to try it but when I finally placed a huge order with JST, I forgot to order the vertical yoke connectors
djcalle wrote: ↑September 17th, 2020, 3:30 amThis tube comes out of a 100HZ tv which implies the yoke supports up to 31Khz.
I don't think these two things are related at all.
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 12:41 pm
by djcalle
duplicate
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 12:44 pm
by djcalle
djcalle wrote: ↑September 17th, 2020, 12:41 pm
nem wrote: ↑September 17th, 2020, 12:18 pm
You can apparently pair up one with a MS9 as well. I've been meaning to try it but when I finally placed a huge order with JST, I forgot to order the vertical yoke connectors
djcalle wrote: ↑September 17th, 2020, 3:30 amThis tube comes out of a 100HZ tv which implies the yoke supports up to 31Khz.
I don't think these two things are related at all.
I've found a few toshiba tubes from consumer TVs that are the same family as the MS2931 tubes (A68KSMxxxx) and compared the yoke values to the actual blast city yoke, well the vertical coil values where the same but not the horizontal, I concluded that it was because those TVs are 15Khz only and there was a link between the horizontal coil values and the maximum horizontal refresh rate. just a theory but I found the evidence pretty compelling. I know the wei ya chassis can do 31K on a MS9 tube with stock yoke though, so who knows, maybe I am wrong.
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 12:46 pm
by djcalle
grantspain wrote: ↑September 17th, 2020, 10:31 am
the new tube is more for pfx or weiya 3129a
cheers for the reply, would you see any risks in trying it on the MS2931?
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 1:00 pm
by grantspain
it will run but it will most likely run the horizontal transistor too hard, I would not do it if it were me
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 1:02 pm
by djcalle
grantspain wrote: ↑September 17th, 2020, 1:00 pm
it will run but it will most likely run the horizontal transistor too hard, I would not do it if it were me
thanks a lot for the reply, which value makes you think that, ohm or mh?
Re: Nanao MS-2930/31 tube compatibility
Posted: September 17th, 2020, 1:15 pm
by grantspain
its both really