| View previous topic :: View next topic |
| Author |
Message |
gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
|
 Link Posted: Tue Jan 20, 2015 3:53 pm Post subject: |
 |
|
THS3201 goes up to +/- 7,5V (additional regulator required) but it has 1,8GHz bandwidth at unity gain.
THS3001 stands +/-15V and has 420MHz BW at unity gain
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
|
|
| Back to top |
|
 |
koldby
Joined: 07 Feb 2007
Posts: 126
Location: Denmark
TV/Projector: GJAKY modded VDC marquee 9500lc ultra
|
| Link Posted: Tue Jan 20, 2015 4:02 pm Post subject: |
|
|
I know.A lot of opamps have great bandwith and could be used with PS regulation, but if the Sony requires higher swing out , it dosent work.
Uups didnīt see the last line. I will check that out. Thanks
|
|
| Back to top |
|
|
gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
|
| Link Posted: Tue Jan 20, 2015 4:31 pm Post subject: |
|
|
| koldby wrote: | | but if the Sony requires higher swing out , it dosent work. |
Then why not calculate, the tube is quite open at 150V G1-K voltage, so that is the goal, the VPA15H has a gain of 15, the VPH06 has a gain of 29. If both swing 75V the input voltage is still 5,5V for the VPA15H, so even a +/-7,5V opamp would drive the ciruit.
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Link Posted: Tue Jan 20, 2015 4:49 pm Post subject: |
|
|
| koldby wrote: | One more thing.
I have not been able to find current feedback op-amps with 300+ Mhz BW AND +/- 12 V ps..? (substitute for el2160) |
el5166
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
|
| Link Posted: Tue Jan 20, 2015 5:12 pm Post subject: |
|
|
| Nashou66 wrote: | | dvh99 wrote: | | koldby wrote: | One more thing.
I have not been able to find current feedback op-amps with 300+ Mhz BW AND +/- 12 V ps..? (substitute for el2160) |
el5166 |
Yeppers!!!
Nashou |
Nope...
| Description: |
|
| Filesize: |
41.72 KB |
| Viewed: |
4418 Time(s) |
|
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
dvh99
Joined: 25 Dec 2009
Posts: 2158
Location: nederland
|
| Link Posted: Tue Jan 20, 2015 5:33 pm Post subject: |
|
|
lol was just planning to write the same comment.
lt1083 would be nice.
_________________
1 answer always poses multiple questions.
marquee 9500ultra HD10L moome hdmi1.3 v3+ some mods.
|
|
| Back to top |
|
|
koldby
Joined: 07 Feb 2007
Posts: 126
Location: Denmark
TV/Projector: GJAKY modded VDC marquee 9500lc ultra
|
| Link Posted: Tue Jan 20, 2015 11:23 pm Post subject: |
|
|
| gjaky wrote: | | koldby wrote: | | but if the Sony requires higher swing out , it dosent work. |
Then why not calculate, the tube is quite open at 150V G1-K voltage, so that is the goal, the VPA15H has a gain of 15, the VPH06 has a gain of 29. If both swing 75V the input voltage is still 5,5V for the VPA15H, so even a +/-7,5V opamp would drive the ciruit. |
Sorry I donīt have the tube data so hard to calculate that.
But thanks for doing that for me!
I agree with all of you it is easy to reduce the voltage for the opamp and very easy to find a suitable opamp @12V Vcc - Vee.
By the way that brings the question up again: Why use a VPH06 for the G1 drive if only75 V p-p is needed?
As Sony did just that I assumend they needed higher swing p-p from G1 to Cathode.
|
|
| Back to top |
|
|
gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
|
| Link Posted: Wed Jan 21, 2015 7:37 am Post subject: |
|
|
| koldby wrote: | By the way that brings the question up again: Why use a VPH06 for the G1 drive if only75 V p-p is needed?
As Sony did just that I assumend they needed higher swing p-p from G1 to Cathode.
|
As I already said the videopack is highly stressed in inverted mode. The VPH06 at 115V supply isn't stressed as much as a VPA15H would be under the same circumstances, but there might be differences in performance of course. One should calculate the slew rate (V/us) of the two ics, that would tell how they are related to eachother.
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
|
|
| Back to top |
|
|
koldby
Joined: 07 Feb 2007
Posts: 126
Location: Denmark
TV/Projector: GJAKY modded VDC marquee 9500lc ultra
|
| Link Posted: Wed Jan 21, 2015 10:58 am Post subject: |
|
|
Sorry for my ignorance, gjaky.
I am new in the CRT circutry business, so I am learning.
What you originally said was, that Sonys reason for using VPH06 is that it is a more rugged type than VPA15h, and it can better handle the stress put upon it in iverse mode (dosent get as warm).
Pls forgive me for asking stupid questions and now again:
Then why not use VPH06 i both places?
_________________
What is home theater without good sound?
|
|
| Back to top |
|
|
gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
|
| Link Posted: Wed Jan 21, 2015 11:44 am Post subject: |
|
|
So I did the math again... 
The VPH06 has about 15kV/us SR, the VPA15H has about 26kV/us (theoretically), so the VPA15 still quite better in this regard, calculating further, the VPH06 in its application has a BW of about 90MHz, assuming the VPA15H really does 150MHz, take the average of the two and voila there you get the advertised 120MHz bandwidth LOL. Of course this is only based on the output stage of the neckboard, all additional stages makeing the BW worse... The marketing guys wouldn't let write the truth in the brochure anyway
Otherwise it is also suspicious that the previous generation of the sony CRT line also used VPH06 (sony 127x) and VPA15H (sony 1292), it very well could be they had too much leftover from these ics, so they decided to build around these. Or someone accidentally mated the old schematics and the G70 was simply born then
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
|
|
| Back to top |
|
|
koldby
Joined: 07 Feb 2007
Posts: 126
Location: Denmark
TV/Projector: GJAKY modded VDC marquee 9500lc ultra
|
| Link Posted: Wed Jan 21, 2015 12:27 pm Post subject: |
|
|
| gjaky wrote: |
Otherwise it is also suspicious that the previous generation of the sony CRT line also used VPH06 (sony 127x) and VPA15H (sony 1292), it very well could be they had too much leftover from these ics, so they decided to build around these. Or someone accidentally mated the old schematics and the G70 was simply born then |
a treacherous thought 
But very likely as the G90, witch to my knowledge came out at about the same time, uses the (hard to get difficult to find data on) VPJ15 instead. Why not use that in G70 ?
Too expensive? Harder to tame?
|
|
| Back to top |
|
|
Marsman
Joined: 11 Mar 2015
Posts: 1
|
| Link Posted: Wed Mar 11, 2015 6:47 am Post subject: |
|
|
I don't do much Projectors anymore but there are 2 versions of the Video output Boards 1 is what looks like Sony custom heat sink darker grey funny looking fins.The other looks like a normal heat sink with 2 VPa15h's .I just scrapped a G70 bad tubes that has the 2 VPa15h's in it.I looked at the same idea some time ago i had both versions of the boards here & tried putting in a VPA15h it but the picture didn't look right.I looked at the board with the 2 VPa15h's & the was many component value changes.That's why some G70's look a bit sharper than others.
Michael
|
|
| Back to top |
|
|
|
|
Forum FAQ
Search
Memberlist
Photo Albums
Register
Profile
Private Messages
Log in
