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Post by barclay66 on Jul 6, 2017 11:11:52 GMT -5
Hi,
Check U32 (74AC86). It's the only single IC involved. All other switching for red, green and blue is done with separate ICs (U13, U19, U25). If one of them failed You would only be missing the corresponding color of the internal video (not likely that all three fail at the same time)...
Regards, barclay66
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Post by barclay66 on Jul 5, 2017 3:40:08 GMT -5
Most likely the VIM is acting up, Try an other VIM. Yes. Most likely the VIM where the video is being switched. Another possibility would be the CLM where the menus and test patterns are being generated. The least probable element would be the backplane where the VIM and the CLM are plugged into (contact problem). It would be wise checking the VIM's and CLM's edge connectors though... Regards, barclay66
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Post by barclay66 on Jun 6, 2017 4:20:38 GMT -5
Hi,
Would it be possible to switch the red/green focus connectors? That could be used for ruling out either the electronics (after switching, the problem stays with the red) or the tube/deflection system (after switching, the problem moves to the green)...
Regards, barclay66
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Post by barclay66 on Jun 1, 2017 9:22:14 GMT -5
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Post by barclay66 on May 20, 2017 10:06:56 GMT -5
Hi,
I have a universal programmer that surely will work. The question is just what pinout the device has. I have DIL and PLCC-44 Adapters...
Regards, barclay66
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Post by barclay66 on May 18, 2017 9:24:40 GMT -5
Thank You for this insight. I always thought that anything beyond 20kHz or digital stuff was a bit like voodoo because of effects that can be ignored at LF and this circuit surely reassures me on that. ;-)
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Post by barclay66 on May 18, 2017 7:05:18 GMT -5
Q12 isn't really limiting bandwidth indeed since most of the time it is working in common base mode which is the highest bandwidth mode a transistor can be used. Hi, I don't know if I understand the circuit around Q19/Q12 correctly, but as it seems Q12 doesn't carry the video signal at all. It only modulates the amplified video with auxiliary signals (coming from a slow MC34072). Another candidate for Q12 could be the 2SC5551 (30V, 300mA, 600mA peak, 1.3W, 3.5GHz)... Regards, barclay66
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Post by barclay66 on May 18, 2017 3:16:14 GMT -5
Hi,
Quite some nice achievement! Just for curiosity:
The 2SC3613 is quite big. How did You fit it onto the SMD pads? Wouldn't a SMD type be even better (less capacitance/inductance)? I thought of using the BFG35 (4 GHz, see datasheet). What do You think? As far as I can see, Q12 can be let alone as it hasn't any influence on bandwidth, correct?
Regards, barclay66 Attachments:BFG35.pdf (283.69 KB)
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Post by barclay66 on May 15, 2017 3:05:55 GMT -5
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Post by barclay66 on May 3, 2017 4:03:23 GMT -5
Hi,
As far as I know, for blending two Barcos at least one of the machines will need the COG (convergence on green) board. Lets assume that we have Barco1 (without COG board) and Barco2 (with COG board). The overall setup should be as follows:
- All electronic settings on both Barcos set to midpoint (i.e. nulled) - Mechanical and optical setup on Barco1 - Mechanical and optical setup on Barco2 (including raw adjustment of blend zone) - Electronic setup of geometry based on the green grid on Barco1 - Electronic setup of geometry based on the green grid on Barco2 - Fine adjustment of the blend zone and remaining grid on Barco2 using the COG menu - Adjustment of red/green and blue/green convergence on Barco1 - Adjustment of red/green and blue/green convergence on Barco2
At least that's how I would do it.
Regards, barclay66
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Post by barclay66 on Feb 7, 2017 6:28:24 GMT -5
I am playing with AD8009 OP amps in place of the HFA1100. Once I am happy with them I will send a set of boards to Casey to compare. These amps have much better slew rate and a bit more and width. Hi,
I will be doing something similar with Marquee Neck Boards soon. Instead of the CLC449 (or HFA1100 on older boards) I will be trying out the AD8009, the LMH6732 and the OPA695. To me, not only the slew rate but especially the 0.1dB bandwidth is crucial. I've made a comparison chart and to me the AD8009 seems to have a weak point with its low 0.1dB bandwidth. The OPA695 looks much more promising...
OP Overview.xlsx (10.79 KB) Regards, barclay66
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Post by barclay66 on Dec 12, 2016 5:19:15 GMT -5
Guys, Yesterday I changed MP VNB with a different VNB (old type on blue & VDC VNB on green & red). Since the picture is still dim, I decided to adjust the contrast on Moore V3 HDMI card by turning counterclockwise. By doing this, I'm able to get the brightness level and I'm quite glad now. The only worry I have is that if I change back another VIM, the setting on Moome card is all wrong and I'm not sure how to adjust it back to the correct setting of 0.7v. Glad You got it working! Don't worry too much about the 0.7V. Did You record the number of turns You made? Just turn the same amount back. It should bring You close enough to the original value. For a precise measurement, an oscilloscope will be needed... Regards, barclay66
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Post by barclay66 on Dec 8, 2016 7:18:15 GMT -5
I think it would be difficult to return the VIM back as I have replaced the RCA connectors unless I can find the same original connector and resolder them back. Too bad. Sorry, but that investment won't yield anything valuable. You still might try to arrange something with Mike Parker directly. Good Luck! If You are desperately in need of a VIM, I have some spares (untouched stock boards). Do you have plan to come over in Singapore or Malaysia again? If yes, I could pass both VIM and VNB to you. Maybe we can manage to spend our Easter holiday in Malaysia. Not quite sure about flights and budget yet. Regards, barclay66
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Post by barclay66 on Dec 8, 2016 4:05:25 GMT -5
Pictures of VIM02. This one is completely different...
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Post by barclay66 on Dec 8, 2016 4:04:28 GMT -5
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