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ckrtech

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About ckrtech

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    Chopper Commander

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    Seattle, WA
  1. I picked up a Heavy that needs some work. I opened it up and there are no pads on the difficulty switches. Seems like a safe assumption that someone else was in here at some point, but I thought I would ask if this is potentially normal for some of the units.
  2. Hey guys - I just picked up Reactor. The cartridge door openers are very stiff - enough so that the cart won't sit in the slot on the Atari - it just springs right out of the slot. I would really like to refrain from poking a hole in this cart's label and opening it up in order to take a look at the problem. Anyone have a fix suggestion?
  3. Do you guys know of any variants for overlay art or materials? For instance - I have two Galaxian overlays. One has a white backing and the other is slightly transparent. Both have the same printed text on the back.
  4. Could any of you guys with a 2600RGB installed provide some NTSC screenshots of River Raid and Seaquest - preferably using s-video? River Raid - The middle stripe through the blue helicopter - Should that be darker rather than lighter vs the rest of the body? Seaquest - When the bar starts depleting, isn't it still mostly red on the right side? I have a rather chunky white block on the right side of the energy bar after oxygen starts to go.
  5. Despite the timing of it not working, are you sure your sync signal is soldered well? Also - what happens if you remove chroma from the equation? Even if you don't use s-video, you could move your wire from composite video out to luma out and see if you get a nice black and white signal.
  6. I did a console refresh kit from console5 and used the UAV kit on a 4-switch woodgrain recently. I still saw diagonal lines in the video and was pretty sure they originated from the noisy power - those lines were present with the original regulator as well as the replacement (7805 and higher amp rating). I added some random 220uf electrolytics to both the output of the 7805 and at TIA power->ground pin. Even added a ceramic .1uf to TIA power->ground as well. It greatly reduced the diagonal lines and even eliminated them at times. But I will fire up a solid color background game (like Seaquest) and see them on occasion. I actually have OKI regulators around here somewhere. Maybe I will try one in the 2600. Do you still swear by these? I am also curious which one Tim used in the 2600RGB kit.
  7. 4-switch 2600. Seaquest. Picking up divers causes the screen to darken/brighten with the counting sound effect. Slight, but noticeable.
  8. Any of you guys experience a slight dimming of the video when certain sounds play while using the UAV + Audio companion?
  9. I don't have the foil tape anymore. I believe those static strips that were included with revision 14+ were also available to place on revisions prior as indicated by the service manual. The intention was to cut down on static build up that could discharge and damage the ICs. That said - Again, the power switch doesn't seem to cause much of a difference when wiggled now. The additional capacitors seemed to have at least tamed the wild responses originally observed by wiggling the power switch. Prior to the change, I could also see the waveform change by wiggling the cartridge a little bit as well.
  10. After the capacitors were added to the 7805, TIA, and to the 4.7uf (in parallel) near the RF module, the power switch does not seem to have as much of an effect when wiggled. There is definitely still noise present at TIA pin 20, and I am fairly certain the noise in the power is what is getting picked up and displayed on video output. Fortunately, the noise is not as wild as in the waveform posted above. I am using the term noise rather loosely here. I believe there is both ripple and high frequency noise on the +5v line at the TIA chip. Adding the 220uf cap across TIA Vcc and Vss reduced both the crazy voltage swing in the TIA pin 20 waveform in the post above as well as diminished the strength of what I am seeing in the composite image on the CRT. Eliminating or significantly reducing the high frequency noise seems like the next step... and I assume that means throwing some ceramic decoupling caps at it.
  11. Just to port over a couple of things I posted in the UAV thread, I have attached a video to this post. It shows a PVM displaying composite video from the UAV in the Atari 2600. "Blue only" is enabled on the PVM in order to make the lines easier to see. I toggle color on for a second in the middle of the video. IMG_4988.MOV In addition, I scoped the power at TIA pin 20 as well as the output from the new 7805 regulator. There is (was/still is) serious noise on in those spots. TIA pin 20: 7805: Playing with the power switch did cause the waveform on the 7805 to change a little bit - I had a bunch of 220uf caps lying around, so I placed them across TIA pins 20 and 1 as well as the 7805. It seemed to reduce the noise quite a bit on the scope - and I believe it has reduced the strength of the noise in the image. It could be that I need a little bit better caps or additional caps or something else to get rid of it. I am not quite sure why the waveform changed so much just from jiggling the power switch. The 5 volt line is much more closer to a straight line - or at least with a much lower peak to peak value - than it was prior to the caps. There are still a few spikes in the line, though. I don't have a new waveform image demonstrating this at the moment. Open to additional suggestions. I suppose I could remove the RF modulator in case it is what is producing the interference/noise (in other words - the noise is generated by the Atari itself).
  12. Wow! Check out that noise! TIA pin 20 (500mV per division!) - 7805 output - Fiddling with the power switch with probe still on 7805 - Fiddling a bit more with the power switch with probe on 7805 -
  13. I have some issues (independent of the UAV) in my 2600 video output - the same thing happened with the Longhorn Engineer mod. The console has been refreshed with new caps, new voltage regulator, and new power jack. I have also tried switching power supplies as well as TIA chips. it seems like I am getting some ...interference, perhaps? in the video output signal. I have attached a video of Stay Frosty 2 with Blue Only enabled on my PVM (makes it easier to see). The lines dance around, and I can somewhat push on the power switch and get them to rotate, expand and retract. (by the way - I also cleaned and eventually replaced the power switch). Do you guys know what I am looking at (RF interference of some sort?) and how I might solve the problem? I have a separate thread about it in the 2600 forum, but I thought I would drop a line here since you guys are doing video mods a lot. IMG_4988.MOV
  14. Hmm. Not sure if I have any ferrite chokes to try, but I am not opposed to using them. Do you think there is a specific area that is more prone to picking up the noise? The RF box itself is still in circuit (but not used), but it sounds like noise people encounter is typically from an external source. Did you choke your ac adapter close to the power input to the Atari? Also - how did you wire your composite output internally? Did you use shielded cable?
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