+scorpio_ny Posted March 23 Share Posted March 23 1 hour ago, Jfcatari said: Nice,,,maybe i am not crazy..So we might be on to a crystal issue! Do you have atari crystal to test with? I have but not had a chance to swap out Unfortunately, I do not have one available. Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 24 Share Posted March 24 @scorpio_ny One question When you tested the composite on the tube TV, did you have JP 7 installed? This is need for composite to work. I want to make sure we have an apples to apples setup, even though I see you are not using a GITA. Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 24 Share Posted March 24 3 hours ago, Jfcatari said: @scorpio_ny One question When you tested the composite on the tube TV, did you have JP 7 installed? This is need for composite to work. I want to make sure we have an apples to apples setup, even though I see you are not using a GITA. @Jfcatari Yes, I made sure that JP7 was installed. I have an old school Dell 2007 monitor with multiple inputs too. I will check to see if it has composite only input and test it with that too. 1 Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 24 Share Posted March 24 (edited) Thanks for confirming and testing this as well. I will try to swap out the crystal today and retest. I have been trying to track this down for a while and would love to know the answer. This issue around composite is not a big deal, but I would like to know the answer. The svideo output is much better than composite! Edited March 24 by Jfcatari 1 Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 24 Share Posted March 24 1 hour ago, Jfcatari said: Thanks for confirming and testing this as well. I will try to swap out the crystal today and retest. I have been trying to track this down for a while and would love to know the answer. I tried it with my Dell 2007 monitor. Same issue: composite output shows only B/W, so the issue is not related to just to CRT’s. 1 hour ago, Jfcatari said: This issue around composite is not a big deal, but I would like to know the answer. The svideo output is much better than composite! Same! I have Svideo and a Sophia 2 installed in mine but, I would to know why as well. 1 Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 24 Share Posted March 24 (edited) I am at my bench now. I will pull the crystal we are both using and swap in an Atari. Brian used a CO61090 from a donor in this build/ I have both a CO61090 from an 800XL and I also have a new CO16010 that I got from Bradley at Best Electronics. Here is what Bradley lists The CO61090 is no longer available. Edited March 24 by Jfcatari 1 Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 24 Share Posted March 24 (edited) @reifsnyderb @scorpio_ny After swapping crystals around in the 800XL Remake. I found the answer we have been looking for. The one from digikey: B/W on composite to tube TV Atari CO16010: I get color but rolling on the tube TV composite. Atari CO61090: I get PEFECT color on the tube TV composite. I hope some of the experts might be able to weigh in here? Edited March 24 by Jfcatari 2 Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 24 Share Posted March 24 because it's a different frequency it's right in front of your eyes Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 24 Share Posted March 24 (edited) 41 minutes ago, _The Doctor__ said: because it's a different frequency it's right in front of your eyes Yes, but I have seen some crystals with caps soldered across them? So can a CO16010 be 'patched' to make it work like the CO61090? Edited March 24 by Jfcatari Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted March 24 Share Posted March 24 (edited) https://techoverflow.net/2021/07/26/how-to-tune-your-crystal-oscillator-to-get-the-best-possible-frequency-accuracy/ explains quite a bit, there are a number of tutorials but many don't take load into consideration consider it an adjust by slight, but a tuning fork can only be stressed so far before it's no longer resonating at the right frequency. You crystal is a tuning fork by all accounts. Edited March 24 by _The Doctor__ Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 25 Share Posted March 25 Thanks for sharing information on crystals and tuning. I am only a novice here and looking for help and patience. Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 25 Share Posted March 25 (edited) I was just checking Mouser, and it seems that they do sell the crystals at the correct frequencies we are looking for: https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=10d31ecbcc Is there any other criteria we should look for in the clock crystal? I am willing to order them to see if they work. Edited March 25 by scorpio_ny Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 25 Share Posted March 25 (edited) Too Funny, I just found the same at Mouser. https://www.mouser.com/ProductDetail/IQD/LFXTAL016962Bulk?qs=e4%2FAndAAwgKhrM9s7PL%2F3w%3D%3D I don't know enough if that will work with a Load Cap of 30pF. They are cheap enough to test with at 50 cents This is the one from Digikey that only produced B/W on composite video using a tube TV (18 pF) https://www.digikey.com/en/products/detail/cts-frequency-controls/MP036S/67661 Edited March 25 by Jfcatari Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 25 Share Posted March 25 I looked at the specs on the other, @scorpio_ny found. This looks closest to the Atari https://www.mouser.com/ProductDetail/549-CY3DM Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 25 Share Posted March 25 1 hour ago, Jfcatari said: I looked at the specs on the other, @scorpio_ny found. This looks closest to the Atari https://www.mouser.com/ProductDetail/549-CY3DM I just placed an order for this component. When I get it I will try it out and report back. I am hoping this would be a viable new replacement for part #CO61090 since it not available from Best. 2 Quote Link to comment Share on other sites More sharing options...
Jfcatari Posted March 25 Share Posted March 25 I just ordered the same to test with as well. I have 600XL's and 800XL's with both Atari CO #'s to test with. 3 Quote Link to comment Share on other sites More sharing options...
olix Posted March 27 Share Posted March 27 I think I have found a switch for the Rom bank (RF switch) SW1 that will fit. Not perfect, but I think it will work: Apem 25536NA6 Mouser No: 642-25536NA6 The switch has the correct pin spacing and fits into the motherboard but it is a little smaller. However, the switch length should be long enough. Unfortunately I can't test this as I only have PAL Ataris and they don't have a cut-out in the case for this switch. 2 Quote Link to comment Share on other sites More sharing options...
Chrisa850 Posted March 28 Share Posted March 28 (edited) On 3/25/2024 at 7:46 AM, Jfcatari said: I looked at the specs on the other, @scorpio_ny found. This looks closest to the Atari https://www.mouser.com/ProductDetail/549-CY3DM It appears from looking at a factory schematic that the oscillator may be a Pierce-gate design optimized to use a series resonant crystal. You would normally *not* use a crystal requiring an 18 or 20pF load capacitor in that design. Load capacitors are commonly used in parallel resonant Colpits oscillator design where a capacitor is placed directly across the crystal to force the crystal to resonate at the proper frequency. I see no such capacitor in the 800XL design. Has anyone tried a series resonant crystal like an ECS 35-S-1X? https://www.mouser.com/ProductDetail/ECS/ECS-35-S-1X?qs=CNVyLAqdhH3RajNnZxGUjg%3D%3D Edited March 28 by Chrisa850 Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 28 Share Posted March 28 1 hour ago, Chrisa850 said: It appears from looking at a factory schematic that the oscillator may be a Pierce-gate design optimized to use a series resonant crystal. You would normally *not* use a crystal requiring an 18 or 20pF load capacitor in that design. Load capacitors are commonly used in parallel resonant Colpits oscillator design where a capacitor is placed directly across the crystal to force the crystal to resonate at the proper frequency. I see no such capacitor in the 800XL design. Has anyone tried a series resonant crystal like an ECS 35-S-1X? https://www.mouser.com/ProductDetail/ECS/ECS-35-S-1X?qs=CNVyLAqdhH3RajNnZxGUjg%3D%3D Looking at the spec for the linked item, the frequency does not seem correct. The Atari XL spec is 3.57945 MHz Quote Link to comment Share on other sites More sharing options...
olix Posted March 28 Share Posted March 28 I think that the component has exactly the right frequency: 3.579545 MHz I don't know where you looked, but in the original Atari Service Manual and in many other sources the crystal Y1 is described with exactly this frequency and not with 3.57945 MHz Quote Link to comment Share on other sites More sharing options...
Chrisa850 Posted March 28 Share Posted March 28 (edited) 46 minutes ago, scorpio_ny said: Looking at the spec for the linked item, the frequency does not seem correct. The Atari XL spec is 3.57945 MHz The NTSC color burst frequency is 315/88 = 3.579545MHz. I have used 3.579545MHz in every Atari I have ever had to change a crystal in, including an 800XL I serviced last month. The error in frequency from what is written in the manual is .00003MHz, which is within the NTSC color burst tolerance. Even Console5 uses them as a replacement for 2600 and 800XL. https://console5.com/store/atari-2600-ntsc-color-crystal-oscillator-c015510-replaces-3-579575-mhz.html Since the NTSC color burst appears to be the issue in question, I would try using the exact NTSC color burst frequency and see what the results are. Edited March 28 by Chrisa850 Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 28 Share Posted March 28 47 minutes ago, Chrisa850 said: The NTSC color burst frequency is 315/88 = 3.579545MHz. I have used 3.579545MHz in every Atari I have ever had to change a crystal in, including an 800XL I serviced last month. The error in frequency from what is written in the manual is .00003MHz, which is within the NTSC color burst tolerance. Even Console5 uses them as a replacement for 2600 and 800XL. https://console5.com/store/atari-2600-ntsc-color-crystal-oscillator-c015510-replaces-3-579575-mhz.html Since the NTSC color burst appears to be the issue in question, I would try using the exact NTSC color burst frequency and see what the results are. Hi @Chrisa850, The spec for the other frequency came from the part listing from Best Electronics which seems to be a typo on the page. As for using the part, I thought I did. I used the following part: https://www.digikey.com/en/products/detail/cts-frequency-controls/MP036S/67661 Svideo works for color but not composite. @reifsnyderb had a similar experience as well. Can you give us some insight to why this is an issue? Thanks! Quote Link to comment Share on other sites More sharing options...
olix Posted March 28 Share Posted March 28 OK, I understand. Best-Electronics has been an important source for Atari stuff you can't find anywhere else for many years, but its website and listings are not necessarily a trustworthy source of information. I even wrote to Bradley Koda at Best Electronics years ago about this fault with the frequency of C061090, but unfortunately he never replied or corrected the list. Quote Link to comment Share on other sites More sharing options...
Chrisa850 Posted March 28 Share Posted March 28 1 hour ago, scorpio_ny said: Svideo works for color but not composite. @reifsnyderb had a similar experience as well. Can you give us some insight to why this is an issue? Thanks! You would need a good understanding of the NTSC RS-170A video standard and how the color burst reference is used for subtractive color. I'm not surprised that S-video (Y/C) works correctly as the chroma channel isn't "composited" on the luminance channel, making reference to the color burst signal much less critical. Quote Link to comment Share on other sites More sharing options...
+scorpio_ny Posted March 28 Share Posted March 28 @Chrisa850: So, since the composite signal is mixed on the same channel, the signal ratio is much more critical, correct? @Jfcatari: I received the new crystals and it did not work. Interestingly, the frequency was actually correct. There seems to be a typo in the Mouser listing. I tried it and I got the same result. Let me know if you have the same results. I ordered the part that @Chrisa850 referenced from Console 5 to see if that one works. Quote Link to comment Share on other sites More sharing options...
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