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@@dajo4349 Hello. This B&H scope appears to be the same as Heathkit model IO-4540. I once owned the Heathkit model. Here's a link with schematics: mrmodemhead.com/blog/gallery/io-4540/

@@AllenDaimond-g6i Hello Allen. I have no plans to make another video however, I will answer any specific questions you may have.

I have bought some vacuum tubes from Antique Electronic Supply in the past. Unfortunately, $40 is way too expensive for multiple capacitors in a single package. My channel is self funded which means I have to do projects as inexpensively as possible. For power supply filter capacitors such as these, I replace them with discrete capacitors. It does take up more room but I save a lot of money that way.

I often do as well, however if I want the can caps there and I have the extra money or want it more original looking I'll get the can caps. I've only restuffed the can caps on a device once and that was because the circuit is on a PC board and one side connects to the line. Removed the cardboard cover then cut the cans off right above the base. Threw the cans away, put the new caps on the base then glued the cardboard cover to the base. One won't ever know the caps aren't original.

I generally only replace components that need to be replaced. For example, you may find that many of the carbon composition resistors are still within their tolerance. These can have tolerances of 5%, 10% or 20%. In some cases when changing any of these resistors you have to make sure that their replacements are more than the right ohmic value, wattage and tolerance. Keep in mind that carbon composistion resistors are non-inductive and can handle energy surges better than other resistor types. Therefore, depending on the circuit function you cannot always directly replace a carbon composition resistor with a metal film, carbon film resistor or etc..

Here in the southeast I've seen more bad carbon comp resistors than not and im not a fan of replacing just the bad parts and have it fail later due to an original resistor that was in tolerance but is now out of tolerance. Also for test equipment using 1% resistors may make it more accurate. Lastly I read somewhere where someone did a test on metal film resistors and found them good to several hundred MHz.

@@ikonix360 It depends on the test equipment and what type of environment it was and is stored in. A lot of the older test equipment dating pre 1970's generally has resistors 5% or larger tolerance unless they are used in oscillator or other precision type circuits. The O-scope in this video I believe has at least one 2% tolerance resistor which if memory serves is used in the vertical attenuator circuit. I also remember at least one resistor with a 5% tolerance. I believe the majority of the remaining resistors in the O-scope are 10% to 20%.

@@alslab2764 true. I usually use the 1% metal film given their low cost and ready availability. Where I work, we have some carbon comp in benchstock and it's common knowledge to test the resistor to see if it is in tolerance before pulling it and put it in a piece of avionics.

Thank You!

Thank you 👍

Hello Jared, It depends on the type of capacitor. If it's an electrolytic cap, it could be completely bad or be of diminished capacitance. Either way these should be replaced. Generally, ceramic, mica and certain film capacitors don't need to be replaced as often unless they fail due to a circuit fault. If you do suspect that you have a failed capacitor of these types then you should measure it to verify its health. These old pieces of equipment do use carbon composition resistors that change with age and exposure to humidity. Therefore, if you find resistors way outside of their stated tolerance of 5%, 10% or 20% then you want to change them. It really matters when these resistors are out of tolerance and are used in oscillator and timing circuits. The test equipment will not function properly across all of its operational range. If you haven't done so, please subscribe to my channel. Thanks, Al

@@alslab2764 Fantastic, thank you for the help! I Just subscribed. These scope diagrams are brutal, I guess that's why I've given up on actually trying to diagnose the problem. So the easy way out for me will just be to check caps and resistors.

@@jaredcravens2658Can you tell me the make and model of the oscilloscope? Also, what is wrong with it? Do you get a trace on the CRT?

@@alslab2764 I've got over 10 CRT scopes that show no trace that need repairing. Some have a trace but it's off screen because either the vertical or horizontal deflection plate circuit isn't working. Diagnosing the sweep circuits is the most difficult part for me, those are so complex.

@@jaredcravens2658 I know you will find the issues. My advice for now is to concentrate on one oscilloscope at a time. If multiple scopes have the same type of issue then they may have the same/similar circuit failures. The more you practice troubleshooting the better you will get at it and along the way will learn some circuit theory. Good Luck 👍 Al

Yes, ATARI was originally planning on phasing out the 2600. They were trying to get people interested in buying the 5200.

Thank You! It is made up of three components, the socket, the lamp and the lens. The socket is made by VCC and their p/n is 2802 and can be purchased here: www.mouser.com/ProductDetail/VCC/2802?qs=9GEuPTpyLrgSjrwnKkPGTQ%3D%3D&countrycode=US&currencycode=USD The lamp is made by VCC and their p/n is 120PSB and can be purchased here: www.mouser.com/ProductDetail/VCC/120PSB-?qs=sGAEpiMZZMt82OzCyDsLFAZoiP5Ye8VJsoD95UCKfIc%3D This lamp is made by others also. Just do a google search. The lens is made by VCC and their p/n is 2811 and was purchased here: www.mouser.com/ProductDetail/VCC/2811?qs=9GEuPTpyLrgp9qL1CvqPxQ%3D%3D&countrycode=US&currencycode=USD The lens appears to be obsolete but you may be able to find it on Amazon or eBay. If you have not already done so please subscribe to my channel. Thanks.

@@alslab2764 THANK YOU SO MUCH SIR ! I'LL LOOK UP THOSE PARTS . I LOVE HOW INVENTIVE YOU WERE IN MAKING IT .

The song is from an Atari commericial

I used a Weller pencil soldering iron along with a EDSYN Solderpult (a.k.a. a solder sucker or desoldering pump) since these were through holes parts. I also used soderwick by Chemtronics (desoldering braid) with the soldering iron that also helped to remove solder for the IC pins.

@@alslab2764 I have 160v on c103 and rectifier BD1 is than normal?

@@nick3200 Having approximately 160Vpeak on the output of the bridge rectifier appears to be correct. However, having 160Vpeak across the electrolytic capacitor C3 is not correct. It should be ~300VDC. Not seeing how you are taking the measurements I recommend this. On your DMM set it to measure Volts DC. Then carefully measure the voltage across C3. Remember the potential across C3 is high voltage and is lethal so extra care needs to be taken when taking this measurement.

@@alslab2764 I did it as you sad, still DC 160v on C3. Maybe i have problem with Q601 and Q602

No, I do not. The part of the schematic I had shown in the video was created by me from tracing out the component connections.

Thanks and Hello. The next video will be coming out soon.

@@alslab2764 Fantastic, looking forward to it

this isn't a scott the woz clip, just a snippet of an old atari commercial

Yes, I did. It can be found here: ruclips.net/video/prE-09FXZE0/видео.html

Hello. Yes there is one cable that is for signal and ground(shield). As I mentioned in the video, the inductor keeps the RF modulated video from getting fed back into the DC power supply while the capacitor simulatenously keeps the DC power supply current from getting fed back to the RF modulator or to the TV. You can think of it another way, if these capacitors and inductors were not in the circuit then the RF modulated signal would be added to the DC power supply voltage. Instead of the RF signal having zero volts as its reference it would now have 9 volts as its reference. This means that the RF is elevated by 9 volts and the 9V power supply has this video riding on top its DC output.

@@alslab2764 but how is collision avoided?? Unless both power and rf signals are code in opposite frequencies to avoid collision.

Hello Andrew, I traced the faulty circuit to the LM393 comparator using an oscilloscope. The LM393 has an open collector output. The output of the comparator is tied to the base of the 2N3906 PNP transistor through the 2k Ohm resistor. When the comparator is functioning properly it pulls one side of the 2 K resistor to GND forwarding biasing the Base- Emitter junction of the 2N3906 transistor. The voltage drop VBE across the Base- Emitter junction of the transistor is approximately -0.7 V. When I troubleshot my RF switch I found it was missing the -0.7 V. I want to further mention that I used my oscilloscope to monitor the inputs to the LM393 comparator so I knew that the comparator was getting an input but producing no output. As for the replacement part I already had it on hand. You can buy them from Mouser which I have provided a link below. The part is ~$1 but with shipping it may not be worth buying from them. You can try eBay or Amazon. Make sure you get a DIP (Dual in Line Package) which is a through hole part and not a surface mount type. The “N” at the end of LM393N specifies a through hole part. www.mouser.com/ProductDetail/Texas-Instruments/LM393N-NOPB?qs=QbsRYf82W3EkdH%2F%252BGxxM5g%3D%3D

Thanks for the info and link Keep making great videos!

Thank You. I really appreciate your comments. I will be working on part 2 this fall.

And to you as well.

Thank you.

www.linkedin.com/pulse/have-you-playedrepaired-atari-today-albert-fabrizi/