Tektronix 222 user manual

I have no affiliation with them, but definitely recommend them. The sections that I printed out were very clear, including the schematics.

Just sharing this because I see someone mentioned it is similar to the A quality video, especially in regards to the battery. It should be available for download or available as a CD. His prices are extremely fair and his service is fantastic. Good troubleshooting!

Is more easy to modify scope charger circuit to charge lithium battery. What were your modifications? BTW, at least the was originally lead-acid gel, not NiCad. The trick is modify charger to Supply 4,2 volt max for element, and modify main power supply to work with voltages at lithium range, 3.

The Tektronix has a lead battery, and it haves a lead voltage temperature compensation that must be cancelled to work with lithium. For security I only use batteries with internal protection. Io wrote: Tried TekWiki? The ideal configuration seems to be using 2x Lithium cells. I have a and mounted a 2-cell holder into the battery cavity and it fits quite well with room to spare. By mounting the holder first on a purpose size cut PC board I am able to make it press-fit securely just right so no screws or new holes where needed.

The mounting on the PC board was actually an afterthought because I had to cut the battery holder in half in order to stretch it a bit so the battery cells with build-in protection that are slightly longer would fit into it lengthwise. For a time some years ago there was a seller on ebay that was offering a 2-cell battery pack kit specifically for the 22x scopes and included detailed instructions on how to implement the charging process internally at the correct voltage by modifying a couple of resistors.

But I don't think it has been available any longer for a good amount of time. In any case its very easy to do it yourself. With Lithium batteries to cut-off at that level it is too early as there will still be usable power left in the cells without harming them.

The scope cut-off point is determined by a simple two resistor voltage divider that feeds the CPU and comprised of two K SMD resistors. The cut-off happens when the CPU input pin sees 3. The desired new specific cut-off point depends on the type of Lithium battery chemistry that you choose, as nominal cell voltages vary a bit.

But basically all that is needed is to adjust the top K resistor of the divider with a somewhat higher value to lower the cut-off point. I still have not finished this project its been on hold now for the better part of 2 years and only got as far as installing the battery holder and to take the voltage readings in order to figure out how the internal low voltage cut-off circuit behaves.

I also put a special Schottky "smart diode" with only 0. So I have yet to modify the resistor of the voltage divider in my scope, but I intend to set it to cut-off when the new Li battery pack reaches 6. I have over time learned more about Li batteries and have revised my plans and will eventually install a 2S 2-cell charging board which I already have received some weeks ago for an unrelated project and that will allow the scope to automatically charge the batteries directly when plugged into AC.

Said charging boards and cell protector boards are both widely available off ebay and very easy to implement. Maybe this thread is what I needed to revive interest in finishing this project. In an effort to maintain full output, a fixed wattage, with a lower supply voltage, the current in the transformer primary and switching transistors will rise. Bruce, KA2IVY I never saw or felt any problems when I extensively ran the scope on the Lithium batteries to determine approximate run times, shut off voltages, etc.

After all where are talking about running the scope between 8. If there is any difference in current it seems to be small enough that the circuit can easily handle it without any complaints.

I seems silly not to take full advantage of the capacity of the new batteries to extend run times. However I did not take a deep dive into this issue nor at the time did I even think about it being a potential problem, so if anybody has recommendations in regards to it, would be good to know.

We will be driving back to Spain coming Friday, so next week I can dive in my unit. Still not sure if the A schematics can be used for my , but I will update on the matter next week.

A minimum recommended VCC voltage of 7 V is recommended for operation, but if the VCC voltage drops below 6 V during operation, then the device shuts off. See Electrical Characteristics for additional information regarding the undervoltage lockout circuitry.

Its 84 pages and about 24MB. Can't remember now where I got it from. I also have the A and A SMs that I purchased from Artek some time ago and I would highly recommend getting from them as the quality is excellent as usual. This one is also on TekWiki and does not contain schematics. I have the Component Level Manual with schematics for internal use and I just scanned it.

It could be found here for some time: www. This cannot be undone. The Group moderators are responsible for maintaining their community and can address these issues. Quote from: timb on October 12, , am. I'm sorry I dishonored your family or kicked your dog or whatever the hell I did to make you so obsessed with me. We had an eBay transaction they didn't work out. You got the item back in as good or better condition than it was sent originally.

I got a refund and paid return shipping. Transaction over, okay? This is not normal behavior. Christ on a fucking cracker. By the way, I am familiar with high voltage; I used to have a bunch of gear including scope probes but it went missing after my move earlier in the year. To Tim etal Supposedly the schematics for the were never released by Tektronix - probably considered proprietary - the attached drawing shows the only differences I could find between the two on the High Voltage Power Supply which was the object of our attention.

Tim, the bodge resistor - what ever that is - was R and R added, photo shows where trace was cut to the Intensity pot to allow the addition. Tim you should take it easy on that cracker - I imagine it is getting soggy. Fraser Super Contributor Posts: Country:. An interesting little thread for me. I own several of the mini Tektronix scopes including the , , and A. It was a pity that the in this thread failed but at least it was a simple fault that did not involve some rare IC.

Failure to do so invites refusal of a refund no matter how harmless the activity may have been. I have done this on occasion and have yet to be refused permission to look inside for obvious transit induced faults. I also advise the seller of my skill-set and responsibility for any damage I cause. I am a long term ebay buyer, and sometimes a seller. Having spoken to many sellers in recent years it is very apparent how many unpleasant people buy on ebay. Many sellers warn that they seal and secuity mark their products.

The reason? Their are many cases of buyers stealing or swapping parts out of a unit to repair their own faulty unit or deciding they do not like the unit and deliberately placing a fault on it as an excuse for a refund. I am NOT suggesting that anything wrong occurred in this transaction BUT it may explain why a seller is concerned aboiut refunding a unit that has been opened by a buyer.

When it arrived it did not receive anything. The buyer reported the issue and asked me if I had another or could repair the unit. He obviously trusted me and wanted a mint condition R at a reasonable price.

I received the R back from teh buyer and sadly he had left the lifting bale in the up position causing damage to it and the underside of the receiver. The fault was the I bought an original ICOM replacement crystal.

Fitted it and fitted a new Bale and lower case cover. I carried out a full specification check and frequency calibration of the receiver and it performed flawlessly. The buyer was overjoyed with the receiver and the repair work that I had carried out. I never told him of the transit damage caused by hos error with the Bale. I trusted him and he trusted me. On this occasion we were two gentlemen of good morals. That is not always the case sadly. It keeps everybody happy and avoids misunderstandings.

The seller may even volunteer to repair the unit at no cost Oh and that blackening on the PCB is unlikely to be charring. A rub with a finger will normally remove it! The high voltage attracts dust to the PCB and such a sight is very common inside TV's and oscilloscope high voltage boards. The dust is convected dirt so is often black. A pcb that has suffered arcing on the surface or within looks quite different. I speak from experience.

Quote from: Aurora on December 19, , pm. Sorry, I am no expert on the internals. Mine is working fine so I have not been inside it yet. I had not realised that the unit was sold by you as "S or R". You are obviously a very honest seller and declared the unit as having an issue. Pretty fair to buyers in my opinion.