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I am looking for a front "clip-on" cover for a Tek2225 but they seem as rare as hens teeth - but it occurred to me that a cover from another scope in the 22xx range may fit. Can anyone suggest a

I have had some further observations, not good, I'm afraid. I thought that I would leave the scope in "store" mode and see if any improvement happened. It didn't. When I powered down, left it a while

Hi Gary, The very first thing you need to do is to measure the low voltage test points for DC level and ripple. They are marked on the board. These scopes usually have bad electrolytic capacitors and

Note: this post was initially posted to Tekscopes2. That post has been deleted.

Thanks Shailendra, Cleaning the pots will be the first thing i do when i open it up again. My go-to is Deoxit-5.

Hi, How on earth did they lose the package? Szabolcs Martin Whybrow <martin@...> ezt írta (id?pont: 2020. szept. 22., K, 10:49):

I have faced a similar problem on my 465B. In my case, horizontal sweep used to shrink and expand at random. There was no linearity issue, as calibrator square wave looked uniform across the width of

A fairly robust way of buffering would use a fast PNP transistor and a fast NPN transistor with the bases connected together and the emitters connected together; PNP collector goes to the Vcc supply;

In my ecstasy about the successful revival of my TDS3014B's Ethernet interface using the procedure described above, I forgot to thank those who helped me. Thanks! Raymond

Hi Gary: See, http://w140.com/tekwiki/wiki/465 to download Tektronix's superb and easy to follow (compared to the stuff we get today.) There is a lot of info on the Web about this very popular

John, A bipolar or JFET buffer is quite feasible but the collector (drain) load resistor has to be quite a small value. With the semiconductor turned off the resistor has to charge up 4 gate input

Its probably a bit academic since I have ordered replacement parts, but funnily enough I was just wondering whether a transistor (or JFET) could be used to buffer the output and reduce stress on the

If you don't want to wait that long, you can temporarily add a NPN switching transistor as a simple pulse inverter. Input via 1k to the base, 10k between base and emitter, emitter to ground. Pull up

satbeginner, that is a good point, thank you, but yes, just to confirm 5V and GND were present at the oscillator and the 74S112 chips when I ran the tests. Just another update on the crystal saga (the

I have a 465B/DM44 that is new to me that I think has issues. I am a relative newby to scopes, but this one does not seem right. There is "compression" of the horizontal trace, but it varies.

I'm after the external keyboard for my 7854; I found one at a good price on ebay and bought it, but ebay's GSP managed to lose the package. All the other units are either stupidly priced or the seller

"I hooked it back up to the board using jump leads, powered up the 5V rail but there was no output. I hooked up the sig gen again and got output from both 74S112s. " Do you have the onboard 5V checked

Roger, saw both of those. Decided to go for 74S112's as per original design. These were NOS and 10 pieces for a fiver and local to me. Interesting that your crystal holds its voltage with a 390Ω load

Philips 74HCT112 in 16 pin DIL package are available from a UK seller on eBay at ?2.99 plus 40p postage, not anyone I have bought from but I don't think I have had any dead or fake parts from UK

You may want to check the other variants of the "74" class, such as ACT, and ACHT.? Note that the T = TTL compatibility on the inputs, but TTL to CMOS (straight) does not.? 2.4 volts minimum output