¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
Date
Free TWD 120
My "new to me" TWD120 arrived today. Thank you Charlie. As Charlie advised in previous email, it did not pass self test, leaving the front panel LED unmistakably solid red. However, the repurposed IBM
By Thomas Garson · #171743 ·
Re: 535 in the Colonies, for only 3,000 CDN pesos
https://www.kijiji.ca/v-general-electronics/calgary/oscilloscope-tektronix-antique-type-535a/1525295543 guess lockdown has made some people a bit silly.
By Snappy · #171742 ·
535 in the Colonies, for only 3,000 CDN pesos
If you are in the environs of Calgary, or just plain rich, and intent on getting a 535.... there's one for sale there, for just 3,000 CDN. And the ad says, it comes with a cart that tilts too! What a
By Roy Thistle · #171741 ·
Front cover for 2225 ?
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
By David Slipper · #171740 ·
Re: 7623A Storage problem
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
By Colin Herbert · #171739 ·
Re: 465B Horizontal Trace Issues - Help requested
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
By Tom Miller · #171738 ·
Re: 465B Horizontal Trace Issues - Help requested
Note: this post was initially posted to Tekscopes2. That post has been deleted.
By @Sabrefencer · #171737 ·
Re: 465B Horizontal Trace Issues - Help requested
Thanks Shailendra, Cleaning the pots will be the first thing i do when i open it up again. My go-to is Deoxit-5.
By @Sabrefencer · #171736 ·
Re: Looking for calculator keyboard for 7854
Hi, How on earth did they lose the package? Szabolcs Martin Whybrow <martin@...> ezt ¨ªrta (id?pont: 2020. szept. 22., K, 10:49):
By Szabolcs Szigeti · #171735 ·
Re: 465B Horizontal Trace Issues - Help requested
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
By Shailendra Krishan · #171734 ·
Re: Is my Tek 468 beyond repair?
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;
By SCMenasian · #171733 ·
Re: TDS 3000B-family 'scope (TDS 3014B) has problem with LAN interface
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
By Raymond Domp Frank · #171732 ·
Re: 465B Horizontal Trace Issues - Help requested
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
By Roy Thistle · #171731 ·
Re: Is my Tek 468 beyond repair?
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
By Roger Evans · #171730 ·
Re: Is my Tek 468 beyond repair?
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
By John · #171729 ·
Re: Is my Tek 468 beyond repair?
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
By satbeginner · #171727 ·
Re: Is my Tek 468 beyond repair?
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
By John · #171726 ·
465B Horizontal Trace Issues - Help requested
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.
By @Sabrefencer · #171725 ·
Looking for calculator keyboard for 7854
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
By Martin Whybrow · #171724 ·
Re: Is my Tek 468 beyond repair?
"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
By satbeginner · #171723 ·