Looks good, thanks for sharing your work, classic Tek. ?
"what is a classic Tek?"
the answer follows the definition of Stan Grifiths from vintage Tek in Oregon.
see
http://reprise.com/ash/clients2/classic.aspSo we can say that Tek 453/454 was the last true classic Tek made from them.
453, 454 have not one integrated circuit, they are fully discrete made with transistors. It was the time of the highest quality made from Tek ever. Later Types using IC, also it was the begin of "low cost engineering", a lot of plastic parts, plastic fronts instead of anodized aluminium, IC and transistor oftenly not in sockets, and so on. There was some high classified Tek where they continue the high quality engineering (see 7k line with 4 slots), but also the typical low cost Tek, like a 465, 475 and so on. Good instruments of coarse, but made with a look to the money.
greetings
Martin
MaritnM, I will freely admit my Tek ignorance, thanks for the information, I found also found the tek-wiki interesting on a brief visit (probing my Tek ignorance)
Still the 485 looks a nice scope and good to see it being saved from the scrap heap, I must admit my only Tek is a 2246 (fully working).
The webpage I linked in is not one of my repair/restores. Just some data I am compiling for my near future restorations of 3 Tek 485's I have sitting on my shelf currently (along with 465, 465B, and soon 453/454 & 7000 series). I will happily start threads for these restorations, as well as others for all of the Cal gear for said scopes that I am collecting. Most recent thread in progress is the 067-0532-00. (awaiting order of resistors, caps, etc)
https://www.eevblog.com/forum/repair/tektronix-067-0532-00-repairrefurb/Thanks for the interest, though. I will link in those threads and any web pages I compile of the builds if you would like.
I personally still consider the Tek 485 to be a classic instrument, as it's the top end of the 400 series. The 465 (with discrete vert out amp) is a definite classic. The 468 certainly is not - although I do repair them as well. ( I used one as my Tek scope repair learning platform since it is of no major classical/historical importance! ) The "500 series enclosure" style of cal-gear is definitely a true classic, of which I have several - 106, 184, 191, 284, '0502, etc) But I've get to get into the total & complete classics of the REAL tube equipment.... soon, soon.. :-)
yeah ... look to get a 517 "big daddy"
greetings
Martin
A little mini-guide here:
How to fix encoder knob on Agilent 33220A
1. Take the whole generator apart. Separate the front panel PCB from the plastic front panel.
2. Carefully bend up the tabs holding the encoder together. Do not bend them farther than just enough to lift the top cover off!
3. With a 1mm flat head screwdriver, carefully bend the wiper contacts a smidgeon upwards. Only a little is usually enough.
4. Optionally, wipe the encoder disc with a clean paper towel. Take care not to leave any traces of paper or other crud from outside in there.
5. Put it all back together.
This is how I got mine to work anyway. The problem is usually NOT the ADC located in the back corner of the main board, as many people seem to think.
No worries, I saw this post, it has a few other good suggestions, worth a look.
I've watched his video about 20 times and I swear I cannot see what he did to make the spring work right. Whatever he does is out of the camera. I've watched the spring flex before and after the "fix" and it looks like it acts the same. If there is any difference it sure is small. All I hear is the difference in sound that indicates it works better. I may have to try what I can however, because all the switches on my 5334B are hard to push.
xrunner, have a look at https://www.eevblog.com/forum/repair/hp-5335a-non-working-enter-key/ the last posts. You have to bend the strip a bit beyond that the button does to get a smal prebend on the strip. As I found out one doesn't need to take the strip out .
Regards
Thanks,
I've torn apart my beautiful 5334B to attempt this fix. What I've been doing is taking out the piece of metal and flipping it upside down and also flipping top to bottom. That works really well - the buttons work like new. I may not finish it today but I'm going to do every single one and get it over with. I'll post how I'm doing it in the other thread.
This fix is
not easy, especially for the buttons in the middle of other buttons. Be aware of this if anyone wants to attempt this!
By the way - I could not find a socket that would fit the nuts on the front BNC connectors - I had to mask off the panel around the nuts and use a 14mm wrench - ugh. Is there a socket that fits it? The flats have an oddly small area ...
xrunner - why keep your solution sticky? Move it to the thread to keep the knowledge gathered in one place as the way you did it is already documented by me
. Good to hear it worked for you too but one doesn't need to remove the stick - just bend it in place as described in the thread.
Thanks and regards