WARNING, TEA CONTENT BELOW, RUN AWAY !!! Got my RM17 glowing Tek scope today !
![Cheesy :D](https://www.eevblog.com/forum/Smileys/default/xcheesy.gif.pagespeed.ic.KPzuH4J-TG.png)
It's past midnight, spent 3 hours on the thing, giving the front panel the usual 30 minute in situ cleaning in the kitchen, so that it's half presentable and so I don't die of unknown germs and bacteria.
Packaging as you can see was... well, I am short of words. I just don't know what's going on in people's brain ?!
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
I did tell the guy to take his time when packing it, that I was in no hurry, that all that counted was that it was packaged properly and the front panel well protected.
Guy replied yeah sure no worries, and translated that to : " let me tightly wrap the scope with card board, and oh he said to protect the front so I will tape half a news paper over it ".
Luckily it arrived intact, miracles do happen.
Exterior : - Once the front was cleaned it looked quite decent, happy with it.
- At the back, air filter is inexplicably clean... not complaining.
- There is a cal sticker dated April 1977, so spot on 45 years ! Sure it must be still in cal today !
![Evil >:D](https://www.eevblog.com/forum/Smileys/default/xevil.gif.pagespeed.ic.tdrs7Uj5gu.png)
77 is my birth year so I am not going to say the cal is old, because that would mean I am old too, and I don't feel all that old ?!
![Fighting :box:](https://www.eevblog.com/forum/Smileys/default/fighting0030.gif.pagespeed.ce.H3HVtgjLEV.gif)
- The power socket is... hmmm... well you can see for yourself. Guy soldered wires to all 3 prongs then wrapped them with black electrical tape, which was well melted / cooked all over the prongs.
It was not a lot of fun cleaning that mess, but had to if I wanted to plug the thing and play with it... I managed to get it back to a decent enough shape.
Interior : - Fan looks big ass, different looking and larger than the one in its 317 bench top counter part. Fan was almost seized, could barely turn the blades by hand, not good at all. Dropped a bit of machine oil in the rear bearing and onto the front on the shaft. Exercised the fan by hand for a bit... not much improvement
![Sad :(](https://www.eevblog.com/forum/Smileys/default/xsad.gif.pagespeed.ic.L3FGyzQrjB.png)
- As I had already seen on the sellers pics, it's very dusty, and a thick disgusting layer all over the tubes, but no rust. A good wash should make it all nice and shiny I think, not worried at all.
- As I saw on the sellers pics again... there was a tube missing. Was a 6DJ8. Pinched one from one of my numerous type 317... I figured it's only fitting for a type 317 bench top to donate an organ to help resurrect its rack mount brother !
Electrical / Test drive : - Fan : it did start up somehow, but as expected very, very.. very... slowly. Was rotating at like I don't know... 10rpm tops ?! ... while making a horrible noise, complaining like hell... but hardly surprising.
However...it soon started to improve, progressively getting better and better, and after only a couple minutes or so, it was now rotating super fast, smoothly, no weird noise anymore... like brand new !
![Cheesy :D](https://www.eevblog.com/forum/Smileys/default/xcheesy.gif.pagespeed.ic.KPzuH4J-TG.png)
I guess the oil I put, must have progressively found its way where it needed to go, and it eventually was able to do its job
![Cool 8)](https://www.eevblog.com/forum/Smileys/default/xcool.gif.pagespeed.ic.cOxV6sPNRd.png)
Fan is freaking loud though ! Oh my goodness... it's like a small propeller aircraft taking off !
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif.pagespeed.ce.oZptHNcbsD.gif)
I don't know if that compared to the old HP gear that are notoriously loud too... as I don't have old HP stuff to compare it with.
But it's... TEN TIMES louder than a normal / bench top type 317. Well at least the thing is weeeeeell cooled down, unlikely to overheat !
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif.pagespeed.ce._hfWAz_QHO.gif)
- Controls : I noticed the AC/DC input coupling switch is stuck. Need to investigate that.
Fire up : looking real bad.... no sign of life from any of the controls, and the CRT looked cooked : all it could do was display some green "clouds"... a bit depressing...
However after an hour or two warming up, and me playing with every control, it progressively was able to do more and more stuff, but mostly completely weird and wonderful, psychedelic things. Things you would not even guess a scope could even do. It was... mesmerizing. Great stuff if one just needs a light show in the living room to amuse clueless friends... but not so good if you want the scope to do what a scope is supposed to do...
![Banging Head |O](https://www.eevblog.com/forum/Smileys/default/bangheadonwall.gif.pagespeed.ce.8iLbFYV4Bc.gif)
But the more it was warming up, the more I was playing with the knobs... the better it got. After 2 hours playing with it, its condition seemed to "stabilize", and I could now start taking notes of what worked and what didn't. So here goes :
- CRT / middle section of the cabinet : excellent. Clean bright sharp trace (picture fails to depict its sharpness sadly, but in the flesh it's excellent), that's stable and doesn't fade when hot. It's solid.
Only little "issue" I noticed is the focus control : it has bugger all effect. If you set it half way it gives you a sharp trace no problem, however if you turn the knob side to side it baaaarely goes out of focus. It is incapable of making a thick blurry trace, not even remotely. So I guess something must be amiss somewhere...
- Right side section : trigger works perfectly. Sweep and time base work impeccably too, and the amplifier is still well calibrated, a first glance. If it needs calibrating then it can only be very minor. Baseline is excellent.
- Left side of the cabinet : calibrator output is perfect. Checked it on my Combiscope: stable signal, sharp square, frequency spot on, 980Hz or so, and amplitude is spot on, on all ranges. Combiscope reads 1% high but plenty within spec and well, the automatic measurements aren't even that accurate on that scope to begin with so... I will say the old Tek is spot on.
So I could use the calibrator output to test the scope, so that's what I did.
The problems in this scope appear to be concentrated on the vertical amplifier. It was all over the shop at first, refusing to display a trace at all 99.999% of the time. That was mostly due to the red uncal knob of the attenuator that was super scratchy. Also, the DC balance control was completely out of whack. So once I had exercised the uncal knob a bit, and gone through all of the attenuator settings twice, to adjust the DC balance... I was able to improve things dramatically. Now, it can display the calibrator square wave beautifully, and most ranges are calibrated spot on
![Cool 8)](https://www.eevblog.com/forum/Smileys/default/xcool.gif.pagespeed.ic.cOxV6sPNRd.png)
There are mainly 2 problems to fix, on some ranges :
- On ranges 20 / 2 / 0.2 and 20mV / DIV settings, it fails to display the square wave. Instead, it displays sharp negative and positive pulses. That is, the square wave is like going through an RC "differentiator" circuit. a parasitic one of course ! Must be a simple fix I guess... broken connection, bad contact somewhere...
Since it affects only all the 20/2 etc ranges, the problem must be localized to a decade selector, hence should be able to narrow it down quite a bit in the schematic, I would think.
- On the 3 most sensitive ranges, 50 / 20 / 10mV, which are all AC only, the amplitude of the trace is way too small ! Like 2 or 3 DIV instead of 10, something like that. Also, the trace incessantly moves up and down, like a roller coaster. So me think the AC coupling cap is dead, and passing only part of the signal. Again, should be an easy fix.
ConclusionBought it for only 15 Euros, 22 Euros delivered, sold for parts.... but... it's a WINNER, I say !!!
![Cheesy :D](https://www.eevblog.com/forum/Smileys/default/xcheesy.gif.pagespeed.ic.KPzuH4J-TG.png)
1AM already ! Have not even eaten anything since breakfast !
![Shocked :o](https://www.eevblog.com/forum/Smileys/default/xshocked.gif.pagespeed.ic.CrwtrNUjLO.png)
Let's cook something quick to fill that stomach a bit, and off to bed !!!
Have a good night ! Fasten your seat belt and turn on all your lights please !!!
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif.pagespeed.ce._hfWAz_QHO.gif)
![](https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1468306;image)