!!! BREAKING NEWS !!!
Vintage HP Scope 120B : I managed to get it in the end !
"Seller"/donator replied to me when I asked why he cancelled the deal. Said " it makes no sense to ship it to the other end of the country to recycle it ! "
What ?! RECYCLE IT ?! What the hell is he talking about now ?!
So he gave it away thinking someone would recycle/sell its 14kg worth of metal ?!
Uhhh... so I replied to him that I meant to RESTORE it and breathe life back into it, which sounded a much more enviable proposition for this little scope, than the prospect of being melted for its metal !!!
I thought he would either not reply to that, or tell me to fuck off, as most people do... but guess what, he said "oh, you sound really interested then !!! OK I agree to ship it to you then.. but are you sure you are OK to spend 100 Euros for the shipping ? It's bloody heavy and big ! "
Uh again.... shipping is only 12 Euros... yes I am willing to pay 12 Euros to rescue that piece of HP history !
I received the scope this evening... packaged badly as always. Zero packing / protection on top, bottom, left or right sides ! A tiny bit of packing at the back, and half decent packing where it matters the most, luckily, at the front !
Somehow the scope was 100% intact, a miracle.
So that's it, I have my first piece of HP equipment ! My first HP scope lost in a sea of Classic Tek scopes ! Hope the Tek won't attack him when I am not home !
Great surprise inside : NOT all tubes have been stolen ! 19 tubes in all, 11 have disappeared, so almost half of them are still in place !!!
Looks like the guy stole only the very few tube types that he thought would interest the audio guys : all the 6DJ8 (x3) and 12AU7(x5). These I had figured by now that the audio people loved them. However he also stole the 6U8 (x3). Didn't know that one was of interest to the audio guys. I take note...
But all the others he left inside :
- 6AQ5 : Glad, because I have only one I could use, so would rather hang on to it !
- 6AU6 : have lots of these anyway
- 12B4A : great, because I had none of those. Only an older vanilla 12B4, and not that many of them.
- 6C4 : COOL -> was the only one I had none at all of ! Was cheap anyway, but once shipped it would still have cost me 10 Euros or so at the least. So, glad I can save 10 Euros.
- 5642 - rectifier tubes for the CRT HV
- 5651 : voltage regulator tube. That one looks toast (all black inside... not too promising), but all my Tek scopes use the same regulator tube, so no worries, plenty to chose from !
So looks like replacing the missing tubes should free of charge and straight forward. Nothing to buy. So this little scope might come back to life pretty soon ?!
It looks in need of a lot of cleaning and love, but it's in great nick overall so should look pretty good once I am done with it ! Lots of labour involved though, so won't happen overnight. Needs to be 100% stripped and patiently cleaned and refurbished. Lots to do. Looks like it sat for decades, definitely the kind of scope that will go BOOM if I dare to power it without taking precautions... need to check the caps, transformer. dig out my dim bulb tester, or look for a variac. Scope is low power so maybe I can find a cheap old used low power variac... will have a look around.
I think I have already found what I could do with it : its abyssal 450kHz , oops sorry, 450kc bandwidth, is hopeless. However, it's got a large CRT, a cool retro look, practical banana jacks instead of BNC or UHF connectors as inputs. Has an external horizontal amplifier input, so could be turned into an XY scope I guess. Also, it has a Z input, and located at the front to boot, which is rather uncommon, it's usually hidden at the back !
So it's pretty useless as a scope, but would male a beautiful and very practical XY display machine, for all sorts of XY goodness, me think !
So that's the plan for this little thing.
Looking inside, I found at least one thing blatantly wrong with it : a couple Sprague electrolytic caps (see close-up pic) that look tired, very tired, shall we say, as an euphemism....
They are nothing vital for the operation of the scope though. Looked them up in the schematic. Part of the trigger circuitry. The two caps are identical in value, 40uF, mounted in series, and form a non-polarized 40uF cap. If I read the schematic right, they are bypassed when you set the trigger to ' AUTO ', and in circuit/active otherwise. So as a first step I could just remove them and still be able to get a trace on the screen when first trying to revive the scope.. Then I can buy new caps when I am in the final stages of the restoration and I put everything 100% right.
Other than that, as far as discovering my first HP piece of gear, I would say it's always fun and interesting to discover how HP made its stuff compared to Tek back then. This HP scope is nothing like a contemporary Tek, but it's nothing to be ashamed of. Very rugged and good looking case/chassis, attention to detail. Inside, top quality PCB rather than Tek's ceramic strips. HP definitely loves shiny stuff : the inner/invisible side of the top and bottom covers are 100% covered int gold ! Well, not gold obviously, must be whatever plating that looks like Gold, but still, looks rich !
Also, the top cover has a large schematic printed on it, representing a top view of the instrument, detailing where all the trimmers and tubes are, and what they do !
Inside, the PCB and and wiring harness don't look as sexy as a Tek scope for sure, but that nice printed "gold" top cover looks the part, and the main transformer looks nice as well. It too, has a nice schematic printed on it ! Detailing the various windings with voltage levels and pinout.
HP also has " a thing " with branding ! Either too much ego, or the other way around, a complex of inferiority.. that led them to put 'hp' logos all over the place, in rather unexpected places ! Found all the feet at the bottom of the unit, had hp logos on them. the CRT, which has an internal graticule (cool thing in itself), has not one but TWO 'hp' logos AS PART OF THE GRATICULE itself !!!!
The neck of the CRT is held in place with a clamp that looks just like what I would find clamping the main radiator hoses on my car's engine !
I thought this can't be legit..... but looking closely, it might well BE !
Clamp reads "made in .... PATENTED 34564XTZ "
Also, has an IEC power socket at the back ! Now this can't possibly be factory for that old a scope.... though the socket itself looks bloody old, judging by the type of plastic it's made of. Shiny and hard/brittle, like bakelite, must be an extremely early IEC socket, like, marketed the very same day that the IEC socket was introduced !
Still, I like that, so practical. I just hate devices with cords sticking out, it's a mess.
This scope is real nice to sum it up.. only let down, strangely, by surprisingly, shockingly cheap looking and feeling plastic knobs and jacks at the front ! What where HP thinking ? Contemporary Tek scopes were 2 steps ahead, much prefer their knobs.
A few piccies below.
So all in all, I am so glad I "bought" this free scope. For only 12 Euros shipping, I got myself a beautiful piece of vintage HP gear, my first one ! I am a bit excited... sorry. So much joy for so little money, it's not often these days ! I am glad I saw it, and insisted to persuade the owner to ship it to me even though he didn't want to at first...
Will be more than happy to restore it, well worth it, deserves it. Will be proud of owning this little gem once it's all working and shining again ! It SO did not deserve to die !!!
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Topic: Test Equipment Anonymous (TEA) group therapy thread (Read 35894617 times)
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