Test Equipment Anonymous (TEA) group therapy thread

[Tomorokoshi]

Vanishing Point...good movie! I especially like the part where he forces that English POS Jaguar into the creek. 

If that's what you're after, "Harold and Maude" also does quite a number on a Jaguar.

[tggzzz]

Yeah the mid-life ham crisis wasn't working out so voltnuttery it is.
...
Also big warning to any potential hams out there - it's scary how much you actually spend on shit and you don't actually realise it until you get screwed off with it and list it all on ebay  ... more money for test gear though.

So, voltnuttery will be a completely different experience. (Cue a snigger from Dick Dastardly)

Oh shit, thought that volt nuttery started with at least 6.5 digits, so if that's not the case, I'm already in that rabbit hole well and truly and that can get as expensive as being a ham I'd have thought, in that case I'd better keep my safety rope firmly attached to something solid to prevent sliding to far into that hole 

In my case the foundations were laid in the early 70s, when school physics practicals required more resolution than we could get from 2% analogue voltmeters. So we used a piece of wire and a weston standard cell to measure voltages to 0.1%. Ergo 3 digit is sufficient.

Just like the herpes simplex virus, voltnuttery erupted decades later when I got an HP3468, then a 1949 weston standard cell, then a Solartron 7075. And those were the gateway drugs in that I couldn't stop there, leading to a Solartron 7081 and Zener based transfer voltage reference and standard resistors, then a 7 decade KVD, then a couple more 7075s,  and a Datron 1061. And all those work pretty well now, even if one 7075 became a parts mule for the other two.

Total cash outlay on that lot: ~£600.

[med6753]

I got the Sony receiver main board out and on the bench. It wasn't as bad as originally thought and I took lots of pictures just in case. Now starts the tedious process of checking the board for cold/cracked solder joints. I already see a few suspicious ones. 

[med6753]

Yeah the mid-life ham crisis wasn't working out so voltnuttery it is.
...
Also big warning to any potential hams out there - it's scary how much you actually spend on shit and you don't actually realise it until you get screwed off with it and list it all on ebay  ... more money for test gear though.

So, voltnuttery will be a completely different experience. (Cue a snigger from Dick Dastardly)

Oh shit, thought that volt nuttery started with at least 6.5 digits, so if that's not the case, I'm already in that rabbit hole well and truly and that can get as expensive as being a ham I'd have thought, in that case I'd better keep my safety rope firmly attached to something solid to prevent sliding to far into that hole 

At 5.5 digits maximum I'm firmly in that rabbit hole too. Just not as deep as the 6.5+ crowd. 

[Specmaster]

@med, that main pcb is a bit more populated then the one on the Kenwood which had a lot going on in the front panel. The area I'd concentrate on is around the centre of the board where I can see the IC's mainly seem to be gathered and the power transistors as they seem to suffer dry/cracked joints thanks to them being mounted to the heatsink while also soldered directly to the main pcb and that area is subject to flexing  from heat and also vibrations. Personally I think that they should flying leads to the PCB from the transistors to absorb that but hey, that costs extra labour 

[URI]

Yeah the mid-life ham crisis wasn't working out so voltnuttery it is.
...
Also big warning to any potential hams out there - it's scary how much you actually spend on shit and you don't actually realise it until you get screwed off with it and list it all on ebay  ... more money for test gear though.

So, voltnuttery will be a completely different experience. (Cue a snigger from Dick Dastardly)

Oh shit, thought that volt nuttery started with at least 6.5 digits, so if that's not the case, I'm already in that rabbit hole well and truly and that can get as expensive as being a ham I'd have thought, in that case I'd better keep my safety rope firmly attached to something solid to prevent sliding to far into that hole 

At 5.5 digits maximum I'm firmly in that rabbit hole too. Just not as deep as the 6.5+ crowd. 

Wait a little, you will dig the hole deeper by yourself.   

Just bought another Agilent 34401A accidentally because the seller accepted my (low) offer. It passes all self tests but seems to need calibration. I don't have to mention that I already have a HP variant of the 34401A and don't really need a second.   
To calibrate it with another meter I think that should be at least a 7 1/2 digit one...       

[med6753]

I've gone thru the board and the only real overt defect I found was an incomplete fillet around a pin of one of the .22 ohm output bias resistors. But I did resolder the output devices, some power amp IC's and the speaker terminals. And a few other joints that looked a little off. Going to put it back together tomorrow and connect up some speakers and burn it in with some loud Zeppelin or Floyd. And see what happens. If it craps out again next step is probably interstage coupling caps. Or maybe get lucky and track down exactly which of the 5 channels is throwing it into protect. I did manage to find a service manual online. I'll tell ya....Sony certainly has let their stuff go to shit over the years. The specs on this unit suck. Several of the rear channels rate their output at 10% distortion. Who the hell listens to music at 10% distortion? Not me and I got tin ears.

Anyway, if it continues to crap out even after some recapping I'm going to tell my Brother that this steaming pile isn't worth any more of my time and to shit can it.   

[med6753]

@med, that main pcb is a bit more populated then the one on the Kenwood which had a lot going on in the front panel. The area I'd concentrate on is around the centre of the board where I can see the IC's mainly seem to be gathered and the power transistors as they seem to suffer dry/cracked joints thanks to them being mounted to the heatsink while also soldered directly to the main pcb and that area is subject to flexing  from heat and also vibrations. Personally I think that they should flying leads to the PCB from the transistors to absorb that but hey, that costs extra labour 

That's exactly the part of the board I checked most carefully and resoldered many joints. 

[URI]

BTW, time nuttery is a deeeeeeep rabbit hole also.      

At the time I have collected two GPSDOs in a box (BG7TBL,amoj1010), three trimble 57963-D and two Samsung UCCM-LP,SE2D608878 (with STP 2878 LF and ublox LEA 6T), uncounted OCXOs and a working rubidium oscillator. All my frequency related gear has a 10MHz reference input (except for the oscilloscopes..).

I experiment with GPS antennas also because I have no good sight of the southern hemisphere so I need better antennas than others with a free sight. So finally I bought a used Nokia active GPS dome-antenna that -unlike all my other active GPS antennas (with magnetic underside for car use)- receives some (1-3) satellites inside a modern, metallised thermo-glass. All the other GPS antennas I have don't receive any satellite inside the window at all.
The Nokia antenna waits for a mount I can put outside the window without drilling a hole or put a screw into something because I'm living to rent.
I'm trying to pimp the GPSDOs with better OCXOs since the GPS-disciplining improves the deviation of the disciplined OCXO...   

[Neomys Sapiens]

The specs on this unit suck. Several of the rear channels rate their output at 10% distortion. Who the hell listens to music at 10% distortion? Not me and I got tin ears.

Maybe it's a special model for consumption of Rap and HipHop?

[Neomys Sapiens]

Re good 'bad' movies, "Dark Star" comes to mind!

Someone heard of 'Liquid Sky'? Unfortunately only ever encountered as a really bad copy.

[med6753]

The specs on this unit suck. Several of the rear channels rate their output at 10% distortion. Who the hell listens to music at 10% distortion? Not me and I got tin ears.

Maybe it's a special model for consumption of Rap and HipHop?

That's not surprising. Shit specs for shit music. 

[Specmaster]

10% distortion is in the realms of unit audio, certainly not true Hi-Fi, that thing really stinks.

[bd139]

10% is fine for rear speakers. If it’s a surround sound box they are mostly there to give you some positional awareness of the sound rather than high fidelity sound. This will mostly negatively affect people with their ears on back to front, pointing the wrong way or wired it up wrong.

[bd139]

Finally got a few minutes to dredge the thread and do some proper replies... wow this thing moves fast!

@mnem / med6753 / bitseeker: taaaaaaaants!

@med6753: re - Sony receiver. I had problems with naff soldering on lots of Sony kit over the years. When I was at university, I was Mr Fixit and was constantly inside Sony stuff. That looks a bit newer but typically same problems. Another problem with Sony was they used to solder the wires directly to the board and they'd wick up solder and slowly fall to bits. Looks like they got that fixed in the end.

@specmaster / @mnem: had a look at the T12. Looks like the tip went short and took the MOSFET with it. MOSFET shorted gate to drain now. Fixable at least! Not too happy about the failure mode. It had a 5A auto fuse in line with it but the MOSFET is clearly a faster fuse by far.

@tautech: still haven't looked at that home made scope thread yet. One day! Have added it to the interesting links to look at while pooping list I have on my phone

@SilverSolder: I like the antenna suggestion

@Brumby: Sharknado. Don't even go there   Now I understand how the thread went onto sci-fi films!

@VK5RC / @wch: Right in the middle of a densely populated bit of London here so have lots of similar noise problems. There's something that moves back and forth over 20m and it's not in my house. I've turned *everything* off. Good news for TEA at least indeed.

@mnementh: Lego Movie has to be one of the best films ever if you ask me. I may actually go and see Lego Movie 2 this week (on my own)

@Kosmic: that electrometer is rather nicely put together. Gives me that warm fuzzy feeling looking at it like HP power supplies.

@tggzzz: on dune ... Dune cannot be compared to Farage. Talking of which, some nice Farage wallpaper here: https://imgur.com/a/GHVQ87Q

@tggzzz: on ham radio vs voltnuttery ... yes it's a money sink (what isn't in life!) but it seems like voltnuttery is less sociable so suits me

@Specmaster: I think voltnuttery starts at 6.5 digits and cruises to a ruinous 8.5 digits. 5.5 is good enough territory. But you need a 6.5 digit meter at the very least to cal a 5.5 ... Hmmm

@tggzzz: on RF ... very interesting with the sub-mW radar. Will read into this. Already have this bookmarked http://lea.hamradio.si/~s53mv/vnr/design.html

@URI: already on timenuttery. Have two counters with OCXOs now. Which means two problems that need solving

[bitseeker]

'll tell ya....Sony certainly has let their stuff go to shit over the years. The specs on this unit suck. Several of the rear channels rate their output at 10% distortion. Who the hell listens to music at 10% distortion? Not me and I got tin ears.

To which specs are you referring, output wattage? If so, that's marketing nonsense that's been going on for some time in order to claim higher wattage numbers. Even audio IC datasheets do that. Silliness.

[beanflying]

Wait a little, you will dig the hole deeper by yourself.   

Just bought another Agilent 34401A accidentally because the seller accepted my (low) offer. It passes all self tests but seems to need calibration. I don't have to mention that I already have a HP variant of the 34401A and don't really need a second.   
To calibrate it with another meter I think that should be at least a 7 1/2 digit one...       

Yes! Yes you do need 7 1/2 digits I think @Inverted still has a shiny month old Keithley 7510 for sale

or

I am about to send my pair of Agilent 6 1/2's (34401A & 34461A) off to Keysight for a Calibration as one has never been and the other is out by a few years. When they get back the pair used in tandem will give me an improved level of certainty to go over the rest of my 6 1/2 digit and PPM level gear is the plan to bring the fleet closer to the 'truth'.

[tggzzz]

@tggzzz: on dune ... Dune cannot be compared to Farage. Talking of which, some nice Farage wallpaper here: https://imgur.com/a/GHVQ87Q

Successful in his previous expoits, so he has now moved on to similarly successful exploits on a larger state. Yes, I do mean "exploits"

But, yes, there is a direct comparison between Farrago and Dune-the-Movie-1984. OTOH, the first and third books were good, and the later miniseries was tolerable.

[bd139]

Yes. Fear not for the fate of Farage. There are some pretty high profile people after his skin at the moment I understand.

I may have been on a bit of a Sean Young thing then so I am excusing myself

[Specmaster]

@tautech: still haven't looked at that home made scope thread yet. One day! Have added it to the interesting links to look at while pooping list I have on my phone

Haha, is this just a male reserve I wonder, I know I tend to do that or play a game or even respond to messages, seems to concentrate the mind I think 

[tggzzz]

Yes. Fear not for the fate of Farage. There are some pretty high profile people after his skin at the moment I understand.

I may have been on a bit of a Sean Young thing then so I am excusing myself

Forgiven

Personally I preferred Jessica Annis in Doon, and Sean Young in Blade Runner.

The scuttlebutt is that Morrison's will be employing extra security staff from the 17th.

[worsthorse]

I thought about getting into HAM at some point but then realized I don't really want to talk to anybody 

That's interesting. Same thought. I used to listen to AMer's on 3.885MHz and those guys were real "rag chewers". Key down for 15 to 20 minutes at a time some interesting topics but mostly bullshit. I quickly came to realize that a lot of these guys had big egos that liked to talk and project themselves as real important. I'm not like that. I'm a person of few words and to the point.     

Yep, me too, at parties I'm the wallflower, not much good at smalltalk 

IMX, amateur radio seems to have an above average blowhard and bullshitter density. But I've also met a lot of truly generous and funny people. I am not much of a talker, nor do I have an appetite for bullshit, so my OTA time is related to community service and experimentation/learning, and it has been a great way to do both.

[worsthorse]

I finally picked up the two HP 3478A meters I found on CL. I didn't need the HP power supply but I bought it, too, because I didn't really need two more DVMs either, right?  I wasn't able to do much more than plug them in to see if they passed the self test before I brought them home but I got them for a good enough price that it was worth the chance.



Within 0.3mV of one another. Not bad. One of them had a cal sticker from 1995 and based on the previous owner's remarks, that's probably the last time they were calibrated.

Now, off to search the forums and see what other folks have done with these things. And though that way lies madness, I caught myself thinking, "I wonder if I should look for a calibration source.

[med6753]

I finally picked up the two HP 3478A meters I found on CL. I didn't need the HP power supply but I bought it, too, because I didn't really need two more DVMs either, right?  I wasn't able to do much more than plug them in to see if they passed the self test before I brought them home but I got them for a good enough price that it was worth the chance.



Within 0.3mV of one another. Not bad. One of them had a cal sticker from 1995 and based on the previous owner's remarks, that's probably the last time they were calibrated.

Now, off to search the forums and see what other folks have done with these things. And though that way lies madness, I caught myself thinking, "I wonder if I should look for a calibration source.

And there goes another one. 

[bitseeker]

I finally picked up the two HP 3478A meters I found on CL. I didn't need the HP power supply but I bought it, too, because I didn't really need two more DVMs either, right?  I wasn't able to do much more than plug them in to see if they passed the self test before I brought them home but I got them for a good enough price that it was worth the chance.



Within 0.3mV of one another. Not bad. One of them had a cal sticker from 1995 and based on the previous owner's remarks, that's probably the last time they were calibrated.

Now, off to search the forums and see what other folks have done with these things. And though that way lies madness, I caught myself thinking, "I wonder if I should look for a calibration source.

Very nice find, wch. You got one of each: early- and late-model. Packaging-wise, I prefer the early ones.

As for what others have done with the 3478A, check out:

https://www.eevblog.com/forum/projects/project-extending-hp3478a-functionality/

and

https://www.eevblog.com/forum/testgear/hp-3478a-rom-modification-relative-mode/