Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 14562352 times)

Jambalaya, Mortymore and 29 Guests are viewing this topic.

Offline worsthorse

  • Super Contributor
  • ***
  • Posts: 1237
  • Country: us
  • aina varma, usein väärin
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26850 on: March 09, 2019, 06:16:04 pm »


med, my 475A has been running without complaint since i bought it in late 2017. but i can't leave well enough alone, so i am getting ready to tear it down, clean it up, and replace what needs to be replaced (as soon as i finish the pile of TMxxx plug-ins that are *almost* done).  since i don't wish to do this twice... is this a "better safe than sorry, replace the tantalums while you're in there" situation?

The beaded tantalums in the series 465/465B/475/475A have a nasty habit of shorting which results in minor explosions and magic stanky smoke. Each of these scopes has an excess of about 40+ of those bastard tants just waiting to ruin your day. It's damn near impossible to get them all but I did just submit an order for about 30. I would recommend if your going to clean up your 475A that you at least change some. And the most important one is C1318 (47uf) on the input side to the HV oscillator.

got it.  i hope to use this beast for another fifteen years and wish to avoid spontaneous displays of smoke and light while i do, so i will add that to my list of must-to-do rework.  thanks.
specialization is for insects.
 

Offline med6753

  • Super Contributor
  • ***
  • Posts: 11313
  • Country: us
  • Tek nut
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26851 on: March 09, 2019, 06:44:40 pm »
Next on the repair agenda. My Brother's Sony STR-K840P Receiver. It goes into intermittent speaker protect mode. I suspect a cold solder joint on either the output devices or the regulators. Very common issue with these late 1990's /early 2000's receivers. I tired flexing the main board with power on but so far still working.

Sony and the other audio manufacturers have gone cheap on their designs. Used to be there was a bottom plate you could remove to gain access to the backsides of the boards and check the solder connections. No more. That board and all the interconnects has to come out in order to access the backside. I've heard that many repair shops will refuse to work on them because of that. I don't blame them. But I'm gonna give it the old college try.  :-DD

   
An old gray beard with an attitude.
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26852 on: March 09, 2019, 06:50:45 pm »
FFS my sodding T12 just blew its arse out. Looks like the MOSFET on the controller exploded.

Sitting in the garden doing RG58 terminations at the time. Thus fuck this, going to go and buy a new extension reel and will run metcal out there
Hmmm... what can I say except that both of mine are still performing well, I'm very pleased with them. I'm glad that I went down your route with the mini unit that you had to provide power source for. Self contained was the right way there I think [emoji106]
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline beanflying

  • Super Contributor
  • ***
  • Posts: 7358
  • Country: au
  • Toys so very many Toys.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26853 on: March 09, 2019, 08:13:57 pm »
Those brackets turned out really well, bean. Bravo!
The only hard part was guesstimating the 30 angles on the verticals where I got lucky first time around. That and I metricated the hell out of HP's decimal inches :horse:  >:D

30 minute print at 0.1 layer and $0.25 of filament. Value $ plenty

That's EXACTLY the kind of application I see FDM filling for a long time to come. Parts where its inherently rough finish don't matter, or can be integrated into the overall design aesthetic like these clips or my HDD Bay bracket. Now if I could only really master SOME CADD program for the making...  :palm:

Such 30 angles and many other aspects of a design are easily expressed in a programming language with variables/parameters - i.e. not squishy draggable wireframes.

My preference is for OpenSCAD, since it is free, widely available, and there are many useful libraries available (e.g. creating glyphs from fonts, parameterised screwthreads etc).

I'm also beguiled by some of the constraint satisfaction languages, but I haven't used them in anger to see where they do/don't work.

Fusion and in particular this design was done with constraints. There is a bunch of // parallel ones in use to keep it all in check as per the initial sketch below. Changing the angle of either arm now the design is fairly much a case of change the 870 to something else unless another constraint borks the shape.

You can for dimensions and initial parametric design use math function for setting dimensions so dimX/2 or 150/2 would work.
Coffee, Food, R/C and electronics nerd in no particular order. Also CNC wannabe, 3D printer and Laser Cutter Junkie and just don't mention my TEA addiction....
 

Offline mnementh

  • Super Contributor
  • ***
  • Posts: 17541
  • Country: us
  • *Hiding in the Dwagon-Cave*
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26854 on: March 09, 2019, 08:46:04 pm »

    Next on the repair agenda. My Brother's Sony STR-K840P Receiver. It goes into intermittent speaker protect mode. I suspect a cold solder joint on either the output devices or the regulators. Very common issue with these late 1990's /early 2000's receivers. I tired flexing the main board with power on but so far still working.

Sony and the other audio manufacturers have gone cheap on their designs. Used to be there was a bottom plate you could remove to gain access to the backsides of the boards and check the solder connections. No more. That board and all the interconnects has to come out in order to access the backside. I've heard that many repair shops will refuse to work on them because of that. I don't blame them. But I'm gonna give it the old college try. :-DD
   
Hmmm.... I'm looking at those big filter caps on the (HI) & (LO) rails. That plastic sleeve shrunk away indicates they've been running hot for a while; high ESR/increased ripple from/indicated by this is also a common cause of that fault, until the finals/preamp drivers or STKs go short or leaky.

mnem
*More than the sum of my voltage differentials*
alt-codes work here:  alt-0128 = €  alt-156 = £  alt-0216 = Ø  alt-225 = ß  alt-230 = µ  alt-234 = Ω  alt-236 = ∞  alt-248 = °
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28142
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26855 on: March 09, 2019, 08:53:17 pm »
For that HP clip Bean, although you have the dimensions in mm I can see them screaming at me in imperial.  :-DD

You must see that too.....1"= 25.4, 1/2"= 12.7, 1/4"=6.3, 1/8"=3.15 and 1/16" that should be 1.6mm.

Are they worth tweaking closer to the HP designers original measurements ?
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 23018
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26856 on: March 09, 2019, 08:53:51 pm »
Well what a shitty day I've had. Got up this morning, thought to myself, hey I'll put my antenna back up now I've got an antenna analyser. So I go out the back (i rarely go in the garden) and one of the border trees has bent slightly onto the property boundary which is where I was going to put up my antenna. FFS. So I thought bugger it I'll do it anyway and just work around it. So antenna goes up, which took three hours due to the tree logistics.  And that's when it all started to go to crap. Went to tune up the antenna and the best SWR I could get was 3:1 across any frequency which is in no way anywhere near acceptable for a simple 40m dipole. Bloody fecking trees are too close to the antenna now. So I put the tuner on it and tuned this out. 6W out WSPR for an hour and I got two contacts in Sweden which is shit. Put antenna analyser back on it after that and it's got even worse at 8:1 SWR. Awful! So I go out and look and half the aforementioned sodding bastard tree has fallen off and taken half of the antenna with it. So I pulled the whole fucking thing down. Feed and balun undamaged but it trashed about 10m of antenna wire.

Gah I think I might be done with this until I move house. I am seriously considering selling all my ham gear and going full TEA until I move which is going to be a couple of years off at the very least at the moment. Got a pile of cash tied up in this which could be spent on less frustrating things.
 

Offline mnementh

  • Super Contributor
  • ***
  • Posts: 17541
  • Country: us
  • *Hiding in the Dwagon-Cave*
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26857 on: March 09, 2019, 09:03:43 pm »


*Click-chirp-chirp* "FREQUENCY MODE...!"

Yup. This still works.  :-DD

mnem
 :popcorn:

alt-codes work here:  alt-0128 = €  alt-156 = £  alt-0216 = Ø  alt-225 = ß  alt-230 = µ  alt-234 = Ω  alt-236 = ∞  alt-248 = °
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 23018
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26858 on: March 09, 2019, 09:04:41 pm »
yeah 2m is ok. I still have luck on that with a shitty antenna  :-DD

Edit: actually the people on 2m here are arseholes  :--
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28142
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26859 on: March 09, 2019, 09:07:14 pm »
Ero-Shan's got a magic eye watching us, now. ;D
Sorting through a box of old tubes and stumbled on one I have.
Anyone want it for a project ?

Ordinarily i'd be tempted to say "ME!" but i'm too busy working on my novel or working myself half to death for profit.

Magic eyes are so cool, but I had to resist as well. Too much in the queue! *sigh*
Just for neo, an RCA 6U5 plus base and ~300mm leads

-snip-

Pulled from a then very old valve receiver.....decades ago.
Glass envelope slightly loose in base.
Filament checks OK @ 5.7 ohms

Consider me tempted. No really, i've given everyone else a chance and i got a project in mind (that may or may not take 6 months to get around to).
Got a PM from neo..........the 6U5 magic eye is now his...........we'll sort delivery out privately.  :)
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline mnementh

  • Super Contributor
  • ***
  • Posts: 17541
  • Country: us
  • *Hiding in the Dwagon-Cave*
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26860 on: March 09, 2019, 09:08:13 pm »
yeah 2m is ok. I still have luck on that with a shitty antenna  :-DD

Edit: actually the people on 2m here are arseholes  :--
Yes, but the BS:J Ratio is off the hook.  ;)

mnem
 :bullshit:
« Last Edit: March 10, 2019, 12:19:36 am by mnementh »
alt-codes work here:  alt-0128 = €  alt-156 = £  alt-0216 = Ø  alt-225 = ß  alt-230 = µ  alt-234 = Ω  alt-236 = ∞  alt-248 = °
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 23018
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26861 on: March 09, 2019, 09:22:53 pm »
Random TEA related thing again. Going through my archive photos I found these pictures. They are of a home built scope. Not built or seen by me unfortunately.

Thus proving, where there is a will, there is a scope  :-DD







 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28142
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26862 on: March 09, 2019, 09:32:11 pm »
Random TEA related thing again. Going through my archive photos I found these pictures. They are of a home built scope. Not built or seen by me unfortunately.

Thus proving, where there is a will, there is a scope  :-DD

Yeah well:
https://www.eevblog.com/forum/projects/oscilloscope-under-construction/
« Last Edit: March 09, 2019, 09:37:24 pm by tautech »
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28142
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26863 on: March 09, 2019, 09:36:07 pm »
And this one from GK too:

Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 23018
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26864 on: March 09, 2019, 09:41:59 pm »
Now we're talking!

Got a copy of "build your own oscilloscope" floating around. Hmm summer project? Sure I have a VCR139A or 3JP1 CRT somewhere as well.
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28142
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26865 on: March 09, 2019, 09:49:34 pm »
Now we're talking!

Got a copy of "build your own oscilloscope" floating around. Hmm summer project? Sure I have a VCR139A or 3JP1 CRT somewhere as well.
Have a hunt through GK's topics for some inspiration.  ;)
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26866 on: March 09, 2019, 10:09:27 pm »
Next on the repair agenda. My Brother's Sony STR-K840P Receiver. It goes into intermittent speaker protect mode. I suspect a cold solder joint on either the output devices or the regulators. Very common issue with these late 1990's /early 2000's receivers. I tired flexing the main board with power on but so far still working.

Sony and the other audio manufacturers have gone cheap on their designs. Used to be there was a bottom plate you could remove to gain access to the backsides of the boards and check the solder connections. No more. That board and all the interconnects has to come out in order to access the backside. I've heard that many repair shops will refuse to work on them because of that. I don't blame them. But I'm gonna give it the old college try.  :-DD

   
TBH that design layout is typical of all the newer audio gear that I've come across, the whole PCB stands on about 5 or 6 pillars and just the act of plugging those interconnecting leads can place the joints under tremendous stress as the sockets tend to sit between pillars thus allowing the board to flex when inserting the plugs  :palm:
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline Specmaster

  • Super Contributor
  • ***
  • Posts: 14483
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26867 on: March 09, 2019, 10:11:32 pm »
Random TEA related thing again. Going through my archive photos I found these pictures. They are of a home built scope. Not built or seen by me unfortunately.

Thus proving, where there is a will, there is a scope  :-DD








Wow, I've also seen these photos before somewhere, I wonder what bandwidth it was.
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 23018
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26868 on: March 09, 2019, 10:22:53 pm »
Probably <1MHz looking at it.

Now we're talking!

Got a copy of "build your own oscilloscope" floating around. Hmm summer project? Sure I have a VCR139A or 3JP1 CRT somewhere as well.
Have a hunt through GK's topics for some inspiration.  ;)

I will indeed. Thank you  :-+
 

Offline beanflying

  • Super Contributor
  • ***
  • Posts: 7358
  • Country: au
  • Toys so very many Toys.
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26869 on: March 09, 2019, 10:23:55 pm »
For that HP clip Bean, although you have the dimensions in mm I can see them screaming at me in imperial.  :-DD

You must see that too.....1"= 25.4, 1/2"= 12.7, 1/4"=6.3, 1/8"=3.15 and 1/16" that should be 1.6mm.

Are they worth tweaking closer to the HP designers original measurements ?

As it is a hybrid one piece instead of the original two there is a but of cludge factor involved  ;) There is also some practical things related to 3D printing with say the PCB slot width that I increased from 1.6 - 1.8 to save post filing. The printer tolerance and the STL 'approximation' of the drawings actual dimensions produce a working result is the important bit.

Good 'nough 4 'stralia  ;D
Coffee, Food, R/C and electronics nerd in no particular order. Also CNC wannabe, 3D printer and Laser Cutter Junkie and just don't mention my TEA addiction....
 

Offline Neomys Sapiens

  • Super Contributor
  • ***
  • Posts: 3268
  • Country: de
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26870 on: March 09, 2019, 10:30:56 pm »
Next on the repair agenda. My Brother's Sony STR-K840P Receiver. It goes into intermittent speaker protect mode. I suspect a cold solder joint on either the output devices or the regulators. Very common issue with these late 1990's /early 2000's receivers. I tired flexing the main board with power on but so far still working.

Sony and the other audio manufacturers have gone cheap on their designs. Used to be there was a bottom plate you could remove to gain access to the backsides of the boards and check the solder connections. No more. That board and all the interconnects has to come out in order to access the backside. I've heard that many repair shops will refuse to work on them because of that. I don't blame them. But I'm gonna give it the old college try.  :-DD


Yes, this construction is truly disgusting. Especially as the connectors are the typical consumer quality and the PCB is sometimes not easy to extract even with the wires gone.
When I work on such stuff for friends and it doesn't have a very solid commercial reason like a collectors item yielding 4 digits, I tend to cheat. Last one was a amplifier of similar construction. two mosfets gone - after localizing them, I cut a square out of the bottom and fitted a little lid over it after performing the repair. Another brought in a amplifier of a bit higher class (H-K, if I recall it right, but I am not very attached to this stuff) where the protection circuit was continually off. I found that of all the components involved, a little 220/12V transformer, which was part of the protection circuit's supply, had a secondary open. I located the primary and secondary tracks, cut them open and scabbed a better transformer on a prefabricated PCB onto the side with a adequately secured wire harness. repair time 30 min after diagnosis.
 

Offline med6753

  • Super Contributor
  • ***
  • Posts: 11313
  • Country: us
  • Tek nut
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26871 on: March 09, 2019, 10:41:16 pm »
Well what a shitty day I've had. Got up this morning, thought to myself, hey I'll put my antenna back up now I've got an antenna analyser. So I go out the back (i rarely go in the garden) and one of the border trees has bent slightly onto the property boundary which is where I was going to put up my antenna. FFS. So I thought bugger it I'll do it anyway and just work around it. So antenna goes up, which took three hours due to the tree logistics.  And that's when it all started to go to crap. Went to tune up the antenna and the best SWR I could get was 3:1 across any frequency which is in no way anywhere near acceptable for a simple 40m dipole. Bloody fecking trees are too close to the antenna now. So I put the tuner on it and tuned this out. 6W out WSPR for an hour and I got two contacts in Sweden which is shit. Put antenna analyser back on it after that and it's got even worse at 8:1 SWR. Awful! So I go out and look and half the aforementioned sodding bastard tree has fallen off and taken half of the antenna with it. So I pulled the whole fucking thing down. Feed and balun undamaged but it trashed about 10m of antenna wire.

Gah I think I might be done with this until I move house. I am seriously considering selling all my ham gear and going full TEA until I move which is going to be a couple of years off at the very least at the moment. Got a pile of cash tied up in this which could be spent on less frustrating things.

Tell the neighbors to piss off and hang that 40M sucker on roof out in open so they can bitch and moan about it. It's your freaking house.  :-+ :-DD
An old gray beard with an attitude.
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 23018
  • Country: gb
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26872 on: March 09, 2019, 10:44:16 pm »
Tell the neighbors to piss off and hang that 40M sucker on roof out in open so they can bitch and moan about it. It's your freaking house.  :-+ :-DD

Gah can't go over the roof unfortunately. Not enough length over the property. Plus right at the front there's bastard EMI pissing LED street lamp  :-- :-- :--

Going to:

1. Piss around with test gear and not much else now.
2. When I move buy something I can get a full porcupine farm in and a moat full of alligators to keep the complainers out.
 

Offline med6753

  • Super Contributor
  • ***
  • Posts: 11313
  • Country: us
  • Tek nut
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26873 on: March 09, 2019, 10:44:26 pm »

    Next on the repair agenda. My Brother's Sony STR-K840P Receiver. It goes into intermittent speaker protect mode. I suspect a cold solder joint on either the output devices or the regulators. Very common issue with these late 1990's /early 2000's receivers. I tired flexing the main board with power on but so far still working.

Sony and the other audio manufacturers have gone cheap on their designs. Used to be there was a bottom plate you could remove to gain access to the backsides of the boards and check the solder connections. No more. That board and all the interconnects has to come out in order to access the backside. I've heard that many repair shops will refuse to work on them because of that. I don't blame them. But I'm gonna give it the old college try. :-DD
   
Hmmm.... I'm looking at those big filter caps on the (HI) & (LO) rails. That plastic sleeve shrunk away indicates they've been running hot for a while; high ESR/increased ripple from/indicated by this is also a common cause of that fault, until the finals/preamp drivers or STKs go short or leaky.

mnem
*More than the sum of my voltage differentials*

Nope....I can't see the brand name but it's a Mylar label going around the aluminum can. It doesn't fold over the top. Unusual, never saw that type before. But when I have the board out I'll check them anyway.
An old gray beard with an attitude.
 

Offline med6753

  • Super Contributor
  • ***
  • Posts: 11313
  • Country: us
  • Tek nut
Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #26874 on: March 09, 2019, 10:48:57 pm »
Tell the neighbors to piss off and hang that 40M sucker on roof out in open so they can bitch and moan about it. It's your freaking house.  :-+ :-DD

Gah can't go over the roof unfortunately. Not enough length over the property. Plus right at the front there's bastard EMI pissing LED street lamp  :-- :-- :--

Going to:

1. Piss around with test gear and not much else now.
2. When I move buy something I can get a full porcupine farm in and a moat full of alligators to keep the complainers out.

Oh sucks. Yes, LED lamps do emit a surprising amount of RFI.

Alligators? Too passive. Toss them chicken and they're happy. Get crocodiles. They always mean and hungry for 2 legged creatures.  :-DD
An old gray beard with an attitude.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf