Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

Heh... y'all will hate me for suggesting it, but the first thing I thought when I saw it was "I wanna replace all the fasteners with stainless button head allen screws." 

mnem
*HotWod Dwagon, thwough & thwough*

[0culus]

Heh... y'all will hate me for suggesting it, but the first thing I thought when I saw it was "I wanna replace all the fasteners with stainless button head allen screws." 

mnem
*HotWod Dwagon, thwough & thwough*

As long as they aren't flatheads, we're good. 

[beanflying]

Heh... y'all will hate me for suggesting it, but the first thing I thought when I saw it was "I wanna replace all the fasteners with stainless button head allen screws." 

mnem
*HotWod Dwagon, thwough & thwough*

As long as they aren't flatheads, we're good. 

No changing the original flat heads on those classic Cambridge decades lest you be struck down

[0culus]

Nah I won't change screws that are already in there. But I won't use flatheads in any project I'm building. 

[mnementh]

The ones in the body of these two are Fillister button heads; the one in the wooden box appears to have upholstery washers under those screws. The ones in the knobs are Fillister socket head screws.

I'd certainly NOT change either of them for flat head screws... any more than I'd "fix" them with a drywall screw. 

mnem
*Yawwwwnnnnn...  *

[bitseeker]

Drywall screws...the duct tape of metal fasteners.

[Specmaster]

Fuck me.

So... trial fitting the radiator to see which way the hoses will go best, and discover that the design of the case places the RAM on my MB too high. I can JUST get the radiator in on the outermost set of slots as I intended, but the frontmost fan occludes the top row of RAM lock-levers. I'll have to drop the RAD any time I need to reseat the RAM.  You can see how close the dimensions are in the pic I posted re: my thermal sensor.

A quick look on NewEgg shows that modern MBs, both AMD and Intel, have the RAM in the same location relative to the I/O header; so this is just plain poor layout in the case. The MB should have been located approx 20mm lower. 

The AIO does not want to play nicely in a front radiator install; the hoses are just a little too short. I specifically want top radiator anyways, so I get gravity-bleed and convection circulation if the pump dies.

I know I'm probably going to just suck it up and install with it blocking the RAM anyways... but right now I'm going to bed.

mnem
 

That's one reason why I have a full sized tower because the ram slots being so close to the top [emoji83]

[VK5RC]

Heh... y'all will hate me for suggesting it, but the first thing I thought when I saw it was "I wanna replace all the fasteners with stainless button head allen screws." 

mnem
*HotWod Dwagon, thwough & thwough*

As long as they aren't flatheads, we're good. 

No changing the original flat heads on those classic Cambridge decades lest you be struck down

Isn't the "Proper" screw a slotted cheese head for that equipment. I haven't seen a new one in decades - bloody torx, Phillips and posidrive rubbish - harrumph!

[beanflying]

Heh... y'all will hate me for suggesting it, but the first thing I thought when I saw it was "I wanna replace all the fasteners with stainless button head allen screws." 

mnem
*HotWod Dwagon, thwough & thwough*

As long as they aren't flatheads, we're good. 

No changing the original flat heads on those classic Cambridge decades lest you be struck down

Isn't the "Proper" screw a slotted cheese head for that equipment. I haven't seen a new one in decades - bloody torx, Phillips and posidrive rubbish - harrumph!

Yes! Yes they are - Documentary evidence in case of secret exchanges to inferior fasteners

'Proper' screws prior to export

[bd139]

Ok so this weekend's project is the Tek 475A. I need to fix the timebase problem which is no sweep on two timebase settings and fix all the knackered bulbs. I know what the first issue is (damn leaf switches again) but the bulbs I'm trying to make a decision over.

I have got a whole bag of bulbs to go in it but I really don't want to take this to bits again one day so I'm thinking of retro-fitting cheap chinese warm white 3mm LEDs instead. I have a billion of these. They have a forward current of 20mA approx to get the same brightness as the bulbs and in most circumstances, at least in the timebase, these will be fine as they are just switched. Probe indicators might require some further thought. Should look original-ish with those in rather than some lurid red/green LED colour.

[med6753]

Ok so this weekend's project is the Tek 475A. I need to fix the timebase problem which is no sweep on two timebase settings and fix all the knackered bulbs. I know what the first issue is (damn leaf switches again) but the bulbs I'm trying to make a decision over.

I have got a whole bag of bulbs to go in it but I really don't want to take this to bits again one day so I'm thinking of retro-fitting cheap chinese warm white 3mm LEDs instead. I have a billion of these. They have a forward current of 20mA approx to get the same brightness as the bulbs and in most circumstances, at least in the timebase, these will be fine as they are just switched. Probe indicators might require some further thought. Should look original-ish with those in rather than some lurid red/green LED colour.

The 465B is a combo of LED/incandescent already. Incandescent for both volts/div switches and then LED's for everything else. As I recall the 465 junker was incandescent/NE-2 neon driven from the 110VDC supply. Isn't the 475A more like the 465 with that same combo or is it all incandescent? It's been at least 35 years since I last played with a 475A so I don't recall. 

[bd139]

This 475A is entirely incandescent. Fortunately all low voltage. No neons. that would require some rework to get LEDs in there. Due to the design of the 475A I can slide these in with a resistor change and dropping an LED in the old bulb holes.

[med6753]

Even if they were neon you could still sub in an LED. It would just have to require a HUGE dropping resistor. But.....subbing in LED's might put a drag on the 110VDC supply because LED's consume 20ma and neon bulbs almost nothing. Luckily you don't have to worry about that.

If I had the white LED's already on hand I would replace the incandescent.

[mnementh]

Heh... y'all will hate me for suggesting it, but the first thing I thought when I saw it was "I wanna replace all the fasteners with stainless button head allen screws." 

mnem
*HotWod Dwagon, thwough & thwough*

As long as they aren't flatheads, we're good. 

No changing the original flat heads on those classic Cambridge decades lest you be struck down

Isn't the "Proper" screw a slotted cheese head for that equipment. I haven't seen a new one in decades - bloody torx, Phillips and posidrive rubbish - harrumph!

Yes! Yes they are - Documentary evidence in case of secret exchanges to inferior fasteners

'Proper' screws prior to export

Cheese head screws are have a thicker root (The area of solid metal under the slot). Those are pan head screws. However, the ones IN the knobs may be cheesehead. Buttonhead screws are domed; proper ones are like the screws in the body of jwc's decade box. The ones that are popular today are kindof halfway between, because they are easier to forge as Philips and the reduced pressure required makes dies last longer. They are still usually called buttonhead.

mnem

[mnementh]

   ...I know I'm probably going to just suck it up and install with it blocking the RAM anyways... but right now I'm going to bed.

mnem
 

That's one reason why I have a full sized tower because the ram slots being so close to the top [emoji83]

Yeah, yeah... this is a mid-tower with what looks like oodles of room; it's just poorly thought out. Or rather, appearance was weighted over function in the engineering scope. Another product designed by committee. 

I used to be the same way about huge tower cases... but really, I have to live with this thing. I don't need another man-eating big black box in the living room. The subwoofer already has cable envy; I don't want to give it an inferiority complex on top of that.

mnem
No, thanks. I'm trying to cut back. 

[neo]

HP 141T teardown, they make those caps impossible to read and seemingly impossible to remove.








Anyone enjoying these?

[bd139]

Thanks for the 141T teardown.

I have nearly bought a couple of them recently but was scared off by the mechanical problems with the plugins and the lack of any decent pictures.

I am now thoroughly put off with the idea 

[nixiefreqq]

HP 141T teardown, they make those caps impossible to read and seemingly impossible to remove.


Anyone enjoying these?

enjoying?   well those pics sure are bringing back lots of memories (and may lead to nightmares).  spent waaaaaaay too much time inside those things.

but when you get it working you will appreciate why 40 years ago we all drooled over them.  so many knobs to fiddle with! 

takes a while to get used to the implications of harmonic mixing, but after you get used to flicking the "signal identifier" switch to prove you are looking at the correct peak it stops bothering you that some signals you can see do not match the band switch setting.

playing with the storage settings is almost more fun than a video game. 

AND if you really like fixing things they are a gift that keeps on giving.   (zoooooorrrrrrch!)



edit--  but they were and still are good instruments, and very very useful tools.

[Brumby]

When I saw the video Bean put up about the 8656B attenuator, my interest was piqued.


The mechanical aspect of the repair was not particularly intimidating
- but my unit did things differently...


Not to worry, I located the low band input to the attenuator (up to 123.5MHz), unscrewed the SMA connector and hooked it up to a scope.  Played around with all the controls and the signal did what I expected - so the attenuator does, indeed, appear to be the problem.  Need to check out the junker.


And here's another gratuitous shot of a little flash of gold...

[med6753]

HP 141T teardown, they make those caps impossible to read and seemingly impossible to remove.

Anyone enjoying these?

Pray tell, what caps are you referring to? I see a CRT, a relay, couple of TO-3's, and a few circuit boards. What caps? They must be hidden real good. 

[neo]

HP 141T teardown, they make those caps impossible to read and seemingly impossible to remove.


Anyone enjoying these?

enjoying?   well those pics sure are bringing back lots of memories (and may lead to nightmares).  spent waaaaaaay too much time inside those things.

but when you get it working you will appreciate why 40 years ago we all drooled over them.  so many knobs to fiddle with! 

takes a while to get used to the implications of harmonic mixing, but after you get used to flicking the "signal identifier" switch to prove you are looking at the correct peak it stops bothering you that some signals you can see do not match the band switch setting.

playing with the storage settings is almost more fun than a video game. 

AND if you really like fixing things they are a gift that keeps on giving.   (zoooooorrrrrrch!)



edit--  but they were and still are good instruments, and very very useful tools.

Oh i'm more than aware WHY people drool over them. Hell, i've yet to have it working and i'm drooling over it. I meant a more in general question, 'why am i doing this?' type question. Little discouraged is all because of my current (seeming) inability to do much except for taking it apart and scratching my head.

HP 141T teardown, they make those caps impossible to read and seemingly impossible to remove.

Anyone enjoying these?

Pray tell, what caps are you referring to? I see a CRT, a relay, couple of TO-3's, and a few circuit boards. What caps? They must be hidden real good. 

@Med These caps and one under the relay. 

[bd139]

Bloody hell. That's a capacitor nightmare that.

[neo]

Bloody hell. That's a capacitor nightmare that.

The whole things a bloody nightmare. Especially the lack of any kind of test point so i have no idea what to ground to or where to probe.

[med6753]

Bloody hell. That's a capacitor nightmare that.

The whole things a bloody nightmare. Especially the lack of any kind of test point so i have no idea what to ground to or where to probe.

Ah ha! There they is.  Good luck! 

[med6753]

Question for tautech. Hopefully he'll see this later when he wakes up.

Siglent SD1052DL. If both channels are connected and I hit "Auto" to trigger it always defaults to channel 2. How can I change the default to channel 1?