Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

LED equivalent with shunt resistor for the dimmer effect...?

mnem
 

[factory]

Quick update on the trigger problem with the hp 1801A & 1821A plug-ins, that came with my 180A oscilloscope.
Will do a more detailed post another night, but the problem turned out to be a failed transistor in the 1801A vertical plug-in, on the sync amplifier board.

Anyway it's now working OK using both internal timebase triggers (main & delayed timebases).


David

Forgot about this, just fixed another problem with it yesterday.

Anyway, to prove whether the internal trigger problem was in the 1821A timebase or 1801A vertical input, I used the other pair of plug-ins (1824A & 1801A), swapping the 1821A timebase for the 1824A, it was still not triggering properly unless a very large trace was present.
And using the other 1801A (only one channel works at the moment) with the 1821A, it was triggering fine. That proved the trigger problem was with the original 1801A plug-in.

Looking at the diagrams, the internal trigger signal comes from the sync amplifier circuit in the 1801A vertical plug-in.




After setting it up as shown on the diagram page and going though the sync amplifier circuit test points, it was found that the signal got reduced to almost nothing after Q714, instead of being amplified (note: readout incorrect as non-Tek 10x probes were used).



Before pulling Q714, I verified the -10V supply rail from that big rusty gold plated Zener was present & correct, it was OK. Then I removed Q714 and found base/emitter was open circuit, it was marked MPS3563 (listed as 1854-0092 in the manual), I didn't have any MPS3563 or 2N3563, but a bit of searching found a donor board with some 4-092 (aka 1854-0092).


After replacing Q714 the internal trigger function was once again working  , pictures in quoted post.

David

[Andrew_Debbie]

This HP 5328B is on my watchlist  -->  https://www.ebay.co.uk/itm/224468336959

It has the DVM option but not the crystal oven.  I know almost nothing about the 5328B.  Need to do some research before getting serious about spending money on it.

[med6753]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

LED equivalent with shunt resistor for the dimmer effect...?

mnem
 

I gave it some thought to do that but would rather stick with old fashion original.

[mnementh]

Quick bit of RF fun. Neighbour has noisy TV because she's deaf. Zero luck talking to her because she's got a "fuck everyone else attitude". However we have a shared antenna which is not boosted and just split.

If I terminate my feed with a short then it's glorious silence! 🤔

Can't you transmit on this channel? Ugly music, blaring children, barking dogs in an endless loop?

The "Build a DVB-T2 modulator to D book 8 standards" project just might keep BD so busy that he'd no long notice the noise. And by the time he had finished she'd probably have popped her clogs.

Not really: https://github.com/drmpeg/gr-dvbt2

Ah, but BD was holding forth against SDR, so he wouldn't be so morally ambivalent as to do that and then pursue the non-solder option when it came to his turn, would he? 

pffffft! I don't see bd giving half a aboot the moral implications. Now whether he'd tell us lot aboot it... well, that's a matter for friendly interrogation accompanied by mind-altering quantities of social lubricant. 

mnem
They took my thumbs.

[mnementh]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

LED equivalent with shunt resistor for the dimmer effect...?

mnem
 

I gave it some thought to do that but would rather stick with old fashion original.

https://www.google.com/search?client=firefox-b-d&q=%2344+bulb

https://www.bulbtown.com/44_Miniature_Bulb_BA9s_Base_p/44.htm

https://www.jacksonelectricsupply.com/44-Miniature-Bulb-BA9s-Base-p/44.htm

https://www.amazon.com/ge-44-bulb/s?k=ge+44+bulb

https://www.grainger.com/search?searchQuery=%2344+bulb&searchBar=true

Looks like a 10-pack from Grainger or Amazon is your quickest source. Or, try to find a shunt resistor to use with a #47 that gives acceptable compromise between max & min brightness without drawing too much current maxed out.

mnem
 

[med6753]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

LED equivalent with shunt resistor for the dimmer effect...?

mnem
 

I gave it some thought to do that but would rather stick with old fashion original.

https://www.bulbtown.com/44_Miniature_Bulb_BA9s_Base_p/44.htm

https://www.jacksonelectricsupply.com/44-Miniature-Bulb-BA9s-Base-p/44.htm

https://www.amazon.com/ge-44-bulb/s?k=ge+44+bulb

https://www.grainger.com/search?searchQuery=%2344+bulb&searchBar=true

Looks like a 10-pack from Grainger or Amazon is your quickest source. Or, try to find a shunt resistor to use with a #47 that gives acceptable compromise between max & min brightness without drawing too much current maxed out.

mnem
 

Got this. Thanks.

https://www.ebay.com/itm/224267641617?hash=item343764a311:g:hK8AAOSwNDVfzUEX

[beanflying]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

Element 14 or Farnells depending on if they have a US outlet  https://au.element14.com/mcm/25-010/44-miniature-bayonet-base-bulb/dp/2785196

or search "MCM 25-010" might get you some hits locally

[Cubdriver]

Here it is nearly 0900 hours and I'm just now rolling my sorry arse out of bed. Need coffee. Lots of coffee.

Anyway, the Type 547. It mocks me again although this time in a different manner. Since my last post yesterday showing status it has not failed with the dancing horizontal again. I had it on yesterday for hours and no issues. Even performed several shutdowns and cold starts and it came up and stabilized. Powered it up just now and other than a few unrelated jitters while warming up it's fine. I'd like to pronounce the horizontal issue fixed but I just know it will make a monkey out of me. So I'm going to tempt Murphy and go ahead and say that issue is fixed and then go have a banana. 

My plan today was to restore the vertical output circuit with a big unload of a parts cannon but I think I'm going to let it cook some more.  Given past history with this beast I think it's the prudent thing to do. I have all the time in the world and since I'm making progress for a change I'd rather take it slow. If all is well today then tomorrow I'll rebuild the vertical.

BTW, the current on the external +100V supply never exceeds 320mA which is within the 400mA design limit.       

Mike, stupid question re the troublesome 547, but could the failure that's overloading the 100 V rail be positionally related?  I notice in your pics you've been doing a lot of the troubleshooting with it on its side, and it's behaving.  Have you seen the failure when it's lying down, or has it only occurred when the scope's standing upright?  Perhaps a tube with some marginal internal alignment that intermittently shorts when hot and upright, but not when it's on its side?

It's a long shot and probably unrelated, but I figured I'd throw it out there.

-Pat

[med6753]

Here it is nearly 0900 hours and I'm just now rolling my sorry arse out of bed. Need coffee. Lots of coffee.

Anyway, the Type 547. It mocks me again although this time in a different manner. Since my last post yesterday showing status it has not failed with the dancing horizontal again. I had it on yesterday for hours and no issues. Even performed several shutdowns and cold starts and it came up and stabilized. Powered it up just now and other than a few unrelated jitters while warming up it's fine. I'd like to pronounce the horizontal issue fixed but I just know it will make a monkey out of me. So I'm going to tempt Murphy and go ahead and say that issue is fixed and then go have a banana. 

My plan today was to restore the vertical output circuit with a big unload of a parts cannon but I think I'm going to let it cook some more.  Given past history with this beast I think it's the prudent thing to do. I have all the time in the world and since I'm making progress for a change I'd rather take it slow. If all is well today then tomorrow I'll rebuild the vertical.

BTW, the current on the external +100V supply never exceeds 320mA which is within the 400mA design limit.       

Mike, stupid question re the troublesome 547, but could the failure that's overloading the 100 V rail be positionally related?  I notice in your pics you've been doing a lot of the troubleshooting with it on its side, and it's behaving.  Have you seen the failure when it's lying down, or has it only occurred when the scope's standing upright?  Perhaps a tube with some marginal internal alignment that intermittently shorts when hot and upright, but not when it's on its side?

It's a long shot and probably unrelated, but I figured I'd throw it out there.

-Pat

Pat, excellent question but no, it's not position related. For over 2 days now it's been sitting upright in it's normal position.

[med6753]

Scope rotation time. Normal rotation to give all my scopes some power up time and catch any issues early. The Type 561B that was occupying this slot for the past 2 weeks has been put back on the shelf. Replacing it are this 465B and 2430. Other than both being slightly dusty no issues.



And this is the parts cannon I'm going to unload on the Type 547 final vertical amplifier. Since I couldn't determine why the final output transistors blew their cookies I figure I'll replace the entire support circuitry.

[Neper]

Given past history with this beast I think it's the prudent thing to do. I have all the time in the world and since I'm making progress for a change I'd rather take it slow.

To paraphrase the Taliban: It has a timebase, you have time. ;-)

Ralf

[Vince]

Grrrr... can't see that video, YT blocked if for French viewers based on copyright grounds... it's a video from a French TV station, might be why...

I can see it just fine up in the GWN... 

mnem

Yes Dwagon, you are precisely illustrating my point, you are NOT in France so you CAN see it !

[Cerebus]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

Element 14 or Farnells depending on if they have a US outlet  https://au.element14.com/mcm/25-010/44-miniature-bayonet-base-bulb/dp/2785196

or search "MCM 25-010" might get you some hits locally

Farnell/Element 14 have been part of Avnet for ages now and with Avnet being based out of Phoenix, Arizona I'd presume that they have some sort of  general distributor presence stateside, even if it's not under the Element 14 or Farnell names.

P.S. I really must be thick, I've just discovered that the "Element 14" is a reference to silicon by atomic number. How come I didn't spot that years ago?

[Cerebus]

Grrrr... can't see that video, YT blocked if for French viewers based on copyright grounds... it's a video from a French TV station, might be why...

I can see it just fine up in the GWN... 

mnem

Yes Dwagon, you are precisely illustrating my point, you are NOT in France so you CAN see it !

Give him a chance - he can be a bit slow before his seventh cup of coffee. Come to it, so can I.

[mnementh]

Grrrr... can't see that video, YT blocked if for French viewers based on copyright grounds... it's a video from a French TV station, might be why...

I can see it just fine up in the GWN... 

mnem

Yes Dwagon, you are precisely illustrating my point, you are NOT in France so you CAN see it !

You wouldn't know that from looking at the labels on your groceries or signs on the highway. Pretty much everything here is in both English and Français, with a reasonably fair mix of which takes top billing. 

mnem
Also... "Liberal" is not a dirty word. 

[mnementh]

Grrrr... can't see that video, YT blocked if for French viewers based on copyright grounds... it's a video from a French TV station, might be why...

I can see it just fine up in the GWN... 

mnem

Yes Dwagon, you are precisely illustrating my point, you are NOT in France so you CAN see it !

Give him a chance - he can be a bit slow before his seventh cup of coffee. Come to it, so can I.

You have no idea how true that has been for the last few days. First, we've had like 2 solid weeks of "Heat Advisory" weather with the Heat Index in the high 30s low 40s. This is painfully reminiscent of Houston, in all honesty. And it seems like it started just as we had to start being out in it all day for the move. Pretty much every day, out in it til I'm drenched with sweat... I literally go through 3-4 bandannas and 2-3 t-shirts a day. I'm a fucking zombie-dwagon until well after lunch, I swear.

And lastly... the quality of our coffee has gone to complete shit since all the stores took the coffee grinders out... seriously WHAT THE ACTUAL FUCK?!? They were there through all of the first 3 waves... and now almost everybody is at least partially vaccinated... and NOW they take the damned things out?!?

Fucking morons at corporate. Probably figured they could use it as an excuse to get rid of something that cost them money... it never occurred to them that they'll lose more on the whole wall of bean coffee that doesn't sell because they took the grinders out; we can't be the only people who went to ground coffee from Costco because if not fresh ground,^* why even fucking bother...?

I'm actually thinking aboot getting my own grinder again from Amazon, but I couldn't be arsed to shop it and the thought of adding all that mess to my life in the middle of a move just makes me cringe...

mnem
^* to certain definitions of the term

[factory]

OK, my Google is failing me today. One of the scale illumination bulbs on the Type 547 is burnt out. It is a #44 bulb which is a higher current version of the #47 bulb typically found in panel lamps. Mouser only has #47 bulb. Quick search elsewhere is yielding nada. Anyone know of a source?

Element 14 or Farnells depending on if they have a US outlet  https://au.element14.com/mcm/25-010/44-miniature-bayonet-base-bulb/dp/2785196

or search "MCM 25-010" might get you some hits locally

Farnell/Element 14 have been part of Avnet for ages now and with Avnet being based out of Phoenix, Arizona I'd presume that they have some sort of  general distributor presence stateside, even if it's not under the Element 14 or Farnell names.

P.S. I really must be thick, I've just discovered that the "Element 14" is a reference to silicon by atomic number. How come I didn't spot that years ago?

The US equivalent of Farnell is Newark, and if I remember correctly they have Allied Electronics instead of RS Components, anything from extended ranges that use those come with an extra delivery charge.

David

[Grandchuck]

I like this grinder:  https://www.amazon.com/KitchenAid-BCG111OB-Blade-Coffee-Grinder/dp/B003WIZ5PC/ref=sxin_13_ac_d_mf_rf?ac_md=6-4-NCB0byA1Ljkgb3ou-ac_d_mf_rf_rf&crid=36KPWCOF2ATVE&cv_ct_cx=coffee+grinder&dchild=1&keywords=coffee+grinder&pd_rd_i=B003WIZ5PC&pd_rd_r=5ba36140-4b1e-4c47-ac08-9495e8e694fb&pd_rd_w=vxXfb&pd_rd_wg=4Ixds&pf_rd_p=e511b89f-6092-4b52-a181-4e1a88ad2c37&pf_rd_r=FJMRD0AK5R806TNYWMFQ&psc=1&qid=1629996093&sprefix=coffee%2Caps%2C207&sr=1-4-1db1fce3-1628-43df-a6c6-84620ba4aaaa

[Vince]

Grrrr... can't see that video, YT blocked if for French viewers based on copyright grounds... it's a video from a French TV station, might be why...

I can see it just fine up in the GWN... 

mnem

Yes Dwagon, you are precisely illustrating my point, you are NOT in France so you CAN see it !

You wouldn't know that from looking at the labels on your groceries or signs on the highway. Pretty much everything here is in both English and Français, with a reasonably fair mix of which takes top billing. 

mnem

Yes that's why I said France no" French speaking countries"....  lots of English stuff here too, way too much, yet even when sick I know I am in France not in England ! 

But that's OK Dwagon, I understand you are a bit overwhelmed currently with your move.. it's just that I am so used to Dwagon being so strong and never failing... only to realize today that even Dwagons can be weak and fragile sometimes ?! It's cute to see that even a Dwagon can be... "human", sometimes, dare I say ?!     Now I am sure a Dwagon won't take it well to be treated of a human, pride and all that.... but still.... yes, it makes you a little human ! Not a bad thing in my book, nothing to be scared of little Dwagon, I like you the more for it !

[mnementh]

   

So while I was at Princess Auto looking for a cheap mower blade... I sat down on a pile of pellet fuel to rest and peruse the sale flyer. Right on the front page was this for CAD$144 (~USD113); feeling a bit tired and deprived, I decided to make it a belated birthday present to myself, as my family had in fact followed my "only token gifts" instructions because of the move.

My original plan was to just use it to get all my "general household & automotive" tools separated out from my electronics tools, so I could start packing the latter down for the move while still having what I need to do the "gotta put this back the way I found it" stuff around the old place.

But while I was assembling it I realized that the footprint of the gimmick slide-out top is like... made for my 54645A. Next thing I knew, I had it and my 4070A out and eyeballing it... and had to share a few pics.

It certainly isn't as big or well-laid-out as my rollaway cart from Horror Fraught, but it is also aboot US$90 less so I wasn't going to quibble. and I really do need to use it as intended; my general-purpose tools have taken over every corner and under-bed space I can stash them, as a tool-dwagon is wont to do.   

But I think that once I have the Trailer of Doom^TM back... and my regular tool boxes with it... this probably will be how my electronics bench gets handled. I love this arrangement.



And now for that all-important peel... You may all submit your best off-color jokes aboot the ridiculous brand-name now. 

mnem
*toddles off into the suck again*

[mansaxel]

I'm actually thinking aboot getting my own grinder again from Amazon, but I couldn't be arsed to shop it and the thought of adding all that mess to my life in the middle of a move just makes me cringe...

mnem
^* to certain definitions of the term

Here, "roasted beans, whole" are TWICE the price of "roasted beans, ground". Same brand. No fucking way am I supporting that because-we-can-fuck-you-too pricing.

Just came home with 2 more 450g packs of vacpac Zoegas Skånerost. Local store has them for "2 for 69SEK" which is markedly better than "one for 46SEK" which is the new usual price. They've had that price all week now, and I've bought 2 packs every time I've gone in. Since we go through 2 packs a week what with home work et c. they'll not go stale, neither from storage nor from standing open while consumed.

[Cerebus]

I'm actually thinking aboot getting my own grinder again from Amazon, but I couldn't be arsed to shop it and the thought of adding all that mess to my life in the middle of a move just makes me cringe...

mnem
^* to certain definitions of the term

If you're feeling rich I can heartily recommend the grinder I treated myself to the Christmas before last when I also got a new espresso machine.

This beastie:



Details here: https://baratza.com/grinder/sette-270wi/

Weights the ground coffee as it grinds it. Adjusts from boulders to Turkish coffee grind. The best bit is that the path is straight from hopper to output so no ground coffee gets trapped in there (maybe a few 10s of milligrams at most) so you get the freshest ground coffee it's possible to get.

I've had, counts on fingers, 20 months of faultless service from it. The downside? The price is what you'd expect to pay for something that is a first class design and made properly, and supported with a proper parts service and advice. They make cheaper grinders and, if my experience with this model is anything to go by, I'm sure that they would make a good purchase too. Baratza have 10 dealers in Ontario.

[factory]

Continuing the hp 180A oscilloscope repair;

A while ago I noticed, when checking all the sweep modes for the 1821A timebase that the light behind the reset switch was never lit, even when set to single sweep. In fact I've only ever seen it lit briefly at power up and the 1821A manual doesn't seem to mention it outside of the single sweep mode.
But comparing the 1821A timebase with the older 1421A timebase, which shares some circuitry in this area, it seems to light when a triggered sweep is running and goes out briefly at the start of the sweep.


Yesterday I had a look at the reset switch & neon problem with the 1821A, first I noted for the single sweep mode the switch had to be pressed quite hard to get the neon on the circuit board to light.

As for neon in that switch, well it's part of the Schmitt trigger circuit on the main sweep circuit diagram.
As before I set the controls & input as listed opposite the circuit diagram page and went through checking the waveforms at the test points (I've added the missing text using a 1820A manual as a reference  ), nothing seemed to be wrong with any of them.



Then I checked what was happening at the collector of Q203, again I was getting something that looked OK (no waveform shown in the manual), I pulled a couple of the resistors in the chain to check they had not drifted and they were all OK.
That only left the neon lamp in the switch, to check this I found one from another 1821A (that has been a parts donor for various repairs) and temporarily connected it across resistor R215. It was working fine and this proved the original was knackered.


The switch with neon isn't the easiest part to replace, but probably not the most difficult either. Once the dozen or so screws were removed, along with the side panel, it wasn't too hard to replace, note the wire colours have faded a bit in this 1821A, I've seen this before in vintage hp gear.

The replacement switch seems to be in better condition too, as it requires less force to operate in single sweep mode.

That's two vintage hp scopes here that work & trigger  , I currently only have this 180A & the 140A here (others are in storage) I had to bring back the other 1421A plug-in from storage to prove the operation of the reset neon, the 1421A I already had here failed last weekend, the sweep length gradually reduced and stopped working.  Oh well something else to repair.

David

[factory]

Anyone noticing a new problem with uploading pictures to the forum, the last two posts I added the pictures as usual (missing out the problematic first attachment option) and found a couple of random incorrect pictures from another a previous post of mine instead.

Here is what I got when I uploaded the last post about the 180A, the two pictures from the manual are incorrect, as is the dead transistor.


And here are the three pictures that required re-uploading, note the filenames shown are the same.


Wonder if this will work first time.  Edit: it did.

David