Test Equipment Anonymous (TEA) group therapy thread

[AF6LJ]

I've seen worse, that 475 is in decent shape..
Looks like it had a rich life, and wants more.

The crusty ones are the most satisfying to finally see cleaned up and working.

Then the power supply I bought to run my Atlas 350XL on will be a truly satisfying piece....
It looks like it sat in a chicken coop on the inside.

[bd139]

On the subject of crustiness, all the crusty bits on this were once blue! https://www.ebay.co.uk/i/372099755572

Shame otherwise I’d probably have that.

[Specmaster]

I've seen worse, that 475 is in decent shape..
Looks like it had a rich life, and wants more.

The crusty ones are the most satisfying to finally see cleaned up and working.

Then the power supply I bought to run my Atlas 350XL on will be a truly satisfying piece....
It looks like it sat in a chicken coop on the inside.

I just hope that isnt what's in store for me when my Fluke 8505A arrives in a couple of days. Its in Heathrow at the minute in the hands of 13ten (never heard of them before) but I suspect there'll be taking almost past my door to their Peterborough dept for resorting and then be bringing it back down to me 

[bd139]

13ten are a fulfilment company. They usually hand stuff over to Yodel drivers from experience. Don’t be surprised if it gets jammed up for a few days though.

They’re only about 5 minutes up the road from me (I live under Heathrow approach) so I’ll hand deliver them some dog excrement if you get any problems.

I think one of us has fallen. eBay user mystic_meg1955 is selling her husbands oscilloscope collection apparently there are over 200 being sold. Keep an eye out.  Might be some good ones and it’ll saturate the market and keep prices low. RIP fellow TEA.

[neo]

Are they going for what their worth or what he told her he paid?

In all seriousness, death is always a tragedy, RIP fellow TEA.

[Cerebus]

Are they going for what their worth or what he told her he paid?

In all seriousness, death is always a tragedy, RIP fellow TEA.

The death is an assumption, although most likely.

But it is possible that he's run off with "a novelty dancer from Penge" and SWBMO is just getting her long awaited revenge. 

[AF6LJ]

I think one of us has fallen. eBay user mystic_meg1955 is selling her husbands oscilloscope collection apparently there are over 200 being sold. Keep an eye out.  Might be some good ones and it’ll saturate the market and keep prices low. RIP fellow TEA.

I hope not that would be very sad.
 

[Mr. Scram]

I'm not seeing any items listed under that name.

[tggzzz]

I'm not seeing any items listed under that name.

https://www.ebay.co.uk/sch/mystic_meg1955/m.html

[bd139]

With respect to a death, it's a sad fact but it does happen. I think it's good to make an arrangement as part of your will for the disposal of such things. As someone who moonlit doing house clearance for a number of years in the 90s, I fully intend to depart with as little trace as I arrived. I'm all written up. Nothing is worse than dealing with it, I assure you. It's even worse for relatives as there is an emotional attachment to everything. It's hard enough when you don't even know the person.

I think it should be a responsibility of a TEA to make arrangements on your demise 

But it is possible that he's run off with "a novelty dancer from Penge" and SWBMO is just getting her long awaited revenge. 

I'm not sure I'd swap 200 oscilloscopes and SWMBO for a novelty dancer from Penge. I can't speak for Penge but I dated a girl from Mitcham once. That was a mess.

[Specmaster]

Strewth, 200 scopes eh, either he was extremely thick skinned and deaf, or SWMBO was very understanding 

If the assumption is correct then RIP follow TEA member, it's not really a laughing matter but you have to admire his dedication to his collection, I wonder how many are working though?

[Cerebus]

I'm not sure I'd swap 200 oscilloscopes and SWMBO for a novelty dancer from Penge. I can't speak for Penge but I dated a girl from Mitcham once. That was a mess.

Talking of that neck of the woods, I suspect that you're of an age where you'll giggle if I quote: "Bal-ham, gateway to the south".

[bitseeker]

The crusty ones are the most satisfying to finally see cleaned up and working.

Then the power supply I bought to run my Atlas 350XL on will be a truly satisfying piece....
It looks like it sat in a chicken coop on the inside.

 

I certainly hope so. It won't be too fun during the process, though.

[bitseeker]

Are they going for what their worth or what he told her he paid?

In all seriousness, death is always a tragedy, RIP fellow TEA.

The death is an assumption, although most likely.

But it is possible that he's run off with "a novelty dancer from Penge" and SWBMO is just getting her long awaited revenge. 

Either way, it's good to see that they'll go to new homes rather than a landfill, as is known to happen under such circumstances.

[bd139]

I wonder how many are working though?

Probably less than 50% of them. That happens whenever I start collecting scopes

I'm not sure I'd swap 200 oscilloscopes and SWMBO for a novelty dancer from Penge. I can't speak for Penge but I dated a girl from Mitcham once. That was a mess.

Talking of that neck of the woods, I suspect that you're of an age where you'll giggle if I quote: "Bal-ham, gateway to the south".

Hahaha yes I know that well. That short film starts near where I live now before they get dive down the side road and end up in Balham

[bd139]

Just got my 475. Good condition. Even the feet are intact! Driving home with it now.

[AF6LJ]

Just got my 475. Good condition. Even the feet are intact! Driving home with it now.

Very Cool

[bd139]

It’s on the bench now. The 15v and -15v , 8 and -8v lines are down. HT isn’t coming up.

Despite this, that’s good news as that means there’s a tant or filter cap gone short somewhere. Whack a mole time.

The DM44 module works nicely!

[Specmaster]

Just modded my Heathkit VTVM so I dont have to keep switching input jacks for measuring AC and DC and while I was in there I decided to replace the MES bulb for the power indicator to a green LED to release a few more mA for the heaters. The power LED is not very bright and thats due to the original design of the meter.

The 1/4" jack is retained so the use of a RF probe (assuming you have one) is still possible.

The 1M resistor that was in the old probe that used to use the 1/4" jack for DC measurements is now fitted internally across the DC 1/4" jack and the AC-OHMS jack. I'm not too sure just what effect this would have with an RF probe connected as I don't have one to try it with.

The big advantage with this modification is that it enables a standard set of leads with finger protection and better grips to be used (if they have shrouded banana jacks, trim the shrouding off) without having to unplug them when switching between DC and AC volts and or Ohms ranges.

As always with these old metal cased test instruments care needs to exercised as the common jack is also connected to the chassis and infact the chassis forms the return path for the 1.5v C cell that is used for the resistance range, so care must used to ensure that when measuring AC voltage, the neutral is always plugged into the common otherwise the entire case will become live.

Important Update
If anyone does these modifications, beware that there is an inherent safety issue when measuring AC volts, the case could become live with the 1/4" jack socket left in place as the battery negative uses the chassis and case as its connection to the meter. This means that the common socket is still connected to the chassis via the 1/4" jack it could become a hazard while measuring AC voltage, particularly if the lead connected to the AC live pole was to be plugged into the common socket then the chassis and case would be live.

To cure this potential problem, I have decided to remove the 1/4" jack socket, which was originally retained to allow the use of a suitable RF probe, and in its place I'm fitting a 10mm LED panel indicator 6v to be wired across the old connections for the 6v MES bulb that previously served as a power on indicator. The old battery holder, (spring and C cup) is being removed and all insulted AA battery holder is being installed and the negative terminal will be wired directly to the common terminal, thus removing all connections to the case and chassis so removing any shock hazard.

I may also replace the current 2 core mains cable and fit a 3 core and earth the chassis, while this is strictly not essential as the whole VTM was designed in the first instance to be a insulated system, although this potential hazard has always been there as far as I'm aware and I'm not aware of anyone receiving a shock from it so maybe it is as much of a problem as I perceive it to be, none the less, I'm making these changes to my own meter, just to be safe.

[Specmaster]

It’s on the bench now. The 15v and -15v , 8 and -8v lines are down. HT isn’t coming up.

Despite this, that’s good news as that means there’s a tant or filter cap gone short somewhere. Whack a mole time.

The DM44 module works nicely!

Wow, if thats all it is, then you have a steal there, well done.

[bd139]

This might just be hiding a multitude of broken yet. I’ve laboriously rebuilt the power supply on one of these before and the moment it came back up it blew the HT multiplier out. I had two organ donors however floating around. This time I need to tread a little careful as I don’t have a harvest of organs at hand.

Think I found a duff tant already. Need to do school run but will desolder it after.

Going to write this up as I go.

[AF6LJ]

It’s on the bench now. The 15v and -15v , 8 and -8v lines are down. HT isn’t coming up.

Despite this, that’s good news as that means there’s a tant or filter cap gone short somewhere. Whack a mole time.

The DM44 module works nicely!

Sounds like you have your work laid out for you.
Should be easy enough to isolate and repair.

[bd139]

Well that was annoyingly easy. The tant on the end of the 15v rail was shorted - C1448.  Diagnostic process:

1. Measure rails and reference voltages.
2. Go through them in order.
3. Measure resistance of the tants. Ooh 0.27 ohms. That sounds like a short! Snip it out.
4. Power up. No explosions.

Bingo:



Going to replace this (I actually have a replacement in stock for once - 10uF 25v) run through and measure ripple, clean it and calibrate it as best as I can with my limited kit. ESR on ALL of the big electrolytics is good.

 

[neo]

That's a nice repair, very rare to have replacements on hand but it always nice when you do. It would help of course, in somethings, if they used standard values and not for example 63V capacitors.

[Specmaster]

Its always nice when a repair is as straightforward as that though, gives you a warm feeling inside knowing that you have scored, and scored well to boot. Makes up for the disappointment with the V-7AUs if you ask me