Test Equipment Anonymous (TEA) group therapy thread

[TERRA Operative]

After that prolongued dry spell, I might have been lucky today. IF they turn out to be ok, I have grabbed TWO Tektronix P5100 x100 probes for laughable 40€ including postage. The ground lead has been modified to connect both to a common ground and there are only those clips which are fitted, but that can be corrected.

I'll take therm off your hands if you like... I need some for my THS720P...

[AVGresponding]

Kathrein MFK 85 TV/Radio Test Receiver 1994
I got this really cool unit at the last fleamarked, sad to see how badly it was thrown into a trashbin,
but it really works, contained 10 leaked D cell nicd, it receives RF video, and direct video in/out in COLOR :-)
super nice CRT size, it also contain a slow scan spectrum analyzer and printer and FM radio.
And how about teletext decoding, i was looking for a way to test that.

video about here : https://youtu.be/JB5W_2c1pcw

You might have to build or modify something. https://en.wikipedia.org/wiki/Teletext
7 data + 1 parity bit is a pretty common format for low speed serial comms, isn't it? This link might be useful too:  https://www.bbcbasic.co.uk/tccgen/manual/tcgen2.html

[m k]

That meter looks worse than the Antikythera mechanism. I assume that a storm washed it up on shore from a shipwreck?

EDIT:

picture -

It's still just a link.
But thumb for trying.

E,
a flip.

[factory]

Here you are, one crusty Solartron DMM wreck, definitely not mine, wonder if the buyer is restoring it or bought it to rob blind? 



David

[m k]

Maybe it's one of those painted to be different.

[factory]

When I first looked at it, I wondered if it was painted black and underneath the casing was some kind of alloy going bad, like Mazak does, but no Vince confirmed it's Bakelite sprayed grey.
Personally I don't like the sprayed grey controls.

An arrival from last week, a HP 5321A, sadly the controls got a bit trashed by use of a small box, USPS/Asendia/Parcelforce had fun beating it up.  I've since had a full refund as it was sent using ePay EIS, so can't complain to much.
Currently unable to safely test it, as it's fitted with a two core bodge lead (metal cased TE  ) and the PH163 inlet is filled with resin, with cut off perished wires still bodged in place. 





A quick update on the two HP 5327B, I removed the CA3046 transistor array ICs from the 500MHz input boards, Mr Peak DCA says they were all still transistors, I'll fit some sockets before putting them back, bias issue must be the custom parts, 1826-0084 amplifier seems to be unobtainium (might be used in early 5328A option 030 PCB and early 5345A ??), second stage is 1826-0085 Schmitt trigger, this is almost unobtainium.

Yesterday I went to the Military fair at the local not-so-secret bunker, near Nantwich, as expected & advertised it was mostly stalls filled with old military gear, clothing etc. The Stoke radio club stall was there, along with two others selling old electronics, not a lot of TE on offer, some old scopes I had seen before, some expensive stuff too.
The only TE I bought was a 350V Farnell E350 PSU, slightly newer than the 60s one I already have.
And I spent a bit of time searching through the parts boxes for TTL ICs, they also had a roll of 0.5mm tinned copper wire. Which I wanted for the HP adaptor boards I made, to test the 8 pin DIP divider replacement in place of the TO99 can IC version, as used in the 5321A. Hopefully they will work, as they will be needed to replace the divide by 6 IC, to get divide by 10, part of the 50Hz conversion for the HP 5221A/5321A.

David

[Vince]

QUAD 303 power amp restoration

Quick contribution of the day.... little by little I am getting closer to finishing this amp so I can sell it.

Today I spent my evening working on the 4 big can caps.

I already replaced them with new snap-on caps a while back, but I thought I would keep the old cans in the end, for several reasons.

- Will look much better, original, which will help sell the amp, will make more potential buyers happy.

- Gives me some training in restuffing old caps. I need to learn, get some practice... because it's a skill I will need a lot when restoring all my old hollow-state Tek scopes...

- The new snap-on caps are a disaster from a mechanical point of view. I often need to solder more than one wire on a single pin, which is tricky at best. I huge pain, drove me nuts, and the results looks like butchery. Also, they are much smaller so I can't re-use the old bracket to secure them to the chassis, so they are just flapping around in the breeze... 
I then thought I could make spacers/rings, or wrap the caps in 14335 turns of tape to fill the gap and get the bracket to get hold of the caps... but still would look ugly.

So, by putting the new caps in the old cans, I solve all these problems. I can reuse the brackets/clamps, and I can reuse the original terminals of the can caps, hence will be able to redo the wiring much more easily with a much better looking result... more satisfying and again, a clean looking job will help sell the amp. And as I said the consequence is also that I conserve the original appearance of these old caps, good for original looks, good for resale.

So in the end I thought it was a no brainer.

So I saw them all open this evening. Only one of them was dry inside... the other 3 were still very much wet, with horrible white jelly at the bottom of the can.
They would not want to come out by themselves like the dired out one did. At first I tried to pry them loose with a screw driver, but not much luck, and it would damage/distort the thin metal can     So I then switched tactics and grabbed firmyl the cap/foils with a pair pliers, and in 2 seconds I could wiggle them out of the can with zero damage 

Once removed, you see inside the can lots of black stuff... I guess must be some potting compound to maintain the cap steady inside the can ? I guess it must be tar.. I gather old transformers used to be potted with tar...
So might be tar. It's completely dried and brittle so I was able to remove most of it with screw driver. Came out pretty nice/clean for two of the caps, but on the other two cans, that black stuff was stubborn in places... oh well. Nobody will see that anyway. The is merely to remove most of the stuff so that I don't have problems getting the new caps to fit inside the can. That's all...
Maybe with a small wire brush mounted on a long shaft into cordless drill, I could remove the remains. Might try that next time.

I think I will also get a pipe cutter to try Terra's method to open the cans. Using the hack saw is a pain the cut is not perfectly square and far from clean. Tomorrow evening I will have to spend a lot of time with the precision files to clean the edges.

Anyway, as far as educational material is concerned, I can tick the box, that was some good hands on experience. Not afraid of the old cans anymore.

[m k]

it was sent using ePay EIS,

How was the customs clearance?

[oz2cpu]

new score :
Boonton McGraw Edison Standard Signal Generator 800 nuvistor 1973
this one actually works, just need a few new light bulbs so the meter and frequency dial will shine nicely.
frequency range 25 - 470 MHz,
one tiny Nuvistor tube, and one voltage regulator tube, the rest is made using transistors.
here is my video
https://youtu.be/bHmMOG6yx1s

[factory]

it was sent using ePay EIS,

How was the customs clearance?

The VAT was prepaid in ePay checkout, item cost was less than £135, so tax has to be collected by ePay, with no clearance issues, VAT was also refunded along with shipping costs.
Above £135 would get held by customs for separate payment, this may differ depending on country.
https://www.ebay.co.uk/help/buying/paying-items/paying-tax-ebay-purchases.html?id=4771

David

[Vince]

Hmmm... a nice / interesting piece of Niksee TE popped up today here... An AOIP 5 digit micro-ohmmeter. First time I see one.

https://www.leboncoin.fr/equipements_industriels/2327436842.htm

For the low low price of 550 Euros...I wonder how long it will take to sell at that kind of price... or maybe I am clueless and it's a good deal, I don't know....

Looks like it's a modular instrument. The top half of it, bearing the displays, reads "Voltmeter", but the lower half reads "micro-ohmmmeter", so I guess it's a "plugin" and you could have other types of plugins.

ISTR HP had a similar line of modular products, in the red LED era. I remember them being talked about here some time ago.

[factory]

Ouch, and 110 Euros extra for the leads on top of it, I don't know why people want so much for ohmmeters.

The HP system with LED displays must be the 34740A/34750A, normally available with different DMM modules, less common is the thermometer module, both my 34750As are very broken, one has the voltage ref missing.


 


David

[Vince]

Yes that's what I had in mind, these are the ones...

[m k]

Money, one of those relative rules of life.

it was sent using ePay EIS,

How was the customs clearance?

The VAT was prepaid in ePay checkout, item cost was less than £135, so tax has to be collected by ePay, with no clearance issues, VAT was also refunded along with shipping costs.
Above £135 would get held by customs for separate payment, this may differ depending on country.
https://www.ebay.co.uk/help/buying/paying-items/paying-tax-ebay-purchases.html?id=4771

David

So below the threshold it is DDP and above DAP/DPU, or self negotiated with the seller.
Now only ebay unknown is how much is the cost of customs clearance.
And how self negotiated do the money back stuff, but if everything goes through ebay it shouldn't be a big problem.

Here self made customs clearance is free, customs is offering a web page.
One slot is for the customs code and it can be a bit different.
Luckily our case is sort of a text search, with final short list of selections.
Different it can be because occasionally it is a bit counter intuitive.
My cases have been so that I've rejected those that it really is not and then picked something from the rest.

So "and an import processing fee from the carrier" was the issue earlier, I missed that.
It's not VAT nor duty, hence the coordinating conjunction.
It's clearly for those not so regular shippings, that must be covered by the document of this kind.
But what ever, it must be known before hand.
Example would be something that needs human labor before it can be cleared, generally customs officials are free of charge but they are a bit picky of what they do and don't do, until they are not.
Actual customs inspection thing is different, so is random inspection from mandatory one.
Means that your small randomly inspected parcel is probably free but how ever small mandatory inspection is charged as the tariff dictates.

If you must the 2nd last section of the link is Customs procedures in the EU.
I guess UK is very similar, just a bit smaller, currently.

Customs clearance documents and procedures
https://trade.ec.europa.eu/access-to-markets/en/content/customs-clearance-documents-and-procedures

[Neomys Sapiens]

Hmmm... a nice / interesting piece of Niksee TE popped up today here... An AOIP 5 digit micro-ohmmeter. First time I see one.

AOIP is a rather interesting company. I have a portable 1/2.5/5kV insulation tester (megger) from them.

[Neomys Sapiens]

The catch of the day: a British capacitance decade from a company called WPA. 5% is just usable and I got it for only 4.50€ (+8.99€ postage)! What is going on here? Normally C decade boxes are much looked for. Will report on its condition and performance when it is here.

 

[Vince]

QUAD 303 power amp restoration

OK, this evening as planned, I spent some time with my set of precision/tiny files, and scotch brite, to deburr the edges of the cans, make them smooth, and try to make the hack saw cut a little less rough...
Happy with the result... but it should be much faster/better/easier with a pipe cutter, so I think it's the last time I use a hack saw to crack cans open...
However pipe cutters are meant for pluming copper pipes so they can't handle large diameters, so I had to measure a few random cans I had in stock to get an idea of the diameters I would have to deal with, and I really do need to pay attention to what cuter I buy... need the one with the largest capacity...

Anyway, so I then drilled two holes into the base of the can and sticked the snap-in cap in there.... first, because the leads on this type of cap are thick and super short, there is no room for error. You need to drill the holes with the exact pitch of the cap leads, and it's not as easy as it sounds... but I did about OK for my first attempt. Was happy... for about a split second,  the time to realize I was now facing another, much bigger problem : the leads being so short... they hardly traverse the base of the can ! They stick out a minuscule amount, maybe one mm or something... no go  !

I bought these snap-in caps, a few months back , because back then it's the only type of cap that was kinda affordable. "regular" caps with long thing leads, were not available in the voltage and capacitance values required : 450V 2,200uF.

The 450V caps these days are meant for SMPS applications, so were all low values, far from the required 2,200uF.

But that was months ago. Maybe the cap shortage situation has improved today and I could find long lead caps with the proper specs.

But since I have alreadty spent a good bit of money to buy these 4 big KEMET snap-in caps.... I must use them now.
So I think the only way to fix the problem would be to solder bits of wires to the cap, which then could stick out the other side as much as I need.
Problem is that the cap would then have no mechanical support and just be rattling inside the can... no good. So I would need to somehow keep the cap from rattling... maybe superglue it to the can ??

Anyway, another real world problem that needs to be solved....

[Vince]

Hmmm... a nice / interesting piece of Niksee TE popped up today here... An AOIP 5 digit micro-ohmmeter. First time I see one.

AOIP is a rather interesting company. I have a portable 1/2.5/5kV insulation tester (megger) from them.

Oh, they don't make TE of own you mean ? They only rebadge existing TE from other manufacturers ?

So this Niksee TE is made by..... who know who ?! Any idea anyone ?!  Just so I learn something... 

[Neomys Sapiens]

Hmmm... a nice / interesting piece of Niksee TE popped up today here... An AOIP 5 digit micro-ohmmeter. First time I see one.

AOIP is a rather interesting company. I have a portable 1/2.5/5kV insulation tester (megger) from them.

Oh, they don't make TE of own you mean ? They only rebadge existing TE from other manufacturers ?
...

I did not say that!

[TERRA Operative]

For holding the capacitors inside the cans, I 3D printed some sabots, but a good blob of neutral cure silicone caulking would do the job just fine I think.

[wolfy007]

Anyone with a Tek SG504 and a small screwdriver want to do me a big favour? 


I need to see what's under the end cap on the rear of the oscillator assembly.... Gotta make sure mine goes back together properly after some extensive repairs and misplaced photos...

I have a SG504 (somewhere, havent used it for a bit), do you still need someone to take a look?

[TERRA Operative]

All sorted now, thanks!

[m k]

Something else.

[Vince]

Just stumbled upon this thing.

https://www.leboncoin.fr/bricolage/2274953382.htm

Caught my eye somehow.

In good nick for 50 Euros.

A Solartron PSU, type AS 870.2 it looks like.

Looks hollow-state era from the outside, but the front panel reads "transistorized" so...

I like the Vintage look with that cool round meter, love this style of meter so much.... which contrasts with the state of the art feature it offers : digital precision selection of the output voltage, using 3 decade rotary switches. Looks like it can go up to 30V in 0.1V increments.

[oz2cpu]

ups i did it again..
Wavetek model 1001A sweep generator 0.5 - 300MHz 1977
very cool unit, it actually works, can sweep all sorts of analog constructions from 0.5 to 300MHz almost like a spectrum analyzer but where the "detector" is your own analog dc voltage from your circuit.

video about it here

https://youtu.be/RRWu1h0XOE4