Test Equipment Anonymous (TEA) group therapy thread

[worsthorse]

It's antenna day here. I put the soaked coax on the NanoVNA and unfortuntely it wasn't very interesting at all. Literally high VSWR down the entire line.

This time I'm not screwing it up so I have put together a new head for it which is a bit better designed than the original i.e. it has the coax entry pointing down, is shrinked properly and then coated in liquid tape just to make sure.



Please excuse the pikey current balun. They are cheap and work! (Fair-rite 5943003801 - Amidon can fuck off with their markup!)

Edit: the wire is sotabeams stuff which is awesome. It doesn't stretch at all https://www.sotabeams.co.uk/antenna-wire-lightweight-100m/

Also the moment I decided to go out and set it up it started pissing it down. 

That's a right proper way to construct a feed line connection. And there's nothing wrong with that choke either, though I'd probably wrap it before I put it in the air.   

I have a couple of wires up with the sotabeam wire. Nice stuff.

[med6753]

Well....that didn't take long. The RCA scope is model 54-45 and is nothing more than a re-badged EICO 430. I thought it looked familiar. And to top it off it was a kit, just like the EICO. No wonder it looks like Gorilla's in there.

I found a copy of the original entire manual including schematic on Bama archive.


 

[worsthorse]

Gettin' rid of something, buyin' something else.    

I have a buyer for the Keithley 197 I posted on CL three or four weeks ago.  That sale will cover the purchase of the allegedly working HP 5328A with GPIB, high stability time base, 500MHz channel, and DVM options.  Not a bad trade!

If the incoming 5328A works as advertised (or I can get it working), I will put the current 5328A on my bench, which doesn't have all the goodies, on the market.

[med6753]

The RCA scope has been powered up for a little over an hour and in addition to some noise on the trace it also keeps drifting up which indicates a leaky inter stage coupling cap. And I don't know where this scope was stored but man does it ever stink.  First order is to pull all the tubes and clean the chassis. Then going to pull together list of replacement capacitors. I'll spot check resistors for now.

For those unfamiliar with EICO they were a kit manufacturer located in NYC and a competitor to Heath. They made decent kits and in some respects were superior to Heath. Some of their stereo equipment is today in high demand and commands premium prices. I don't know if they ever did business in the EU. By the early 1980's they were pretty much out of business. I do have one of their catalogs in my records.     

[0culus]

Well....that didn't take long. The RCA scope is model 54-45 and is nothing more than a re-badged EICO 430. I thought it looked familiar. And to top it off it was a kit, just like the EICO. No wonder it looks like Gorilla's in there.

I found a copy of the original entire manual including schematic on Bama archive.

Huh, I'm wondering exactly how useful such a scope is other than "hey look there's an AC signal here" or displaying X-Y mode (since it has separate vertical and horizontal inputs).

[med6753]

Well....that didn't take long. The RCA scope is model 54-45 and is nothing more than a re-badged EICO 430. I thought it looked familiar. And to top it off it was a kit, just like the EICO. No wonder it looks like Gorilla's in there.

I found a copy of the original entire manual including schematic on Bama archive.

Huh, I'm wondering exactly how useful such a scope is other than "hey look there's an AC signal here" or displaying X-Y mode (since it has separate vertical and horizontal inputs).

That's really about it. I didn't realize until now that apparently when you were a student at the RCA Institutes that part of the program was to build this scope for your use. They also had home correspondence courses so I assume building this scope was part of that program too.

And yes, to us this is real mundane. But to a newbie it really seems amazing.   

[0culus]

Yeah, it's a pretty cool project. You certainly would learn a lot from building it. 

[Neomys Sapiens]

I will find a way to put the little ONYX2 also in this work room, to play with the amazing grafix ("reality engine"). Not museum.

I tried to look this up and I need a bulk shipment of brain bleach right now!

[Barbouri]

Huh, I'm wondering exactly how useful such a scope is other than "hey look there's an AC signal here" or displaying X-Y mode (since it has separate vertical and horizontal inputs).

I have two of the EICO 435's and use one for looking at AC signals and the other in X-Y mode for component curve tracer, just as you mentioned.
They are not used very often, about twice a month but handy when I do need them.
They also make great heaters for the room during the winter.

[tautech]

It's antenna day here. ......

This time I'm not screwing it up ........

But you still did, sort of ! 

Nutthing wrong with the ferrite just the way you used it with the tight coax wraps exceeding the min bending radius of the coax. 

Use a couple of ferrites and secure them in place with cable ties not tight radius coax wraps.

[bd139]

Mind bend is repeated bending. You can half it for permanent bends on non foam RG58.

Edit: see datasheet for example https://www.pasternack.com/images/ProductPDF/RG58C-U.pdf

[med6753]

Huh, I'm wondering exactly how useful such a scope is other than "hey look there's an AC signal here" or displaying X-Y mode (since it has separate vertical and horizontal inputs).

I have two of the EICO 435's and use one for looking at AC signals and the other in X-Y mode for component curve tracer, just as you mentioned.
They are not used very often, about twice a month but handy when I do need them.
They also make great heaters for the room during the winter.

Interesting, those 435's have blue cabinets. This 430 clone has gray with some rust and crud. Not for long! 

[Specmaster]

I had been casually watching this rather rare Time Electronics 5075 DMM on eBay over the last few days and it had sat at £80 for the best part of that time but in the closing seconds of the auction it shot up and finally went for £361.77. Just wondering if it was anyone from this thread who was the winner in the end.

What attracted me to it was the firms reputation for top notch gear, British made and its lovely rich blue display, but hell it one hell of a boat anchor.

[Specmaster]

Wow, is this a audiofool or an audiophil, thoughts please, but this is alledged to be a 1,000,000$ audio system and to me, it sounds nothing special at all.

And the unique thing about it is that does not use any capacitors at all in its design.

[bd139]

Ah so they’ve worked out how to sell invisible capacitors now too!

Incidentally all audiophilery is absolutely bullshit through and through. Even spending £10k on something which is pretty low balling in the audiophile stakes means you’ve spent £10k on something to listen to a low rate recorded by some cheap ass muso hammering shit out on a set of instruments held together with duct tape while the sound engineer was stoned and drunk at the same time. Buying a £50 cable doesn’t get rid of that rusty POS Chinese 1/4” patch they used when they recorded it.

Honesty the nearest thing I’ve heard to reality and this is quite surprising was a concert I went to (penguin Cafe). I recorded a couple of tracks on my phone’s built in mic and listened to them later on the provided earphones and it was pretty damn on the mark. You could hear all the piss poor tuning and mistakes. None of that edited shit.

[Zucca]

Yardsale:

https://www.eevblog.com/forum/buysellwanted/fs-(eu)-bk-precision-8500-dc-load-350/
https://www.eevblog.com/forum/buysellwanted/fs-(eu)-bk9310-psu-2x/
https://www.eevblog.com/forum/buysellwanted/fs-(eu)-tenma-72-2645-2-x-0-30v-0-5a-1-x-5v-0-3a-usbrs232/

and... and...

https://www.eevblog.com/forum/buysellwanted/fs-(eu)-immaculate-agilent-msox3054a-full-opt-4500/

boom

[Neomys Sapiens]

I had been casually watching this rather rare Time Electronics 5075 DMM on eBay over the last few days and it had sat at £80 for the best part of that time but in the closing seconds of the auction it shot up and finally went for £361.77. Just wondering if it was anyone from this thread who was the winner in the end.

What attracted me to it was the firms reputation for top notch gear, British made and its lovely rich blue display, but hell it one hell of a boat anchor.

Rather rare indeed. Maybe being rare as well as British, in addition to having a rich blue display and a top notch manufacturer were only secondary. I have to admit that I was unaware of it's existence, even as I have a R decade and a current source from them. It has some unique features.
A 7.5 digit instrument with integral 10kV DC and 3 kV AC ranges as well as 30A. I already like it.

[Zucca]

With rotten shellac on still-good copper like that (all those "dark" areas of Shellac over copper are "rotten"), leaving it will just result in the rot spreading; but you have to balance the need to repair against the possibility of damaging a trace. Correct solution is to mask off the edges of the trace with something like Kapton tape to protect the substrate, use fine steel wool to scrub all rotten shellac off a section of trace leaving shiny copper, then remove the masking and move to the next area of trace until it is all either clear shellac or shiny copper.

After that, clean with IPA and paint with new shellac or clear fingernail polish. Epoxy is also perfectly fine, I've used it in a pinch; just be sure to make a thin coating using a flattened & cut-off Q-Tip stick or coffee stirrer as a squeegee.

If i have any doubts as to whether the thickness of the trace has been compromised by acid etching, I consider reinforcing with wire or tinning the trace. This is best done by applying rosin to the shiny cleaned copper trace, then starting at a solder pad and adding a fair blob of solder, then dragging the iron across the bare copper through the flux. Work a little hot & as fast as you can to avoid lumps and to avoid damaging the trace/substrate bond. This requires a fair amount of practice and soldering skill; you need to practice a lot on junk boards to get your technique down pat. After the trace is tinned, clean up the solder pad areas where you started tinning from and paint the trace as above.

mnem
moo...?

mnementh what about now? Thanks for making me work like a dog during the week-end. Sorry the out of focus....
PS: glass fiber cleaner is like magic...

[xrunner]

Incidentally all audiophilery is absolutely bullshit through and through. Even spending £10k on something which is pretty low balling in the audiophile stakes means you’ve spent £10k on something to listen to a low rate recorded by some cheap ass muso hammering shit out on a set of instruments held together with duct tape while the sound engineer was stoned and drunk at the same time. Buying a £50 cable doesn’t get rid of that rusty POS Chinese 1/4” patch they used when they recorded it.

Yes but it takes a whole lot of expensive gear to reproduce the sound of that crap faithfully. 

[bd139]

Incidentally all audiophilery is absolutely bullshit through and through. Even spending £10k on something which is pretty low balling in the audiophile stakes means you’ve spent £10k on something to listen to a low rate recorded by some cheap ass muso hammering shit out on a set of instruments held together with duct tape while the sound engineer was stoned and drunk at the same time. Buying a £50 cable doesn’t get rid of that rusty POS Chinese 1/4” patch they used when they recorded it.

Yes but it takes a whole lot of expensive gear to reproduce the sound of that crap faithfully. 

That’s a fair point 

[Neomys Sapiens]

mnementh what about now? Thanks for making me work like a dog during the week-end. Sorry the out of focus....
PS: Carbon fiber scraper is like magic...

(Attachment Link)

Carbon fibre? I was going to recommend using one of the well known glass fibre cleaners/burnishers, but I have not heard of such one. Please tell us more!

[tggzzz]

I had been casually watching this rather rare Time Electronics 5075 DMM on eBay over the last few days and it had sat at £80 for the best part of that time but in the closing seconds of the auction it shot up and finally went for £361.77. Just wondering if it was anyone from this thread who was the winner in the end.

What attracted me to it was the firms reputation for top notch gear, British made and its lovely rich blue display, but hell it one hell of a boat anchor.

It also had a manual, which is useful since there's bugger all info on the web.

I was looking too, but the price was more than I am prepared to pay - at least until after I have sold some of my other 19" multimeters. Certainly at least one Solartron 7075 has to go, and if I get something like that 5075 then maybe a Datron 1061 disappears - but that would leave me with no Panaplex displays[1].

My Solartron 7081 is staying

[1] unless I repurpose the display from the third 7075

[med6753]

Wow, is this a audiofool or an audiophil, thoughts please, but this is alledged to be a 1,000,000$ audio system and to me, it sounds nothing special at all.

And the unique thing about it is that does not use any capacitors at all in its design.

There's no limit to how high you can pile bullshit. 

[tggzzz]

Incidentally all audiophilery is absolutely bullshit through and through. Even spending £10k on something which is pretty low balling in the audiophile stakes means you’ve spent £10k on something to listen to a low rate recorded by some cheap ass muso hammering shit out on a set of instruments held together with duct tape while the sound engineer was stoned and drunk at the same time. Buying a £50 cable doesn’t get rid of that rusty POS Chinese 1/4” patch they used when they recorded it.

Yes but it takes a whole lot of expensive gear to reproduce the sound of that crap faithfully. 

... and then consider an orchestra recorded with the hypothetical perfect recording chain.

Where do you put the microphones? By the conductor, in the first/tenth row, central/left/right, etc. In all those places you would perfectly reproduce different sounds. Which of those would be "righter" that all the others.

[Neomys Sapiens]

That Time Electronics DMM is no boat anchor.
THIS is a boat anchor - and a strange beast to boot!

https://www.artisantg.com/TestMeasurement/83660-1/RCA_DAAH01_70_A_0039_Digital_Multimeter