Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 2023550 times)

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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43150 on: November 20, 2019, 08:18:10 pm »
the both bulbs are interesting
Indeed, additional winter lab heating.  :)

Watch out with those black metal tubes, it could be the anode (Yes, personal experience  :( )

Not an issue with those 6SH7's. No connection to the metal shell.
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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43151 on: November 20, 2019, 08:29:22 pm »
Finally received the capacitors for the RCA 54-45 Scope. Here's the new B+ filter capacitors installed on the terminal strip. 1- 47uf/450v and 3- 22uf/450V. This replaces the original 4 section metal can. After that was complete re-installed the CRT.




Replaced 1 -50uf/10V cap in the vertical pre-amp and decided to give the scope a test before going any further. All I can say is "Wow".  :-+ The trace is now sharp and stable. The B+ can was definitely defective. And I still have to replace the caps in the Horizontal/Sync section and the HV caps. But this guy is looking great as is. And at this point I don't see the need to perform the OA2 VR mod.



Tomorrow I'll replace the balance of the capacitors and then this one should be done.  :-+

An old gray beard with an attitude.
 
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43152 on: November 20, 2019, 08:38:45 pm »
Ahh yes the wanton disrespect of RFC email addresses across the internet buggers that up. I do a Cerebus and I’ve got an email alias for each account I create. It’s all in keepass so I don’t give a crap :). I use the last 8 characters from a GUID for each one. Not automated as it wasn’t worth it.

Still trying to not buy an IC-7300. Come on people you are enablers. Do your jobs!
I like the IC-7300 a nice SDR with a brilliant display and is fully customisable, go on you know you want it don't you so what are you waiting for.....  >:D

There you go, I sorted it for you  :-DD
Who let Murphy in?
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43153 on: November 20, 2019, 08:44:55 pm »
(Attachment Link)


Wow, are they Philips handheld DMMs in the background?
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Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43154 on: November 20, 2019, 08:49:41 pm »
I have washed it with windows cleaning fluid  :)
the both bulbs are interesting
I think that those bulbs might be part of a feedback circuit, I remember reading about bulbs being used for purpose somewhere.
Who let Murphy in?
 

Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43155 on: November 20, 2019, 08:54:17 pm »
I have washed it with windows cleaning fluid  :)
the both bulbs are interesting
Any special procedure?
 

Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43156 on: November 20, 2019, 09:02:22 pm »
The flip side to that scheme is that it's relatively easy to guess what the 'add part' is and so if a malicious party has obtained a legitimate 'base part' it's trivial for them to automate trying alternative 'add parts' on the most lucrative targets to find a valid combination by brute force. The random user part is impractical to brute force (the scheme I use has ~ 44 bits of entropy) but requires you to have access to a mail server where you can add as many user parts as you like to an email domain without (significant) additional costs to oneself.

Although all the above is true, I don't regard it as a significant weakness in your scheme. I tend myself to regard the random email address as 'security by obscurity' and really use it for the purposes of 'traitor tracing'. It's having a unique, random password per site that gives me some comfort. As you say, broken implementations that don't follow RFC822 et seq are the pain point for your scheme, and they are, from experience, so common that it's a serious drawback.
I've abused the catch all functionality before to generate as many unique addresses as is needed without having actual mailboxes or even aliases attached to them. It saves a bit of work and you can use cheaper hosting schemes if you don't run a mailserver yourself.
« Last Edit: November 20, 2019, 09:04:11 pm by Mr. Scram »
 

Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43157 on: November 20, 2019, 09:08:21 pm »
The flip side to that scheme is that it's relatively easy to guess what the 'add part' is and so if a malicious party has obtained a legitimate 'base part' it's trivial for them to automate trying alternative 'add parts' on the most lucrative targets to find a valid combination by brute force. The random user part is impractical to brute force (the scheme I use has ~ 44 bits of entropy) but requires you to have access to a mail server where you can add as many user parts as you like to an email domain without (significant) additional costs to oneself.

Although all the above is true, I don't regard it as a significant weakness in your scheme. I tend myself to regard the random email address as 'security by obscurity' and really use it for the purposes of 'traitor tracing'. It's having a unique, random password per site that gives me some comfort. As you say, broken implementations that don't follow RFC822 et seq are the pain point for your scheme, and they are, from experience, so common that it's a serious drawback.
I've abused the catch all functionality before to generate as many unique addresses as is needed without having actual mailboxes or even aliases attached to them. It saves a bit of work and you can use cheaper hosting schemes if you don't run a mailserver yourself.

What catch all functionality? Can you expand a bit, please, since you hint at something which might be easy and general purpose.
There are lies, damned lies, statistics - and ADC/DAC specs.
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43158 on: November 20, 2019, 09:12:09 pm »
Probably any unmatched local-parts go to one mail box. You can do it with virtual_alias_maps in postfix. I don't like that because you can't nuke individual aliases when you've had enough of receiving crap from them :)

I no longer run any mail servers. Horrible horrible job with the big players thinking you're shit, DKIM, DMARC configs etc. Using Fastmail. Not sure if it does that. I haven't checked.
 

Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43159 on: November 20, 2019, 09:27:48 pm »
Ahh yes the wanton disrespect of RFC email addresses across the internet buggers that up. I do a Cerebus and I’ve got an email alias for each account I create. It’s all in keepass so I don’t give a crap :). I use the last 8 characters from a GUID for each one. Not automated as it wasn’t worth it.

Still trying to not buy an IC-7300. Come on people you are enablers. Do your jobs!
I like the IC-7300 a nice SDR with a brilliant display and is fully customisable, go on you know you want it don't you so what are you waiting for.....  >:D

There you go, I sorted it for you  :-DD

That's what I like to hear! Taking some deep breaths and a run up. ML&S have some in stock  :scared:

 

Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43160 on: November 20, 2019, 09:39:37 pm »
What catch all functionality? Can you expand a bit, please, since you hint at something which might be easy and general purpose.
What bd139 says. :) You can set an address to receive all mail without a valid mailbox address on that domain. So you can supply a party with a random non-existing address and it will arrive in the catch all mailbox. Most hosting services allow this. You'll still be able to see to which address it was sent so catching a rat is no problem. This method allows you to pull an address out of your nether parts and use it without configuring anything specifically for that address. It works by default.

I guess not being able to block specific parties is a drawback but I guess you could use something like mail rules to mitigate that. Or you could always create a proper mailbox to catch any mail going to the offending address when things go awry after the fact. It's all pros and cons.
« Last Edit: November 20, 2019, 09:42:27 pm by Mr. Scram »
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43161 on: November 20, 2019, 11:18:43 pm »
Ahh yes the wanton disrespect of RFC email addresses across the internet buggers that up. I do a Cerebus and I’ve got an email alias for each account I create. It’s all in keepass so I don’t give a crap :). I use the last 8 characters from a GUID for each one. Not automated as it wasn’t worth it.

Still trying to not buy an IC-7300. Come on people you are enablers. Do your jobs!
I like the IC-7300 a nice SDR with a brilliant display and is fully customisable, go on you know you want it don't you so what are you waiting for.....  >:D

There you go, I sorted it for you  :-DD

That's what I like to hear! Taking some deep breaths and a run up. ML&S have some in stock  :scared:


Its also quite small by the look of it, ideal for your little bench, assuming thats where you'll put it
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Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43162 on: November 20, 2019, 11:20:13 pm »
Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43163 on: November 20, 2019, 11:30:25 pm »
I have washed it with windows cleaning fluid  :)
the both bulbs are interesting
I think that those bulbs might be part of a feedback circuit, I remember reading about bulbs being used for purpose somewhere.
ALC as rendered by HP's original 200A oscillator, I'll wager.

mnem
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Online Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43164 on: November 20, 2019, 11:37:52 pm »
Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.

Hmm, you seem to have the knack for domestic appliances dying on your watch. However, I won't taunt you like I did with my menus of roast and baked things when your oven went west. I'll just grab a cold beer, lean back and watch everybody else taunt you...
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Offline Mr. Scram

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43165 on: November 20, 2019, 11:39:22 pm »
Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.
Could be worse. You could have found out tomorrow.
 

Online Carl_Smith

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43166 on: November 20, 2019, 11:39:58 pm »
So there is a site called https://haveibeenpwned.com/ where you can enter your email adddresses and it will tell you if they have appeared in any data breaches.

But it has another useful feature if you are not of the type to generate unique passwords for every site.  If you choose to trust the site, click the "passwords" link at the top, and enter your passwords, and it will tell you if they have been seen in any of the data breaches.

Why does this matter?  The hackers hoover up all those passwords and put them at the top of the list, ordered by how common they are, when they brute force crack logins with a dictionary attack.  So if you or anyone else has lost your passwords in a data breach your account will be cracked much faster if someone actually makes an attempt.


Online bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43167 on: November 20, 2019, 11:44:34 pm »
I have washed it with windows cleaning fluid  :)
the both bulbs are interesting
I think that those bulbs might be part of a feedback circuit, I remember reading about bulbs being used for purpose somewhere.
ALC as rendered by HP's original 200A oscillator, I'll wager.

mnem
*dwagon on the loose in the Great White North*

That be correct. I build those occasionally using opamps. They're pretty good. It's possible with a not too shoddy opamp to get a remarkably good sine out. Heathkit also featured the same feedback mechanism in the ET-3100 trainer which actually had a better signal generator than some function generators on the market!





Only problem is they take time to settle, age poorly and usually require manual trimming. Thus they are replaced with a JFET as a variable resistor driven from a peak detector on the output now.

I noticed a design in AoE 3e which was quite interesting. They used a crap square oscillator running at 10x the frequency desired and rammed it through a switched capacitor filter. Very neat. I might build one.

Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.

Hmm, you seem to have the knack for domestic appliances dying on your watch. However, I won't taunt you like I did with my menus of roast and baked things when your oven went west. I'll just grab a cold beer, lean back and watch everybody else taunt you...

Hahaha I'd completely forgotten about that disaster  :-DD

Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.
Could be worse. You could have found out tomorrow.

Indeed. Turns out most of the stuff didn't need to be refrigerated that was in there. I'll stick the meaty things in the freezer (fortunately separate) and deal with it tomorrow!
 

Offline Sam Spastic

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43168 on: November 21, 2019, 12:33:35 am »
Glad to see another Firefox user. Chrome is such an asshole of a browser.

Long-time Firefox user here, too. I have other browsers installed for testing, etc., but FF is my daily driver.

My browser history: NCSA Mosaic > Netscape Navigator > Netscape Communicator > Mozilla Application Suite/SeaMonkey > Mozilla Firefox

I also used Waterfox for a couple of years during the Quantum/extensions fiasco so I could keep using existing add-ons.
Same here - except dual-based with IE. One can say many things against MS and IE, but their Favorites storage is transparent and stable over the versions. Came also from Netscape to Mozilla.
Running TenFourFox here.(PowerPC) Have about 50 tabs open to the evilBay.
Also started with Mosaic. (Amiga computer)
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43169 on: November 21, 2019, 12:44:57 am »
@bd bugger re the fridge, re the sdr, I had the 7300 and was pretty happy with it, but got the 7610  -  I think well worth the extra money - I sold the 7300.
Both good radios really - the man made noise is the big problem here - a -'big' (about 40m perimeter) horizontal loop at about 10m height with ladder feedline - 4:1 balun then atu SGC 230 works the best at my place.
de Rob
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Whoah! Watch where that landed we might need it later.
 
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Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43170 on: November 21, 2019, 12:50:30 am »
Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.

My fridge is >30 years old, as is my dishwasher. I've had them from new. No, they weren't particularly expensive examples.
My freezer is >25years old, and cost £10 second hand.
Car is 15years/0.11Mmiles old, gets serviced twice a decade whether it needs it or not.

So, WTF is going on under the flightpath into Heathrow? :) Alternatively, since I used Which?'s reports as the basis for most of those choices, I consider that subscription a bargain :)
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline tggzzz

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43171 on: November 21, 2019, 01:03:04 am »
I noticed a design in AoE 3e which was quite interesting. They used a crap square oscillator running at 10x the frequency desired and rammed it through a switched capacitor filter. Very neat. I might build one.

Or look at a DDS data sheet, which often has a 7th order elliptical filter on the output. Cuts the oversampling down significantly.

Oh, don't use X7R capacitors in the filter :)

Quote
Indeed. Turns out most of the stuff didn't need to be refrigerated that was in there. I'll stick the meaty things in the freezer (fortunately separate) and deal with it tomorrow!

Chill out (ho ho):
  • think of game, where traditionally pheasant is ready when its body is found on the floor
  • in a supermarket the decent steak has been aged for a month at ~10C - i.e. current outside temperatures
  • this place http://meatboxbristol.co.uk/ ,where some of the (expensive) beef has been in the fridge since mid-August
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
Having fun doing more, with less
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43172 on: November 21, 2019, 01:29:19 am »
Yeah it is. Have had to put it off for a couple of days. Just found the sodding fridge has conked out :--. Literally 2 hours after a week of shopping arrived FFS.

My fridge is >30 years old, as is my dishwasher. I've had them from new. No, they weren't particularly expensive examples.
My freezer is >25years old, and cost £10 second hand.
Car is 15years/0.11Mmiles old, gets serviced twice a decade whether it needs it or not.

Two things spring to mind here, yes of course appliances will typically last that long if you don't switch them on  >:D :-DD :-DD 

Seriously appliance were really made much better than they are today, back in the day when you brought those, even over engineered in some cases, barn door engineering is the phrase I think?

So, WTF is going on under the flightpath into Heathrow? :) Alternatively, since I used Which?'s reports as the basis for most of those choices, I consider that subscription a bargain :)

Do you still subscribe? If so and have done ever since you made those purchases then its possible that you might have over the years paid the différance once you get round to actually replacing them no? :-// :-DD :-DD
Who let Murphy in?
 

Online Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43173 on: November 21, 2019, 01:38:52 am »
@bd139, That's a real bummer but look on the Brightside, its also Black Friday this week, you might find a real bargain fridge. Start trawling the web looking the early bird deals, Amazon have emailing me with their earlybird deals because I'm a prime user, just got myself an Amazon Echo Plus with a £100 off for just £49.99, now to look for compatible gear that I can remotely control via it and then I can be a proper coach potato  :-DD :-DD
Who let Murphy in?
 

Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #43174 on: November 21, 2019, 04:12:05 am »
Mmmmhmmm... and have your WiFi credentials cyclically broadcast in plaintext by the front doorbell.  :palm: Fuck Amazon Echo and everything it does for to you.

mnem
I didn't do thaaaat... >:D
 


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