Test Equipment Anonymous (TEA) group therapy thread

[factory]

  a stupid film for clicks, nothing more.

That one was a bit crap, unless I missed it he never explained why the lead free 2N3055 failed originally. I enjoy the wasp HV experiments more.

There is plenty of more sensible content on that channel, mostly of vintage electric meters.

David

[mnementh]

time to keep that glowing, my test eq oldies want to test anything sometimes.
I will start with construction of a FM radio, tubes, solding stripes, black, wires binding,  same design then my audio amplifier see below 

Which glowing tubes will you use Martin ?

[img height= 120]https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=635731;image[/img]

it must not be compatible to all common tube radios.
really fascinating is a inductive mechanical tuning, but at first something to study: What is the good vs. bad of self oscillating mixer stages? Why they never used a seperated oscillator and mixer system??
There will be some breadboarding required to find a nice solution 

1. system = triode (HF preamplification, selective, tuned)
2. system = mixer to 10.7 MHz  (self oscillating or..
2a: oscillator
3+4: EF184 or like that, penthode IF i need a high signal level
5: FM demodulator stage, 6BN6
6: any audio, EL84 can do the job

catalog parts make me tired, means I use homebrew filters, solding stripes, coils, all selfmade.

Using sweeper, Spec, Oszi, DMM, heathkit tubes PSU, Tek130 for unknown L or C, nixie frequency counter  and a lot of junk and sheet metal.

Martin

No mercy on those of us NOT named Tesla, eh?  Going to go entirely with values which can't be approximated using off-the-shelf... so we can't even IMAGINE ourselves playing along at home...? 

You glorious bastard you! 

   That reminds me of this. I don't know the source but it's in my "wtf" folder:

Oh, wow.  TO3 twilight!

mnem

"Because nobody doesn't love Molten Boron!!!"

[med6753]

All this talk of PC's lately have persuaded me to open up the Media PC up and take a look for dust/dirt. Been a few years.

Not bad at all. Some dust on the fan blades and a little in the processor heat sink. Brushed it out.

Yes, my cable dress sucks and it's no where near purty as mnem's. It works and I'm leaving it alone. 

   

[tautech]

All this talk of PC's lately have persuaded me to open up the Media PC up and take a look for dust/dirt. Been a few years.

Not bad at all. Some dust on the fan blades and a little in the processor heat sink. Brushed it out.

Yes, my cable dress sucks and it's no where near purty as mnem's. It works and I'm leaving it alone. 

Next you'll be telling us you're strapped for time to clean it up to something like respectable.     

[Martin.M]

oh my god what I have done there ... 40 bucks for this adventure ..  need TEA
so this little HP will go on the way to a house full of tube scopes, to be restorated there.
looks to be under volted in the vertical deflection of the monitor part.

[bd139]

That’s a nice scope that and in very good condition. Easy fix as well. Check the small electrolytic near the rear left of the CRT assembly looking at it from behind. It will have leaked. This will fix display. Have to take the CRT module out then get the board off that to get at it though. Standard failure mode for these 

If you’d got it earlier I would have send you a free knob as I had some but alas eBay buyer got there first.

[Martin.M]

thank you 
when the scope is here I will do that and report what is comming.
Martin

[Martin.M]

may be I can buy the knob in the HP group

[Mr. Scram]

Plenty of cheap knobs here, I'd say.

[bd139]

Yeah they should have them floating around. I just checked my junk box to see if there were any I missed but they’re all gone. I have a power switch bar and brightness control and that’s it.

[med6753]

Next you'll be telling us you're strapped for time to clean it up to something like respectable.     

It's respectable. It's under the covers. It works. I'm not trying to win any beauty contests. Out of sight. Out of mind. 

[tautech]

Next you'll be telling us you're strapped for time to clean it up to something like respectable.     

It's respectable. It's under the covers. It works. I'm not trying to win any beauty contests. Out of sight. Out of mind. 

LOL, I know.....just poking some borax. 

Like mnem I like to have them tidy under the hood just in some way to not hinder airflow and to have better access when chasing the dust out.

[bd139]

I'm a cable nazi so mine are always tidy. Or in AWS where there are no cables I have to organise

[med6753]

I'm a cable nazi so mine are always tidy. Or in AWS where there are no cables I have to organise

Hey, you guys are always poking me about my neat bench. So I gotta be sloppy somewhere. 

[bd139]

My sloppy is in the housework department 

[Specmaster]

oh my god what I have done there ... 40 bucks for this adventure ..  need TEA
so this little HP will go on the way to a house full of tube scopes, to be restorated there.
looks to be under volted in the vertical deflection of the monitor part.

Wow, I think you did well there and if bd is right about that cap, you got yourself a steal.

[tautech]

I'm a cable nazi so mine are always tidy. Or in AWS where there are no cables I have to organise

Hey, you guys are always poking me about my neat bench. So I gotta be sloppy somewhere. 

I didn't care too much about neatness under the hood of a PC either until I was asked to look at one that was intermittent booting, once it did it was fine. You had to keep pressing the power button until it latched and booted. 
Turned out the PSU was shutting down due to high current draw from dud motherboard caps....they looked OK but one nearly burnt my finger while poking around to see if there were any hot spots. Amazing it hadn't already launched its can and covered the PC insides in confetti. 
Replaced all the 1000uF caps.......some were sick and some buggered and the PC behaved perfectly thereafter.

Since then I've been just a little anal about unimpeded airflow inside a PC case. 
Bit of a fan of modern mainboards with solid caps now. 

[0culus]

Too early to be certain yet, but I think the OCXO in this 8568B RF unit might be the culprit for the noise floor issue. I hooked it up to the ref out on my 5335A and, so far, the noise floor in max hold is staying put, whereas I can watch it go up on internal ref. I'm hoping that I can replace the OCXO and the attenuator and fix the problems.

[bd139]

Found my thread on the HP 54602B ... same display problem: https://www.eevblog.com/forum/testgear/hp-54602b-oscilloscope-problems-repair/

[tggzzz]

My sloppy is in the housework department 

... Engineering approximation...
... Appropriate tech...
... The best is the enemy of the good...
... Life's too short...

[beanflying]

I'm a cable nazi so mine are always tidy. Or in AWS where there are no cables I have to organise

Hey, you guys are always poking me about my neat bench. So I gotta be sloppy somewhere. 

Wonder why we only get shots above the nice clean bench from the top. What rats nest lurks below? 

[VK5RC]

If you don't mind, I am a quite expensive knob!
HiHi

[mnementh]

↑ Knob 1.

mnem  _←  Knob 2.

Weeth seex you get egg loll.

[mnementh]

http://www.collectspace.com/news/news-012519a-sundance-apollo11-documentary-premiere.html

Holy shit. They found them; the archives Buzz Aldrin was talking about. This is amazing.

mnem
*Salute*

[Inverted18650]

Modified Gen_Rad_ Type_1432-M. featuring the 1M & 10M range's