Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

Now, which vendor do you think I'd like to recommend?

my experience may have been overcome by events, but tellabs was one of the best for documentation.
<snip>
it may have helped that my mailing address was always an official one..........like "camp swampy" or "ft lots-o-tanks". 
ymmv

You worked for a customer they loved to get orders from. Remember the Bradley. It even ended up as a movie..

In this case, the actual customer was one of the Russian university networks. Not someone I've ever had a relation with, except on TCP port 179.

/Måns, now AS201641, ex-1653,2603,47708,9201

[Cubdriver]

thanks!   will ask the same question i just asked the guy with those 3 nasa nixie counters?

is local pickup available?

(he said yes)

I was contemplating throwing a bid at those, but really shouldn't as I have too much of a repair queue already.  If you're thinking about going for them, then I know they'll go to a good home and will refrain.  Good luck!

-Pat

have not actually made up my mind about them.   for one thing.....they are not hp.

2 hours 12 minutes.   107 miles.  right on the edge of being tempting.

6 days to decide.

You know you want them....   

-Pat

[mnementh]

thanks!   will ask the same question i just asked the guy with those 3 nasa nixie counters?

is local pickup available?

(he said yes)

I was contemplating throwing a bid at those, but really shouldn't as I have too much of a repair queue already.  If you're thinking about going for them, then I know they'll go to a good home and will refrain.  Good luck!

-Pat

have not actually made up my mind about them.   for one thing.....they are not hp.

2 hours 12 minutes.   107 miles.  right on the edge of being tempting.

6 days to decide contemplate your doom.

You know you want them....   

-Pat

There, FTFY.

mnem

[capt bullshot]

This is my audio streaming box (Raspi and hifiberry soundcard inside):



driving a pair of these old speakers:



The small box does bluetooth, pulseaudio and mpd (for home dlna or upnp or whatever you'd call that stuff). The files to be streamed are on my NAS.
Pulseaudio does a nice job for playing sound if your PCs are Linux boxes, and I'm using a smartphone app for internet radio, DLNA playback also controlled by a smartphone app.

The speakers is the second pair of speakers I've bought in my life, IMO still the best ones I have. Though I probably need new ones, because the woofer membranes start to fall apart.

[mnementh]

Hoo boy. I am stayin' oot of this one.

My HT/Audio tastes are too exotic for the one side, and my current near-zero tolerance for assache makes my present setup entirely too plebian for t'other.

No way I can say anything more than I've already said and still be "constructive". 

mnem

You think we have disagreements? Have to ever visited an audiophool forum and watch the fur fly? And those guys play and hold grudges for keeps.

It just proves there is no one "right way" when it comes to audio. Being happy with your set up is all that matters. And I am a happy camper.

Yeah, that is kindof where I was going. I remember a 3-day flamewar over OFC speaker cables with fucking direction arrows on them... 

mnem
not without my chainsword.

[Saskia]

@captn bullshot they can be reconed if the membranes themselves are still good.

[mnementh]

My current streaming solution is: My son's old Kindle Fire playing Amazon Music through 1/8" headphone cable to the HT receiver in ProLogicII/Concert mode.

Simply the least PITA means of commercial-free music, and it leverages an account I'm already paying for. Sound is tolerable; CD-quality most of the time.

Those of you who know better may now point and jeer. 

mnem
Nice pants.

[tautech]

@Cerebus just got a phone call from someone who wanted to buy a PC. I told him that I am selling off my surplus PC test/eval equipment and that my stuff has been slightly used. Then I asked him what he wanted it for to assess if the stuff I had was suitable and sufficient for his requirements.

He said that part was a completely new experience for him.

Normal Modus Operandi here.

Certainly the big retailers are generally just focused on getting units out the door whereas the little guys are more interested in finding the 'best fit' for a customers needs.
Repeat business tells you when you've got the balance right. 

[capt bullshot]

@captn bullshot they can be reconed if the membranes themselves are still good.

It's that foam ring that holds the membrane in place

BTW: now playing:

[AVGresponding]

@captn bullshot they can be reconed if the membranes themselves are still good.

It's that foam ring that holds the membrane in place

BTW: now playing:

Pretty much every part of a speaker can be replaced, it's just whether it's economically viable.

People that can do a good job of it tend to charge quite a bit for their time.



Finished going through the resistor haul, the final count is:

2 x 150W
9 x 100W
277 x 50W (1 faulty)
56 x 25W
62 x 15W
83 x 10W (almost all R22)
51 x 5W

Most of them low ohms values, with a handful of exceptions. Mostly 5%, with a few 10%, and nicely two 1% 5W which would cost £5 each from Mouser.

All in all I think a decent value score, 539 metalclad resistors for £50 shipped, and 1/4 of what the seller originally put them up for.


EDIT: I suspect shenanigans on the part of the manufacturers regarding the power ratings for the 5 and 10W units, as they are physically the same size.
Some kind of constant vs duty cycle rating perhaps.

[mnementh]

Replacing the surrrounds is easy-peasy; just requires careful measurement, patience, and some cement appropriate to the material. Usually rubber cement or latex. I've probably done a hundred or so over the years; dozens for sure. Bigger ones are much easier; you want PITA, try doing it on Bose 901s! Eighteen 4.5" drivers... that turns a "fixup" into a marathon. But they were still worth it.

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20210115111537&isPremium=y&SearchText=speaker+repair

There are oodles of shops on AliEx selling surrounds, coils, cones and spiders as well as all the little gimcracks to spiffy 'em up.

Search YoobToob for "subwoofer surround repair"; there are oodles of videos.

Good hunting! 

mnem
 

[Saskia]

yep, reconing will do the job.
There are reconing services out there that do that for you.

[capt bullshot]

yep, reconing will do the job.
There are reconing services out there that do that for you.

49EUR plus shipping and handling for a 25cm speaker (first hit). I'll think about it. Thanks to mnem too, but I won't try this myself, I guess it'll end up like you tried to replace that tiny smartphone chip.

[Saskia]

don't wait too long, if more of that breaks, the membrane will suffer.

[Robert763]

@captn bullshot they can be reconed if the membranes themselves are still good.

It's that foam ring that holds the membrane in place

Pretty much every part of a speaker can be replaced, it's just whether it's economically viable.

People that can do a good job of it tend to charge quite a bit for their time.


Finished going through the resistor haul, the final count is:

2 x 150W
9 x 100W
277 x 50W (1 faulty)
56 x 25W
62 x 15W
83 x 10W (almost all R22)
51 x 5W

Most of them low ohms values, with a handful of exceptions. Mostly 5%, with a few 10%, and nicely two 1% 5W which would cost £5 each from Mouser.

All in all I think a decent value score, 539 metalclad resistors for £50 shipped, and 1/4 of what the seller originally put them up for.


EDIT: I suspect shenanigans on the part of the manufacturers regarding the power ratings for the 5 and 10W units, as they are physically the same size.
Some kind of constant vs duty cycle rating perhaps.

The big problem with all these resistors is that the rating is only valid when mounted on a big heatsink! It varies by make and model but typically they need a foot square 1.5mm thick aluminium sheet (Welwyn WH50) Even then they will be running very hot .
Note model number may not reflect power raing for resistors below 25W. For example Welwyn WH5 and WH10 are not 5W and 10W  WH5 is 10W WH10 is 15W. You need to check the datasheet for the exact part. Low resistance (<0.5R) typically have a max current rtin of 15A. High resistance values are often voltage limited before they hit their power rating.

[mnementh]

yep, reconing will do the job.   There are reconing services out there that do that for you.

49EUR plus shipping and handling for a 25cm speaker (first hit). I'll think about it. Thanks to mnem too, but I won't try this myself, I guess it'll end up like you tried to replace that tiny smartphone chip.

touche'.

Tho honestly... the big ones tend to be easiest to work with as they are more robust and you can get a hand behind the cone to support it while you work. Hardest part is getting the old surround off; requires patience and sometimes a razor blade. For a first attempt, 10-in/12-in are probably the best mix of easy to handle yet big enough to get a hand into.

Cheers,

mnem
 

[Robert763]

Not only is there bugger all on ebay, the UK site has a new bug. when you run a saved advance search it keeps popping up a "Pardon our interruption" page saying it thinks you are a bot 

[capt bullshot]

The big problem with all these resistors is that the rating is only valid when mounted on a big heatsink! It varies by make and model but typically they need a foot square 1.5mm thick aluminium sheet (Welwyn WH50) Even then they will be running very hot .

That's how they look when not appropriately heat sinked:


BTW: The smell is really toxic

[mansaxel]

Hoo boy. I am stayin' oot of this one.

My HT/Audio tastes are too exotic for the one side, and my current near-zero tolerance for assache makes my present setup entirely too plebian for t'other.

In the hi-fi realm, I've long been an advocate for taking the best from the pro audio sphere and repurposing it. French company L-Acoustics who are some of the most respected in pro audio (together with the likes of d&b Audiotechnik and Meyer Sound) have made versions of their sound reinforcement speakers available for domestic use. Not cheap. Soooo tempting.

But I guess I'll keep looking for a decent pair of Yamaha NS-1000M. That would be something. I had a pair of them at pre-previous employer. I remember that fondly.

[mnementh]

Whaaaaaaaat...?

   

*just recovered from storage and awaiting redeployment in the LR*

mnem
 

[mansaxel]

It's that foam ring that holds the membrane in place

These people might just have what you're looking for.

[Saskia]

I have a friend doing speaker repairs.
Should I ask him ?
Let me know.

He's one of the pros. Not cheap, but takes pride in his work.
Alternative: he can get you 2 new chassis and tell you how to adapt the crossover.

Just an offer.

The speakers he designed:

https://www.hifi-spectrum.de/cms/index.php?id=365

[AVGresponding]

The big problem with all these resistors is that the rating is only valid when mounted on a big heatsink! It varies by make and model but typically they need a foot square 1.5mm thick aluminium sheet (Welwyn WH50) Even then they will be running very hot .
Note model number may not reflect power raing for resistors below 25W. For example Welwyn WH5 and WH10 are not 5W and 10W  WH5 is 10W WH10 is 15W. You need to check the datasheet for the exact part. Low resistance (<0.5R) typically have a max current rtin of 15A. High resistance values are often voltage limited before they hit their power rating.

Yes, I am aware of the heatsinking requirements, and I took the ratings from the manufacturers data sheets.

[cyclin_al]

On the topic of TEA, here is the best I can do so far this year:

[Robert763]

The big problem with all these resistors is that the rating is only valid when mounted on a big heatsink! It varies by make and model but typically they need a foot square 1.5mm thick aluminium sheet (Welwyn WH50) Even then they will be running very hot .
Note model number may not reflect power raing for resistors below 25W. For example Welwyn WH5 and WH10 are not 5W and 10W  WH5 is 10W WH10 is 15W. You need to check the datasheet for the exact part. Low resistance (<0.5R) typically have a max current rtin of 15A. High resistance values are often voltage limited before they hit their power rating.

Yes, I am aware of the heatsinking requirements, and I took the ratings from the manufacturers data sheets.

What part numbers were the 5W and 10W of the same size? I've never seen that.
The Ohmite 805 is 5W and similar to the 10W Welwyn WH5 but the WH5 is actually 1.1mm longer in the body than the 805 despite having the same mounting centres.