Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

I was already into the hobby but my first Heathkit was an AA-14 Amplifier. And it did work the first time I plugged it in. 

For how long? 

My kit-built Heathkit AR-2000 is still going after 50 years.

Built it with my father over Christmas; I mounted components during the day, he checked them and I soldered them.

Ought to open it up and have a look at the soldering, to see whether it is better/worse than https://entertaininghacks.wordpress.com/2015/02/21/a-40-year-old-hack-disinterred/

[tautech]

Yeah... I'm in desperate need of a decent 3/4 horse bench grinder; something can handle a 8 or 10" wire wheel. I'll prolly have to build that myself too, unless I get really lucky on Craigslist. 

mnem
"damn... another hole in my hide..."

Yep, once you've had a wire wheel in the workshop it's not complete without one.

Built a little crappy 6" one with a 1/4hp decades back and it was as handy as hell until it got good and properly heat tempered in the workshop fire however a 3/4hp 8" grinder with wire wheel was one of the first purchases with the insurance payout along with 9" and 5" angle grinders.

[vk6zgo]

I was already into the hobby but my first Heathkit was an AA-14 Amplifier. And it did work the first time I plugged it in. 

For how long? 

First kit I built (well first kit I could afford to buy to build) was a Maplin CMOS logic probe in 1992. Didn't work because I blew up the 4001BE in it.

I didn't build no steenkin' kits!. 

My first builds were radios-- from a "one valve regen set" using a 1T4 battery valve, which didn't work, to a "two valve regen set" which used 6SH7s, but I added a a 6V6GT so it could drive a speaker(it worked, but had a few problems), to a "5 valve mantel radio, built into a bakelite speaker enclosure, with a 8" speaker (after a few initial problems, it worked a treat!
All of the above were built from magazine articles, with all the bits purchased separately when I could afford them.

I gave up on making stuff for a few years, but then built my one & only  audio amplifier---a Mullard "3-3" amplifier (not as you may assume, a stereo amp, but a mono one --"3 valves-3 watts").
My mate had the transformers & some other bits,but still not a kit.

I have built a few trifling doo-dads from "short form" kits since then, but kits were never a major orientation for me.

[mnementh]

         

Have y'all seen these speaker enclosures being sold all over AliEx? It looks to me like someone is leveraging local availability to make a business doing something I did as a side hustle when I was a teen: using 30mm shipping container plywood to build speakers. 

My regular source was Seneca foods; they had these shipping gaylords with a liner for fruit juice concentrate that were like 6ft x 7ft x 6ft made of tropical hardwoods. I usedta make/rebuild instrument speakers and sub enclosures; was a lot of work and heavy AF... but they were so fucking rigid... yumm. These guys are taking them much more boutique with the addition of tropical wood veneers... mine were sanded, stained and urethaned; warts, hickeys, biscuit patches and all. Or covered in speaker carpet.

strange how that big wheel just keeps turning...

mnem

[Cubdriver]

Reason #25678 why I live alone. Screw that. Turn it up! 

How many people got into electronics by way of audio?  It was certainly the case for me and a good number of people I know so it's sad seeing the passion that's kicked off so much being forced out so many times.  I'm glad to be on my own too for reasons like that.

I got BACK into it as a hobby by way of audio.  A wiki walk reignited my interest in tubes, and I found and built a guitar amp kit.  Then the output transformerless 15 WPC audio amp, then got into the audio forums, bought the HP Dynamic Signal Analyzer, got onto the HPAK mailing list, bought the 5245L and it’s been a downhill ride from there.  And I’m sure it goes without saying that other than my feline lab assistants, I live alone too.

I was already into the hobby but my first Heathkit was an AA-14 Amplifier. And it did work the first time I plugged it in. 

IIRC mine was a code practice oscillator.  Forget what the second was, but about the third was the single trace 5 MHz oscilloscope I got for Jr. High School graduation.

-Pat

[GreyWoolfe]

In the garage while I'm working I have a 8-year-old Kindle Fire/Prime Music app & a 10-year-old iHome BT speaker... It just works. Put Kindle to sleep, speaker goes to sleep. Start playing music and the Kindle reconnects, speaker wakes up in less than a second. 

Too simple. I've got a central matrix with balanced outputs to all rooms, and a collection of sound sources, among those a bluetooth receiver.  The matrix, being old, is controlled via MIL-STD-1782, which is used by a Perl-CGI script (running on the media web server VM) that makes a routing panel webpage available. In each room, there are active loudspeakers or passive ones with a power amp. There also is a simple voltage divider potentiometer volume control.

Bet you wish you had one-a deez!

I will admit to having one of them, not as nice or as long as yours but I do have one. To go along with my RJ-45 crimping tool, safety scissors, coax strippers, 88/110 punch down tool and a fox and hound (toner set to those who never heard the term).  In the 90's, I had a side hustle working doing network cable drops, satellite TV and AOL Plus Powered by DirecPC satellite internet installs-download only, still needed a modem for upload.  Hated the satellite internet installs.  We needed a laptop with special software to point the 3 axis dish as it had only 1 degree cone of acceptance.  It either took 20 minutes or 2 hours to point the damn thing. And that's with 2 people, one driving the laptop and the other manipulating the dish.

mnem
 

[mnementh]

https://www.aliexpress.com/item/10000102562868.html

maglev. huh. 

mnem
 

[med6753]

https://www.aliexpress.com/item/10000102562868.html

maglev. huh. 

mnem
 

Is that motor on a separate mount NOT attached to the turntable base? If yes how do you keep proper tension on the drive belt? And for that kind of cash you don't even get a dust cover. What a freaking joke. 

[srb1954]

https://www.aliexpress.com/item/10000102562868.html

maglev. huh. 

mnem
 

Is that motor on a separate mount NOT attached to the turntable base? If yes how do you keep proper tension on the drive belt? And for that kind of cash you don't even get a dust cover. What a freaking joke. 

Any vinyl fanatic who shells out that much money, and more, on a turntable would likely have their own class 100 clean room for their stereo installation. Therefore, no need for a dust cover.

[mansaxel]

The idea that drove Bose was that if the distance between the drivers is much less than a wavelength, they will sum slightly less badly. Hence, their puny 4" drivers will play LF at a level that is impressive for the size, but pathetic compared to a real, say 15" or so, driver...

Y'all do know that Bose made lots of other models than the 901, right? And that most were conventional designs?

mnem
CV makes the rockin' world go round...

They look different, but most are based on the basic idea of 'many 4" drivers not playing coherently and a too high "sub" crossover';

Furthermore, at this advanced stage of computer modelling, Bose has leveraged their R&D and science to build conventional speakers that sound as bad as their original designs.

[Saskia]

The idea that drove Bose was that if the distance between the drivers is much less than a wavelength, they will sum slightly less badly. Hence, their puny 4" drivers will play LF at a level that is impressive for the size, but pathetic compared to a real, say 15" or so, driver...

Y'all do know that Bose made lots of other models than the 901, right? And that most were conventional designs?

mnem
CV makes the rockin' world go round...

you sure that yer not mixing up Bose with B&W ?
Bose sucks. B&W has reasonable offerings ...

[Saskia]

https://www.aliexpress.com/item/10000102562868.html

maglev. huh. 

mnem
 

Is that motor on a separate mount NOT attached to the turntable base? If yes how do you keep proper tension on the drive belt? And for that kind of cash you don't even get a dust cover. What a freaking joke. 

Any vinyl fanatic who shells out that much money, and more, on a turntable would likely have their own class 100 clean room for their stereo installation. Therefore, no need for a dust cover.

I would LOVE a Nakamichi Dragon CT or TX1000 and would even be willing to spend reasonable money for it. Reasonable being up to 5000 € for the Dragon CT provided it is in good condition (technically plus cosmetically)

[BU508A]

https://www.aliexpress.com/item/10000102562868.html

maglev. huh. 

mnem
 

Is that motor on a separate mount NOT attached to the turntable base? If yes how do you keep proper tension on the drive belt? And for that kind of cash you don't even get a dust cover. What a freaking joke. 

One of the most expensive turntable I'm knowing of: The Transrotor Quintessence, comes usually with a SME Series V audio pickup system.

[Peter_O]

https://www.aliexpress.com/item/10000102562868.html

maglev. huh. 

mnem
 

Is that motor on a separate mount NOT attached to the turntable base? If yes how do you keep proper tension on the drive belt? And for that kind of cash you don't even get a dust cover. What a freaking joke. 

One of the most expensive turntable I'm knowing of: The Transrotor Quintessence, comes usually with a SME Series V audio pickup system.

To pour some oil in the fire: 

I know those Transrotors as "Teelicht-Dreher" or "tea light turner". 
I never found one playing at the hifi fair, same as all other oil drilling rigs, they were just presented for optics, they might be made for optics, which might be the main purpose for most owners. 

I very happily use a good old understated sub-chassis belt drive with the phono pre-amp inside the device to have the small signal cables short and flexible.

Bose: If money is no issue, those devices are quite decent kitchen radios. 

[capt bullshot]

🎵🎶Someone is getting a package🎵🎶
🎵🎶Someone is getting a package🎵🎶

Someone got a package

(not been thrown over the hedge and not been dropped into the pond)
ATM I don't have the time to check the contents, more later or tomorow.

[mansaxel]

I know those Transrotors as "Teelicht-Dreher" or "tea light turner". 
I never found one playing at the hifi fair, same as all other oil drilling rigs, they were just presented for optics, they might be made for optics, which might be the main purpose for most owners. 

I very happily use a good old understated sub-chassis belt drive with the phono pre-amp inside the device to have the small signal cables short and flexible.

I have a SL1000 in wheeled base, with the professional Technics arm, built-in XLR-out preamp and monitoring amp. Designed for Swedish Radio and also slightly later for Finlands YLE.  Used prices around 5000 €, but I'm not selling mine. Too busy playing records on it.

[Specmaster]

These are stupidly pouncy turntables, when I was into Hi-Fi, the deck of choice for broadcasters in the UK was the Garrard 401 301 which was way too expensive for me, I had to make do with the 2nd choice, a Garrard 86sb which was nicely engineered belt drive unit with a heavy finely balanced turntable and came with its own tone arm and a Shure cartridge, cost IIRC was around the £100 mark.

[Saskia]

Nakamichi TX1000. My all time favorite. Don't have 50k€ to burn for it though.

But as I said: will shell out up to 5000 for a Dragon CT if in acceptable nick.
In the mean time, my Denon DP47F will have to do.

[Specmaster]

Nakamichi TX1000. My all time favorite. Don't have 50k€ to burn for it though.

But as I said: will shell out up to 5000 for a Dragon CT if in acceptable nick.
In the mean time, my Denon DP47F will have to do.

Why does the brush only brush the run out area?

[Specmaster]

You may find this video of interest, making a £13,000 turntable and uses the Garrard 301 (I incorrectly called it 401 earlier). I find this video very worthwhile watching, such craftsmanship, beautiful.

[Saskia]

2nd streamer fixed. The cmos battery was dead as a dodo, the replacement I ordered was a 100% fit.
Ok, Haswell based, this is quite ancient, so the battery may be dead after 10 years or so.
Anyway, it's back among the living.

[TERRA Operative]

Just now I used the new late model Tek SG503 to fix the old version SG503. Finally it works perfectly (I wasn't getting the full 250MHz in the upper range, only hitting 230-odd MHz)

What I posted on Tekscopes groups.io:

I replaced the metal film resistors I put in positions R145, R150 and R146 with SMD resistors that I soldered tinned copper wire to to make them axial components, and I also found I had put a 130R part in position R150 (I was copying like for like when replacing the carbon composites that were already there) and it helped marginally by increased the maximum frequency by a few MHz. Hmmm.

In the mean time, I got my hands on a late model SG503, so I was able to compare my faulty one to a virgin unit unsullied by human hands... This new unit had the L143 air-cored coil used for the 100-250MHz range adjustment stretched way out compared to my faulty one for less inductance, so I matched it in the faulty unit and found the frequency limit rose by a few more MHz.

Ok, so we have too much inductance, so I checked LR140 (a 47R carbon comp resistor with enamel wire wound around it for 20nH of inductance) in the new unit and saw it has just one and a half turns.
I had previously made my own replacement part for the faulty unit with the same ingredients, as the original was broken by some ham-fisted pokings before I purchased it. However, it was difficult to count the number of turns, so I made a best guess and it turns out I used to many turns......

I found my last spare 47R 1/8W carbon composite resistor (mil-spec too!) and replicated the one found in the new SG503 with just 1.5 turns and stuck it in.

Bingo! My max frequency is now at 261MHz, perfect! A good bit of headroom to compress the air-core inductor L143 back down for best performance when I get my hands on a spectrum analyzer (planned as my next big purchase).
I assume that a few bits were somehow broken in that area in the past and some were replaced (badly), that 130 ohm R150 must have had an incorrect replacement installed before I got it, and LR140 was broken along with C150 (51pF) which I have already replaced with an NP0/C0G part.

Anyway, now that the parts in the no-longer-faulty unit match the working late model SG503, it's fixed, working well, and ready for me to hold my tongue at the right angle and give the adjustments a tweak.

[Neper]

Bose sucks. B&W has reasonable offerings ...

That was long ago. Nowadays, B&W have become one of the four evil Bs - Bose, B&W, B&O, and Beats -  companies whose advertising budget by far exceeds that of their R&D and where the marketing departments have taken over all product planning.

I've chucked out a pair of B&W CDM7 SE after weeks of alternatively listening to them and a pair of Castle Howard S2. The B&Ws are made to stand out in the showroom, literally yelling "buy me!" while the sales clerk is switching between them and other speakers. Take them home and after some time they'll begin to get on your nerves.

B&Ws reputation is a mix of old glory (including the clever 'Abbey Road' PR stunt where they were never used for any serious work) and aggressive marketing. They have become just another 'brand' like Nike, Prada, CK or whatever.

[Neomys Sapiens]

Yeah... I'm in desperate need of a decent 3/4 horse bench grinder; something can handle a 8 or 10" wire wheel. I'll prolly have to build that myself too, unless I get really lucky on Craigslist. 

mnem
"damn... another hole in my hide..."

I would rather have a slow-running grinder. I had access to one in only one place where I worked once and it was totally amazing what you could achieve with it. I still have several tools (pliers, cutters, tweezers and sccrewdrivers) which were reground on it. It does not cause thermal damage and allows very controllable grinding. It is the next best thing to a real tool grinding machine without the setup time and angular calculations.
Remark: a short review of offerings told me that the definitions vary considerably. I a not referring to those machines which run at 1450/min but merely several 100s. They are mostly used with a wet wheel, only some diamond wheels on a metal basis might be an exception.

[med6753]

Turntables? This has been my personal favorite for many years.