Finally got around to trying this thing

I splurged a few bucks on a manual

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I hooked it to a box fan 

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So it has life but I couldn't get any response from the single phase mode aside from a small reverse movement I did reverse polarity to try it to no avail

I don't see any fuses anywhere on the unit or in the manual nor a power cord 

I need to calculate approximate watts of a dollar store box fan 

I searched I promise  there is so much ➗ divisive content on the interwebz a guy could spend the rest of his life reading about it.

So the standby switch on my toob amp savage rohr 15 is a good thing  or...no it's killing toobs   

I'm not 🚭 stressin out about it I'm 61 (eek  ) so the amp and toobs will probably outlive me 
And I'm a strictly at home bedroom wanker no three sets a night at the pub 

The only time I use or was using it was start up and shut down and in between changing pedals etc

Like I said it's not a big deal I'm just gonna do what you guys tell me to or not to do.   

Also it is toob rectified if it matters
Also if it matters I always have the preamp maxed out and the power section set at 0.000001   

Made another go at this since I worked a few chapters in my text book

Wiring this old artifact ballast in series with a 1000 ohm resistor and putting variable frequency through it.  With predictable results 

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So now when people see me wandering around wondering what I'm thinking about it's gonna be....."so the resistance of the inductor (ballast) goes up.....

Interesting last night I did an experiment out of my textbook they had me put 125 hz in a transformer primary (channel one scope probe attached) and then channel two scope probe on secondary with a 100ohm resistor.

They had me ground one side of the resistor and then the other side.  One side was in phase and the other was out of phase.

I was like hey cool but then I realized some speakers (or amps rather) dont have output transformers   

What's really 🪲🐛 bugging me now is not remembering if it was in or out with no ground 

Noticed this in a trash 🗑�🚮 picked Crate
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After a little research maybe it's possibly a TDA2030 or LM1875 ?

 

I am seeing old Dukane 🎤🎙� mic preamps and they have stuff like "24v DC input"

Wondering if there is/was a specific reason for this 

Maybe the answer is because it works? Idk 

Btw HAPPY HOLIDAYS 🎄 🎁

Man talk about a nightmare


Btw this is not something I'm working on trying to repair.  Just a junk PCB 
They had some cool heatsinks on them too.

I'm blaming it on lead free solder but I don't know if it is or not.  I tried some tricks I have read about like adding flux and leaded solder.

On both there was one leg 🦵 🍗 that would not melt 

Ultimately they did give up.

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If you listen to fools...
The newbz rules....

Anyhow...been looking at power supplies

I'm trying to decipher terminals that show up in the pictures 🖼� of many of them

I have attempted to identify and lable appropriately....

What the heck is S- and S+ ?

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Thank you in advance 

Also I'm seeing older power supplies that are called switch mode I'm kinda familiar with those rectangular plastic ones that look like what hooks to laptops and stuff but I guess early older switch mode externally kinda looked like linear power supplies I see some called Op-Amp power supplies.

Also I see some schematics for a (7815 and 7915 ?) power supply looks like I could assemble if you like that. 

 

I have a harness from a boat anchor power supply I don't want to cut it up so I desoldered the male connectors from a circuit board 🛹
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Here they are with the harness (the big 🔌 plug top right connects to the PS)
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I just need to attach some wire/leads whatever to the male doodads
I think the pins remove and I attach wire or just get pins with wire and install

Thanks   

So I got this bag of fuses (1A 250V) and they looked good but I thought hey why not check one of these things 

So I came up with a plan....put the fuse in circuit with a 10 ohm fuse and run it up to 10v
while keeping an eye on it.

Well I started at 7.9v and the smoke show started quickly
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So I did some calculations wow I was going for one amp I never dreamed I would be cranking out some watts
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That resistor is like a quarter or half watt.
 

Btw the fuse survived 

But as I type this now it makes sense why I see these big ceramic wire wound ? resistors and they are low resistance

 
 

Ok this is what I did

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So I hooked everything up

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Then did some requested calculations

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Seems like a lot of trouble for nothing but I did get the "right answer" the book said for the 741c Op-Amp the typical value for the input offset voltage is 2 mv. 

I'm not yet running through the streets shouting eureka but hopefully later the significance of this will become apparent.

 

I have a topward dual power supply the left side doesn't get up to full voltage.
If you look in the swap meet section there is some discussion pictures and schematics.

I had an idea that maybe since there aren't that many parts just order some stuff and shotgun it.

However after reading about these units I saw a few instances where some transistor replacements fixed the problem(s).

So for the sake of clarity the focus of this discussion is to simply focus on transistors for the preliminary investigation.

Reading some old threads I saw where I can probe the collector and emitter of said devices in circuit and check for shorts. 
-if there is no short then move along
-if there is a short it may be good because of the circuit but remove and test

If I have interpreted this correctly I like this plan  because for starters the power is OFF. 

Also it will give me some experience discerning a voltage regulator from a transistor 

So if you like that then that is my plan nothing more or less.  Just check every transistor in circuit for C-E short and report back.

Big thanks to Mick for encouraging me (almost a year ago) to try and get something out of this ancient artifact 

I wanted to put on my big ugly dim bulb tester but was kinda perplexed by the results.

60w bulb unscrewed and 43w bulb screwed in
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Now 60w bulb screwed in and 43w bulb unscrewed
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And both screwed in
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I didn't know if this was good or bad...they both glowed but more pink and orange not like a bright light.

So I figured ok might as well try something but maybe it's got blown outputs (?)

I grabbed a speaker and not having the slightest idea where to attach I picked two terminals and attached them and when I plugged it back in I was stunned to hear some noise 

I grabbed my cable to attach a signal and I can't believe it works           

But when I increased signal output it got really ugly sounding like it was in a blender 

So I removed some jumpers that had been there probably forty or fifty years and tried it again this time nice and clean 

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Also I saw the bulb would get brighter when I increased signal 🚦

If you are wondering there are no controls or power switch. 

It came with another piece that had knobs and level controls and one medium sized speaker.

Btw attached to the power cord were a couple of tags like instructions how to attach speakers
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So wow I'm really glad that I tried it and got sound thanks again Mick 

If I can get it set up to listen to ball games from a tuner or maybe even some music man that would be awesome 

Hey guys do you think that is a transformer and a choke or two transformers 

I ordered some 10 and 15 mh inductors off da bey.

No big deal but they measured IIRC like 8.8 and 13.2

I'm just using them in my experiments for my lab text. And will make sure to use the actual values in my calculations.

They don't have color codes so no tolerance I like em enough the leads are right for breadboard  and they were cheap no indicators of manufacturer.

Just more stuff I'm learning I reckon time to look for or start paying attention to specs    or if I actually need or want the primo to pay up.

Btw all good my house isnt los alamos these are great for my mickey mouse 🐭 🐁 setup. 

Check it 

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Briefly looking through it it has tons of experiments where he has you make little circuits to make and do cool stuff.

Like....make an op amp differentiator.  And integrator.

Or how not to 

I needed to make my transformer bread board friendly things are getting Rube Goldberg enough around here.

So I soldered some jumper wires to the primary and secondary transformer leads.

For your entertainment 

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The finished product

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And some okrer gumbo with shrimp 🦐 and fake 🦀 crab
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I think 

I need a transformer for an upcoming chapter in the book I have been working through
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I remember this artifact having 12v outlets on the back
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Open it up looks good  You cannot view this attachment.

But testing is disappointing
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But there are two 12v outlets on the back right gotta be a way to get 24v but I look and they are wired in parallel (?) 

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Have I been defeated by decepticons 

Practicing some desoldering trying out my new toy
I have extracted a few TO-220 (?)
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Pretty cool they have these clips to help hold them fast to the heat sink ?
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I like the solderpullt it seems to work good I like braid too but some times it drives me bananas 

I'm going after these capacitaters next

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I'm kinda worried about the plastic tip on this tool melting I suppose I need to get on with it and do not tarry 

If you are wondering what this artifact is I can answer that question....it's a GR5D Digital Convergence Board
(why of course... )

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This old Paco B-10 battery eliminator and charger has two outputs
One labeled as special low ripple output

So I turned it on and connected my scope to check it out

On the special low ripple terminal
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Now on the normal terminal

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I think 

Seems like people could make bad stuff look really good with a few different settings...or vice versa 🐱

Man I was pretty stoked they threw this in at the pawn shop    it's like twenty foot long 

Unfortunately it always hummed like crazy    so I did a little testing and I didnt see any shorts etc
Also I tried flexing it along the length of the cable like maybe it had a break idk

Apparently after further review....it's not the same as instrument cable ?   

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So....dude...it's not a guitar cable...