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Questions tagged [vintage]

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1
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2answers
96 views

EM Vs PM Speaker

Modern Speakers have permanent magnets and are called PM speakers.Permanent magnet materials technology has improved a lot over the last 80 years .Around WW2 EM speakers were common because permanent ...
0
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1answer
51 views

Design questions regarding LM2735 (boost-converter) for DC-DC

I'm doodling with a future circuit. The application (Commodore 64) expects 5VDC (which I will provide with a pass-through) and 9VAC 50Hz. I do not have any working circuit or a schematic, because the ...
1
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2answers
102 views

What connector did this IBM Model M keyboard have?

I got got hold of an old IBM Model M (Model 1391403, to be precise). Unfortunately, the fixed cable was cut off by an unknown idiot. Does anyone know what kind of connector (I assume PS/2?) was ...
2
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0answers
61 views

old 80C31 circuit not working. EPROM data retention issue?

I have an old piece of pro-audio gear in for repair. It dates from 1990. It was a fairly high-end piece of gear at the time and still has some value so it is worth repairing. But the symptoms I see ...
2
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1answer
148 views

Can old vintage quartz crystals handle more power?

Old crystals are very large compared to present day devices. Vintage transmitter circuits did not have many valves in their line up. I have seen a 2 valve 50 watt CW transmitter for 80 meters in a ...
7
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1answer
490 views

Identify Vintage Power Cord for 1980s Organ [closed]

I Recently acquired a Technics SX-C600 organ but it needs a power cord. Does anyone know what type of power cord I should get for this? My understanding is that this is a rare organ.
0
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1answer
76 views

How does a rocking arm voltage regulator work?

I am trying to determine the suitability of replacing a (ancient) rocking arm voltage regulator with a modern digital device. I assume a rocking arm regulator has an electromechanical or magnetic ...
0
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1answer
42 views

Increase rotational velocity of synchronous motor

I recently got my hands on a Philips PM8110 (a single pen recorder which is basically an analog printer for voltages) which sadly provides paper with a velocity of 8 cm/hour. Although this would ...
14
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1answer
595 views

Old equipment to identify

I volunteer at the Dauphin Railway Museum in Manitoba, where we recently received a donation of equipment collected by CNCP Telecommunications in the 1970s and earlier. Most has been identified, ...
1
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0answers
112 views

Please help identify this vintage component

I got this item in a bidding lot and have been trying to figure out what it is ever since. The nearest I can tell it is either an electro shock therapy device or perhaps a remote detonator. It has ...
14
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1answer
978 views

What is a “universal bridge”?

I recently came across this intriguing instrument from the 1970s(?): It's a "Universal Bridge" made by Wayne Kerr. It's not a type of device I've come across before and I'm curious what these are (...
2
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2answers
130 views

Old-school pseudorandom pulse generator (requesting assistance with hardware design)

I would like to design an old-school pseudorandom pulse generator to trigger various types of events (hardware suggestions only please - no programmable ICs). The events that I want to control need to ...
9
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2answers
575 views

Identifying an old RF circuit

I got an old RF circuit (I guess), probably used for pedagogical purposes. Here's the schematic: I chose the positive and ground rails as it seems right to me, looking at transistors and resistor ...
12
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7answers
1k views

What kind of capacitor blew up in my old IBM monitor?

I pulled this out of an old IBM 5154 EGA monitor from the 80's. Clearly both are bad (though the monitor itself works anyway...). I know they're capacitors, but what kind? What would a replacement for ...
1
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1answer
77 views

Stereo Enhanced Mono

Medium Wave AM in most countries is monophonic. AM stereo was never universally adopted. Given a monophonic signal, how can one create a stereo output? I know there are some 'tricks' you can play on ...
7
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2answers
207 views

1977 GE 6RS20SP9B9 - what the heck is this component?

Ok so, ordinarily I'd not ask a "what is this" question, but this component really has me scratching my head - both at its function in the circuit and how it is constructed. Anyone know what a GE ...
0
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0answers
21 views

Restore or replace an old NiCad battery

I was finally able to buy a used Toshiba T4700CT to play my DOS games. I cleaned it, disassembled it and replaced both the backup battery and CMOS battery, but I have a question regarding the main ...
0
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1answer
31 views

Pearmability Tuning Vs Cap tuning for MW AM

I constructed a wide band Hi Fi TRF tuner for MW AM that sounds great. It used an old 365 pF air spaced 3 gang variable capacitor that had equal sections. Selectivity was marginal at the top of the ...
2
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1answer
156 views

Amplify Raspberry Pi Zero W Audio with 60s Tube amplifier circuit

Dear Electronic Goorus, First of all, thank you for taking a look at my question. Electronics is not my field of expertise, and I have found myself a bit stuck. I have been restoring some old 50s ...
0
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1answer
114 views

Tape Deck solenoids

I found an old Tape Deck recorder that I tore apart to scavenge for interesting parts. Two different kinds of solenoids left me wondering: From an old service manual (not related to the tape deck ...
0
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1answer
117 views

Help looking for an 220V AC transformer replacement [closed]

My old Philips MC-M250 stereo transformer has died after a power surge. I can't find spares so I'm looking for some compatible replacement. I found a power board circuit in the service manual. AC is ...
0
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1answer
196 views

Germanium Diode 455KHz AM Detector

Ge Diodes have been used for AM detection many decades before Si Diodes became cheap.They were attractive when compared to the large power hungry valve .Nowdays Si diodes are much cheaper and easier ...
5
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2answers
979 views

What do “cycles” in a capacitor mean?

I'm trying to replace some old leaky capacitors for this radio I'm working on and in the data sheet they have this rating of cycles for the large capacitors near the bottom of the sheet here: What ...
1
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1answer
128 views

how to drive 1930s bakelite headphones

I’ve received a very old pair of mono bakelite headphones that I would like to re-use for demonstration purposes. Just for voice audio and morse code tones. The writings on the side of each headphone:...
49
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10answers
9k views

Amplification before tubes and transistors were invented

Telephones are older than vacuum tubes and of course transistors. How was signal amplification done? I mean the technology, not the details. EDIT Some additional informations that I should ...
5
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3answers
1k views

How to identifiy this “2222 063 90025” vintage capacitor?

I am restoring an old stereo valve amp and would like to test (and replace if needed) some components. I don't know the history of the amp, but it's made in New Zealand and looks to be from the 1960'...
1
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1answer
299 views

How to “fake” a megawattmeter

I have a vintage megawattmeter. It is able to indicate values from -1 to 7 MW. I wish to be able to provoke it to display any value I want, preferably without actually generating megawatts of power. ...
1
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3answers
89 views

Figuring out a substitute for an old amp capacitor #2

What type are the yellow caps in the picture and what do I substitute them with?
0
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2answers
329 views

Capacitor value for rectified magneto PSU

## Need capacitor value for below circuit ## Hi guys, Kindly help me with the situation below. I want to run my LED headlamp (with upper & dipper functions) via flywheel magneto. Current setup:...
0
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1answer
397 views

AM Detector Peak Vs Average

The Envelope detector is over 100 years old .In its classic form it is a simple half wave diode that peak detects the carrier with the load resister and load capacitor time constant chosen to allow ...
4
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2answers
1k views

Should I replace these resistors on my vintage radio?

The one in the image isn't the 250k one exactly, but it's one I had a picture of. The 250k just has a different colour but is the same kind of resistor. EDIT, the big red one is a capacitor, the ...
0
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0answers
172 views

Ascertaining Valve Part Numbers

Old valves (vacuum tubes) sometimes do not come in their original boxes. Sometimes the part numbers seem impossible to read. Is there an easy way to read an apparently illegible part number? Would UV ...
-2
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2answers
211 views

Old AMD portable charger [closed]

I found this device in my garage a few hours ago. It seems to be a very old portable charger, but I can't find what it's called or the model: The cables plug into a small jack like so: It uses a ...
3
votes
3answers
464 views

Do I need to terminate my oscope in a specific way for viewing video signals?

I'm a novice and have used my Rigol scope to look at small circuits from kits and attempt to diagnose issues on my vintage computers. I'm at a point where I want to check out composite video (for ...
0
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2answers
619 views

455 KHz Double tuned IFTS for Wideband MW AM reception

Vintage AM MW radios often had double tuned IFTs .The shape of the frequency response curve is well documented elsewhere .The coupling coefficient of these double tuned transformers is low and the Q ...
1
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0answers
67 views

Ge Vs Si for AM envelope detector

Early solid state radios used Ge diodes as a detector .Si was not available then so this makes sense .Impedances were much lower than the Valve stuff.A 5k Log volume control pot was common for early ...
13
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4answers
2k views

Are there special protocols one should take when handling vintage/old electronics?

UPDATE: I am mainly interested in learning about vintage chips, ics, cpus etc, mainly non-soldered chips. It would also be interesting to know about any other component (i.e., capacitor) that could ...
1
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0answers
231 views

Datasheet Cross Reference for Old Military Part?

I am looking for a datasheet for a part labelled 0N088586, but have been unable to find a datasheet. Does anyone know if there is a way to cross-reference the NSN with an equivalent part? The part is ...
14
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5answers
2k views

A story behind a weird inductor

This old, crusty inductor found in an old Iskra (Yugoslavia) TV intrigued me, and I was hoping that someone could tell me what's the story behind it's design. I don't know if the pictures are ...
3
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5answers
130 views

vintage auto headlamp dimming

I am restoring a 1930 Stutz, the headlamps originally used a resistor to dim the single filament bulbs from high to low beam. The vehicle is now 12 volts, to dim the lamps the correct amount I have ...
66
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6answers
10k views

What happened to electrolytic capacitors in the 21st century?

We can sometimes see decades-old capacitors (such as ones made in the USSR) still working. They are bigger and heavier, but durable and not desiccating. Modern aluminium capacitors serve for about 11 ...
1
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1answer
593 views

How dangerous are portable CRT televisions?

I want to use an old portable CRT for a project, but I don't know how dangerous the capacitors are, and if they'd be as bad as the ones inside a normal CRT. It takes in 12v dc via adapter, or 8 D ...
2
votes
1answer
712 views

Germanium transistors becoming noisy

Germanium transistors would sometimes become very noisy despite the in-circuit DC bias voltages testing normal. This failure was cured by replacing the offending BJT. I have found this as a teenager ...
2
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3answers
390 views

“High Voltage” Logic levels why they are rare

I'm continuing to dissect and learn from this old (1974) calculator. One thing that surprised my was that the pins of the main IC have both negative and positive voltages 0 to ±28V. Having worked ...
0
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1answer
50 views

Adding an optional external supply

I'm a electronics hobbyist and I have an old computer, a VIC-20, that I like to build hardware peripherals for. The computer's logic runs on 5V and there's a user port which can supply up to 100mA at ...
0
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2answers
370 views

Determining voltage requirement of unknown circuit board

I have a vintage, home-built metal detector from the 50's/60's with a simple circuit board. It apparently had a home-built battery pack that plugged in but it is now missing (9-volt battery style ...
3
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2answers
2k views

The back of a pot used as a signal ground, in a grounded chassis design; how reliable?

This question relates to those large pots with solder terminals that are still used in electric guitars; they used to be common in metal-chassis radios, amps, TV, as volume and tone controls. It was ...
1
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1answer
331 views

powering old portable 80's radio with powerbank

I'm trying to connect an old radio to a powerbank. I used the the wires from the 6v battery holder and connected them to a usb cable. Now, when I insert the usb cable into a powerbank, the radio will ...
0
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3answers
3k views

Help me identify this audio connector on a turntable

I have recently purchased a West German NECKERMAN 830 record player (1960s), which requires a separate set of speakers for audio output. Could somebody tell me the technical name for this cable so ...
2
votes
1answer
2k views

Modern replacements for old DRAM memory chips

I have an old video card for a computer from the 1980s era, but unfortunately the memory chips on it have gone bad. As it's quite a rare device today, I would like to repair it. Unfortunately I can'...