Found this today - thought it was interesting from the perspective that the author has no clue LOL
"Each of these electrodes received power from separate vacuum tube batteries. We can’t say why this was the case, although it does suggest vacuum tubes were energy hungry. The engineers designated the batteries ‘A’ and ‘B’ too, presumably to avoid confusion."
I can bloody well tell you why, and nobody was confused LMAO
https://www.upsbatterycenter.com/blog/vacuum-tube-batteries-remind-us/
"Each of these electrodes received power from separate vacuum tube batteries. We can’t say why this was the case, although it does suggest vacuum tubes were energy hungry. The engineers designated the batteries ‘A’ and ‘B’ too, presumably to avoid confusion."
I can bloody well tell you why, and nobody was confused LMAO
https://www.upsbatterycenter.com/blog/vacuum-tube-batteries-remind-us/
Not necessarily. There were portable radios using 4 or 5 tubes prior to the existence of transistors, powered with 45 and 87.5V dry cells, and also earing aid with small pen tubes specifically designed. Search in old magazines at worldradiohistory.com
The article does have some serious mistakes. For one, Alkaline batteries as we know them today did not exist in the battery radio days. The non rechargeable cells at the time were carbon zinc, though the paste inside was of an alkaline nature.
Most early radios used batteries because line power was not always available, and not totally standardized across the US yet. The Galvin Manufacturing Corporation, later called Motorola got its start by making a power supply for these radios called a "battery eliminator."
The standard nomenclature that is still used today called out an "A battery" to power the tube heaters or filaments. The common flavors were a single lead acid cell at 2.1 volts, or a 3 cell "car battery" at 6.3 volts. These were rechargeable since most or the radio's power consumption was used to power the filaments. Most auto shops or gas stations offered a recharging service for a few cents. This is why the most common tube heater voltage is 6.3 volts. As smaller low powered tube heaters became available a 1.5 volt "dry cell" primary battery appeared. When things got small enough to make a "portable radio" there was a common 7.5 or 9 volt A battery to run a few 7 pin miniature 1.5 volt tube heaters in series.
The "B" battery provided the plate supply, which is still referred to as "B+" since B- was common ground. The common voltages that I can remember were 22.5 volts mostly for vacuum tube "hearing aids." 45, 67.5, 90 and 135 volts. Of all of these the 22.5, 67.5 volt and the 45 volt were still stocked at Olson Electronics when I worked there in the early 70's for vacuum tube radios.
The "C" battery provided negative bias and was usually a 15 or 22.5 volt dry cell. It disappeared about the time that radios changed from open "breadboard" looking things to closed boxes, though some Atwater Kent's needed a C battery.
Some radios like the Zenith Transoceanic used a single "battery pack" that contained all the necessary cells.
Most early radios used batteries because line power was not always available, and not totally standardized across the US yet. The Galvin Manufacturing Corporation, later called Motorola got its start by making a power supply for these radios called a "battery eliminator."
The standard nomenclature that is still used today called out an "A battery" to power the tube heaters or filaments. The common flavors were a single lead acid cell at 2.1 volts, or a 3 cell "car battery" at 6.3 volts. These were rechargeable since most or the radio's power consumption was used to power the filaments. Most auto shops or gas stations offered a recharging service for a few cents. This is why the most common tube heater voltage is 6.3 volts. As smaller low powered tube heaters became available a 1.5 volt "dry cell" primary battery appeared. When things got small enough to make a "portable radio" there was a common 7.5 or 9 volt A battery to run a few 7 pin miniature 1.5 volt tube heaters in series.
The "B" battery provided the plate supply, which is still referred to as "B+" since B- was common ground. The common voltages that I can remember were 22.5 volts mostly for vacuum tube "hearing aids." 45, 67.5, 90 and 135 volts. Of all of these the 22.5, 67.5 volt and the 45 volt were still stocked at Olson Electronics when I worked there in the early 70's for vacuum tube radios.
The "C" battery provided negative bias and was usually a 15 or 22.5 volt dry cell. It disappeared about the time that radios changed from open "breadboard" looking things to closed boxes, though some Atwater Kent's needed a C battery.
Some radios like the Zenith Transoceanic used a single "battery pack" that contained all the necessary cells.
For some reason I can remember unimportant things from my youth easily but can't remember what I had for lunch yesterday.
Maybe it's because lunch is, well lunch, but finding a new treasure in someone's trash as a kid and taking it apart was an adventure. I also had a few old timers around to fill in the details as to what stuff was and what it did.
Maybe it's because lunch is, well lunch, but finding a new treasure in someone's trash as a kid and taking it apart was an adventure. I also had a few old timers around to fill in the details as to what stuff was and what it did.
Mother had a grey bakelite portable radio with an A & B battery. I took the battery door off once and looked at those eveready batteries. I never heard it work. We lived in a coal mine town then and there wasn't a lot of selection at the company store. The parents had a AC powered Howard radio/phonogragh by the time I was listening (age 3) and I suppose it still works. No electrolytic caps in it, just paper. Trouble with AM radio, the music all blew away. If I want to listen to 1953 radio, I have to access 1940sradio from Bristol UK on the internet.
The buzzer B+ radios weren't much better. The radio in my Dad's 1950 Chevrolet was dead by 1954. I didn't learn about vibrator power until 1966 from my high school chemistry teacher. He'd been a radio tech in the Navy WWII, at a blimp base. The RCA radiotron handbook at the library didn't say squat about vibrator power. I fixed my Dad's 1956 Ford radio (in a 1959 Ford Ranch Wagon) with a new $4 vibrator. A real 1959 Ford radio would have had 12v B+ tubes according to the shop manual, but this Ford was a price leader with the obsolete radio, a dropper resistor, and 1957 hubcaps.
The buzzer B+ radios weren't much better. The radio in my Dad's 1950 Chevrolet was dead by 1954. I didn't learn about vibrator power until 1966 from my high school chemistry teacher. He'd been a radio tech in the Navy WWII, at a blimp base. The RCA radiotron handbook at the library didn't say squat about vibrator power. I fixed my Dad's 1956 Ford radio (in a 1959 Ford Ranch Wagon) with a new $4 vibrator. A real 1959 Ford radio would have had 12v B+ tubes according to the shop manual, but this Ford was a price leader with the obsolete radio, a dropper resistor, and 1957 hubcaps.
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The vibrator circuit was somewhat similar to the points / coil ignition system in the same car. The ignition was SE with a charging duty cycle that got narrower as the engine RPM increased since the on time got shorter and the "flyback" time is was controlled by the capacitor. The Vibrator power supply was push pull with a set of contacts for each side of the transformer primary and a third set of contacts for the coil that moved the vibrating element that opened and closed the contacts. Timing was controlled by the weight on the end of the vibrating arm. With both of these the sparking at the breaker points / contacts increased as the paper and oil cap dried out with age.
The old sets used a vacuum tube rectifier, usually a 6X5 or 6X4. Later on, the OZ4 gas rectifier eliminated the heater in the rectifier.
The old sets used a vacuum tube rectifier, usually a 6X5 or 6X4. Later on, the OZ4 gas rectifier eliminated the heater in the rectifier.
I knew about single ended vibrators but never saw one. I am currently using a Becker Brescia german radio with vibrator power supply. I had to open it and polish the contacts as it stopped runing some years ago.
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Old radios are sometimes updated with a solid state vibrator, a simple two-transistor mulitivibrator does the trick, feeding the same transformer.
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Lots of folk like to collect old radios and I understand it's a common thing to simply use a small transmitter to re-broadcast music for the radio to receive. If you like building stuff you could put together all sorts of options. Heck, they used to do this back before the internet, before the transistor, before Bluetooth - called a Phono Oscillator, it was a way to listen to your records if your only hi-fi was a table top radio.
I can remember the "Accumulators Charged" sign from the early 60's......
My first Holdsworth came from there, happy memories
My first Holdsworth came from there, happy memories
They are worse performing as real vibrators. A saturated bjt may have 1.5V ce at saturation, while a clean contac doesn't. At 6V this loss is unsupportable.
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Paul Galvin, Bob Galvin etc. They made Illinois Institute of Technology famous!
Also because 60cps AC. Line-power radios mostly waited for large cheap caps (electrolytics) as well as cheap good rectifiers and indirect-heat cathodes. (There were a couple filament types which were not-so-bad for small signals and AC heat, but proper sleeve cathodes were much better.)
A proper B-eliminator had a resistor divider, for bleed, but also so you could run 130+V on your final stage and 22V on your detector for better sensitivity. I worked that out for someone, a long time ago.
I remember 45V as the reference B batt, with 22.5 and 90V (2*45V) for picnic and large room use radios, then 67.5V and 135V (2*67V) to fill in the gaps.
6.3V heater is of course Motor-Ola car-radio influence. Heaters in US types had been 2V and 5V and others until then. UK types ran 4V until US influence and joint war production overwhelmed that custom.
The C battery could be had with 1.5V, 3V, 4.5V taps. Savvy operators could re-bias as B batts ran down. Of course a C batt was soon simplified-out of consumer radios.
Love how the author "Richard" refers to " ...flickering vacuum tubes..." ??? Maybe the magic-eye indicator types yes , but I saw them as a soft glow... & yes, that glow makes for some heat. I'm guessing he actually never has seen a vacuum tube in operation, kinda sad. Myself seeing my folks old RCA color set with its "Danish modern" cabinetry...the back off & running, me scoping things out, figuring out why it was out...that big flat chassis & the sea of tubes.
------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick...
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Hello ,
picture from a german catalogue from 1966 , prices are in DM 🙂.
Kind regards , Alexander .
picture from a german catalogue from 1966 , prices are in DM 🙂.
Kind regards , Alexander .
I had that exact same TV back in about 1975. It was one of the first 100% solid state TV sets. I got it for $100 at a department store because it had been repossessed and was somewhat damaged. It did not power on because one of the small plug-in modules was missing. A call to the local RCA dealer revealed that I could not buy the missing module, only trade in a bad one for a new one for a fee. I finally found a repair shop that would sell me a module for $50 so I drove to the shop. When I saw the $50 module I asked for a piece of paper and a pencil. The guy was quite cooperative as the $50 module only contained 5 or 6 black silicon diodes worth, at best a few $$$ and he only had one because they never die. If a little 2 inch module was $50 I really wouldn't want to buy one of the big ones.
The TV failed twice in the 20 some years that I had it. Neither failure was module related. The horizontal sweep SCR 's died. The old XL-100's used neither a horizontal sweep (line output) tube or transistor. They used a pair of SCR's in a flip - flop kind of circuit. The SCR's were prone to failures which usually popped the breaker or soldered in fuse. Even the RCA branded SK series replacement parts would instantly fail in this circuit, you had to get the $10 SCR's from a RCA shop.
Sometime later the picture got dim and out of focus. The focus rectifier is inside the HV trippler brick, so you had to replace the whole module which included the fat red wire to the CRT, to fix the set. I thing they were about $30 at the time.