Not that easy, AGC works both ways, if you disable it you need to provide a manual control to not blow your speaker or your ears or both. AGC controls the screen voltage of some tubes with a big factor of amplification. A typical remote cutoff pentode like a 6sk7 can change some 30-40 dB for stage. 70-80 dB AGC action is not rare.
> manual control to not blow your speaker or your ears or both.
Distinct from the volume knob?
It could be that rather than completely disabling AGC, it switches to milder compression.
Another idea is that while tuning, we can delay the volume recovery of AGC. In other words, the same fast compression attack, but very slow release, so that as the user tunes across the center of the band, they can still feel the volume swell.
A simple voltage divider could be introduced when AGC is turned off to attenuate the overall volume, so that the loudest blast is not that loud.
AGC is not compression, is a negative feedback loop that reduces gain to maintain a relatively stable output level. If you try to tune on a faint station near strong ones, the stronger carrier pumps the gain down, making tuning difficult. if you cut AGC the gain goes full up. You can cut AGC and reduce gain, but then you'll lack amplification to hear the weak stations.
If manual AGC and volume should be different controls depends on gain distribution across stages in the receiver. In superheterodyne AM receivers, most designs will need both to get best performance.
I'm not, the post is what adds fog to what should be clear and direct conversations about technical solutions as per their ability to solve a product concern.
I clearly said I buy for two and would go more often if I shopped for more. Many, many people with families do this.
I'm in Norway. Vehicles are expensive, children (regardless of age) are used to going outside and going to the stores. It is a common situation in larger cities. Heck, elementary children are often enough at the store unsupervised. I'm not sure why you think a 20-30 minute car ride plus at least an hour at the store is worse than a 20 minute round trip to the store with a 10-15 minute store break is bad, even if it is a few times a week. And even that can be avoided by just spending a little time on your way home from work.
I have a family of four and we manage just fine. The kids aren't toddlers any more (which only means that we can't put everything in the bottom layer of the stroller), but when they come to the age where they eat a week's shopping in a single sitting they will be old enough to take over a few shopping trips on their own.
yeah, I think people come at this from very different life expectations.
It is hard to take a toddler, a weeks groceries, and 50lb bag of dog food on a bike or bus.
Living without a car is easily possible, lots of parts of europe do it. They do it by living in small aparments, consuming less with more staples
Those were originally Philips devices, but like with the American JEDEC part names, after a device with an European part name, like BC337 was registered, any semiconductor device manufacturer could sell equivalent devices.
The European part numbers provided much more information than the American part numbers.
JEDEC 2Nxxxx just told you that this is some kind of transistor or thyristor, instead of being a diode like 1Nxxxx.
BC told you that this is a silicon small-power audio-frequency transistor.
There were separate codes for other materials and for many other kinds of transistors, diodes and thyristors (for example AD = germanium high-power audio-frequency transistor, BF/BL = Si low/high-power RF transistors, BS/BU = Si low/high-power switching transistors, BR/BT = Si low/high-power thyristors, BA/BY = Si low/high-power rectifiers, BB = Si varicaps, and many others).
Motorola and some other US companies, like Texas Instruments and Fairchild, entered the transistor market very early, when they defined types like 2N2222, which became industry standards.
However, because these devices were defined early, they had rather poor characteristics. When European companies like Philips, Siemens, Thomson, SGS-ATES entered the market later, they defined transistors and other devices with improved characteristics.
Because of this, in Europe the devices with European part numbers, like BC337, were generally preferred, because they provided better analog performance, e.g. lower noise and higher bandwidth.
However nowadays this has become mostly irrelevant, because a legacy transistor vendor makes only a small number of different kinds of transistors, distinguished mainly by die size, because bigger sizes are needed to handle bigger currents. Then the transistors are packaged and marked with any of the legacy part numbers, depending on what part number the customer orders.
So while old transistors may have quite different characteristics depending on the part name, many modern transistors behave the same, regardless how they are marked.
> BC told you that this is a silicon small-power audio-frequency transistor.
BC breaks down as a silicon device, with no heater voltage, and a "triode".
If it was germanium, it would be AC <something>.
So BC548 is a silicon "triode", AC128 is a germanium "triode", and PC97 is a triode with a 300mA-rated heater (P is series connected with other valves, 300mA) in a B7G base (the 9).
"BF" might be an RF transistor although "F" was really used to mean a pentode in valves.
And those dual NPNs used in expo converters in synths might be accurately enough labeled as BCC548, similar to the ubiquitous ECC83 dual triode.
You also see this with diodes, were AA119 is a germanium small-signal diode, and BY127 is a silicon high(-ish) power rectifier diode, for example.
No. "B" is just the material (for instance "A" = Ge, "B" = Si, "C" = GaAs and related materials).
The letter that encodes the semiconductor material replaced the letter that encoded the voltage or the current used by the heating filament of vacuum tubes.
The material letter has nothing to do with the kind of device.
Examples of silicon diodes: BA (small power rectifier), BB (varicap), BY (high power rectifier), BZ (Zener diode).
It is true that some of the letters that denote kinds of devices have been inherited from the previous nomenclature of European vacuum tubes.
So C, D, F, L, used for low-power/high-power AF/RF bipolar transistors come from the letters used for low-power/high-power triodes/pentodes.
However other letters, like S, U, R, T, used for switching transistors and thyristors (a.k.a. SCRs), were new for the semiconductor device nomenclature.
Exactly, I grew up playing with BC547 and BC337s (my father was an electronics engineer) and only later found 2N2222 and 2N3904. Those were almost entirely unheard of in India.
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