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You can fashion an AM radio receiver from very basic parts and it needs very low power. Transmitting and receiving is very easy, although the transmitter needs

by foepys 4y ago

You can fashion an AM radio receiver from very basic parts and it needs very low power. Transmitting and receiving is very easy, although the transmitter needs more power. Digital radio is bad when it comes to components, for both transmitters and receivers. Receivers also have a very high power draw compared to AM radio. In case of a catastrophic event (like war) digital radio will be next to useless and analog will be king. Decommissioning a fully working system while Russia is reviving the cold war again, is foolish. Especially since renewables are coming up strong now and the power draw of transmitters in terms of ecological impact won't matter anymore quite soon.

iasay 4y ago
FM is no more complicated than AM to transmit and receive. Simple FM discriminators for receivers like pulse counters only require a few components. On the transmit side, it's a lot easier getting decent high power modulation on an FM transmitter than an AM one. The AM transmitter you tend to have to modulate the power to the final amplifier which requires huge great obsolete tubes running in semi-linear modes. The FM one you do the modulation further up the chain, be that at one end something digital or just a simple varactor and the final amps work entirely outside the linear region meaning low power dissipation with filtering on the output. Cheaper and simpler. Agree with digital radio concerns. That's absolutely no good for anyone. Analog may be king but don't be too romantic about it. If you've ever actually done any operating on any analogue radios you'll know what I mean. I spent 20 years designing and building them for fun.
- skeptically 4y ago
  "FM is no more complicated than AM to transmit and receive." FM is simple compared to WiFi6, but its an order more complicated than AM. An AM receiver only needs a diode and a coil of wire. The diode can be a rusty blade. I dont think you can make an FM receiver without a transistor (which for me, as a former solid state guy is an order of magnitude more complicated than a diode)
  - Johnythree 4y ago
    Actually the Radio hobbyists have build many successful FM Crystal sets (using a simple diode detector). Do a search on "Slope Detection" and "FM crystal set"
- Johnythree 4y ago
  Try building an FM crystal set. It can be done (as many hobbyists have demonstrated) but it will only receive very strong and local signals. Unlike an AM crystal set which can hear stations many hundreds of miles away.
  - iasay 4y ago
    I’ve built AM crystal sets before back in the 80s. Fine if you have the space and materials for a high up long wire antenna or something. But absolutely hell if you have any local noise sources. I actually had a large inverted V trapped dipole on my property which could be persuaded to tune up on AM broadcast with some effort and pick up all sorts. But ugh you need a decent noise blanker or nulling device unless you live in the middle of nowhere. Add a couple of transistors and some discrete components and you can build a fairly decent FM receiver instead of a crystal set which performs adequately with a couple of metres or so of wire taped to a bamboo garden cane.

by foepys 4y ago

iasay 4y ago

FM is no more complicated than AM to transmit and receive. Simple FM discriminators for receivers like pulse counters only require a few components. On the transmit side, it's a lot easier getting decent high power modulation on an FM transmitter than an AM one. The AM transmitter you tend to have to modulate the power to the final amplifier which requires huge great obsolete tubes running in semi-linear modes. The FM one you do the modulation further up the chain, be that at one end something digital or just a simple varactor and the final amps work entirely outside the linear region meaning low power dissipation with filtering on the output. Cheaper and simpler. Agree with digital radio concerns. That's absolutely no good for anyone. Analog may be king but don't be too romantic about it. If you've ever actually done any operating on any analogue radios you'll know what I mean. I spent 20 years designing and building them for fun.

skeptically 4y ago
"FM is no more complicated than AM to transmit and receive." FM is simple compared to WiFi6, but its an order more complicated than AM. An AM receiver only needs a diode and a coil of wire. The diode can be a rusty blade. I dont think you can make an FM receiver without a transistor (which for me, as a former solid state guy is an order of magnitude more complicated than a diode)
- Johnythree 4y ago
  Actually the Radio hobbyists have build many successful FM Crystal sets (using a simple diode detector). Do a search on "Slope Detection" and "FM crystal set"
Johnythree 4y ago
Try building an FM crystal set. It can be done (as many hobbyists have demonstrated) but it will only receive very strong and local signals. Unlike an AM crystal set which can hear stations many hundreds of miles away.
- iasay 4y ago
  I’ve built AM crystal sets before back in the 80s. Fine if you have the space and materials for a high up long wire antenna or something. But absolutely hell if you have any local noise sources. I actually had a large inverted V trapped dipole on my property which could be persuaded to tune up on AM broadcast with some effort and pick up all sorts. But ugh you need a decent noise blanker or nulling device unless you live in the middle of nowhere. Add a couple of transistors and some discrete components and you can build a fairly decent FM receiver instead of a crystal set which performs adequately with a couple of metres or so of wire taped to a bamboo garden cane.