Jim,
Then Miro's question remains: What happens to power reflected back from the antenna feedpoint
if there is no antenna tuner? Without a tuner, it is not all getting sent back out to the antenna.
Conservation of energy says the transmitter has to put it somewhere.
I can't think of anything the transmitter could do with this energy other than turn it into heat.
Either by design with your isolator and load, or just heating up whatever's handy.
I don't know for sure exactly where it goes in a typical amplifier.
Hence my weasel words: "What happens then depends on the transmitter design."
Jerry, KE7ER
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On Thu, Aug 20, 2020 at 06:55 AM, Jim Lux wrote:
On 8/19/20 10:09 PM, Jerry Gaffke via groups.io wrote:
Without the antenna tuner, that reflected power comes back to the
transmitter.
What happens then depends on the transmitter design.
At least some of it will likely be getting dissipated as heat in the
transmitter.
Only if the transmitter has some sort of isolator (in a logical sense) to push
the reflected power to a load, and that's pretty rare in a HF transmitter.
What really happens is that the transmitter is operating less efficiently with
a load other than its optimum. And that depends a lot on whether it's
something like a tube amplifier with a tuned tank, or a broadband solid state
design.
