Well, so will taking a 100' braided cable, jacking it up 50' and putting a variable capacitor across the ends.
Varying the make-up of the jury-rigged antenna will vary reception, but I think it goes without saying that you will not have reproducible results.
As it is not a purpose-built radio receiver, what you will end up receiving depends on components in the amplifier, how they are oriented, what your antenna is, how objects in the room the amplifier is in are oriented, and the time of day due to atmospheric RF propagation.
If you're interested, how this works is that any length of wire that is exposed can serve as an HF detector.
Now, HF travels through an audio amplifier differently than audio. As most amplifiers have capacitively-coupled triode cascades in their pre-amp stages, the high-frequency signals induced in the cable cannot pass into the grid and modulate the amplifier in the normal way. Instead, it travels through the grounding of the jack to the cathode of the first stage, where the diode effect of the tube rectifies it. At the plate you have only the positive side of the carrier, more specifically the positive envelope of whatever frequency the carrier was modulated at in that specific moment.
At that point it is as good of audio as any, and can proceed to be amplified in the usual audio manner.
Treatments for this are to place a <500 ohm resistor in series with the input line to the grid, or to place the same resistor as a shunt to ground on the jack itself. This is a resistance that most modern amps (usually at 100K, 220K, or 1M grid-load resistance) wouldn't blink at, but for extremely-low-magnitude signals such as what you're evidently trying to receive, serves to nearly infinitely attenuate them, or at least to the point of insignificance.
Varying the make-up of the jury-rigged antenna will vary reception, but I think it goes without saying that you will not have reproducible results.
As it is not a purpose-built radio receiver, what you will end up receiving depends on components in the amplifier, how they are oriented, what your antenna is, how objects in the room the amplifier is in are oriented, and the time of day due to atmospheric RF propagation.
If you're interested, how this works is that any length of wire that is exposed can serve as an HF detector.
Now, HF travels through an audio amplifier differently than audio. As most amplifiers have capacitively-coupled triode cascades in their pre-amp stages, the high-frequency signals induced in the cable cannot pass into the grid and modulate the amplifier in the normal way. Instead, it travels through the grounding of the jack to the cathode of the first stage, where the diode effect of the tube rectifies it. At the plate you have only the positive side of the carrier, more specifically the positive envelope of whatever frequency the carrier was modulated at in that specific moment.
At that point it is as good of audio as any, and can proceed to be amplified in the usual audio manner.
Treatments for this are to place a <500 ohm resistor in series with the input line to the grid, or to place the same resistor as a shunt to ground on the jack itself. This is a resistance that most modern amps (usually at 100K, 220K, or 1M grid-load resistance) wouldn't blink at, but for extremely-low-magnitude signals such as what you're evidently trying to receive, serves to nearly infinitely attenuate them, or at least to the point of insignificance.