For reception in the medium wave range (500-1600kHz) a ferrite rod (loopstick) has a measured inductance of Lc=2mH and a resistance Rf=5 ohms, whereas an RF choke with Lf=2mH has a resistance Rc=8 ohms.
Given that a choke is much smaller than a ferrite rod, why do medium wave (AM) radios use a ferrite rod rather than a choke to tune into radio stations?
Context: I am using a choke (4mH) and a capacitor (2.2nF) in parallel in a tank circuit with a resonant frequency of 50kHz, and I am wondering if I should be using a loopstick instead of a choke. I am using a choke because I need to minimise weight.
EDIT1: The following text and image were added for information after answers were received. From the comments below, it seems to matter that the choke has ferrite caps. Not sure if this is relevant, but I am trying to receive (not transmit) RF signals.
Figure 1. Picture of a (very) spare choke, with the plastic coating removed (I managed to break the wires inside in the process of removing the plastic). The material at both ends (caps) of the coiled wire is magnetic (ferrite?).
EDIT2: This edit has also been included as a new question, so please put any responses there.
The circuit in Figure 2 was used to test predictions made in answers to this question.
The inductor was either a) a choke with Lc=0.54mH (R=3.2ohms) (as in the figure 1), or b) a loopstick with Ll=0.6mH (R=8.3 ohms)) (Figure 3, from a radio clock).
A sinusoidal 1V (p2p) signal from a signal generator was injected across the whole circuit. The frequency was adusted to maximise the voltage across the tank circuit, which corresponds to the resonant frequency, measured as f0=40kHz (for both the choke and the loopstick).
As an aside: The measured p2p amplitude across the tank circuit at f0 was 57mV, so that
57mV/1000mV = Z/(Z+20k),
so, solving for Z yields Z = 1200 ohms at f0.
Finally, I disconnected the scope from the circuit, and used the scope to generate an RF signal at f0 through a long wire antenna. I then measured the amplitude V induced across the tank circuit at a short distance from the antenna.
Result: With the loopstick, Vl = 4mV, whereas with the choke, Vc = 3mV.
This seems to suggest that both the choke and the loospstick are almost equaly good at converting the RF signal into voltage. What am I missing?