gojamo wrote:
Can you connect a broadband rf transformer to a receiver front end tank
circuit rather than to a resistive load?

Yes.

The inductance of the side of
the transformer connected to the tank circuit would be several times
the inductance in the tank circuit, and changes to the overall
inductance (parallelled inductances) of the circuit would be taken
into account.

You can often make a better broadband transformer by using
low-frequency, high-permeability ferrite for core material than by using
higher-frequency, lower-permeability ferrite. This results in a winding
impedance that's high, but primarily resistive through the HF range and
above. The advantages are that a high winding impedance is relatively
easy to achieve, and it stays quite constant over a very wide frequency
range -- typically several decades -- since it's free of resonant
effects. What you have to insure, then, is that the winding impedance is
at least several times higher than the impedance seen by the circuit
it's across. If it is, the fact that it's resistive rather than
inductive is of no consequence as far as the external circuit is concerned.

Roy Lewallen, W7EL