Ridge,
Maybe, just for kicks, give that loop another try but without the balun this time.
You are going from a balanced loop to unbalanced coax but the mismatch in a receive only application
is usually not a big concern.
Full wave loop impedance at resonance (in your case 5580 kc, as f= 1005/L with F in mc and L in ft) in free space is about 100 ohms.
So, with a 50 ohm input on the R-75, your mismatch is 2:1. A 2:1 mismatch on a receiver is really not that big of a deal.
This will, of course, change at different frequencies. So, if impedance matching is desired, then use an antenna tuner (transmatch).
In your urban environment, if front end overload becomes an issue, then a preselector may be useful.
Just some thoughts off the top of my head that you may want to consider.