Ferrite Loopsticks

I posted this question to another antique radio forum site but did not receive much help. Maybe I can do better here! How does one choose a ferrite loopstick tlo replace a loop antenna? Is there a "universal" loopstick replacement for just about any 5-tube AC-DC receiver? I've seen directions for making your own loop antenna, which one responder at the other site suggested, but I'm not interested in that project and would prefer replacing a bad or missing loop antenna with a ferrite loopstick as is recommended in a couple of radio repair texts I refer to.

Check tubesandmore.com, they carry two ferrite style antennas & they're only about $3.00.
Dave

I have a mid 50's plastic Philco that brings in AM OK with a ferrite rod I salvaged out of some newer model transistored radio. So I chose what I had and it worked. I don't know the science involved, but I'm sure impedance matching is important for best performance.