Unfortunately, the HOA where I live has rules against outdoor antennas, so I have to make do with something interior.

I've managed to get a pretty reliable signal by placing my current antenna (a pair of passive rabbit ears) high up on the top floor of my house, but I've gotten more channels when placing it in different spots around the room.

Are there any amplified multidirectional antennas that might work better?

Do you have an attic or crawl space above the top floor? If you do you could put an outdoor antenna up there... maybe even with a rotor. UHF should fit up most crawl space hatches, but VHF/UHF ants may require dismantling the VHF elements to fit the hatch and reassembling in the attic.

If no attic and no weak VHF stations are in your area you might want to try a 70s UHF unamplified bowtie antenna... I've had better results with those than some expensive new amplified antennas. If you can remove the original 300 ohm twin lead from the bowtie and connect the 2 shortest possible leads between the bow and your 300 to 75 ohm balun.

I have a spare bowtie. I might could cut into that and clip it onto one of the antenna leads I've already got.

I technically have a crawlspace, but I'm not gonna call it accessible. It's so tiny I doubt an antenna would even fit up there.

Are there any standards against setting up multiple antennas and combining the leads? I'm wonder if I couldn't run another antenna somewhere else and join the wires at my transmitter.

Are you sure you can't? https://www.fcc.gov/media/over-air-reception-devices-rule

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