The home TV broadcast is working!
I have an older Roku with analog output connected to a UHF modulator in the garage. From the modulator it goes into a 24db antenna amp and finally to a little set of rabbit ears. I can pick it up cleanly both in the garage via a paper clip antenna and on the CRT in the den with its own rabbit ears. I can even control the Roku from the couch with the Roku app on my phone.
I'm profoundly pleased with how well this is working.