Likely first-gen cell phone service (AMPS)[1]. Calls were entirely unencrypted analogue audio transmitted in bands formerly allocated to UHF television. Your VCR was likely a pre-83 model, which is when the frequencies were reallocated to AMPS[2].

[1]: https://www.telecomtrainer.com/amps-cellular/

[2]: https://en.m.wikipedia.org/wiki/Pan-American_television_freq...