I have a new toy. It's a Rigol DSA815 spectrum analyzer.
It's quite a step up from the Tektronix 495P I've been using for years now. This is not a review but just an example of how I'm using it for TV stuff. There are many YouTube videos demonstrating its many functions.
The display can be saved to a USB thumb drive so no more photographing the display like I have been doing.
Below are some examples of viewing antenna Front-to-back ratio using two of the three traces. The first image is KCRA under normal conditions with an SNR of 28 dB. The yellow trace is pointing at KCRA and the purple trace is pointed in the opposite direction. The second image shows KCRA under degraded conditions with an SNR of 17 dB. The reflections are stronger than the main signal. Only the F/B ratio of the antennas allows the signal to be decoded. The final image is KSBW which is largely unaffected by reflections. The difference between the traces is essentially the F/B ratio of my VHF antennas.