Very strange situation. System has been solid for months.
DVR on Mac
2 HDHR Primes with cable cards.
No issues on other channels.
NBCSports Bay Area records the Warrior games.
Tonight the recordings can barely play the signal is so bad. I try to watch live. Same issue.
Stop recording and try to watch live: looks fine
Start recording and signal issues return.
Tried restarting HDHRs and Mac DVR. No change.
Any ideas or troubleshooting steps appreciated.
To narrow it down, figure out if you're watching the recording in progress from the DVR Server, or watching it from another tuner on the HDHR Prime.
If your client has Tuner Sharing enabled, it will get the stream from the DVR, which gets it from the HDHR Prime.
If your client has Tuner Sharing disabled, it will get the live stream directly from the HDHR Prime.
You can also try the Official HDHR app on your client, which will bypass the Channels DVR Server and get the stream directly from the HDHR Prime.
You may also want to go into the Tuner Web Page and monitor which individual tuner is being used. If recording uses Tuner 0 On Prime1, but live is using a different tuner, say Tuner 1 on Prime 2, you may have an issue with one of your primes (either the entire device or any one of the 3 tuners within).
If the same tuner is used for both recording and live...... 
Thanks for the suggestions. There's another Warrior game on now and the automatic recording had the same issue.
Looking carefully at the channels in use on both Primes I was able to see that there was a bad signal on one of them. I stopped the recording. Used manage channels to remove the Warriors station from the Prime with bad signal and restarted the recording. This seems to have fixed the issue for this recording.
I also double checked the signal with the HRHomeRun Apple Store app so that's good new tool in the toolbox.
Thanks!
Next step is figuring out the signal problem for the one with issues.