The discussion hits one of my pet peeves with channel numbering and frequency differences between cable mode and antenna mode. Channels 2-13 were the same in both modes but 14 and higher were completely different. Channel 73 in cable mode is lower in frequency than channel 60 antenna mode. In fact, it is actually close to channel 22 antenna mode. (But 2MHz offset).
For consistancy, I never use cable mode. If I need to drop the freq, I go to ch 21 or 25. One of my biggest headaches is a setup with 2 TVs mirrored/cloned off TV2 and the customer calls dish and the CSR has the cusomer change to cable 73, gets everything screwed up and I have to go out and spend 2 minutes getting it all back to where it belongs. Even worse in when TV! in turned on to mirror that one. I have a customer with 8 TVs running off of an 222k. 'His' channel is 23 and and 'her' channel is 25. They can watch 2 different things on any two TVs' in the house. (One HD, seven SD) I told him under no circumstance to call Dish for help, or he will own me.
I have years of experience trouble shooting analog signal quality/strength issues for TV2 distribution. In my experience, the biggest culprits are poor connections and too many splitters. Followed closely by RG59 (and once I even saw RG58 cable, (shudder)), and corroded fittings in exposed outdoor connections. Signals passing backwards through taps and splitters does not help either. My best friend is a 30 year-old analog antenna meter that I inherited from a retired tv repairman. The original standard for a clear picture on a TV was 0 db (equal to 1 mV) (think 1940s). Modern electronics has no problem with -10db. If I remember correctly, the last time I measured the output on an 625 TV 2 it was about 50 db. A cable company supplying an analog service was usually trying to get about 20 db to the side of the house. A 2 way splitter with drop about 3.5 db, a 4 way looses 7 db and an eight way is 10.5 db. If you have an amplifier, they have a limit an how strong a signal you can feed INTO them with out saturating the circuits and causing so much distortion that the picture actually comes out WORSE. My experience with amps is a signal stronger than about 10 db on the input can cause problems.
I saw a customer install 3 amps in series because he said his his signal was so bad. I found ONE bad connection in his outside cable connection box. I replaced it and bypassed his amps and he had a nice clear picture again.
If you are interested in the channel allocations, here is a nice table:
Television Frequency Table