[mtownsend]

Originally Posted by MTVhike

The antennas are pointing to trees about 50 feet away - how will that affect the signal when they leaf out? These trees are about 100 feet tall!

Trees do have an effect on signal quality and strength. Signal blockage is the worst when they have full leaves and are wet (i.e., soaked from rain). The amount of signal loss depends on too many variables (tree species, water content, spacing between trees, length of path through trees, angle of approach, etc.), so predicting the severity of the signal loss is near impossible. All you can do is wait and see how much your signal changes.

Should I recable the system so the 7777 is not used for VHF - it doesn't appear to be necessary

As long as the amp is not overloading, I see no reason to bypass it. It's unlikely that your VHF stations are overloading the amp, so I'd just leave it as is.

how do I combine the signals with minimum loss, and I would then have two cables.

Just for future reference, the best way to combine separate UHF and VHF signals onto one cable is to use a diplexor like the UVSJ. It can combine or split different frequency bands with very little loss (~0.5 dB) compared to an ordinary 2-way splitter/combiner (~3.5 dB loss).

I have about 100 feet of RG6. I also have a cheap RS distribution amp, which doesn't appear to be either good or bad, except that it works as a splitter.

Since the CM 7777 has very high gain, it's already more than enough to compensate for your 100 feet of RG6. That is why you see no difference with/without the distribution amp. If you had another 100 feet of coax AFTER the distribution amp, then it might have actually made a difference.

The main thing to look out for when daisy chaining amps is to make sure the first amp doesn't overload the second amp.

In your case, the second amp in not necessary, and I'd recommend leaving it out until there's an actual need for it. The fewer active components you have, the less things there are the break over time.