I too carry just one 25' cable. I was having problems with the rear set having a bad picture and the front set was great. Removed all the slip on ends and just use the screw on connectors. Picture improved and then I installed a 45' HDMI cable to the rear set and the pictures both in front and rear are fantastic, but, now there is a lot of noise on the old 75 ohm cable feed to the rear set. I goofed when installing the HDMI cable, I should have installed a new 75 ohm cable at the same time.
May have corrected the problem, I disconnected all four cables on the back of the switching box and disassembled the box. Nothing there to service but I did see several places where it looks like the shielded cables from switch to switch and F connectors looked like they melted to bottom of the box. No marks on the wires. Moved them so they were'nt touching the bottom of the box. Tried using the antenna on the cable circuit and no noise. Also checked the cable by the rear TV and all was tight. When I put it all back together everything worked fine on both sets with all three inputs. Who knows.When I had to remove my Winegard bat wing because I couldn't move the cable, I found if memory serves me(it usually doesn't)right, three pieces of cable with two couplers going to the distribution box from the antenna. I have a feeling that this morning I will find the old 75 ohm cable going to the rear TV is bad and that I will need to replace that too. From past experience and talking with some older cable installers who use signal analyzers and not just install, hookup and leave, that couplers and slip on adapters do attenuate the digital signal noticeably. There are good couplers and adapters and there are not so good. Personally, no more adapters or couplers, with the new sets you need two cables anyway so I just tighten up the 75 ohm cables and don't switch things around.
The reason I installed the HDMI cable was to have the ability to show the same BluRay movies on both sets. This past week we had the DGKs camping with us and sure enough there was Nana and the DGKs in the back on the beds and I was at the dinette. They raved about the picture. I sure hope the new rigs providing both cables when they are being built.
"I travel not to go anywhere, but to go. I travel for travel's sake. The great affair is to go". R. L. Stevenson
David Bishop
2002 Winnebago Adventurer 32V
2009 GMC Canyon
Roadmaster 5000
BrakeBuddy Classic II