http://www.videokarma.org/attachment.php?attachmentid=167154&stc=1&d=1273460215
It's 3 CECBs, two of them modified to modulate on channel 2 and the other channel 5, and the Zenith box set to channel 4. So sets like the Admiral will have a choice of channels tunable on its own channel dial.

These modulators don't strip off the lower sideband, so normally the next lower channel is full of trash and not usable. So that's why no channel 3. But because there's 4 MHz between channel 4 and 5, channel 5's lower sideband trash stops short of channel 4, so no interference to channel 4. Yes, the channel 2 modulator will trash the 6 meter ham band, but this is a closed cable system, so that shouldn't be a problem, as nothing to very little should leak out over the air.

The UHF converter is not being used.

Hi,

I'm currently running a similar kind of scheme with 5 analog channels (the same 5 VHF channels we used to have here in the Bay Area) created by 5 Blonder-Tongue agile modulators fed by 5 DTV converter boxes.

Nice to be able to run the TVs on more than just channel 3.

Right now I'm feeding a bunch of TVs on a display shelf off this system, but will soon pipe it through the entire house so all of my vintage TVs can run this way. I'll have both analog and digital TV signals on the same coax, so that both the new and old TVs are happy.

Tom

Very interesting guys!!