On Dec 14, 2011, at 5:31 PM, Tony Duell wrote:
AFAIK from reading hte manuals, the US CoCOs have a
VHF modulator
switchable (esternal swithc on the rear of the machine) to channel 3 or
4.. The outptu is an RCA phone socket.
This was pretty common practice over here in the '80s; Most game consoles, computers
which could connect over RF and VCRs had a choice of channel 3 or 4. The RCA jack usually
cabled to a coupling box with an F-connector input and output to pass the other signals
through; my experience was that they did a rather poor job of spectral isolation, though,
so channel 3 would leak into channel 4 a lot. I suppose the switch was in case you had
local broadcasts occurring on channel 3 or 4, which we certainly didn't in Baltimore;
anyone know the story behind that?
I also recall that the VCR made a much better modulator than the one built into most game
consoles (the ones that had composite output, anyway), interestingly enough.
Our VHF channels go from 2 to 13 (I don't remember the story behind why channel 1 is
missing) and UHF covers 4 to... 68? Most of time the 3 major networks ran on VHF, because
it reached further; we always had a harder time receiving the UHF channels at home when I
was growing up.
- Dave