Sunday, April 19, 2009
 

How to record on one channel while watching another channel on Digital TV

recorder remote, television remote, cable remoteBackground: The Sony Betamax was introduced in 1975, and the VHS hit the market in 1976. By the late 1980's, most people were recording programs they would have otherwise missed by being absent as well as recording something on one channel while watching another channel. Advances in technology gave us the digital video recorder (DVR) in the 00's which did the same functions, recording something on one channel whether you were watching another channel or not at the time, and this activity became known as "time-shifting". Further advances in technology have caused the Federal Communications Commission to rule that all future broadcasts (after a date that keeps sliding, from Feb to June) must be transmitted in digital format rather than analog. Up until recently, all televisions and recording equipment people already own were analog devices. There are several converter boxes available, either on the shelf or provided by the cable television sources (I got one from Comcast free the other day) to accomidate this, and some new recorders (DVD as well as VCR/DVD combos) have digital tuners. DVR's should already have digital tuners.

Issue: Pretty much every new recorder, however, lacks the ability to record on one channel while viewing another channel. Not even the Panasonic VCR/DVD model displayed at Costco with a big placard saying "you can watch while recording" lets you do what those words appear to mean -- what they meant was that you can watch a videotape while recording programs to a DVD (or vice versa), not watching one channel while recording another. The wiring diagrams for converter boxes and digital tuner recorders may include how to hook multiple items up to one television, but none of the manuals say how one is supposed to watch "American Idol" while recording "NCIS" on your average (analog) TV.

Solution: I was looking at the wiring diagram for my new VCR/DVD recorder with digital tuner, which for the "to use with cable box" (if you have premium channels thus require one) section showed the wiring going from the wall to the RF jack on the recorder, the recorder to the RF jack on the cable box, cable box to the RF jack on the television, but then additionally cables going from the A/V-in jacks on the television to the A/V-out jacks on the recorder, and the A/V-in jacks on the recorder to the A/V-out jacks on the cable box. Hmm, maybe if you have a digital TV since the recorder has to be turned off to record (just like VCRs always did) and the TV would be doing the signal processing, but this is not what most of us have. So I got to thinking, what if I put that free converter box back into use -- a nice idea anyway since what the recorder determines as channels is vastly different than what the cable box lists (example: HGTV is 68 on the cable box and 102.7 on the recorder) and Comcast's special offerings are exclusive to their box -- on a splitter, then had the recorder going to the TV's RF jack and the cable box going to the TV's A/V jacks? I could flip between the two by pressing the TV/AV button on the television's remote, same as I already was doing before the changeover to go between cable or VCR and the DVD player. And in a few minutes of rewiring, I had things working such that I'm recording a Maniners baseball game on Fox Sports Network at this moment while watching "Good Buy, Bad Buy" on HGTV. Had enough of my balloon juice?

Procedure: I had a coaxial splitter from Radio Shack laying around, it's a pretty common piece of equipment. All the new equipment came with wires and cables, which I didn't necessarily need because I'd replaced the old VCR and DVD players so had existing rigging. I went from the wall to the splitter, then on one splitter jack the coax goes to the RF-in on the recorder, then from the RF-out to the RF jack on the TV (what comes this way is shown on channel 3) -- and on the other splitter jack the coax goes to the RF-in on the converter box, and connected A/V cables from the A/V-outs on the converter box to the A/V jacks on the TV (what comes this way is shown on the Video screen). See my rather bluish diagram below, cut-and-paste pieced from the Panasonic manual for my purposes, for a schematic. The TV/AV button (also known as TV/Media) does flip between the two, and both paths are providing crystal-clear digital signal to the TV.
watch digital cable on one channel while recording digital cable on another

Comments:
sometime I should diagram what I had to do when we had an old projection screen with speakers that failed to work.

as for the subject at hand, I use the comcast dvr on my hd box. it's only 6 a month and I can record two things and watch one of them or something else as long as it's already recorded. apparently it has two tuners.
 
sometime I should diagram what I had to do when we had an old projection screen with speakers that failed to work.

as for the subject at hand, I use the comcast dvr on my hd box. it's only 6 a month and I can record two things and watch one of them or something else as long as it's already recorded. apparently it has two tuners.
 
Post a Comment



<< Home

This page is powered by Blogger. Isn't yours?