I want to feed the video output from my dvd player to my vcr video input as
well as the video input to my tv. Should I use a video splitter to feed both
or is paralleling to both devices ok?
If a splitter is required can I use a 75ohm tv antenna splitter otherwise
can someone point me to a circuit.... thanks, Don
since you say 75ohm, i guess you *don't* mean baseband so the answer is
yes, you *could* use a splitter. you could also use an A/B switch. i
suppose you want to record the DVD on VHS at the same time you are
watching the movie. you also have the antenna/CATV line to deal with so
here's what i'd do barring anything useful you find in the manual as per
Jim's suggestion.
note: CATV is running up to 1GHz in some systems these days (some of
it's for inet and some for digital tier) and i'd watch out for cheap
Radio Shaft splitters if you decide to use a splitter. The frequency
range should be on the label.
.--------------
CATV -- | .---------.
| -o | .----------. | |
| __--o- |---| |------ |
| -o | | VCR | | TV |
| | '----------' | |
DVD --- A/B Switch | | |
'--------------' '---------'
created by Andy´s ASCII-Circuit v1.22.310103 Beta
www.tech-chat.de
if you want to watch TV while the movie records, there are some other
creative things you can do with splitters and A/B switches.
note: CATV splitters have a 3.5 dB insertion loss for a 2-way splitter.
3-way splits have 2 -7dB ports and 1 -3.5dB port. 4-ways have 4 -7dB
ports. if you have a splitter installed elsewhere to run multiple
outlets, these losses add up. the *most* signal you'll see at the
pole/pedestal is 20dBmV hi channel ( i just found some end of line notes
from a 750 MHz system (chicago) - EOL readings were from 23dBmV down to
17dBmV on ch. 78 IIRC - don't count on having that much) with less on
the low channel. some systems have maybe 15/10 or even 12/10, so after
adding in cable and passive losses...
RG-6 cable losses per 100ft. would be approx. 1.53dB on ch 3 (USA),
4.9dB ch. 78 (about 550 MHz), 5.65dB ch. 117 (~750 MHz), and 6.55dB at
1GHz (ch. 144 is 912MHz, so i need a new pocket ref
) so if you have
only 12/10 at the tap and a 3-way/4-way splitter on the house, you're
running out of signal fast. you'll know when your pix goes to hell after
adding a splitter and a half-assed radio shaft jumper or a fubar'd DIY
F-connector.
BTW, all this dB loss stuff just subtracts from the signal and you
should have 0dBmV min. for a CATV box. older (?) sets were designed to
run from as low as -15dBmV antenna signal, IIRC. i wouldn't expect newer
equip to do that, in fact, the CATV company here has a line terminator
installed on my EOL tap which is a self terminating tap ( the retrofit
was done in-house and those dweebs never stopped to ask themselves why
certain taps have an extra housing port cap). of course, the installer
knows absolutely nothing of line gear, so i have a signal 6dBmV down and
can't even loop thru my VCR without near total loss of pix. i'd bitch
but i plan to move and they can have their stinkin' 2 node system. for
now i'm switching between CATV and VCR with an A/B switch.
hope this helps,
mike
