gnd@targhee.idaho.amdahl.com (Greg Darnell) (02/21/91)
I have a barn about 100 meters from my house where I plan to install a
video camera to monitor a mare about to foal in March. I would like to
get the signals from the barn to the house so that we can watch from a
heated area. I have signal cables from the barn to the house already,
with multiple extra pairs, both twisted and non-twisted; however, no
coax installed, and I can't put that in now because the ground is frozen.
So...
1. Can I send the audio/video signals across twisted pair with an
acceptable amount of loss/crosstalk? Should I send it as raw video
and audio, or modulated to channel 3?
2. Are there other ways that might work better, such as an infrared
link or some sort of RF link? I have seen the VCR Rabbit but it
lists range as 150 feet "under ideal conditions". Could I add
bigger antennas to it and make it work? The nearest neighbor is
over 1/2 mile away so RF interference should not be a problem if
the power is low enough.
Any help would be appreciated...
Greg
--
Greg Darnell Amdahl Corporation 143 N. 2 E., Rexburg, Idaho 83440
UUCP:{ames,decwrl,sun,uunet}!amdahl!tetons!gnd (208) 356-8915
INTERNET: gnd@idaho.amdahl.comrobf@mcs213f.cs.umr.edu (Rob Fugina) (02/22/91)
In article <9942@tetons.idaho.amdahl.com> gnd@targhee.idaho.amdahl.com (Greg Darnell) writes: > 1. Can I send the audio/video signals across twisted pair with an > acceptable amount of loss/crosstalk? Should I send it as raw video > and audio, or modulated to channel 3? It would seem to me (and I may be wrong) that you could send audio and video via just about anything...I would think even telephone wire would do... then just plug it all into the inputs of a VCR back in the house... Rob robf@cs.umr.edu
jgd@Dixie.Com (John G. DeArmond) (02/22/91)
gnd@targhee.idaho.amdahl.com (Greg Darnell) writes: >I have a barn about 100 meters from my house where I plan to install a >video camera to monitor a mare about to foal in March. I would like to >get the signals from the barn to the house so that we can watch from a >heated area. I have signal cables from the barn to the house already, >with multiple extra pairs, both twisted and non-twisted; however, no >coax installed, and I can't put that in now because the ground is frozen. Service Merchandise has a "video rabbit" that uses 900 mhz RF to send video/audio up to several hundred feet. It is meant to allow one to view alternative video sources from anywhere in the house. Price is about $90 for a pair. There are other "rabbits" that use twisted pair wiring to do the same thing. They predate the FCC's permitting RF rabbits and are generally less expensive. I think Radio Shack carries these type. John -- John De Armond, WD4OQC | "Purveyors of speed to the Trade" (tm) Rapid Deployment System, Inc. | Home of the Nidgets (tm) Marietta, Ga | {emory,uunet}!rsiatl!jgd |"Politically InCorrect.. And damn proud of it
mcovingt@athena.cs.uga.edu (Michael A. Covington) (02/24/91)
In article <2220@umriscc.isc.umr.edu> robf@mcs213f.cs.umr.edu (Rob Fugina) writes: >In article <9942@tetons.idaho.amdahl.com> gnd@targhee.idaho.amdahl.com (Greg Darnell) writes: >> 1. Can I send the audio/video signals across twisted pair with an >> acceptable amount of loss/crosstalk? Should I send it as raw video >> and audio, or modulated to channel 3? > >It would seem to me (and I may be wrong) that you could send audio and video >via just about anything...I would think even telephone wire would do... then >just plug it all into the inputs of a VCR back in the house... > >Rob robf@cs.umr.edu No, the inductance and capacitance of the cable will get you if you're not careful. Remember that video (TV type) goes to 4 or 5 MHz, and what's more, all frequencies in the range 30 Hz -- 5 MHz have to be passed equally well, with no difference between the highest and the lowest. However, you can use a wire of any (reasonable) length if it's a coaxial cable of known impedance, and the driver and receiver (at the two ends) are matched to that impedance. This is a way of making inductance and capacitance cancel each other out. It's what makes large TV studios possible.