PAGE 1...VHF/UHF TV Signal Distribution&nbsp; ____________________________________________________________________ PAGE 1 DISTRIBUTING SIGNALS AROUND THE HOUSE Once you get your satellite system installed, most people find it necessary to have the signal available in other parts of the house besides the primary viewing location next to the satellite receiver. Several methods are available: I prefer to run direct video and audio on RG-6 coax, with RCA to F type adapters, and send top quality video signals to a monitor, and stereo audio to the tape inputs of a "ghetto blaster" or other stereo receiver that allows auxiliary inputs. Most situations demand the capability of multiple locations, so unless you want to buy an expensive audio/video distribution sys- tem and run lots of separate cables everywhere, signals will be best distributed via RF modulator. Inexpensive channel 3 or 4 mixers are the least costly way to mix one signal into an existing TV system, provided one of those channels is free to insert programming. Most mixers are of borderline quality, and it usually takes an experienc- ed technician with a field strength meter and a knowledge of exact levels and how to "tweak" filter pots. to make things watchable. In most cases, you will degrade either the existing adjacent off- air channel or the satellite signal. If you are connected to a cable system, the use of one of these mixers is usually not an option, as all channels are normally in use. In this case, using the built-in channel 3 or 4 VHF modulator, and running a parallel cable to each location plus an A/B coaxial switch is the cheapest conventional method, but if you have multiple satellite receivers, or multiple VCRs, and/or a lot of TV sets to feed, the economics quickly favor using a low-cost UHF modulator for each device. This prevents having MTS stereo in each location (unless your satellite receiver has a built-in Ch 3/4 MTS stereo modulator). If that is the case, running separate cables (one for existing off-air system, and one for your "new" TV system) to each location in a "home-run" fashion; directly to each location from a central power divider, is the wiring method most often advised. My method of running video and audio directly to a single location to get stereo is another option. If you don't mind spending $300 or more, CHANNEL PLUS has some MTS stereo type modulators that allow video plus stereo audio to be patched from your satellite receiver (assuming it has these RCA jacks) to the CHANNEL PLUS modulator. This allows you to leave your existing TV distribution system pretty much undisturbed, and find an unused UHF channel in which to place a satellite signal. If you have cable-ready TV sets that tune cable channels between 65 and 100, it is a little known fact that UHF modulators between UHF channels 14 and 35 will appear on cable tuners in the 60s through 80s. If you have cable TV, and a mix of cable ready plus UHF/VHF tuners, the best method of adding channels is to put them on channels above existing cable signals. If you have off-air TV, and UHF channels are in use, you can usually squeeze a few channels in between the existing broadcast signals. Let's talk budget! If you don't mind MONO audio, two relatively inexpensive modulator types are available. PICO makes the USM-8 modulator, which can be tuned between channels 14 and 30 UHF; sometimes up to Ch 32. If you have no existing signals on the UHF band, seven of these boxes can be used to provide 7 channels of in-house programming, provide you set them on channels 14, 17, 20, 23, 26, 29, and 32. We suggest maintaining three-channel spacing to minimize interference. If you have existing off-air channels in this range, you can probably insert signals 2 channels above or below an existing TV signal without much interference. If you have a need for even more signals, two products come to mind. [Please see next page] PAGE 2 UHF DISTRIBUTION IDEAS PICO has a medium powered Digital modulator called the CAM-25, which changes channels with front panel buttons, and can be set anywhere from CH 14 to CH 69. Its digital design makes the unit more stable than the USM-8, which tend to drift slightly if the temperature in the room is not maintained at a steady level. This is not generally a problem, but slight drift is a possibility. We also have a couple of other vendors supplying 2-channel devices similar to the CAM-25, allowing CH 14 to CH 69 selection and the ability to provide two channels of programming from one box. These are the higher-quality digital tuning variety, and are proportionately more expensive. The CAM-25 and other digital modulators can be set by pushing buttons...something even the novice can do. The PICO USM-8 has three adjustments that are tuned with a fine flat head screwdriver. Video and audio level plus channel frequency. Units are shipped from the factory at no particular frequency. For an additional $5.00 per unit, GLOBAL COMMUNICATIONS will set individual USM-8 modulators to the channel of your choice, and get the video and audio levels close to specification using one of our test satellite receivers. You may have to make slight adjustments when connecting to your own satellite receiver, but at least you will have more to work with than an un-set unit. Here is an approximate conversion chart for viewing of UHF signals from these devices on cable ready sets, or cable converters: UHF/CATV UHF/CATV UHF/CATV UHF/CATV UHF/CATV UHF/CATV 14 65 15 66 16 67 17 68 18 69 19 70 20 71 21 72 22 73 23 74 24 75 25 76 26 77 27 78 28 79 29 80 30 81 31 82 32 83 33 84 34 85 35 86 36 87 37 88 38 89 39 90 40 91 41 92 42 93 43 94 Here are some rough drawings showing system configurations... a lot more can be designed with a little bit of imagination. ADDING A UHF MODULATOR FOR SATELLITE OR VCR SIGNALS ON SAME WIRING SYSTEM AS EXISTING CABLE TV SERVICE ! NOTES: USM-8 may __________ ! Existing CATV require slight USM-8 UHF ! Input inside amplification with Modulator ! house Distribution Amp __________ ! such as PICO TA-25. ! CH 18 = ! CABLE CHs 2 to 62 ! CABLE 69 ! This may need to be ! ___________ "padded" down to !............! DSU-2 ! achieve an exact ** ! Combiner! level match with Optional ___________ existing cable Dist. Amp. ! service. If there ! To existing splitter is any interference If interference serving house to VHF or cable affects any cable channels, additional reception, add a UHF/VHF combiner at filter is advised. output of amplifier [PICO UVSJ] and terminate VHF output with F59T terminator. PAGE 3 UHF DISTRIBUTION Continued Please be advised that if you cause interference to your local CATV service (to yourself, requiring a service call from the cable co., or to other subscribers), you will be responsible for eliminating any problems. Do NOT hook up additional equipment such as this, find a problem, and call them for help. You will very likely be asked to remove the offending device, and possibly pay for a service call. When in doubt, call a competent service technician that is experienced in television distribution systems. ADDING MULTIPLE UHF CHANNELS: ________ ________ ________ ________ USM-8 USM-8 USM-8 USM-8 Ch 14 Ch 17 Ch 20 Ch 23 ________ ________ ________ ________ ___________ ! ! ! !...... ! ! ! ! !................... ! DSU-4 ! Out ! !................................ ! Combiner !.... !.............................................. ! ! !__________! Please note that DSU-2, DSU-4 and DSU-8 units are sold as combiner/ splitters, and labelled for use as splitter (power divider). In the above application, 4 ports labelled OUTPUT are actually used as inputs, with the single INPUT port being used as an output. When adding 2 or more modulators, the output should definitely be amplified with PICO TA-25 or equivalent Distribution Amplifier. Normal output of USM-8 Modulators is about dBm. Losses from insertion into DSU-4 typically approach 7 to 8 dB. If your level gets below dBm, resulting signals will appear more grainy, so it is important to amplify before degrading signals. You COULD use an 8-way combiner such as the PICO DSU-8, but are starting to approach a 0 dBm level, which will probably appear on upper frequencies used. If adding multiple channels, especially above Ch 32, use signal units such as the PICO CAM-25, which has a dBm output. This will compensate for cable losses at higher frequencies, and might even need to be padded with a small fixed attenuator (, or db devices) if levels are objectionable. Please call, write, fax or Email us for advice on designing a UHF distribution system. </BODY></HTML>