rjr@mgweed.UUCP (09/26/83)
I have some questions on TV components; 2 set couplers, splitters, etc: I am trying to upgrade my TV antenna/distribution system in my house. I believe I have adequate antennas. I use a midrange Radio Shack VHF antenna and a separate UHF antenna, which is a 4-bay bow-tie. This bow-tie has been cut to favor the part of the UHF band of interest, which made a heck of a difference. To combine the 2 antennas, I was told by an "expert" that I should use a device called an "antenna coupler". It looks like the old 2 set couplers with three sets of screws for the 2 inputs and output. I originally thought that the best bet would be to use a VHF/UHF splitter (backwards) but was told this did not work as well. Does anyone know what this so-called "antenna coupler" is? I still think the splitter is the way to go. A few years ago I helped a friend install a new antenna and we borrowed a Jerrold field strength meter to find the best spot on the roof. We also checked the loss thru the splitter at the set and found there was no noticable loss thru it. The signal on the UHF output port was the same as directly off the lead-in and it made no difference if the VHF port was properly terminated, open, or shorted. The same was true on the VHF port. So that is why I am inclined to think the splitter is best. The "antenna coupler" does not distuingish between VHF and UHF inputs so it seems to me that it must be made like the ordinary 2 set coupler and would have 3 dB loss at each port...... Since I am trying to improve the signal level at each set (I need 3 locations) I can't stand the loss involved with ordinary passive multi-set couplers, however I have been reluctant to go to an amplifier since I know from other's experiences how badly they pick up undesired rf. (For example, All Radio Shack's antenna amps I have seen, oscillated and were really TVI prone). Any recomendations on antenna amplifiers would be appreciated. (Yes, I could measure the loss of the antenna coupler, but I hate to tear into the system until I know what the final configuration will be). Oh yes, another thing: I have always stuck with twinlead since (at least in dry weather) it is much less lossy than RG-59. All my sets have 300 ohm inputs anyway. I live 40 miles west of Chicago and can almost see the Sears tower but am not impressed with the signal levels out here. Before stations went up there, signal levels on an average antenna system were only about 1000 uv on a 300 ohm antenna...... Bob, K9EUI