[Repeater-Builder] 440 - 450 Low in High Out Repeaters

[John Lloyd]

Skipp and group,   Years ago back in the 60's when we planned our Amateur 420-450 band we probably were considered a "rural" area. Now we have every commercial two way frequency, FM and TV Broadcast and even the 2 Mtr and 440 Amateur bands are full with transmitters and they are at multiple repeater sites.   Even today, my  449.500- repeater is currently co-located with a broadcasters 450.5125+ repeater at an 8800 Ft site and they both work fine. They are on separate DB408 antennas. This is at a site that uses every frequency known to the broadcast, 2 way and paging world. Several other Ham repeaters are located on this mountain. By the way, all of the broadcasters that I know of have repeaters that transmit in the low end of 450 Mhz. I thought that this was the same all over the country. Maybe this is different in your area.   All I am trying to say is that with the Broadcasters repeaters transmitting near the low end of 450 Mhz, it seems prudent that the amateur repeaters would want some frequency isolation from them especially at a co-located site and would want to use a low input frequency for their repeaters. It just make sense! I guess your local bandplan will take precident in how you operate with either a low input or high input.   Our Ham repeaters use top quality Cavities, Duplexers, Combiners where needed, Heliax cables and rugged antennas to exist in the high RF environment.   Over the years, I have built and managed Commercial Repeater sites that have had hundreds of repeaters which included 138-174, 450-470, 806-866, 900 mhz repeaters and oh yeah that 940.225 Mhz Skytel pager running 500 watts output. We even had a full power CH 14 TV transmitter on site! Life gets real interesting in this environment. Combiners and antenna management are a must in high RF environments!   By the way, all we had back many years ago were GE mobiles and repeaters so we just bought the crystals for the Ham frequencies we wanted to operate on.   Thanks and 73's   John, K7JL     http://www.ussc.com/~uvhfs/snowlink.html           Message: 5    Date: Thu, 11 Mar 2004 21:32:40 -0000    From: "skipp025" <[EMAIL PROTECTED]> Subject: Re: 440 - 450 Low in High Out Repeaters Hello Sailors, As I replied direct to John, the "trend setters" statement was made tongue in cheek. His reasons for their bandplan make sense in rural areas. When you get into large metro areas, all the rules go out the window at busy mountain tops and repeater sites. You just can't hide from that nearby 1/4kw paging transmitter... Receiver distribution and transmit combiner systems become a lot of science, experience, budget management and magic with mirrors. Cheers Skipp Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/   To unsubscribe from this group, send an email to: [EMAIL PROTECTED]   Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.