Batboard

someone told me to build a simplex repeater, i need 2 mobile radios and a cable to connect them....

i have 2 cdm1250's and they told me to buy a cable on ebay, and either 2 antenna's or a duplexer and i will be set.....


the scenario is, the end user has mobiles and portables , but wants to set up a repeater to extend the range of the portables at 1 location to hit location # 2...

does this make sense? b/c im new to repeater making

In other words you want to use simplex operation around location 1 on freq 1, and simplex operation around location 2 on freq 2, and you need a method to connect the two locations.

If the frequencies are far enough apart, then it's as easy as building any repeater with the exception that the mobiles alternate as both rcvrs and xmitters. You'd connect the cor to the ptt, and rx hi to mic hi on both radios. A duplexer would be preferred especially if you stay in band (uhf to uhf, or vhf to vhf).

i try to make explain it better


there are 2 locations about 3 miles apart


say for instance both are using 450.000 with pl 100.3 ( example only)

both locations have 10 mobiles and 10 portables each



the mobiles reach each site great, but the portables do not, so we want to make it so the portables will reach each site !!!

So, location 1 & 2 are using the same simplex freq & PL. They are physically too far apart for portable operation, but well within mobile range. That makes it really tough, if not impossible, to build a repeater since there is no isolation between the two sites either by freq or by range. A store and forward system would drive you nuts. You need another freq to act as the transport between the two sites that won't cause local interference, and another PL to prevent a loop since they are within mobile range of each other.

you may want to consider several remote mount W4 W5 W7 W9 astro spectras with vrs750s, 1 for each location. if your portables and mobiles are UHF get a pair of VHF astro spectras with UHF vrs750s. mount the astro spectras with vrs750 in the locations you want to use the simplex repeater radios you mentioned. attach the vrs750 to a base antenna too to provide local service to the mobiles and portables. the range of the vrs750 would be dependant on the height and gain of the antenna, but on average you should get about 1 mile range to the base location with portables and maybe 3 miles away with mobiles. this is a unconventional use for astro spectras and vrs750s but it really does work. if you read the link below it will talk about loostening the squelch on the VRS750 to give more range.

heres a thread that talks about hooking them up in detail. i have been personally involved in setting up a system with multiple locations
http://batboard.batlabs.com/viewtopic.p ... lit=vrs750

i spoke to the site manager, the total site is almost 3 miles long.... the mobiles work fine, and the portables are spotty.... what kind of repeater can they put up?

legally they can pay for more freq. if needed , and change freqs. they will apply for proper license, first... just the local dealer is trying to put them on his repeater and they dont want that

There you go. If mobiles cover well, and they are willing to license and purchase a real repeater, that would be the best solution. A plain vanilla GR type repeater would be sufficient. Just get the low gain antenna above the tree canopy if at all possible.