6 replies to this topic

[ronnthompson]

I am sure that this has been asked a hundred times before, but now it's my turn.   I need communication in a 50 to 60 mile radius from my base.  Terrain is piedmont/upstate area of South Carolina, so mainly flat with some hills and small towns.  I think GMRS will do what I need, but I need suggestions on equipment, tower height, etc.  Looking at a budget of around $3,000.00 to $4,000.00 with 4 or 5 mobile radios. 

 

Thanks for your help.   

[Logan5]

for that kind of coverage, antenna height is far more important than an expensive repeater. get your repeaters antenna up as high as you can. I and some other members have BridgeCom repeaters and they are very nice. about $1k not including cable, antenna and duplexor. They are part95 certified and put out 40 watts. you can get a usable two radio repeater for much less. but you get what you pay for.

[zap]

Very depending dependent on site...

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[WQEJ577]

Yeah, 50-60 mile radius is hard to achieve with one repeater, and very hard to achieve a good enough signal to make it practical over all 50-60 miles.

 

I agree with the others, you need to get your antenna VERY high up to have a chance. The alternative is to set up multiple repeaters to give you the coverage you need. There are methods to link them via VoIP that are within the Part 95 rules as long as you protect the linking from unlicensed users (don't use something open to the public or you're asking for trouble). More repeaters means more money, but the cost of getting access to a tall enough tower (if you can even find one who will let a GMRS repeater up there) may be more than setting up several smaller sites.

 

Send me a PM if you're interested in linking them privately, I have quite a bit of experience there.

[n4gix]

Height is very critical. W9CTO has a UHF DMR repeater in Gary, Indiana that has a solid 40 mile radius, but then his transmitting antenna it 480' off the side of his host's tower, with the receive antenna near the top at 520'. Input power at the duplexer port is set at 50 watts.

 

His 2m and 220MHz repeaters are about the same height and get closer to 60 mile radius, but VHF propagates just a bit further than UHF.

[ASRM]

I can personally echo what everyone else has suggested. We are using a Vertex VXR-7000 (they can be had for around $700 on ebay with a duplexer) running 30 watts out the duplexer.

 

Original location was our home at 40 Feet above the ground, range was okay, it covered 90% of what we wanted (about 15 miles on mobile and 5 miles depending on portable).

 

We relocated to a commercial site at 220 feet. Now I find were mobile was sketchy at best, portable is like an S3 (some hiss in the background) and this is in basements or 12 miles from the repeater in an aluminum sided house.

 

We are running 7/8 hardline, 10dbd collinear omni but mount on the east side of a tower (which is not towards my optimum coverage want (I would probably be shocked at a pattern that covered what I wanted)

 

Long story short, height, height and more height. Little 20 watt repeaters at his location on the tower scream!

[NavyBOFH]

I work for SC ETV as a Field Engineer and know we have several towers in your area, with several ham, commercial, and state repeaters on them along with the SCHEART and NC-PRN ham radio network which we own... and all those sites have beautiful coverage at 40-50w. Finding a tower will be your hardest part, and even for us we have limited tower space for antennas even though our actual buildings have space for several more repeater racks.