chazcarly
Member
How far can I run LMR 400 ?? I was looking to put a Discone ant out side my home up on a 30' tower. I will need to run about 150' will this work?
Thanks
Thanks
LMR 400
- Thread starter chazcarly
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n5ims
Member
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- Jul 25, 2004
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Work, sure. The real question is can your situation work with 5.6 dB of loss in your feedline from a no-gain antenna. 150' is quite a long run (especially for a tower that's only 30' tall) so you may want to figure out how you can reduce the run.
chazcarly
Member
Thanks yor you reply.
Let me ask because i am green when it comes to this stuff.
I have a diamond discone Ant. in the attic, I has worked good for the last two years, We just had a standing seam metal roof installed this summer, Did not loose too much reception but a town that is about 10 miles away that i use to recive. That is why I want to get the Ant outside. I have a chase under ground from my house to a pool shed that is about 60 feet away. I would erect tower behind Pool shed, so that is another 30' to top of tower. In house I need about 50' to get to scanner from chase in basement.
Any ideas how to do this correctly woud be appreciated.
Thanks
Let me ask because i am green when it comes to this stuff.
I have a diamond discone Ant. in the attic, I has worked good for the last two years, We just had a standing seam metal roof installed this summer, Did not loose too much reception but a town that is about 10 miles away that i use to recive. That is why I want to get the Ant outside. I have a chase under ground from my house to a pool shed that is about 60 feet away. I would erect tower behind Pool shed, so that is another 30' to top of tower. In house I need about 50' to get to scanner from chase in basement.
Any ideas how to do this correctly woud be appreciated.
Thanks
prcguy
Member
The OP didn't specify the frequency range, if its VHF the loss would be much less.
prcguy
prcguy
teufler
Member
since you have not put the tower up yet, can it be stood next to the house, or attached to the house? If so,less coax fun and signal loss in the coax will be less.At 800 mhz, at q50 feet of lmr 400, you are at 5.9 db loss,at 80 feet next to the house, abouit 2.85 db loss.Coax Loss Calculator
Belden 9913 is about as good, cheaper and easier to find. Maybe 1/1 a db more loss which I don't think it would matter.. Or its about Christmas, tell your wife the discone is charlie Browns tree, decorate the discone, put the tree close to a window and you should hear the town.
Belden 9913 is about as good, cheaper and easier to find. Maybe 1/1 a db more loss which I don't think it would matter.. Or its about Christmas, tell your wife the discone is charlie Browns tree, decorate the discone, put the tree close to a window and you should hear the town.
prcguy
Member
4" waveguide would have a low frequency cutoff around 1.2GHz and nothing would pass through it in the normal bands you would scan.
prcguy
prcguy
prcguy
Member
I would avoid Belden 9913 at all cost, every run I have seen eventually filled with water and failed. Its partially hollow inside and water somehow finds its way in no matter how well you seal it.
prcguy
prcguy
chazcarly
Member
"Or its about Christmas, tell your wife the discone is charlie Browns tree, decorate the discone, put the tree close to a window and you should hear the town"
That is Good !!!!!!! But She tells me to turn the volume down all the time.....unless the Towns fire alarms are going off then she asks me whats burning?? LOL
Cant put the tower any closer to house....cant wait untill i start to build it and she asks what is that??
Normal bands 'you' would scan. :wink:
Beg to differ on the Beldin 9913. Yes, if the connectors are not properly sealed they will leak. I had a run not properly sealed and water did get in to the coax. Have run two more lead in's of 9913 (it's all I had at the time) and no water at all. Used two layers of coax seal & tape, works great...
prcguy
Member
LMR coax
I use LMR 300 during the summer during Wild land fire season because the repeaters are like 45 miles away from my house in the mtns. Very easy to work with to where LMR 400 is stiff not very bendable. When putting an antenna up that high with this coax becareful of your scanner ending up with a front end over load. What is the frequency range that you are looking to pick up. I too use a discone antenna during the summer. It just may be that you have to change the mode on your scanner or work with your ATT button. Such as an example: For me to pick up the forest service I have to use NFM - not FM and I have to turn on the ATT which normally the ATT cuts out unwanted noise. If I turn the ATT off I pick nothing up , same when I use just FM I get a hit and miss. I live in a apartment mid level of a 3 story building facing away from the mtns. Anyway just suggestions.I use a pro197 scanner.
I use LMR 300 during the summer during Wild land fire season because the repeaters are like 45 miles away from my house in the mtns. Very easy to work with to where LMR 400 is stiff not very bendable. When putting an antenna up that high with this coax becareful of your scanner ending up with a front end over load. What is the frequency range that you are looking to pick up. I too use a discone antenna during the summer. It just may be that you have to change the mode on your scanner or work with your ATT button. Such as an example: For me to pick up the forest service I have to use NFM - not FM and I have to turn on the ATT which normally the ATT cuts out unwanted noise. If I turn the ATT off I pick nothing up , same when I use just FM I get a hit and miss. I live in a apartment mid level of a 3 story building facing away from the mtns. Anyway just suggestions.I use a pro197 scanner.
chazcarly
Member
OK The Frequency that I lost is 453.3500 It use to come in fine, last night I picked up some transmisions faintly.....very low..... I dont know if it is somthing I did or the metal roof. The way it is now when i tune in the state police on a trunked system, they come in 40 miles away?
chazcarly
Member
Anybody ???
It's the metal roof. Put the antenna ON the roof, not under it. Build a tower.
Move your scanner closer to the tower. Use a tower top preamp with a power inserter and a power passing lightning arrestor if you can't get close enough.
Use the best coax you can afford. Minimum LMR400. Better yet, 1/2" hardline. If you are putting it in the ground, PUT IT IN CONDUIT.
Move your scanner closer to the tower. Use a tower top preamp with a power inserter and a power passing lightning arrestor if you can't get close enough.
Use the best coax you can afford. Minimum LMR400. Better yet, 1/2" hardline. If you are putting it in the ground, PUT IT IN CONDUIT.
chazcarly
Member
OK Thanks to all who responded .....
One more question "Connectors" what is the best to use for scanning all Frequencys.
chazcarly
Member
OK just to throw this out there. The Freq. that i cant get is 453.3500 police dispatch.... ? the same town fire dispatch is Freq. 46.4200, that comes in fine ? What gives ????
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