Wannabe Posted March 2, 2023 Report Share Posted March 2, 2023 Setting up a small base station at home. The antenna location is roughly 35’ from the radio. Will I have issues with running 40-50’ of cable to my antenna? I’m sure closer is better, but to keep the wife happy I need to keep my “toys” out of site lol. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
SteveShannon Posted March 2, 2023 Report Share Posted March 2, 2023 It will depend entirely on the type of cable and how well your system is performing now. Every type of cable has a characteristic loss figure that is much higher at the UHF frequencies of GMRS. It’s usually specified in terms of dB loss over 100 feet and the loss is linearly proportional, so for 50 feet you would expect half that loss. Getting an antenna with some gain and getting your antenna up in the air can make up for that though. Using LMR400 you lose 3dB over 100 feet. That’s half of your output power and half of your input signal strength that you would be losing. That doesn’t mean that you cannot use it, but be aware of the limitations. So, over 50 feet, using LMR400 you would expect to lose a quarter each way. If you have a good strong signal both ways you might not notice. Switching to better cable will reduce the losses. Getting your antenna in the air will also. Wannabe 1 Quote Link to comment Share on other sites More sharing options...
Wannabe Posted March 2, 2023 Author Report Share Posted March 2, 2023 Thanks for the quick reply, it won’t be a full 50’. That’s worst case. Was thinking mounting on the chimney as it’s the highest point on the house. What is better, longer cable with higher antenna mounting, or lower antenna mounting with shorter antenna? I know it’s case by case, but in general which would be the better sacrifice? Quote Link to comment Share on other sites More sharing options...
SteveShannon Posted March 2, 2023 Report Share Posted March 2, 2023 12 minutes ago, Wannabe said: Thanks for the quick reply, it won’t be a full 50’. That’s worst case. Was thinking mounting on the chimney as it’s the highest point on the house. What is better, longer cable with higher antenna mounting, or lower antenna mounting with shorter antenna? I know it’s case by case, but in general which would be the better sacrifice? You’re right, it’s case by case, but I would lean towards getting the antenna up a little higher. Quote Link to comment Share on other sites More sharing options...
SteveShannon Posted March 2, 2023 Report Share Posted March 2, 2023 Also, consider the use case. If you’re mostly just hitting a repeater you might not need much. Quote Link to comment Share on other sites More sharing options...
haneysa Posted March 2, 2023 Report Share Posted March 2, 2023 High gain antenna, mounted as high as possible, using the lowest loss cable type that you can afford. LMR400 as a starting point, especially for 50' or less run. More than a 50' run, look at LMR600, or 1/2" heliax. $$ goes up the higher you go due to the cost of the coax. Look for an antenna with 5dB (7.1dBi) or more of gain. You want an antenna that has 465 mhz as its center frequency, or as close to that as possible. Some base station omnidirectional antennas can be tuned for optimum performance. A 450-470 mhz commercial antenna will work well. Height = Might on GMRS frequencies. Quote Link to comment Share on other sites More sharing options...
Wannabe Posted March 2, 2023 Author Report Share Posted March 2, 2023 Thanks for the quick responses on this. SteveShannon 1 Quote Link to comment Share on other sites More sharing options...
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