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Reliable connection!!


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I've just got a MXT400 and the power supply recommended for Midland, 50' of RG8X UHF coaxial, and UHF Base Antenna with +5dB Gain which came in a plastic bag and you have to fit in a 3 1/2" of 200psi plastic pipe. Everything is installed and the antenna is located at 20' from the ground at the rooftop of my house, but I don't have a reliable connection between my base and the rest of my devices. It not give more than a one or two miles of range. I would like to ask someone for help if I'm doing something wrong? Thank you for your help!!!

 

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That sounds like an Ed Fong antenna. Quality product, just make sure to follow his instructions (including using the correct type of PVC, and not messing with the wound coil). 

My first thought is the cable.  50' of RG8X might have a fair bit of loss.  For long runs, LMR-400 is a much better choice.  To test, bring the antenna close to the radio, use a short cord (less than 6 feet), and see what the range is like.  If you get equal (or better) range with the short cable, then the problem is either the cable, or interference along the cable's route. 

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The RG-8X cable cuts the power being fed to your antenna by half for the 50-foot length in use. The gain of the antenna makes up for the losses in the cable so the result is you are even power wise. From the info you have provided though, it appears you don't have any test equipment. The best place to start will be with a SWR/Power meter for UHF measurements. I would add to that a dummy load handling 50W at a minimum. The dummy load will provide a known value so you can see how well the SWR/Power meter is calibrated. Both items are available from radio shops selling radios and Amazon. While not a recommendation, many people use UHF meters from Surecom that provide the transmit frequency, power being sent, the amount of power reflected back because of impedance mismatch and the percent of power being fed to the antenna. These will tell you how well your antenna and/or radio is performing.

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Thank you both for the advisement!! And I'm sorry for the late response, but I would try to move the antenna to a higher position, I will try a different kind of cable and use a short piece of coaxial in order to check the communication. I'm already order online a new SWR tester, so I will be able to see where is the problem. I used to be a VHF radio user in another country, and let me tell you that Im impressed with the range of signal of the VHF, and I only operated a pair of Yaesu H.T. and a 25w. Vertex as a base and I covered a big distance with no problem. With those devices I could easily cover the whole city in VHF, but GMRS looks to be a weak radio signal, even if you have a 40 or 50 watts base. It looks like you have to live in a building near to the top of the building and mount the antenna at the rooftop of the building in order to have a "reliable connection" between your base and the mobile devices. Once again, thank you very much for your answers and advisement.

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Posted
Thank you both for the advisement!! And I'm sorry for the late response, but I would try to move the antenna to a higher position, I will try a different kind of cable and use a short piece of coaxial in order to check the communication. I'm already order online a new SWR tester, so I will be able to see where is the problem. I used to be a VHF radio user in another country, and let me tell you that Im impressed with the range of signal of the VHF, and I only operated a pair of Yaesu H.T. and a 25w. Vertex as a base and I covered a big distance with no problem. With those devices I could easily cover the whole city in VHF, but GMRS looks to be a weak radio signal, even if you have a 40 or 50 watts base. It looks like you have to live in a building near to the top of the building and mount the antenna at the rooftop of the building in order to have a "reliable connection" between your base and the mobile devices. Once again, thank you very much for your answers and advisement.

The higher up in frequency you go, the more line-of-site it becomes. This means that, in part, obstacles have an increasingly adverse affect on range. In GMRS, height is might. The fewer the obstacles between two antennas the greater the effective range of the signal travel. 50, 60, 70 miles on earth is truly possible, but these ranges are also truly exceptional, not the norm.

When a city has a repeater that seems to work well and covers the whole city it is because the repeater antenna is usually way above average terrain and well above most buildings. If you could put an antenna up to that same degree at your home you too would experience that same wonderful coverage.

Case in point. I can open a repeater 50 miles north of my home using just a 5w HT while standing outside. Why? Because the repeater antenna is 500’ or so higher than me. Now, if I hook up that same HT to my base antenna at 40’, 5 watts is more than enough to carry on a clear conversation through that repeater. However, the base antenna, again at 40’ feet, is still only sufficient for reliable simplex communications from my base to a 5 watt HT out to about 1.5-2 miles. My base antenna needs to be raised higher to get more base-to-HT range. When I do raise the antenna to 55’ or so and I gain an additional couple of miles. Raising the antenna nearly always decreases the number of obstacles that attenuate the signal, so that is why it is so important for good communications.

Hope this helps some.


Michael
WRHS965
KE8PLM

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