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Using beofeng UV5R HTs. Changed antennas to retevis whips. Will adding coaxial cable to HT & antenna for height reduce or increase reception. As i'm in a valley. I receive only. As i'm still studying for my licence. Gratitude in advance for any help. As i'm very new to this world.

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The answer is that it depends, although in my experience increasing height will always improve range. Height matters a lot in most VHF propagation. For your UV5R HT, antenna height will generally trump any loss in the coaxial cable. A few dB makes very little difference. I recently raised my antenna from 24' to 50' and I've seen 20dB or more improvement from signals 20-50 miles away That's many times more improvement than you would lose from an extra 26' of coax.

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  • $\begingroup$ Gratitude. Your answer helped. I had heard, height is might but was out my depth regards cable. Is it true that using a metal base. For example, a baking tray. To mount a magnetic antenna will boost both transmit & receive also. $\endgroup$
    – Snowy
    Jul 18, 2023 at 13:12
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    $\begingroup$ @Snowy, that depends on the antenna as well. Many (most? all?) magnetic antennas are designed for use on top of a car, so they are engineered expecting the large metal ground plane that the roof of a vehicle would provide. For an antenna like that, providing a ground plane would definitely help. $\endgroup$
    – spuck
    Jul 18, 2023 at 15:54
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    $\begingroup$ @snowy, great news! it is very easy to build your own ground plane antenna for 2-meter use . If you put that on top of a tall pole you will be very pleased with the results. try searching for "DIY 2 meter ground plane antenna" on the google. -Niels $\endgroup$ Jul 19, 2023 at 1:03
  • $\begingroup$ You answered my next question before i asked. I've been pondering experiments with home built antenna. Will check out you're search. And any further tip's would be well received. Are these similar to the UK military setups from the 40s & 50s? I used rigs in Army cadets were the set had a length of copper wire trailing to the ground. With a dog tag shaped piece for grounding. Or possibly the antenna itself? $\endgroup$
    – Snowy
    Jul 21, 2023 at 0:26
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    $\begingroup$ 1/4 wave verticals commonly used on car roofs require a ground plane, which the car roof provides. When used elsewhere, you would normally see 3 or 4 radial elements sloping down from the feed point. Fortunately for the 2m band these are only about 19" long. There are other antennas that can be home-built like a j-pole or colinear that are omnidirectional, but if you're only trying to go in 1 direction a Moxon antenna is very easy to build. It provides some gain in the direction that it's pointing. $\endgroup$
    – Deepstop
    Jul 21, 2023 at 2:36
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You have to be pretty high up in frequency (basically in GHz instead of MHz) where the coax loss becomes more of a factor than the gain you'll benefit from getting an antenna that much further away from the ground.

The further you get an antenna away from the ground, you get:

  1. dramatically increased line-of-sight distance
  2. somewhat less signal losses to the soil
  3. possibly less local noise (?)

And especially when receiving, any coax loss really isn't a problem. See e.g. https://ham.stackexchange.com/a/17922/1362 for more details, but basically:

for reception quality we're interested in signal-to-noise ratio

Your receiver can usually add the gain back it needs to compensate for any coax loss (which should attenuate both the signal and the noise ± equally anyway). So usually far better to give a good antenna a better "bird's eye view" — out of the valley, away from all the phone chargers and LED transformers and whatnot in your house with a little bit of coax loss, than to use a stubby antenna down by the ground.


All that said though, one important caveat! What I said is all good in theory but in practice sometimes especially the more cost-effective receivers end up doing worse with a better antenna: Why do Baofeng radios have such poor reception reliability?

With my Baofeng's I often find:

  1. poor reception with stock antenna
  2. no reception with a good antenna (!!!)
  3. good reception with a good antenna and a filter to block 88–108 MHz which is the FM broadcast band here in the USA (quite strong signals from good towers for commercial music/news programs/advertisements)

Basically the receiver could amplify a weak signal however much it needs. But if there's also really strong out-of-band signals those throw a wrench in that idea, because in the real world the amplifier itself ends up distorting on the strong signals and making hash of everything, before it can get the weaker signals up to their proper level.

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    $\begingroup$ Your answer gave me plenty to think about. I have mostly been receiving in my home with the stock, Duck antenna. Now i know that ambient "noise", from other home electronics radically affect my signal/sound quality. I will use a recently purchased whip antenna with mentioned cable. Any answers on best place to mount. And info on procedure to do so would be extremely helpful. I live in a 3 story apartment block. So roof may not be viable for my set up.As i'm on the ground floor. Hence question about remote positioning with cable, etc. $\endgroup$
    – Snowy
    Jul 18, 2023 at 13:31
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Adding coax will reduce power. A common mistake is to think that power and range (or even antenna and range) have anything to do with each other. It is possible to hear and contact a satellite in orbit with 1/2 watt of power, and that's a lot further away than you are likely to be attempting. The key is that it has to be in your line of sight.

Power helps overcome noise. For receiving, this only matters if your coax acts like an antenna and receives noise that buries the signal.

As others have said, raising the antenna will help range more than any other factor.

Coax might make the signal weaker, but it won't reduce the range. However, a very long poorly shielded high loss coax might reduce the signal and increase the noise to the point where there is little signal left. Higher quality coax would help this. If the coax is very long (100ft or more?), then adding an LNA (amplifier) at the antenna would overcome this easily.

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  • $\begingroup$ Thanks. after seeing these answers. I now feel confident to try. original antenna is sitting about 10". With coax i intend to raise it to, 50". Apart from initial, 5". The coax will be running vertically. $\endgroup$
    – Snowy
    Sep 6, 2023 at 13:52
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You've received some good answers here saying height means everything.

The exception to that is if part of the coax has a long horizontal run.

For example, this chart asserts that there's 1.7dB loss per 100m of RG8 type cable at 146MHz. So if you're running 100m of RG8, then you'll want a signal gain of at least 1.7dB to break even in terms of receiving a particular repeater or station.

And it may be worth it regardless if the new height gives new line of sight to signals you're missing completely today.

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    $\begingroup$ "The exception to that is if part of the coax has a long horizontal run" why? $\endgroup$
    – webmarc
    Jul 21, 2023 at 18:41
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    $\begingroup$ @webmarc Good question, and I should explain that. Do you remember that cartoon in older ARRL publications titled "Line loss can nullify height gain"? It showed a long run of coax running from the guy's shack, through his yard, and to an antenna not much higher than his shack. ;-) $\endgroup$ Jul 21, 2023 at 19:39
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    $\begingroup$ hah! I don't recall that specifically, but I appreciate the description. Your observation is valid, I was just prompting for more, for ex: "This chart asserts that there's 1.7dB loss per 100m of RG8 type cable at 146MHz, so as long as your signal gain is more than that, it's worth it for signals you can already receive, and may be worth it regardless if the new height gives new line of sight to signals you're missing completely today." or something to that effect. $\endgroup$
    – webmarc
    Jul 22, 2023 at 19:43
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    $\begingroup$ I decided to go ahead and add the info implied by your cartoon reference to your answer, hope you don't mind. Obv, feel free to revert or edit! $\endgroup$
    – webmarc
    Jul 26, 2023 at 1:24
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    $\begingroup$ @webmarc No problem. :-) $\endgroup$ Jul 26, 2023 at 11:13

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