"FARS" and wattage....an alternative view

[73blazer]

So I can definitely say for our usage, the wattage makes a difference. I always see people saying there's basically no difference in 3 or 4 or 5w. But, there is. It's specific though. We live in very dense woods. And where we hunt, also very dense woods. All my HT's have Nagoya 771g on them, HT to HT, the 4watt radios (1 retivus ra85 5w rated, measures 4.1w and 1 baeofang uv5g rated 5 measures 3.8) don't make it but 3/4mi. the KG-935G (which mine puts out 5.9w measured at full batt, rated @5.5) makes it 1.3-1.4mi. I always seem to be just about 1.1-1.2mi away from the rest of the group and the 4w radios do not make it while the 5.5w radio does. I also bow hunt about 1.4mi away from our house and the 4w radio won't reach back but the 5.5w radio does. I don't think it's the radio either as I can set the KG-935G to medium power (4.5w rate, measured 4.3w) and it won't make it, but high power does.

I would agree once your signal is out in the open it probably doesn't matter much. There's one area we go where there is a repeater on a 80' mast and same 4w radio that won't reach through the woods a mile to my buddy also in the woods... can hit that repeater 12mi away from the same dense woods I'm standing in. But most areas we use don't have any repeater nearby. So when there is nothing but trees and brush and dense woods between you and what your trying to talk to......nothing beats a little more juice.

[marcspaz]

There is a lot more to it than just power.  UHF is a line of sight service and things like trees and terrain make a difference.  Where you are compared to everyone else makes a difference.  If you move 1 foot in one direction or another, depending on whats around you, that 1 foot could make the difference between another operator hearing you perfectly or not at all.  You could also be dealing with things like receive sensitivity on any given radio.

 

A 1 watt difference does make a bit more of a difference when you are at a 4 or 5 watt power output, compared to starting with 20 watts... not so much.  That said, if you increase your power 100%... going from 4 watts to 8 watts for example... you will see an slight increase in range, but we are talking measurements in feet or maybe yards... best case.

[KAF6045]

Unless you had all three radios with you, at the same spot (same height, same orientation, etc), when doing these "tests", the results are mostly irrelevant. UHF is heavily attenuated by moist vegetation (2W MURS units might propagate better in those woods); if the position changes enough to put a dense bush between you and the receiver it could be enough to kill reception. Heck... 4W 11m (CB) HTs might propagate better (ignoring skip conditions -- where a CB might hit 150 or more miles, but with no signal BETWEEN those end points -- around 1976/77 I was in the car, backyard [Kent County, MI], with a CB running; I was hearing a distress call coming in from Missouri [or other state in that vicinity])

I don't know if these low-cost radios make any attempt at a meaningful "S-meter" or just pop up a bar-graph almost as a whim... Common wisdom is that a 2 S-unit increase requires 10X power change -- that's going 5W -> 50W just for a small change on an S-meter (most S-meters display S1-S9, so we are talking, say, taking a 5W S6 signal and getting S8 with 50W).

[73blazer]

Well, the tests I've conducted have been pretty rigid. The purpose of which was to find a setup that actually works at 1.2-1.4mi in the woods so our whole group can actually talk.

The tests have been same spots for each distance point as well as some "random" spots at known distances to simulate walking around. Conducted in three different areas all heavily forested with near zero open areas and only mild elevation differences. One of which was our real hunting area from our actual various spots (and right now is full foliage so I would think better in fall). 

I've also tested MURS and CB. MURS falls off at 3/4mi no matter what but seems better, more stable on it's edge. CB absolutely sucks, and I had the 51" telescoping antenna on it. 1/2mi at most with CB. Yeah, I had high hopes for CB, but...it was not to be. So I honed in on a few GMRS radios and have been conducting tests. The Nagoya 771g antenna helps them all out ALOT, a good 1/4mi more. My point was at the same distance points with each radio in hand and my wife on the other end, with same radios (i have 2 of every type), so I ran same radio to same radio, same radio to different radio, etc..at the far edge about 1.4mi the KG935G at high power will make it, and at medium power (4.3w) will not make it. The other 4w radios will not make it the 1.4mi.  By not make it I mean mabey you get some words and alot of static, but unusable for an actual conversation.

 

[axorlov]

What is likely in play here is deviation. Baofengs often are certified with 5K0 deviation for narrow band, while better radios are usually 11K0 or 10K0 for narrow band. Baofeng has 6dB disadvantage vs Wouxun. Retevis likely too is a narrow-narrow band radio.

Now if you switch your radios to wide band, you will gain another 3dB advantage.

[73blazer]

Al the radios are wideband capable and all tests performed on wideband.

[axorlov]

I checked UV5G in FCC database, certification says narrow band is 9K84 and 9K78. So, not as bad as some Baofengs. No wide bad certification there, so who knows what real deviation on wide band might be.

[73blazer]

well thats interesting  ill have to start checking the fcc certs for these.. thanks for that! its menus have option for wide or narrow and defaults to wide on the 15-22 channels. of all  the gmrs radios its the worst ...sounds bad no ip rating nasty tail crap at EOT.