axorlov
-
Posts
891 -
Joined
-
Last visited
-
Days Won
33
Content Type
Profiles
Forums
Events
Gallery
Classifieds
Posts posted by axorlov
-
-
2 hours ago, HCCFCA said:
This is a timely topic as I just set up a base station and needed a lesson on grounding. All the above is VERY helpful.
I have a very basic question: How do you knock an 8 ft grounding rod into the earth? I live in an area with clay soil and many many rocks and that seems an impossible task.
I use hammer drill and 4' of 1/2" rebar flattened at the end and sharpened to a spear point. After 4' hole is drilled, the rest of the rod goes much easier, with sledgehammer.
-
Michael (mburn) explained it in the detail. OP also may search this forum for "antenna grounding", since this topic is being brought up every 6 months.
-
Channels 1-22 are High powered, channels 1-7 and 15-22 are Very High powered, channels 15-22 are Blow-your-head-off High powered. The total number of channels is an exercise for the reader.
Not sure if you are serious. If you are serious, then I guess originally it was something like: "15 GMRS channels with the power level higher than FRS", which than was reduced to what you see by marketing department.
-
More power will help you to "burn" through the forest, from your base to HT, but not the other way, from HT to base. And not through the horizon. And I'm not fong of Fond antenna. Or wait, that should be other way around, fond - Fong. You can search this forum about Ed Fong antennas, was discussed in lengths.
- MichaelLAX and Muzic2Me
-
1
-
1
-
5 hours ago, MichaelLAX said:
50 Watts AND 15 High Powered GMRS Channels?!?
It's 22 High power channels, 15 Very High power channels, and 8 Ultra High power channels. And a brazillion private codes! For a modest price of $400. And wait, there is more!
- PACNWComms and JohnE
-
1
-
1
-
Agreements... Yawn. NotaRoundhead should just declare Canadian border abolished.
- marcspaz, Blaise and FranktheTank
-
1
-
2
-
40 minutes ago, gman1971 said:
Wrong, measured data proves that adding 6dB inside a forest did NOT yield double the range, adding 10dB on a more favorable frequency with a 5/8 wave antenna (vs a rubber duck) increased range only by about 2.7 times, at best, so a 6dB increase will NOT double the range inside a forest as you claim. Now, the data did prove that adding 120 feet of antenna elevation showed at least a four-fold increase in range, from <4 miles to at least 16 miles. Do you have any data collected? or you just guess stuff up with some formulas? Back at a previous job I used to joke that everything done in simulation is doomed to succeed...
And where did you say that you ask? What about you just told Marc that going from .8W to 42W will likely experience a 2000% percent increase in distance.... , so adding x52 times the power yields a 2000% range increase too... do you really guess this stuff?
I guess sometimes not even sleep can fix the problem, darling...
G.
Look, Gman
I do not argue with the importance of the height, ok? Do you understand that? Never I said, that your glorious beautiful 120' mast has no effect or has little effect. Can we, sort of, seal that? Because you keep bringing that back all the time. Yes, you have a long, tall, fat, strong mast. OK! Can we put it aside now? With the note, that it was you, my friend, who totally invented the argument about the mast just to brag about it.
You keep accusing me of magic bro-formulas, but do not seem to understand how electromagnetic field works and throw terms like "Fresnel clearing" without any clue, because it absolutely not applicable to what we are talking about. Just stop using words that you do not understand.
I stand behind my claim that in the forest, on UHF, quadrupling the power from 5W to 20W doubles the distance from 0.5 mile to 1 mile. This is proven and tested by yours truly many times. In European plains and in California coastal forest. I did not have notaries, or Guiness book recorders to fix it officially, sorry. But talk to any hunter here, and they will confirm to you that moving from 1W FRS to 4W GMRS radio doubles the distance in the forest.
Keep Marc out of our small tiny scuffle here. He is a good guy.
With that said, I stand behind my claim that 0.8W -> 42W will increase distance from around the corner to 8 blocks. The number "2000%" is an educated guess. Want to show how wrong I am? Go measure the average city block and the "around corner" distance, have 2 witnesses to sign the affidavit, and if I'm off by more than 1dB, I will send you a pair of used earplugs as a symbolic token of me being wrong on that point. -
4 minutes ago, gman1971 said:
Bumping power to 200 Watt doesn't allow my mobile radios to reach 40 miles. Period
And where did I said that? Get to bed, darling
-
1 minute ago, gman1971 said:
Here is another place where you claim this nonsense:
"Where did I say that? Care to quote me? In space it will. On earth it won't. In the forest, on UHF, quadrupling 5W to 20W will double the distance from 0.5 mile to 1 mile. It it clear now?"
Goalpost again, now we are back in free-space... not inside a forest anymore?
And you are wrong, 5W to 20W does NOT achieve double the range,that is some serious BS you've been told. Max UHF/VHF radio range in the real world is determined by antenna height above ground, not by power.
Bumping power to 200 Watt doesn't allow my mobile radios to reach 40 miles. Period.
A 6dB loss, while a waste, it will only affect my max range by about 5 miles at worst, not cut the range in half as you claim it would. Now, if my antenna was placed 150 feet, 6 dB loss will be insignificant, as stated by Marc.
G.
I underlined important part. We are still in the forest. You need to have some sleep.
-
36 minutes ago, marcspaz said:
@axorlov The point behind sharing my road test results are to demonstrate how insignificant a 6 dB loss is in the world of recreational family radio. In my example, it took more than a 7 dB improvement in power to add spotty communications for about 1/2 mile.
And I disagree. Should you repeat your test 800mW -> 42W in the center of the city, you would likely experience 2000% increase of the distance: from around the corner to 8 blocks.
-
38 minutes ago, gman1971 said:
because you seem to be defending that four times the power = double the range..
The the power density is proportional to the inverse square of the distance. In open space. On earth it is often not because other factors at play. What's so hard to understand. You're dense tonight.
-
1 hour ago, gman1971 said:
And before you go claiming that a 20dB preamp is like adding 20 dB of power...
Care to quote me?
Edit:
Re-reading the post carefully I now have a question. Why 20dB pre-amp is not like adding 20dB of power to the signal from the remote transmitter? You seem to imply it's better, the pre-amp. Why? I'm seriously, genuinely curious.
-
3 minutes ago, gman1971 said:
And no, 200W doesn't yield 40 miles as you claim it would
Where did I claim that? Stop the BS
-
Gman, either I can't formulate it's clear enough, or you choose not to understand what I'm saying.
7 minutes ago, gman1971 said:As measured, my best UHF portable radios, two XPR7550e on 5W ground to ground inside a Wisconsin forest, can barely reach a mile before you can't hear anything. Two 5550e (albeit VHF), both on a backpack with a 5/8 wave antennas, on 50W are lucky to reach more than 4 miles inside the same dense forest, that is on VHF!!, which has a 10dB advantage over UHF in free space... 4 miles at best.
You are comparing apples with bulldozers here, but ok. Try same with 5W and 50W on UHF. You will get same increase of the distance. Why same, you may ask? The VHF has 10db advantage in free space? Because we are not in free space, that's why. When we will be talking to colony on Mars we can get back to this tidbit.
And I'm not changing goalposts it's you who do.
15 minutes ago, gman1971 said:Quadrupling the power on the base won't reach 40 miles (double the range ) as you claim it will, not even close!
Where did I say that? Care to quote me? In space it will. On earth it won't. In the forest, on UHF, quadrupling 5W to 20W will double the distance from 0.5 mile to 1 mile. It it clear now?
In the mountains quadrupling 5W to 20W may (may! not guaranteed!) increase distance from 0.5 mile to 2 miles. Is it clear? Although, I routinely experience more.
22 minutes ago, gman1971 said:Quadrupling the power on the base won't reach 40 miles (double the range ) as you claim it will, not even close! At 20 miles, current measured RSSI levels are already in the -118-124 dBm range... so adding 6 more dB to the signal (4x power) won't make it to 40 miles, not even close. But according to your bro-science magical formula, if I added 5kW I should be able to reach all the way to Iowa from Madison, WI... LOL... If I ever needed to reach 40 miles, reliably, I will need to increase the mast height probably by about 150 feet.
And where did I say that? Care to quote me? Stop the BS
-
2 hours ago, gman1971 said:
I've learned this the hard and very expensive way: managing to extract 20+ miles out of a site that originally was lucky to reach <1 mile... with power output kept constant at 50W. So, how did I do it? Elementary, by increasing the antenna elevation from 30 feet to 45 feet, then ditched all the hammy grade garbage, including but not limited to garbage CCR radios, garbage cables, garbage connectors, and garbage antennas, and installed a 2-bay dipole, heliax, trimetal/silver/gold/ N/TNC connectors with double shielded coax patches, plus added a crap-ton of filtering, plus isolator and a preamp. None of those things even remotely resemble adding more power to the system, yet range improved by 20-fold.
I just re-read the conversation and want to add something. The quoted above is about improving the reception of your base (repeater?) station. You could have saved a ton and a half by quadrupling the power of your remote nodes (HTs) from 5W to 20W. That's a joke, of course, 20W HT is not practical and not safe for RF exposure. However, I bet that your remote nodes (HTs) did not feel any of these improvements when they are receiving, except for the heliax and connectors. And this is what the thread was originally about: the loss in the feeder line.
-
3 hours ago, PACNWComms said:
to buy amateur radio equipment, setting it up also for GMRS
This is not cool with FCC. I'm not a cop or anything, everybody chooses what they want to do. But for some people it might be important to stay legit from the letter of the law point of view. Such suggestions should be accompanied by disclaimers.
Another consideration is that Part 90 and 95 equipment could be programmed in a way that it is hard to screw up, and safe to give to 5-yo kid. Amateur stuff is not fool-proof, in general.
-
2 hours ago, gman1971 said:
Proves your point? Sorry, but I disagree; range problems are NOT solved with "more power", which is what marc tried to explain.
In his example, at 10 miles with 800mW no signal, with 42W is a signal. The difference between no communication and communication is very significant. This is how he proves my point.
2 hours ago, gman1971 said:You need height and radiation pattern to reduce that attenuation factor, along with a Fresnel zone initial clearing so the signal behaves closer to free-space... etc... all that well before you even consider adding a single watt of power
What?? The height reduces the attenuation??? The radiation pattern reduces the attenuation??? Dude... With UHF frequencies anything higher than 1.5m off the surface is close to a free space. It's a roof of the SUV or just tippy-toe with your HT.
2 hours ago, gman1971 said:Elementary, by increasing the antenna elevation from 30 feet to 45 feet, then ditched all the hammy grade garbage
You guys do not get one thing here: you are already in the field with top of the line non-hammy garbage. You have your mast in place with antenna made of pure gold and coax is 33" hardline. You cannot get more god-beloved non-hammy stuff here (Amazon trucks do not go where you're hiking and you're broke from the hardline), you have to roll with what you have. Now you have a choice: transmit at 20W or transmit at 40W. Which will reach farther?
In real life most of this talk about LOS and Frensel cleaning does not make much sense because other factors are in play. In dense forest it's attenuation by the greenery. In urban canyons it is reflection, refraction and scattering. In mountain setting it is also reflection, refraction and scattering. The only place when LOS and antenna pattern is an absolute king is a flat field (marcspaz's Florida?) and even there there are some imperfections of our sinful world that allow for reflection and scattering and increase of the distance when power is bumped up. He told it himself.
In dense forest, where attenuation of UHF by the leaves is the biggest problem, quadrupling the power always (always!) doubles the distance. It is repeatable. Go try yourself with your Motorola gear. In mountain canyon quadrupling the power will easy quadruple the distance, at very least. No LOS here.
2 hours ago, gman1971 said:None of those things even remotely resemble adding more power to the system, yet range improved by 20-fold
And now, what's going to happen when you quadruple the power? Nothing?
-
I don't want to beat this horse into pulp, but marcspaz proves my point. When you in the fringe, you can't afford loss and can't reduce power. I'm always dumbfounded when people say "it's only one step on S-meter", because in reality it's the "whole whopping 400%" of tension of electromagnetic field.
-
20 minutes ago, gman1971 said:
For TX range, antenna radiation pattern and height are far more important
1. With antenna pattern and height is not changing, station transmits with power P, then it makes second transmission with power 4 x P? Which transmission going to be heard farther?
2. You are in the fringe zone of my station. Your S-meter (if you have one and you trust one) shows 0 bars. You still can hear me under current conditions with the specific noise floor and specific sensitivity. Now I reduce power 4 times. Will you still hear me?Loss of 6dB is a waste. I would ignore loss under 1dB.
-
12 hours ago, marcspaz said:
Space weather, Geomagnetic storms, and atmospheric propagation combined with good antenna design plays a much larger role than power
That's often repeated, and often misunderstood. To overcome what you listed (storms, weather, etc), you need power. When antenna design and placement is not changing, power is what helps you to have [more] reliable communications.
-
-
3 hours ago, marcspaz said:
I can't imagine the harmful interference that could potentially be added around here by using 20 simplex with the 4a tone.
I'd hazard to guess, it'll be close to zero. Only these in a simplex range will be affected.
-
Great! The audience of NotaBubblegum will keep with their queen at chan 19, the rest will do whatever they want. Some will stick to .675. Win for the community from every angle.
-
On 1/7/2022 at 7:17 PM, marcspaz said:
Now, lets say you are running 50 watts from the radio and you have a 6dB loss to the antenna, that gives you 12.5 watts into the antenna. It seems like a lot
It not only seems like a lot, it is a lot. It's 4x reduction in power. In space, it would mean reduction of communication distance in half. On the surface of this miserable planet it may be a difference between reliable comms and no comms at all.
I do not care what [poorly calibrated other dude's] S-meter says. I do not want to waste the power to warm up the atmosphere if this power can be put into signal.
GMRS Real World Emergency Communication Experience?
in General Discussion
Posted
I thought it's a bit cheaper nowadays. Like $400/year to keep account active + whatever you use (the cheapest plan). But does not change a big picture.
Some of my former riding buddies who ride dirt bikes alone in the mountains (crazy a-holes) carry inReach. I do not, I do not do motorcycling in boondocks, just MTB-ing, but I'm sure that $15 a month is all you need to pay, without any additional payment to the Iridium.