New GRMS Repeater Site

[WSBQ643]

I recently decided to stand up a GRMS repeater in my area since we have a limited amount in Arkansas. It was suggested I use the "Tool Kit" on "support.nautel.com" to see what my coverage area was going to be. I went to the site and had to register and then the "Took Kit" was free to use. It did point to point plots and site plots. I put in all my infomration and it made a coverage plot and placed it on a map. I was amazed at just how accurate this tool was. For the antenna type and car coverage I had to select "custom" from the drop down. I would suggest this site and this tool for anyone who was looking to stand up a repeater or just wanted to know their point to point plot. 

I kind of blame "notarubicon" for peaking my interest in all of this and getting back into radios after 30 years and multiple deployments in the Army. I was a 25F/W40 in the Army and ranged from microwave to satellite communications with multiple radio's in between. Good to be back. 

[WRKC935]

Doesn't matter,.  no one needed to know or was curious anyway

Edited March 23 by WRKC935
people don't want to be smart

[OffRoaderX]

28 minutes ago, WRKC935 said:

So to explain how that all works

Pro Tip: Normal people only answer questions when someone asks a question.

 

14 hours ago, WSBQ643 said:

kind of blame "notarubicon" for peaking my interest in all of this

You're welcome.

[Socalgmrs]

53 minutes ago, WRKC935 said:

So to explain how that all works, you first need to understand what is being calculated.  And there are a number of things that are looked at when generating a coverage map.

First thing is path loss.  That is the signal level drop between the transmitting antenna and the receive antenna in free space.  Then there is the consideration of LOS or Line O Site.  That is important because open space has less path loss than talking through trees.  And tree's offer less path loss than a light suburban environment, then there is medium and dense populations centers (cities) that offer very high path loss and finally the ground, which you simply can't talk through.  Meaning if you are in a valley, and the repeater is in the next valley over and there is a mountain between you, you can't use that repeater.

Then there is antenna gain, cable loss, antenna height and output power on the transmit side of things.  On the receive side, it's a bit easier, because the power required (yes, its' still a power reading) for 3 levels of signal.  First level is a solid full quieting signal, which is about -95 to -100dBm.  Then you get into a reasonable and usable signal of around -105 to -110dBm.  After that the radio is going to get noisy, with a good bit of static in with the intelligence.  But you know what needs to be there for all three so you 'map coverage' based on those numbers.

A key part of doing all this is conversion from watts to dBm.  Reason for that is the addition and subtraction of signal is easier to do with normal number equations.  If all the signal levels that you are needing to work on range from -115 to +60 the math is easier than calculating from 100 down to .0001 watts (microwatts) but you can convert all those levels in to dBm and do the math, then convert back.  And the gain and loss calculations are simple as 50dBm signal plus 6dB of antenna gain minus 3 dB of cable loss ends up being 53dBm.  Which is 200 watts ERP.  Now back to the 53dBm.  If you take 53dBm and pull 103 dB (notice there is NO 'm') of path loss off that signal and you end up with -50dBm.  Of course that is a wonderful signal level to feed into an antenna and receive.  But the truth is that all those coverage calculators do is figure out ERP and path loss based on geographic maps of the area. 

Wow. This is a load of info that most “normal people” dont care about.  Hears how it works for most people.  Find the highest point they can in the area they want to set up in, buy a 20-50w repeater system, coax, antenna, tower if need be,  Install and use.  
These are usually the same people that tell me I can’t get over 200miles from California to Las Vegas for the twice weekly nets a check in on. 

[Socalgmrs]

15 hours ago, WSBQ643 said:

I recently decided to stand up a GRMS repeater in my area since we have a limited amount in Arkansas. It was suggested I use the "Tool Kit" on "support.nautel.com" to see what my coverage area was going to be. I went to the site and had to register and then the "Took Kit" was free to use. It did point to point plots and site plots. I put in all my infomration and it made a coverage plot and placed it on a map. I was amazed at just how accurate this tool was. For the antenna type and car coverage I had to select "custom" from the drop down. I would suggest this site and this tool for anyone who was looking to stand up a repeater or just wanted to know their point to point plot. 

I kind of blame "notarubicon" for peaking my interest in all of this and getting back into radios after 30 years and multiple deployments in the Army. I was a 25F/W40 in the Army and ranged from microwave to satellite communications with multiple radio's in between. Good to be back. 

This is a good fun tool kit to use.  When I used one similar it was very accurate.  

[WRKC935]

22 hours ago, OffRoaderX said:

Pro Tip: Normal people only answer questions when someone asks a question.

 

You're welcome.

Don't be a dick because I know more than you. Quick scanning Grinder, do some research and learn stuff.  Then maybe you will know as much as I do.... but  I doubt it.

You're the one doing GMRS video's.  How about you explain it detail what I was talking about in my post?  I mean that was a really watered down version of how that all works.  You could go into the weeds about how path loss is actually effected by different environments, the amount of expected per city block and how the calculations are done and averaged in a 360 degree plot for a distance specified by the user.  You could explain the time  it takes depending on the granularity of the mapping.  How it's normally only done in 5 or 10 degree increments but can be done in finer increments at the cost of processing time.  That a 10 degree map is averaged and can miss certain things that might block a signal that will show as good on a map.  How the maps that are used for a reference are really important to be up to date so that they will indicate those area's that will have the signal blocked.

You could go into what HAAT (height above average terrain) is and how it effects things.  How the same maps are used for those calculations.  The 6dB realized gain that you get every time you double your antenna height and how radio stations ERP is actually calculated using that information.  There is a LOT that can be discussed with UHF coverage.  Could talk about multipath fading and why moving less than a foot in some instances can get a poor signal full quieting.  Lot's of things to cover. 

But I know Grinder is waiting for you.  SO you go boy. 

[OffRoaderX]

1 hour ago, WRKC935 said:

Don't be a dick because I know more than you. Quick scanning Grinder, do some research and learn stuff.  Then maybe you will know as much as I do.... but  I doubt it.

You're the one doing GMRS video's.  How about you explain it detail what I was talking about in my post?  I mean that was a really watered down version of how that all works.  You could go into the weeds about how path loss is actually effected by different environments, the amount of expected per city block and how the calculations are done and averaged in a 360 degree plot for a distance specified by the user.  You could explain the time  it takes depending on the granularity of the mapping.  How it's normally only done in 5 or 10 degree increments but can be done in finer increments at the cost of processing time.  That a 10 degree map is averaged and can miss certain things that might block a signal that will show as good on a map.  How the maps that are used for a reference are really important to be up to date so that they will indicate those area's that will have the signal blocked.

You could go into what HAAT (height above average terrain) is and how it effects things.  How the same maps are used for those calculations.  The 6dB realized gain that you get every time you double your antenna height and how radio stations ERP is actually calculated using that information.  There is a LOT that can be discussed with UHF coverage.  Could talk about multipath fading and why moving less than a foot in some instances can get a poor signal full quieting.  Lot's of things to cover. 

But I know Grinder is waiting for you.  SO you go boy. 

Geezus.... Thank you for proving that the people we make fun of actually do exist.

But don't worry, because we are all VERY impressed with how smart you think you are!

[WRQC527]

Well that escalated quickly.

[marcspaz]

@WRKC935... who hurt you?  LOL

[OffRoaderX]

12 minutes ago, marcspaz said:

@WRKC935... who hurt you?  LOL

How DARE you sir!  Have some respect!  After all, he memorized a test, he has been a H.A.M. for OVER 30 years and a radio tech for over 15 years!  By God, he is even R-56 certified!!!   That is why he put all that in his forum-signature, because he DESERVES respect! 

[marcspaz]

12 minutes ago, OffRoaderX said:

because he DESERVES respect

 

That ship sailed loooong time ago.

[Borage257]

The Nautel Tool is just a copy of RadioMobileOnline

[WRKC935]

20 hours ago, OffRoaderX said:

How DARE you sir!  Have some respect!  After all, he memorized a test, he has been a H.A.M. for OVER 30 years and a radio tech for over 15 years!  By God, he is even R-56 certified!!!   That is why he put all that in his forum-signature, because he DESERVES respect! 

What ever..... you win, you're the greatest.

 

Edited March 23 by WRKC935
because fuck it

[WRKC935]

20 hours ago, marcspaz said:

@WRKC935... who hurt you?  LOL

doesn't matter

 

Edited March 23 by WRKC935
don't matter