My Range Experience, Looking for Input

[gman1971]

You're welcome, sir. Just remember: I started out with only a couple of Baofeng UV5Rs...  

 

IMO, its all about the tools you have, not the radios: they say tools, tools, tools, you can't get anything properly done without the proper tools. Having a VNA, an SG, or an ISOTEE, a RF power checker, etc, a far more important thing to have than having fancy Moto radios.

 

G.

 

That is really great input on your part. Thank you.

It would be nice to have a couple of premium radios to contrast and experience first hand the difference.

You know the phase “seeing is believing”? “Hearing is believing” is appropriately applicable in radio.

73s

Michael
WRSH965




Sent from my iPad using Tapatalk

[8nannyfoe]

Just stumbled across the following link which shows probable distances for a variety of different conditions.

 

http://hflink.com/hfpack/radiorange/

 

Not sure how they came to these numbers, but it sure looks interesting.

 

Michael

WRSH965

 

 

Sent from my iPad using Tapatalk

From my experience / location, I have a guess how they came up with these numbers.   They set their squelch on 9!

[8nannyfoe]

Over the last few weeks I have been doing some range experiments with my GMRS radios to get a feel for what I can expect under different conditions.

 

All my tests have involved use of a pair of Wouxun KG-805g 5 watt HT.

 

I have done:

1. HT to HT (both with rubber ducks).

2. HT to HT (one with rubber duck, one with Midland MXTA26 on car)

3. HT to HT (one with rubber duck, one with Midland MXTA26 on house roof on the back of the metal trash can serving as a ground plane)

4. HT to HT (one hooked up to a Comet 712EFC 9dBi at 25’ AFG and one hooked up to Midland MXTA26 on car.

5. HT to HT (one hooked up to a Comet 712EFC 9dBi at 41’ AFG and one hooked up to Midland MXTA26 on car.

 

All tests are conducted with one unit at home, the other unit mobile.

 

Every combination results in perfect communications out to 1/2 mile. Beyond that static gradually creeps in at various rates and with increasing usable distance with each.

 

Configuration 5 has been my best performer thus far which was expected but, to my surprise, it was still only a solid performer at 1 mile and then only moderately usable at 2.3 miles in multiple directions.

 

My Comet was jury-rigged as high as I can get it without purchase of a tower or mast. I must admit, at 41’ I was expecting much more solid usable coverage.

 

I live in an semi-rural area southeast of Cininnati and the terrain is a mixture of dense full-grown trees, fields, businesses and homes. Land is mostly-flat to mildly rolling.

 

My current objectives are solid reliable simplex coverage from home to HT out 3 + miles (much more would really be sweet); communication with home via a mobile system in the car from about 10-12 miles out; and hit the repeaters on the northern side of Cincy from the home so I an participate in various GMRS nets and local chats using a radio and not a phone app.

 

OK, so there you have some backfill.

 

So, given the modest distance I have achieved around my home, I am hesitant to go the expense of mast and guy system to get my antenna up to 56’ feet (the highest I believe I can achieve with my Comet and guyed mast alone) since the antenna will still not clear the trees, and the HT will still be near ground level. Thoughts? Experience? Advice?

 

I am wondering if others live in similar conditions and have experienced better results?

 

Also, although I can break squelch on the nearest repeaters (about 20 miles North) with the HT there really is no usable audio in to speak of. Repeater frequently drops halfway through while I am giving my call sign. WIth the HT and Comet there is enough signal to get me in but with inconsistent quality for good useful communications. I have to repeat messages regularly. I imagine (but don’t know for certain) that a 40-50W rig in the home would ultimately solve that.

 

Michael

WRSH965

 

 

Sent from my iPad using Tapatalk

HI Mike.  I live in Florida which is basically flat.   I have similar range experience as you (17.6 miles from repeater).   My HT (5w) can hit the repeater, but it is mostly unusable.  BUT,  my 50w Wouxon blasts through all the cinder blocks, shingles, and terracotta roofing around here that is slowing down my 5w HT from reaching the repeater and I have NO PROBLEMS holding a clear convo on the Wouxon (with it's antenna being only 6' off the ground!!!).    

[mbrun]

HI Mike. I live in Florida which is basically flat. I have similar range experience as you (17.6 miles from repeater). My HT (5w) can hit the repeater, but it is mostly unusable. BUT, my 50w Wouxon blasts through all the cinder blocks, shingles, and terracotta roofing around here that is slowing down my 5w HT from reaching the repeater and I have NO PROBLEMS holding a clear convo on the Wouxon (with it's antenna being only 6' off the ground!!!).

Glad you are having good experience. If I interpret correctly, you are operating 50 watts using an indoor antenna. If so, for the safety of you and your family, make sure everyone remains a safe distance away antenna when transmitting.

 

Here is a link to one free online calculator you can use to determine what the safe distance is in your environment.

 

http://hintlink.com/power_density.htm

 

BTW, get your antenna higher and you will be even most amazed at what you can do.

 

Enjoy!

 

 

Michael

WRHS965

KE8PLM

[Extreme]

See if this picture attaches.

I commented on this path in Montana.  Loud and clear with 805G to Kenwood TK-880 and an obstruction.

 

I like the webpage.  I used Google Earth, ground level, entered GPS and voila. 

 

Here is another website I stumbled upon that allows you to enter two points on a map, graph the terrain between them and then add antenna elevation to both to see what amount of elevation is needed to eliminate terrain blockages.

https://www.scadacore.com/tools/rf-path/rf-line-of-sight/

WRHS965


Sent from my iPad using Tapatalk

 

Here is another website I stumbled upon that allows you to enter two points on a map, graph the terrain between them and then add antenna elevation to both to see what amount of elevation is needed to eliminate terrain blockages.

https://www.scadacore.com/tools/rf-path/rf-line-of-sight/

WRHS965


Sent from my iPad using Tapatalk

 

[Extreme]

Here is another website I stumbled upon that allows you to enter two points on a map, graph the terrain between them and then add antenna elevation to both to see what amount of elevation is needed to eliminate terrain blockages.

https://www.scadacore.com/tools/rf-path/rf-line-of-sight/

WRHS965


Sent from my iPad using Tapatalk

 

Nice!  Tried this with GPS from Google Earth and it way waaaay off.  Did the drag/drop with map zoomed way in and much better result.  25.2km/15.66mi.  See attachment. 

 

Simplex 805G to Kenwood TK-880.  5x5 both directions.

Elevation:  Mobile - 6321'  HT - 6249'

[mbrun]

//forums.mygmrs.com/public/style_images/master/attachicon.gif radio-path-study (1).jpeg

 

Nice! Tried this with GPS from Google Earth and it way waaaay off. Did the drag/drop with map zoomed way in and much better result. 25.2km/15.66mi. See attachment.

 

Simplex 805G to Kenwood TK-880. 5x5 both directions.

Elevation: Mobile - 6321' HT - 6249'

Glad it worked. BTW, did you add your antenna elevation at both ends?

 

 

Michael

WRHS965

KE8PLM

[Extreme]

Just for kicks here's another one.  The repeater ID'd on my Kenwood last hunting season but my TX was fried so couldn't play.  Will make a concerted effort to try 2-way from home to the far end this year.

 

Repeater @ 5941'

Mobile @ 8182'

 

Distance:  68mi/110km

 

P.S.  The portable repeater I've been pondering would be placed near the 8180' spot, considerably higher however (to conceal).  Can see forever  and I expect I might hit Boise area repeaters from there.  Did hear some hams on that same night, but on listen only for now.. and my TX was shot..lol.

[Extreme]

No, I did not.  SxS: 450 1/4-wave mobile antenna was about 8' I suppose, on the roof and with an 8 x 8" ground plane.  HT would have been in the driver's seat of my wife's 2500HD pickup, so another 8' or so. 

 

Glad it worked. BTW, did you add your antenna elevation at both ends?


Michael
WRHS965
KE8PLM

[Extreme]

Ok, give me a toy..

 

Here's the path from my 'spot' on top to Boise State U.  Zoomed in on myGMRS and see it's a Network Hub.  So theoretically I could get on the Net Sunday nights from my hunting spot and shoot the breeze.  Gonna get back up there when the weather warms and give it a shot if I can get the access and permission required.  Long shot with 25w but man is it clear sailing.

 

Perch:  8182' approx.

Boise:  2732' approx.  

127mi/205km

 

How's that for elevating the antenna?  Feel bad for you flatlanders  

[OldRadioGuy]

I think your problem is mostly terrain.

 

I have a pair of Wouxun 805G's and I can hit the repeater OK 12-15 miles away on the factory antenna and pretty darned clean with my Nagoya 771G antenna or the Smiley super stick.

The repeater and I are both on slightly elevated ground.  If I walk down the hill I can still trigger it but I'm not intelligible.

So it doesn't take much at 460MHz.

 

I do not see why a better brand radio with the same transmit power would have dramatically better range to the same repeater.

Receivers have more latitude in quality than transmitters. So I could understand having better sensitivity on a better radio.

 

Here's something to be cautious of.

Could any of the radios involved be getting desensitized by an in band signal nearby?

If I try to talk to my wife downstairs using the repeater she can not hear me at all.

But the guy across town on the repeater hears me just fine and she hears him too.

Her radio is getting clobbered by mine as I am transmitting to the repeater from so close by.

This is pretty normal and only exceptional radios would be immune to it.

 

One more minor point.

dBi gain is "gain over isotropic" which is pretty unrealistic.  There are no isotropic antennas.

An isotropic antenna radiates in all directions.

So it's easy to make an antenna look better by spec-ing dBi.

 

Gain over dipole is about 2 dB less for the same antenna and a more realistic number.

 

I doubt if this is enough to cause your problem though.

 

Just some thoughts.

 

Vince

[haneysa]

Google Earth elevation profile does show the straight-line terrain between two points, but do not automatically accept that the intervening terrain depicted prevents usable comms. I live in NE WA where we have mountains and canyons. I routinely make comms using GMRS in places that it should be impossible to do so. I guess that some of this is due to signals bouncing off of the rocky terrain, going around corners and down into canyons. The only way to know for sure is to do your own signal survey in the field.

[SkylinesSuck]

I love that SCADACore site!  I have been spending way to much time playing with it lol.  So just to add data and maybe get some input, here's what I got.  All of these are with the high point being my kid's treehouse with a 50w KG-1000 and a J-pole mounted about 34' above the ground.  The other ends are at my kid's friend's houses with either a) my Jeep with a MXT275 15w and external Midland antenna a UV-5R with Nagoya 701 antenna and c) .5w Retevis bubble pack radio.  

 

First up is their closest friend's house.  We can hear them loud and clear and they can hear us using the bubble pack to the treehouse.  We can just barely hear them break the squelch and they are unintelligible inside our house at ground level though with the UV-5R to their bubble pack.

 

Second is another friend's house a little farther away.  Loud and clear to and from the treehouse to the Jeep, pretty good with the UV-5R, and nothing with the bubble pack.  Also I can kind of hear them a little inside our house at ground level UV5R to UV5R but they can't hear me at all.

 

Last one is one I've been working on but still no luck.  Maybe I'm kidding myself and it'll never work on simplex?  No contact on all three radios to the treehouse, but at the time of testing, the radio in the treehouse was a was only a 8w F8HP and the antenna was only about 24' off the ground.  I'm hoping to test again soon with the higher antenna and 50w radio.

 

 

Anybody with any input on that last one feel free to comment.  I don't know if a new gain antenna would help or if the 50w radio will blast down there now.  Maybe it's just not going to work that far with the terrain I have to contend with.  I can hit a repeater about twice as far away in the same direction, but I have no idea what elevation it's at or exactly where it is.   

[gortex2]

Sorry but you can't expect great performance with $20 CCR's. This is a common misconception on GMRS. Antenna's are most critical than lower frequency bands. As said in other posts get a real antenna and feedline and not the Jpole and you'll notice improved coverage from the tree house. UHF is line of sight so a 4 watt UHF radio will talk fine if terrain is not an issue. I have run TLMR systems that are portable only with 4 watt UHF to a repeater site with very few issues. One agency had nothing but portables and talked 20+ miles to the repeater site. All depends on location and equipment.

[SkylinesSuck]

Not really expecting much from the Boefangs, just giving range data points.

 

But yes, I'm considering a high gain antenna. Just wondering if, considering the terrain and almost 20km, it would actually help or if that hill is just going to stop it from working regardless. It seemed that lower gain antenna might be better in slightly hilly terrain? Maybe I'm not understanding how gain works correctly.

Moving the antenna even higher isn't an option unfortunately as it would be in the trees :-)

[n4gix]

Google Earth elevation profile does show the straight-line terrain between two points, but do not automatically accept that the intervening terrain depicted prevents usable comms. I live in NE WA where we have mountains and canyons. I routinely make comms using GMRS in places that it should be impossible to do so. I guess that some of this is due to signals bouncing off of the rocky terrain, going around corners and down into canyons. The only way to know for sure is to do your own signal survey in the field.

 

That is the result of a phenomenon called "knife-edge diffraction," where a signal is diffracted from a sharp edge (such as a tall building or mountain.

 

I take advantage of this with a yagi antenna I use to reach a repeater in the far north of Chicago. The NSEA repeater is located in Parkridge, Illinois and is 47 line of sight miles from my house. By careful aim of the yagi, I'm refracting signals off the 'sharp edge' of the Willis Tower (formerly known as the Sears Tower).

 

[n4gix]

By the way, now you know the answer to one of the questions for the Technician ham license. 

[axorlov]

Yes, knife-edge propagation is why I'm able to watch off-air TV being in the shadow of a mountain ridge.

[Extreme]

Just for kicks here's another one.  The repeater ID'd on my Kenwood last hunting season but my TX was fried so couldn't play.  Will make a concerted effort to try 2-way from home to the far end this year.

 

Repeater @ 5941'

Mobile @ 8182'

 

Distance:  68mi/110km

 

P.S.  The portable repeater I've been pondering would be placed near the 8180' spot, considerably higher however (to conceal).  Can see forever  and I expect I might hit Boise area repeaters from there.  Did hear some hams on that same night, but on listen only for now.. and my TX was shot..lol.

 

Made a 50mi LOS hit on our local repeater from the Jeep.  Not 100% it was LOS (still have to visit the repeater site to know) but either way quite a shot with 30w Kenwood 8180.  Could barely see the mountaintop and the repeater is not on top.  FWIW.

[Extreme]

Beating the dead horse.  My latest long shot.  Going for 70 miles as soon as the snow melts and we get access.

46.8 miles.  30w/1/4 wave NMO - gonna pull an SWR on it tomorrow just for snicks.. seems to be working just fine.

 

Edit:  Just got info on the repeater gear (approx 6500' elevation):  

 

"Hytera 40 watt commercial machine, fed into a low mounted (7 ft from the ground) 3db 4 foot fiberglass pole antenna, pondering at moving it to the high gain antenna mounted at 22 feet." 

[mbrun]

Beating the dead horse. My latest long shot. Going for 70 miles as soon as the snow melts and we get access.

Good Luck!

 

 

Michael

WRHS965

KE8PLM