Your Longest GMRS Contact?

[DeoVindice]

What is the longest distance you've been able to talk on GMRS? Specify simplex or repeater, and your equipment used.

 

My personal record is a confirmed 88 miles from the high desert to a mountaintop repeater. I was using a TK-390 with a KRA27 whip, then swapped out for a KRA23 helical and experienced some signal degradation but no difficulty communicating.

[marcspaz]

My longest ground level to ground level simplex contact has been 5.5 miles.  Which is an achievement in my area.  That was ragged edge.

 

My longest simplex contact, regardless of elevation, was 46.6 miles from Strasburg, VA to Second Mountain, mobile to mobile.  It was full quiet. 

 

My longest repeater contact was from a mountain top near Glengary WV to Dumfries VA... 70 miles as the crow flies, but 77 miles for the RF path.  Also full quiet.

 

 

I was on a MXT400 with an MXTA11 antenna. Don't know what the other guys had.

 

 

In the Amateur radio world, I have talked from Flagpole Knob VA (mountain top) to South Houston TX on 446MHz with a homemade 1500 watt amp and a beam antenna.  I would love to try a high-gain beam antenna on GMRS, but I don't think its legal because of the limit on effective radiated power... I may research that a little.

[berkinet]

...but Ii don't think its legal because of the limit on effective radiated power... I may research that a little.

GMRS power output is defined as transmitter output power, not ERP. Go have fun with your beam, or even a beam array.

[Durake]

My furthest was contact was 100 miles. Dallas, Texas all the way to Waco, Texas down south. It was a really clear night and I was able to hit repeaters on all of the repeater pairs using the 141.3 tone. I was talking to an operator down in Waco on the Waco repeater, I can't remember his callsign but I did write it down somewhere. 

 

I was using my Motorola PM400 on 25 watts with a 1/4 wave drilled on the center roof of my car. I was really impressed. We have a 600 and 675 repeater in downtown Dallas and other repeaters on 600 and 675 were doubling with eachother when I keyed up so I couldn't even hear my local repeaters, the band must've been really open that night..

[mcallahan]

I was able to hit my clubs's repeater from 92 miles away:

 

 

I was on a peak at 7500' with my TK-380 at 4 watts and stock antenna. The repeater sits at 3800'. I had a clear line of sight and had no issue making contacts, full quieting.

 

Atop a mountain here in town I routinely make simplex contacts on GMRS ~20 miles away.

[marcspaz]

I have something for you guys to try. Near Vertical Incident Skywave propagation. I had my ham antenna about 5 degrees off the horizontal plane, running 35 watts on 446MHz. I made a contact from Ft. Lauderdale to Panama City Beach... 300+ miles.

 

GMRS is in the same service band (UHF 462 and 467) so the same principles apply. You should have someone on the other end to set it up to conduct the Comms. In ham, it's a bit easier because it is a regular contact/propagation method. Using a long whip antenna helps, too.

[RCM]

I have something for you guys to try. Near Vertical Incident Skywave propagation. I had my ham antenna about 5 degrees off the horizontal plane, running 35 watts on 446MHz. I made a contact from Ft. Lauderdale to Panama City Beach... 300+ miles.

 

GMRS is in the same service band (UHF 462 and 467) so the same principles apply. You should have someone on the other end to set it up to conduct the Comms. In ham, it's a bit easier because it is a regular contact/propagation method. Using a long whip antenna helps, too.

 

I don't doubt that you made the 300+ mile contact, but it wasn't NVIS. If the MUF reached UHF, the radiation would fry us all!

Probably tropo ducting.

[marcspaz]

I don't doubt that you made the 300+ mile contact, but it wasn't NVIS. If the MUF reached UHF, the radiation would fry us all!

Probably tropo ducting.

 

 

LOL...  You may have a point there, and I wouldn't rule out tropo.  Typically NVIS maxes out around 70MHz.  I use it a lot down in 27MHz for QRP contacts on CB.

 

However, I think its NVIS and mentioned it because high geomagnetic activity regularly creates auroras that reflect VHF and the lower portion UHF, allowing NVIS as far as 400 miles.  Especially in the tropics... which is where Florida is and I am.  And... even though we are in an aurora "break", the K index is above 5, which is severe enough for NWS to issue an alert for the 24th (when the contact was made) and 25th.  Its primarily poleward of 60 degrees Geomagnetic Latitude, but that is enough to impact RF performance globally, wherever an aurora occurs.

 

I could be completely wrong... but I think.  I can always test again when the storm is over... that would probably tell me for sure if its tropo or NVIS.

[RCM]

NVIS usually maxes out below 10 MHz and pretty much never reaches into low VHF and never reaches into UHF. If this were not so, satellite communications would be impossible. NVIS occurs at and below the frequency that a radio signal directed straight up is reflected back to earth instead of penetrating the ionosphere.

[marcspaz]

It must have been awhile since you studied for your general exam. LoL

[berkinet]

Well, I'm not sure when @RCM last studied for a ham exam, but, I'd be pretty sure the laws of physics haven't changed in the meantime.

 

According to the Wikipedia

 

The most reliable frequencies for NVIS communications are between 1.8 MHz and 8 MHz. Above 8 MHz, the probability of success begins to decrease, dropping to near zero at 30 MHz.

[marcspaz]

I'm not trying to be a pain, but the previous and current official General Class training material is stating exactly what I said (I copied and paste a portion of it).  Also, I have a copy of the current test pool, of which there are test questions on the material specifically asking about these values.

 

I didn't study physics for my profession, but I am currently studying for my upgrade.  Like I said... I could be wrong, it could be ducting and not NVIS.  However, I am basing my guess on what I am currently being taught to pass the FCC General exam.

 

EDIT:

Ignoring the training guides, because they are written by someone for ARRL... this is straight from the official question pool, which I got from the FCC...

 

G3A09 (A)
What benefit can high geomagnetic activity have on radio communications?
A. Auroras that can reflect VHF signals
B. Higher signal strength for HF signals passing through the polar regions
C. Improved HF long path propagation
D. Reduced

 

So, we are not discussing a regular D layer / F layer skywave propagation method... we are talking about geomagnetic storms causing anomalies that can reflect signals that are not normally reflected back to earth.

[RCM]

It must have been awhile since you studied for your general exam. LoL

It has. In fact when I studied for my Extra exam, we still had Morse code requirement. Also when I was using NVIS propagation on 160 Meters with a buried antenna.

In fact, that is a good test: dig a post hole and put a directional UHF antenna (a Yagi for example)in it, pointed straight up. If you can't still get at least 100 miles out of it, it ain't NVIS.

 

In fact, try it on 27 MHz too and report back. Or just take a road trip to the nearest canyon and try 27 MHz there. I can definitely talk out of a canyon on 75 Meters, using NVIS. 10/11 Meters, not so much.

[RCM]

I'm not trying to be a pain, but the previous and current official General Class training material is stating exactly what I said (I copied and paste a portion of it).  Also, I have a copy of the current test pool, of which there are test questions on the material specifically asking about these values.

 

I didn't study physics for my profession, but I am currently studying for my upgrade.  Like I said... I could be wrong, it could be ducting and not NVIS.  However, I am basing my guess on what I am currently being taught to pass the FCC General exam.

 

EDIT:

Ignoring the training guides, because they are written by someone for ARRL... this is straight from the official question pool, which I got from the FCC...

 

G3A09 (A)

What benefit can high geomagnetic activity have on radio communications?

A. Auroras that can reflect VHF signals

B. Higher signal strength for HF signals passing through the polar regions

C. Improved HF long path propagation

D. Reduced

 

So, we are not discussing a regular D layer / F layer skywave propagation method... we are talking about geomagnetic storms causing anomalies that can reflect signals that are not normally reflected back to earth.

 

Well, NVIS is regular F layer propagation. Also, 400+ MHz is not VHF.

 

I don't dispute aurora propagation, nor meteor scatter propagation for that matter. I'm just saying you're using incorrect terminology, which would not be a big deal except that NVIS is a thing, and what you are experiencing ain't it.  I'm not trying to be a pain either, but NVIS is one of my favorite types of radio propagation and one I have used quite a bit.

[marcspaz]

Also when I was using NVIS propagation on 160 Meters with a buried antenna.

Wow! That's awesome!

 

I'm still trying to learn this stuff. I know book smart often doesn't match reality, which is why I am glad I have folks like you to talk to.

 

That tests sounds like a brilliant idea. I'll have to keep an eye on the geomagnetic weather and see if I can run that test. With any luck, I learn something in the process. LoL

 

I appreciate the convo with all of you. I'm going to take my General exam on November 8. Hopefully I'll pass and get some new gear.

 

Oh, I almost forgot... do you guys (or gals, if you're out there) know how to repeat tropo ducting? I read that fog and cloud cover helps... but should I be mindful of takeoff angles, etc.? Any advice would be much appreciated.

[RCM]

Wow! That's awesome!

 

I'm still trying to learn this stuff. I know book smart often doesn't match reality, which is why I am glad I have folks like you to talk to.

 

That tests sounds like a brilliant idea. I'll have to keep an eye on the geomagnetic weather and see if I can run that test. With any luck, I learn something in the process. LoL

 

I appreciate the convo with all of you. I'm going to take my General exam on November 8. Hopefully I'll pass and get some new gear.

 

Oh, I almost forgot... do you guys (or gals, if you're out there) know how to repeat tropo ducting? I read that fog and cloud cover helps... but should I be mindful of takeoff angles, etc.? Any advice would be much appreciated.

Have you seen this? http://www.dxinfocentre.com/tropo_eur.html

 

I think you're in Florida, right? If so you might want to try shooting along the coast.

ETA: with your directional antenna, that is.

[marcspaz]

Have you seen this? http://www.dxinfocentre.com/tropo_eur.html

 

I think you're in Florida, right? If so you might want to try shooting along the coast.

ETA: with your directional antenna, that is.

I haven't seen that. I'll definitely look through it. Thank you.

 

Yes. I am in Florida currently. I have homes in Virginia (NOVA) and Florida (St. Petersburg & Ft. Lauderdale). I go back and forth between the two.

 

I have a 5 element beam, which should do the trick.

[RCM]

Yeah, that should do fine.