Trimble R8s range with external radio

I used R8 3's and got an easy mile on the internal. If you are getting half that something is broke.

@thebionicman that's pretty much been the case since they were brand new. I have never really used RTK without an external until these, so I figured it was normal. With the base set up on a 50' tall landfill in the middle of a crop field, with an external antenna in the air at the rover, it reached a mile, but typical average environment, 1500' if I am lucky.

Which R8?

Most have only a half-watt radio internal.

Rule of thumb is 1km range per watt.

The R10's have a two watt internal

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I get line of sight for at least three miles with my R8 internal 1/2 watt radio, using the PDL as a repeater the range is almost unlimited at 25 watts. There has been a decrease in range and effectiveness dropping into canyons and behind higher hills with narrow-banding. Antenna types will help you depending if you are in flat ground or hilly ground.?ÿ

Clearly you have radio issues.

Switch out antennas on the base and rover, find out just what the range is, try and eliminate antenna issues which are the first thing to go. A rubber duck is a cheap fix for the base/rover radio, a replacement mother board isn't so cheap. Using the rover antenna at the base and the repeater radio you may see an improvement which will tell you it's the base antenna. From there it's a process of elimination to figure out the issue, use all available wires and antennas you have to check it all out. A bad antenna is not good for the radios.

Are you using the 1/4 wave antenna( rubber duck antenna) or are you using 4 sections of rang pole secured to a fence or tripod etc?
You can attach the full wave antenna via cable and get that signal off of the ground( ground plane physics are real) and you can get a decent increase in your signal.
PM me for more information if you want.

@jitterboogie I have tried both a rubber duck antenna and two different whip antennas with about the same range 2000'. I tried swapping the base and rover heads but the controller spits out a message that says "receiver does not support cmr". How difficult would it be to swap the radio modules?

@mightymoe Which model R8 do you have? The R8S is the latest model, and from reading, they don't have the range the previous models had.

It is like the rover is ignoring the radio signal after a certain range. When getting out of the truck about a mile from the base yesterday, I got signal long enough to get initialization and then lost it and never got a signal until I got back within 2000'.

@aaron-fitzhugh?ÿ :?ÿ?ÿ taking apart the receivers is a "Trimble" no-no if you're signed up for their warranty services, and could potentially damage the device/s if you're not an electronic comfortable person.?ÿ That being said, its just screws and connectors, and that shouldn't be a problem.?ÿ HOWEVER?ÿ they might have different ROMS and the firmware might cause a freak out event and brick it until an authorized Trimble rep or dealer can help, if theyre willing to do so.

Try getting the antenna up off the ground 30 feet.

and if you can use the PDL 450 as a repeater, that would definitely give you a wider broadcast area.?ÿ just need to see where you start to lose signal from the R8 base and set up there if it will work.

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And are you in a lot of dense trees??ÿ if so, get a powerful chainsaw and start clearing, until you REALLY get the line of sight response you want.?ÿ?ÿ ;)?ÿ

@jitterboogie we didn't renew our warranty. I'm just having a hard time believing they sold me something that wasn't at least as good as the two models before it. The local Topcon dealer tried to tell me they were going to suck but I figured he was just trying to make a sale.

@aaron-fitzhugh:

Understood.

I used a model 2 on top of a hill ( okay, small mountain....) and was miles from the base getting good signal.
Is it possible you're being stepped on by another user in the same Freq range/ID?  maybe.

  the other thing is you mentioned the CMR message, what models are these R8s?  Model 3 or newer?

Posted by: @aaron-fitzhugh

It is like the rover is ignoring the radio signal after a certain range.

I have seen Trimble deliberately do that with some product.

The construction range particularly springs to mind.

The range is artificially limited, and you have to pay more $$$ for more range.

@aaron-fitzhugh

I have the R8-2 model, I've not had an issue with is the radio when it's working correctly. I have had some antenna issues which of course effects the radio. One thing I can say is that the rover will lose signal going over a moderate hill where way down the same hill the repeater will pick up the base, test the radio range with the repeater as basically a radio only rover.

@jitterboogie They are the latest R8 models I believe. They came out after the model 4. They are "R8S" Receivers. We bought them from a local Trimble dealer in February 2019. At the time we were given the impression that other than not being as compact and working as well in canopy, there were no other benefits in going with R-10 or 12. Looking back, I am feeling like we may have purchased an "economy model" of the R-8 instead of a better one, and would've been better off buying a used set of model 2s or 3s.

I talked to the dealer and they said I should be reaching much farther than I am. He believes it was a problem with the External radio I bought. They had a used "tested good working condition" PC ADL 35 Radio in stock that I agreed to purchase but I am worried I may end up with the same result. I guess we will see in a day or two.

As far as me being stepped on, I'm testing in the boondocks a good 15 miles from the nearest town.

@jimcox those are my thoughts exactly. They are getting to be worse than Autodesk.

@aaron-fitzhugh

more a case of Autodesk catching up with them 🙁

According to Trimble's datasheet the radio in the R8S is only 0.5 watt

Optimists that they are, they claim a 3 to 5km range, with 10km optimal)

Dont use CMR use CMRx. I go 5 to 7 miles with a 25w trimble radio on the upper great plains.

If you are normally in cell range you could try setting up an NTRIP connection between your base and rover using Sim Cards. Smartnet sells SIM cards set up for this on your choice of provider. You don't have to use their correction service, these will have a static IP set up already that is a requirement for the base. There are probably numerous other options as well in the USA.?ÿ You could probably get away with one Sim Card in your base and WIFI at your rover to save on the cell network charges. That's if the R8s lets you do any of this.

Jon Collins is right, CMRx also uses less power so you'll get more life out of your battery, and you can utilize more satellites to increase the accuracy of your solution.

After the new unit came in, it reached about 6500' with a whip antenna on the rover. That's still not what the old R-8 and Pacific Crest PDL combo would do but is more acceptable than 2500'.

After finding the new radio "worked" I swapped it for the other radio I bought and found it to work as good as the new one. Apparently just as several suggested the antenna cable I was sent with the old radio was bad. ?ÿ

Needless to say, I have an Pacific Crest ADL radio and a Pacific Crest PDL Radio on Ebay both including power cables if anyone is interested. Thanks for all your help everyone.?ÿ