Real world comparison of Trimble's R8 vs R8 GNSS M2 / M3 / M4 vs R8s.

If you're looking to purchase a new or used Trimble R8 series GNSS receiver for land surveying – you have probably discovered that there have been several iterations of the R8 since it was first released around 2002. This inevitably leaves you asking, which R8 is the best? What are the differences? And how many channels do I really need?

From the original R8 GPS receiver to the GNSS capable R8 Model 2, 3 and 4, through the latest R8s, we provide real-world experience and compare and highlight the differences between Trimble's R8 series receivers to help you make the best decision for your application and budget.

Trimble R8

The R8 is the original R series GPS receiver which was released around 2002.  Building on the 5800 “smart receiver” platform, the R8 was the first introduction of Trimble’s R-Track technology – which was capable of tracking the L2C civil signal – a stronger satellite signal that assisted maintaining fixed RTK solutions around tree canopy and other obstacles that obstruct clear view of the sky.  Another feature that separated the R8 from the 5800 was the newly added ability to transmit RTK corrections from its internal UHF radio.  With integrated Bluetooth, the TX radio option offered a clean and cable-free base station and rover setup. 

R8 Highlights:

• 24 channels L1/L2/L2C/WAAS/EGNOS/SBAS
• GPS (only)
• Base and rover operation
• Internal radio transmit (paid upgrade optional)

Takeaway:

The original R8 (model 1) is a GPS only receiver that’s good for open areas with unobstructed views of the sky. The R8 added L2C tracking, so it’s a better performer vs the 5800, but struggles to maintain a fixed RTK solution around medium-height trees, buildings and other obstructions. Expect longer wait times when initialization has been lost due to obstructions. Used prices range between $1,500 and $2,300 USD.

 

Trimble R8 Model 2

The R8 GNSS Model 2 (R8-M2) was released around 2004 and continued to build on the same “hamburger” form of the 5800 and R8 - with a noticeable bulge on the top cover (radome), as if it were flexing its new GNSS muscles.  Expanding beyond tracking the L2C civil signal, the R8-M2 added additional capability of tracking L5 and the Russian satellite constellation GLONASS.  A second iteration of the R8-M2 came around 2006 to meet the European Union's ban on electronic devices containing lead solder.  The new R8 Model 2 - version 2 adopted a grey trim instead of the yellow and blue of the previous version.  Possibly a byproduct of the lead free solder - the second version seems to hold up better to vibrations and drops and offers extended Bluetooth range (up to 30 feet).

Compared to the R8, the R8-M2 is a better choice if you’re surveying in areas that have moderate sky obstructions – e.g. intermittent tree coverage and multilevel buildings.

R8 GNSS Model 2 Highlights:

• 72 Channels L1/L2/L2C/L5/WAAS/EGNOS/SBAS
• GPS + GLONASS
• 11 MB internal memory
• Base and rover operation
• Internal radio transmit (paid upgrade optional)

Takeaway:

The R8 Model 2 tracks GPS and GLONASS constellations.  Along with L2C and L5 tracking, it provides better performance around obstructions compared to the R8 (model 1) but still struggles to maintain a fixed RTK solution around medium-height trees. Slower re-initialization times when signals are lost due to obstructions. Used prices to range between $2,000 - $3,500 USD.

 

Trimble R8 Model 3

Other than the new flat-top radome design, the R8-M3 didn’t look much different compared to the R8-M2. But looks can be deceiving. Released around 2008, the R8-3 was now loaded with 220 channels and the ability to track the Galileo constellation (optional upgrade).  It featured “R-Track Signal Prediction” which greatly improved the receiver’s performance around canopy and other sky obstructions (for short bursts of time).  Where the R8-M2 would maintain a fixed solution at the outer extents of a tree’s foliage, the R8-M3 enabled you to take shots under light to medium canopy. CMRx was a new protocol that was necessary for the receiver to compress and transmit the data that was now being tracked on those 220 channels. 57 MB of internal memory was upgraded for storing GNSS observations (post processing). Finally – the internal UHF radio transmit option was now a standard feature.

R8 GNSS Model 3 Highlights:

• 220 Channels L1/L2/L2C/L5/WAAS/EGNOS/SBAS
• GPS + GLONASS + Galileo*
• 57 MB internal memory
• Base and rover operation
• Internal radio transmit

Takeaway:

The R8 Model 3 is a great performer in challenging environments.  R-Track with Signal Prediction™  (prelude to Xfill) offers roughly 20 to 30 seconds of precision after the RTK signal has been interrupted.  220 channels offer faster initializations - which reduces downtime. *Galileo tracking was an optional upgrade. Used prices range between $4,000 - $6,000 USD.  At over 15 years old, it might be tough to find a Model 3 in good condition, so if you have more in your budget, look for an R8 Model 4 or R8s. 

 

R8 GNSS Model 4

440 Channels, GLONASS, Galileo and BeiDou tracking included…what’s not to love? And if the R10 is out of your price range, the R8-M4 is the best alternative.

Identical in appearance and similar in performance to the R8 Model 3, the Model 4 is an excellent surveying receiver that performs very well in traditionally challenging areas - enabling RTK shots around, and in some cases, under light to medium tree canopy.  Released around 2013, the primary difference between the R8 Model 4 versus the Model 3 is Galileo (European Union) tracking was now included as a standard feature - as well as the addition of BeiDou (China) constellation tracking (also standard feature).  The additional channels not only tack more satellites, which can help when GPS and GLONASS satellites are in a bad position (PDOP), they help with faster initialization times when signal is interrupted due to obstructions of the sky.

R8 GNSS Model 4 Highlights:

• 440 Channels L1/L2/L2C/L5/WAAS/EGNOS/SBAS/QZSS/GAGAN
• GPS + GLONASS + Galileo + BeiDou
• 56 MB internal memory
• Base and rover operation
• Internal radio transmit (TX)

Takeaway:

The R8 Model 4 is a great performer in challenging environments. R-Track with Signal Prediction™  (prelude to Xfill) offers 20 to 30 seconds of extended precision after the RTK signal has been interrupted. 440 channels offer fast initializations - which reduces downtime. Galileo and Beidou tracking can help when GPS and Glonass satellites are not enough.  Used prices range between $6,400 - $8,000 USD (in 2023). At over 10 years old, finding a Model 4 in good condition can be tough, so if your budget allows, look for the R8s.

 

R8s

Released in 2017 the R8s is the latest in the R8 series.  Think of the R8s as a deconstructed R8 Model 4 with some additional benefits.  As far as satellite tracking goes, the R8s offers the same constellation tracking as the R8 Model 4. 

The R8s is an option-based receiver where you only pay for the features that you need.  Starting from the bottom, the R8s can be enabled for post processing GPS L1 signal.  From there, you can purchase upgrade codes to enable the R8s to track each individual constellation (GPS/GLO/GAL/BED) and signal (L1, L2, L2C, L5).  RTK is also a paid option – as is Base station or Rover functionality. 

If you’re buying a used R8s receiver it’s important to know which features have been enabled.  At Positioning Solutions, we typically offer those with RTK options in either a base or rover configuration and list which constellations are enabled.  When an R8s includes all factory options, we offer them as an R8s "MAX".

It’s worth mentioning that the R8s has a more current cellular modem option (compared to the R8-M4) and a single wide-band UHF radio (403MHz to 473Mhz).  Also - if you’re running Trimble’s Field Link software (M.E.P.) this is currently the only R-series survey receiver that is fully supported (by Field Link 5.3).

R8s Highlights:

• 440 Channels L1/L2/L2C*/L5*/WAAS/EGNOS/SBAS/QZSS/GAGAN - *L2C / L5 are purchased options
• GPS + *GLONASS + *Galileo + *BeiDou – *purchased options
• 56 MB internal memory *purchased option
• *Base and *Rover capable – *purchased options
• *Internal radio transmit -*purchased option
• Compatible with Trimble Field Link 5.3 and newer

Takeaway:

Updated cellular modem or wide-band UHF radio options. When fully optioned, the R8s is an excellent performing GNSS receiver. R-Track with Signal Prediction™ (prelude to Xfill) offers extended precision after the RTK signal has been interrupted. 440 channels offer fast initializations - which reduces downtime. Since every feature is “al a carte”, used prices are difficult to pin down because each receiver can be configured differently.

Expect to pay between $6,500 - $7,500 USD for dual frequency (L1 & L2) GPS + GLONASS rover-only or base-only options.  Adding Galileo / BeiDou is not too expensive, but the L5 “triple frequency” option will set you back a few thousand dollars.  The average price of a preowned - fully optioned R8s "MAX" is around $10,000 USD.  Trimble stopped production of the R8s in 2020, so it's not to difficult to find these in excellent or even like-new condition. 

Final thoughts:

The R8 GNSS series receivers are the best performing, survey grade receivers for mid-range budgets.  The R8 Model 4 and R8s outperform most of the competition and continue to be the number 1 selling GNSS receiver that we sell at Positioning Solutions.

Please use this information as a guide to help you make your purchasing decision. Some features and functions listed as “standard” or “optional” may change over time.

R8 receivers are always coming in and out of stock so we recommend checking what we have available by clicking the link below or contacting us.

Shop Used Trimble R series receivers

 

Datasheets for all receivers are available on our Product Support page >>