Only couple of weeks passed since we had reviewed the latest family of FrSKY flight controllers and we are ready again to impress you with the two new FrSKY receivers: R-XSR and G-RX8! Both seem to become the bestsellers in the nearest future!

Honestly, which other company in R|C field brought so much new products to the market for the last quarter? New radios and their revisions, new FCs, new receivers, new modules, new sticks…, together with the new company website…  Seems as FrSKY staff never sleeps  But we would never have enough, right?

So, two new and very interesting receivers today. Let�s start with the R-XSR:

Currently, one of the most popular FrSKY receiver on the market is XSR. It has reasonable size and weight, full telemetry, 16CH SBUS and SPORT. Many FPV racing copters and smaller class helicopter pilots would choose this receiver as their favorite because it fits perfectly in almost any setup and frame. It works flawlessly, very stable and reliable, gives very good flying range.

Some time ago, when some smaller FPV racing frame classes (like 190 and less) started to emerge, FrSKY introduced XSR-M receiver — very similar to XSR but with significantly smaller weight and dimensions of: 26×19.2 V/S 20x20mm, 4.3g V/S 1.8g.

XSR V/S XSR-M dimensions:

Additionally, it has slightly improved range and easier procedure of changing antennas which are detachable now…

And guess what!? It seems that FrSKY would always find a way for further improvements: R-XSR is the newest receiver in XSR family, packed in tiny dimensions of 16x11mm, having almost no weight (1.5g) and features highly demanded redundancy function!

XSR-M V/S R-XSR dimensions:

Technical specifications:  

• Dimension: 16*11*5.4mm (L*W*H)
• Weight: 1.5g
• Number of channels: 16CH (1-16CH from SBUS channel, 1~8CH from CPPM channel)
• Operating Voltage Range: 4~10V
• Firmware Upgradable
• Compatibility: FrSky X Series modules and radios in D16 mode

Features:

• Ultra mini size and light weight
• Support telemetry and Smart Port enabled
• Full range
• Switchable SBUS/ CPPM signal output
• Supports redundancy function
• IPEX connector, replaceable antennas

Manual can be found HERE

Get your FrSKY R-XSR HERE 

In real life it means that while having all features of XSR or XSR-M receivers, R-XSR would:

• be an appropriate choice for any model of any size and class
• would fit perfectly into something like 90mm FPV copter frames
• outperform any other tiny receivers by functions, features and range
• would bring more range and radio link stablity if used with second receiver as a slave

Quick note on redundancy feature: R-XSR (as well as other X-series FrSKY receivers that have extra «R» in the name) has the ability to accept signals from the second (slave) receiver over SBUS and to select and forward the strongest signal among them to flight controllers over SBUS (or to servos over PWM). Consequently, having two receivers — master and slave — on the same model would significantly improve signal quality and help to maintain good RSSI levels even in the most complex environmets. Any SBUS equipped receiver could act as a slave (telemetry should be turned off on slave). The best slave option would be to use XM+ or other receivers with the ability to turn on «telemetry off» mode.

As the result — if you were flying in some highly «contaminated» environments like forests, buildings or just with many other models and experiencing RSSI problems — R-XSR might help a lot to get rid of radio signal warnings and get the most reliable link with your model. Along with all other features it has and all other usage scenarios it provides concerning its tiny size and weight.

Example: KingKong GT90 (FrSKY Vantac 90GT) with AC800 receiver V/S FrSKY R-XSR:

Range test:

Tested it against XSR and XSR-M receivers. Our previous test of XSR V/S XSR-M showed a slight advantage of XSR-M due to the newer antenna design.

Newest R-XSR is slightly behind regular XSR in terms of RSSI range test figures — 1-2 RSSI points less at the same range and in the same places… As with any other full range small FrSKY receiver — you can expect ~1.5km in the open flield and some different results in highly «contaminated» enviromnemts depending of amount of obstacles or radio interference around. But it is absolutely win over FrSKY XM (not XM+) and any third-party tiny receivers that have very limited range of ~150m. But even if you feel that it is not enough for you — there is an ability to use redundancy function and a slave receiver to make radio signal almost bullet proof.

I would say that R-XSR is a must for any pilot with >80mm copter frames or other small models. There is no other so capable, so small and full range receiver on the market.

Note: keep in mind that total antenna length of R-XSR is only 9cm in comparison to 14.5cm in XSR-M. 

As always — this receiver has SPORT which means that we can unpgrade or change (EU LBT to FCC) FW version and daisy chain other SPORT telemetry sensors. 

Get your FrSKY R-XSR HERE 

Now, lets jump to G-RX8 receiver:

FrSKY claims that G-RX8 receiver is mainly addresses glider model pilots. Why? Because among all other tasty functions it has in built high precision vario sensor capable of registering flying altitude with 0.1m resolution along with the vertical speed.

In contrary to XSR-family, this receiver belongs to more universal type which is more common for planes, helis, gliders and larger copters. The absence of the hard case also tells us that it is mainly intended to be used with planes and gliders. 8 regular PWM ports togehter with 16CH over SBUS, analog telemtry input pin (A2) and SPORT create many possible usage scenarios. I would say that the closest relative in all FrSKY family would be RX8R receiver that has a hard case and more PWM output ports but the same features and no variometer inside.

Technical specifiations:

• Dimension: 55.26*17*8mm
• Weight: 5.8g
• Number of Channels: Up to 16 CH
• Operating Voltage Range: 4.0 -10V
• Operating Current: 100mA@5V
• Operating Range: Full range
• Firmware Upgradable
• Compatibility: D16 mode

Features:

• Intergrated high precision variometer sensor
• Support redundancy function
• Support telemetry data transmission
• Switchable SBUS/PWM mode (1~8CH from PWM outputs and 1~16CH from SBUS output)

Manual can be found HERE

Get your FrSKY G-RX8 HERE 

Similarly to other X-series receivers with extra «R» in the name — G-RX8 also features redundancy function which would greatly improve radio signal reception on the model.

Quick note on redundancy feature: G-RX8 (as well as other X-series FrSKY receivers that have extra «R» in the name) has the ability to accept signals from the second (slave) receiver over SBUS and to select and forward the strongest signal among them to flight controllers over SBUS (or to servos over PWM). Consequently, having two receivers — master and slave — on the same model would significantly improve signal quality and help to maintain good RSSI levels even in the most complex environmets. Any SBUS equipped receiver could act as a slave (telemetry should be turned off on slave). The best slave option would be to use XM+ or other receivers with the ability to turn on «telemetry off» mode.

Some more peculiar abilities of G-RX8:

• Can be programmed to output 1-8CH or 9-16CH range over PWM
• Can be used in pair with other X-series PWM equipped receiver to output 1-16CH over PWM
• In SBUS mode: 1-6CH PWM would output high precision PWM signal (error <0.5us), SBUS IN would be used to connect slave receiver for redundancy system and SBUS OUT would output 1-16CH.
• PWM mode: 1-4CH PWM would output high precision PWM signal (error <0.5us), 4-8CH PWM would output regular PWM signal and SBUS IN|OUT would not be used.
• In built variometer sensor can be turned On|Off

As always — this receiver has SPORT which means that we can unpgrade or change (EU LBT to FCC) FW version and daisy chain other SPORT telemetry sensors. 

Glider function:

Along with:

• RSSI — signal strength
• RxBT — receiver voltage
• A2 — analog port for main battery voltage (with voltage divider like FLV02)

G-RX8 would provide:

• Alt (m) — altitude
• Vspd (m/s) — vertical speed.

There is a dedicated Variometer setup under Telemetry tab in model settings menu in which we can choose vario source (sensor) and setup all necessary model ascend, descend and Alt hold tones. While flying the model we would be able to hear whether our model gaining or loosing altitude and understand climb and descend vertical speed. Additionally, there are some telemetry LUA scripts that would also provide visualization of this data.

Note: it might be very handy to setup and use telemetry data reset function right before the flight to bring Alt readings to zero while on the ground.

Range test:

Range was checked in comparison to RX8R and X8R receivers. No problems here. This receiver is a full range model which can deliver >1.5km flight range in open field with ease. RSSI figures are the same as on X8R and RX8R receivers at the same places and on the same distance. In best circumstances such receivers can have ~ 3km radio link. But even if it would not be enough for you — you can always use redundancy feature and a slave receiver with G-RX8 to get the best possible flight distance.

Get your FrSKY G-RX8 HERE 

Thank you for reading!

Stay tuned, more reviews to come….

For a long time FrSKY XSR receiver that featured S.PORT telemetry, good flight range, small size and light weight was the most preferred by racing quad and rc planes pilots. But FrSKY has finally decided to revise this receiver to satisfy all market demands. And today we would like to review the new XSR-M and compare it to the older XSR receiver.

FrSKY XSR-M technical specifications:

• Dimension: 20*20*4mm (L x W x H)
• Weight: 1.8g
• Number of Channels: 16Ch (1~16ch from SBUS channel, 1~8ch from CPPM channel)
• Operating Voltage Range: 4.0~10V
• Firmware Upgrade with S.PORT
• Antenna: 15cm
• Exposed antenna: 32.8mm
• Compatibility: FrSky X-series Module & radios in D16 mode

In the box:

XSR-M comes in a soft package with 4 wires plug and instruction manual.

You can buy XSR-M here

Features:

• Smart Port
• S-BUS/CPPM output (BLUE LED indicates XSR-M in S-BUS mode, otherwise in CPPM mode)

The direct comparison to the older XSR receiver would show us the obvious differences:

• Length and width have been reduced: from 26×19.2mm to 20x20mm
• Weight has been reduced from 4.3g to 1.8g
• Antennas on XSR-M are detachable and have a connector
• Exposed part of the antennas are longer (32.8mm)
• Connection port has 4 wires on XSR-M (S.PORT, CPPM|SBUS, Vin, GND) instead of 5 on XSR (S.PORT, CPPM, SBUS, Vin, GND)

Enabling CPPM output instead of SBUS and vise-versa: long press the F/S button on the receiver for 3 seconds -> GREEN LED will flash three times indicating that the mode change is completed.

Points 3 and 4 are the most critical upgrades: first would make it much easier to change the antenna in case if it has been damaged (no soldering required) and second would aid to resolve the issue that older XSR had less flying range due to shorter exposed antenna area comparing to X4R receivers. XSR-M has the longer exposed part and might improve the range. I have tested both receivers on the ground and found that there are changes….. Both of my receivers work perfectly in terms of range at the open space… But situation changes in the surroundings with some numerous obstacles… All tests are at the end of this review. Let�s move along with the features for now.

The size of XSR-M became more convenient — this receiver would now easily fit into most of the frames and in very tiny places. Weight decrease would help those pilots who are constantly fighting for the lightest setups  This new receiver might now fit such smaller builds as 80-110mm frames!

The rest of the features are the same: XSR-M board has dedicated RSSI and CPPM pads (besides output pins), bind button and status leds. Moreover, the board now has mounting holes at the corners (21x21mm).

Testing and final word:

XSR-M definitely an upgrade for XSR receiver especially if it would be used for racing quads. Lighter, smaller, antennas are easy to swap, should have a slightly improved range, full telemetry support… all of those features make it superior to older XSR version.

I�ve tried to do ground and flight tests and compare XSR to XSR-M receivers in terms of range and I�ve found some significant difference: they both seem to work fine and deliver >1km at the open space. However, XSR-M RSSI figures were 2 — 10 RSSI points higher at all times than on XSR at the same locations and when there are a lot of obstacles are one massive obstacle. So, XSR-M is capable of delivering longer range in saturated environment.

What really stand out when using XSR-M is how easy it is to fit into the board. So, I think that I would finally end up with ordering only XSR-M for the future builds.

You can buy XSR-M here

FrSKY premium dealers list

If you didn�t know yet, there are some products that FrSKY already make to get the most bulletproof radio signal by adding full-duplex relay with 2 parallel receivers together with doubling onboard batteries — Redundancy Bus and RB10.

But, if you don�t want to mess with such complicated setups, want to keep the weight of your model as low as you can, want to spend less yet having some compromise between a mere receiver and the full redundancy setup — RX8R is here for you.

Technical specifications:

• Band: 2.4GHz ACCST
• Channel: 16CH / 1-8ch from PWM
• 1-16ch from SBUS port
• S.Port
• RX IN port
• Two PCB antennas
• Full Range
• Full Telemetry
• Dimension: 46.25×26.6×14.2mm (L×W×H)
• Weight: 12.1g
• Operating Voltage Range: 4.0-10V
• Operating Current: 100mA@5V
• Firmware Upgradable
• Compatibility: FrSky radios/transmitter modules in D8/D16 mode

Those, who used X8R and X6R receivers before, would not find any difference in casing design, size and weight of the new product. What�s different — RX IN port instead or RSSI out and newly designed PCB antennas with no plastic covers. Moreover, you would follow the same steps to set it up as you�ve done with X8R and other jumper-equipped SBUS|PWM, S.Port receivers.

Despite the possibility of this receiver to work as a conventional X8R, the main goal of RX8R is to be used as master with some X-series, SBUS equipped receiver connected to RX IN port as a backup slave receiver. The only demand in such setup — slave receiver should be configured to no telemetry mode with PWM channels set to 9-16 (or else) output, if any, and master RX8R should be configured to 1-8PWM with telemetry. Than, you can connect SBUS output of RX8R to your flight model controller or ESC/servos to PWM 1-8 channels and connect other electronics to PWM channels of slave receiver, if any. Moreover, you have to configure failsafe values for 1-16 channels in master and 9-16 channels in slave to the desired positions.

You can bind both receivers to 1 radio module or bind the them separately to 2 separate modules ( in case if internal and external XJT are used — both switches of the exteranl module should be set to ON)

Such combination of 2 receivers would do the following:

1. RX8R, as a master, would give out SBUS channels 1-16 and PWM 1-8 as long as it stays online. With all telemetry and RSSI values.
2. When RX8R looses the signal, it would take the signal from slave receiver if it is still online with no interruption to all channels functionality. Unfortunately, you�d loose the telemetry.
3. In case if slave fails and master works — you�d loose PWM channels from the slave receiver (9 — 16) if any, and slave receiver would output failsafe values for those channels. But there is a telemetry from master to the radio.
4. In case if both receivers fail — they would both output corresponding failsafe values.

As you can see, the only real drawback of such setup is that you�d loose the telemetry and RSSI value whenever master goes offline. Even despite the fact that you model still controllable because slave�s receiver signal is relayed to the master.

Other combination would be to have 2 RX8R connected together. There are 2 options:

1. If you�d connect them with only one cable — system would act the same as in the previous description.
2. If you�d interconnect them with 2 cables in circles there would be 2 changes: one is that you no longer have SBUS channels because master SBUS port is busy with the cable, but, what is good is that you would have 16PWM channels system (1-8 from master and 9-16 from slave) that would work at any time, no matter which one of the receivers goes offline. Still, slave should be configured to have no telemetry, thus, again, if master fails all 16 channels work but no RSSI and other values….

Binding 2 interconnected RX8R (with 2 cables) to 2 separate radio modules would bring even more reliability and give you the most out of such system setup.

I have conducted the test to check the first situation: 1 RX8R as master and 1 X8R as a slave. No problems here (look at the video review). They work as described, making the radio link more reliable especially if receivers are situated at different locations on the model to get the most out of such kind of diversity or redundancy setup.

I have noticed that right at the time when RX8R master looses signal the servo connected to its PWM output has a momentary freeze or uneven movement and then continues to work smoothly. This is due to the signal overtake (relay) time period when master fails and slave starts to output its signal is about 900ms. In case if you want much faster relay time — you should use RB10 instead. I have reported this to FrSKY and hope that they would be able to reduce the lag.

FrSKY has updated RX8R FW and now it has no visible lag of master to slave switching at all!!! Excellent!!! Newer FW is available by this LINK.

I don�t have 2 RX8R to check the other described situations, but I don�t see why it shouldn�t work.

Therefore, I can conclude that whenever someone wants to reinforce or defend his radio link with the lowest possible cost, weight and amount of wiring — he should consider having one or even two RX8R receivers with redundancy bus feature.

Link to the shop of my own preference

Stay tuned, more reviews are coming!!!