RCTestBen.ch: VTX RF Power Testing (FPV AiO - micro VTX - VTX)

muteFPV

youtube.com/muteFPV
Products tested (index):
- AKK BS2 FPV AiO
- Eachine HC48D FPV AiO
- Eachine ATX03 micro VTX
- Eachine VTX03 micro VTX
- Eachine VTX01 micro VTX
- EWRF e7086TM3 VTx
- Runcam TX25 micro VTX

-> subscribe to this thread for upcoming tests | comment below for VTXs you would like to see tested <-

------------------------------------------------------------
** Attention: As always, make sure you use frequencies that comply to your country's legislations. **
------------------------------------------------------------

The test rig:
The RCTestBen.ch test rig for VTx RF Power Output is a DIY setup. The RF Power Meter is made by ExpertRC and you can find it here: https://goo.gl/lfhgqd
(the RF Power Meter is produced in small batches - check back if it is currently not available)
The case is 3D printed, you can find the design here: https://goo.gl/34pk3M

Just to be clear: These tests are far from scientific BUT the main goal here is consistency and repeatability, so that you can compare the results between all the hardware tested. These tests focus in the transmitted power per channel/band. Channels, Bands and Frequencies are displayed according to manufacturer's spec sheets.

The measuring equipment used has been tried and tested repeatedly before starting out this RCTestBen.ch series.
The hardware that is tested is brand new and unused, in stock condition. Only 1 unit is tested and presented in this video. To my knowledge, this is not a cherry-picked product and certainly not a "best-of" measurements video. This is how the product performed right out of the box.

The tested hardware (FPV AiO / VTx) is powered from a regulated DC source. You can watch the voltage and current draw throughout the test.
The most prominent min and max values are logged on each channel of each band / power output. If you see a different value on the RF Power Meter in a still capture, it just happened to show up briefly when the photo was taken. Same applies for power consumption. It is monitored throughout the whole duration of the test and the most prominent min and max values on each channel are logged.

The FPV AiO camera/VTx combos are tested by de-soldering the stock antenna and soldering a coax cable in its place, which is connected on the other side to the RF Power Meter. There are plenty of the exact same conductor with the exact same length from the same batch, as spares. VTx boards with u.FL (IPEX) connector are tested via a u.FL to SMA thin coaxial cable. VTx boards with SMA or RP-SMA connector are tested via an SMA to SMA cable plus an adapter for RP-SMA. All these cables and adapters are available as spares (the exact same types, from the same batch).

Cooling plays a huge factor in the RF power output of VTx boards. Leaving a VTx running for a short period of time in room temperature results in a quick drop of power output - even by blowing with your mouth results in a quick rise in power output. All FPV AiO and VTx boards are tested with a constant airflow over both sides of the VTx PCB board. Testing is done slowly and may take up to 35 minutes, depending on the amount of bands/channels available on the tested VTx board - after all the channels are cycled through, settled, measured and logged, the first channels are re-checked in order to confirm accuracy, consistency and stability of the transmitted power.

------------------------------------------------------------

Enjoy!
 
Last edited:

muteFPV

youtube.com/muteFPV
AKK BS2 FPV AiO

The product:
Brand: AKK
Model: BS2
Type: AiO

The specs:
Operating voltage range: 3,3 - 5,5 V
Power consumption: 280 mA
VTX
Power output: 25 mW
Number of channels: 48 CH
Antenna: Dipole
Antenna connector: (Soldered)
CAMERA
Resolution: 600 TVL
Field-of-View: 120 Degrees
Video format: NTSC

For pricing and availability you can check the links below:
https://goo.gl/OaNzeT
https://goo.gl/JaoJ5z

The test:

The results:
Overall.png
 

muteFPV

youtube.com/muteFPV
Eachine HC48D (V1.0) FPV AiO

The product:
Brand: Eachine
Model: HC48D (V1.0)
Type: AiO

The specs:
Operating voltage range: 3,3 - 5,5 V
Power consumption: 200-215 mA
VTX
Power output: 25 mW
Number of channels: 48 CH
Antenna: Cloverleaf
Antenna connector: (Soldered)
CAMERA
Resolution: 600 TVL
Field-of-View: 120 Degrees
Video format: PAL / NTSC

For pricing and availability you can check the links below:
https://goo.gl/ZFEafF
https://goo.gl/EShdWy
https://goo.gl/CpTWJt

The test:

The results:
RCTB Eachine HC48D - Overall.png
 

muteFPV

youtube.com/muteFPV
Eachine ATX03 micro VTx

The product:
Brand: Eachine
Model: ATX03
Type: micro VTx

The specs:
Operating voltage range: 3,2 - 5,5 V
Power consumption: 360 / 450 / 570 mA
Power output: 0 / 25 / 50 / 200 mW
Number of channels: 72 CH
Antenna: Dipole
Antenna connector: u.FL (IPEX)
Audio: Yes
Microphone: No
Video format: PAL / NTSC

For pricing and availability you can check the links below:
https://goo.gl/PS4E37
https://goo.gl/7jH6yq

The test:

The results:

@ 25mW
RCTB Eachine ATX03 - OVERALL 25MW.png

@ 50mW
RCTB Eachine ATX03 - OVERALL 50MW.png

@ 200mW
RCTB Eachine ATX03 - OVERALL 200MW.png
 

PsyBorg

Wake up! Time to fly!
Wow now I see why the U,O,L, and H bands are not used in the USA. Their radiated power off the same amplifiers is well over 60% of max rated power somehow.

Neat test runs and good information to see how certain channels seem to "penetrate" or radiate better then others. I would like to see somehow someone measure radiated power with the stock antennas these manufacturers use to see where the real loss comes from. I fly 25 mw on my five inch and can go well past 50 meters (I don't have a need to go further atm) while the AIO 25 mw unit's I have tried can not seem to go 25 - 35 feet reliably. I have a feeling there is a lot of loss in that pcb riser they add to connect the antenna as well as the shorter cable riser from the VTX to the actual antenna. That has to be radiating signals which cancel a percentage of what comes off the antennas.
 

muteFPV

youtube.com/muteFPV
Wow now I see why the U,O,L, and H bands are not used in the USA. Their radiated power off the same amplifiers is well over 60% of max rated power somehow.

Neat test runs and good information to see how certain channels seem to "penetrate" or radiate better then others. I would like to see somehow someone measure radiated power with the stock antennas these manufacturers use to see where the real loss comes from. I fly 25 mw on my five inch and can go well past 50 meters (I don't have a need to go further atm) while the AIO 25 mw unit's I have tried can not seem to go 25 - 35 feet reliably. I have a feeling there is a lot of loss in that pcb riser they add to connect the antenna as well as the shorter cable riser from the VTX to the actual antenna. That has to be radiating signals which cancel a percentage of what comes off the antennas.

Thank you PsyBorg.
I wanted to remove as many variables as possible during these tests, in order to ensure consistency and repeatability throughout the hardware tested.
But this is a nice idea for a separate test, with the same VTx and different types of antennas. Can't promise on a timeframe but I added it in my to-do list.
 

PsyBorg

Wake up! Time to fly!
If you have those capabilities you would be helping the community in a big way to understand more the difference in rated power vs radiated and just how much antenna performance changes those values. In any case thanks for what you are already doing. That sheds a bit of light on the mysteries of FPV.
 

muteFPV

youtube.com/muteFPV
If you have those capabilities you would be helping the community in a big way to understand more the difference in rated power vs radiated and just how much antenna performance changes those values. In any case thanks for what you are already doing. That sheds a bit of light on the mysteries of FPV.

Thank you for your kind words.
For the time being I will be slowly populating the data from tested VTXs, I have plenty of hardware in queue for testing.
I will be updating this thread as often as possible with new data.
 

muteFPV

youtube.com/muteFPV
Eachine VTX03 micro VTx

The product:
Brand: Eachine
Model: VTX03
Type: micro VTx

The specs:
Operating voltage range: 3,2 - 5,5 V
Power consumption: 360 / 450 / 570 mA

Power output: 0 / 25 / 50 / 200 mW
Number of channels: 72 CH
Antenna: Dipole
Antenna connector: u.FL (IPEX)
Audio: No
Microphone: No
Video format: PAL / NTSC

For pricing and availability you can check the links below:
https://goo.gl/C6mvrW

The test:

The results:

@ 25mW
RCTB Eachine VTX03 - OVERALL 25MW.png

@ 50mW
RCTB Eachine VTX03 - OVERALL 50MW.png

@ 200mW
RCTB Eachine VTX03 - OVERALL 200MW.png
 

muteFPV

youtube.com/muteFPV
Eachine VTX01 micro VTx

The product:
Brand: Eachine
Model: VTX01
Type: micro VTx


The specs:
Operating voltage range: 3,2 - 5,5 V
Power consumption: 300 mA

Power output: 25 mW
Number of channels: 40 CH
Antenna: Dipole
Antenna connector: u.FL (IPEX)
Audio: No
Microphone: No


For pricing and availability you can check the links below:
https://goo.gl/cXSt9c


The test:

The results:

@ 25mW
RCTB Eachine VTX01 - OVERALL PERFORMANCE - muteFPV.png
 

muteFPV

youtube.com/muteFPV
EWRF e7086TM3 VTx

The product:
Brand: EWRF
Model: e7086TM3
Type: VTx


The specs:
Operating voltage range: 6 - 25 V
Power consumption: 140 / 250 / 300 mA
Power output: 0 / 25 / 200 / 600 mW
Number of channels: 48 CH
Antenna: not included
Antenna connector: RP-SMA
BEC: 5V / 1A
Audio: Yes
Microphone: No


For pricing and availability you can check the links below:
https://goo.gl/kA3z31
https://goo.gl/YzkFSY
https://goo.gl/QHYw1B


The test:

The results:

@ 25mW
RCTB EWRF e7086TM3 VTX - OVERALL PERFORMANCE 25mW - muteFPV.png

@ 200mW
RCTB EWRF e7086TM3 VTX - OVERALL PERFORMANCE 200mW - muteFPV.png

@ 600mW
RCTB EWRF e7086TM3 VTX - OVERALL PERFORMANCE 600mW - muteFPV.png
 

muteFPV

youtube.com/muteFPV
Runcam TX25 micro VTX

The product:
Brand: Runcam
Model: TX25
Type: micro VTX


The specs:
Operating voltage range: 3,5 - 5,5 V
Power consumption: 105 mA
Power output: 25 mW
Number of channels: 48 CH
Antenna: Dipole
Antenna connector: soldered
Audio: No
Microphone: No
BEC: 4,5V / 0,25A
Video format: PAL / NTSC


For pricing and availability you can check the links below:
https://goo.gl/iU5CNE (Runcam)
https://goo.gl/vtZ66z (Banggood)
https://goo.gl/a8cp77 (Gearbest)
https://goo.gl/gzCYRv (Ebay)
https://goo.gl/Ncv3R6 [bundle with Runcam Micro Swift 2] (Banggood)

Manufacturer's website:
https://goo.gl/6HBLqm (product manual)


The test:

The results:

@ 25mW
RCTB Runcam TX25 - OVERALL PERFORMANCE - muteFPV.png