BEVRC ChainLink UHF Long Range System

[Shikra]

Cheap chinese rubbish.

[electricmick]

I'm very pleased to say that FirstPersonView.co.uk supplies all its EzUHF units on 459MHz and one hundred mW.  

The firmware came through very recently and our versions all ship like this. :-)

Here's the link: http://www.firstpersonview.co.uk/rc-control-systems/ezuhf-459mhz-fhss-robust-digital-rc-system

Simon, good to hear this at last. From a theoretical viewpoint, what sort of range is expected from the 459MHz UK version in comparison to the standard version? Does it still have the high power switch to be used in an emergency due to loss of control?

Thanks, Mick

[simondale]

Hi Mick,

On the range; I think the theoretical maximum of the normal version (based on RSSI at 10km and then predicted range based on that) is about 100km.  So I would have thought even at 20dBm (100 milliwatts) the system will give far more range than we could ever legally use in the UK (in terms of LOS specified in the ANO), and far more range than your video system would ever give you.  

The low power switch is there but toggles between 18.5dBm in low power (about 71 milliwatts) and 20dBm in full power (100 milliwatts).  We couldn't have the system transmit over 100 milliwatts or else it would not be allowed but I'd certainly recommend flying on low power most of the time, so that you can flick to high power in the event of a problem.

All the best

Simon

[venquessa]

Its just not worth the risk.  35MHz with a Corona RP8D1 receiver will give you up to a maximum of 1.5kms.  That's as far, or beyond, as far as the eye can see and therefore as far as you are allowed to FPV by law.

Simon, my experience of 35Mhz was not a plain sailing as this.

On two completely independent 35Mhz setups (Futaba/Corona) - ie. different Tx, Rx, Plane, motor, esc, battery -  the only reused things were my Vtx and GoPro, I had frequent twitching on all channels at all ranges, from sitting in front of me to 300m out where they became so intense I always turned back.  I found that dropping the radio voltage from 6V to 5V stopped the close range twitching, but instead I got mid range (200m) twitching on all channels and complete loss of signal fail safes at 500m for several seconds, nearly losing the plane twice.  Model was still within LOS and I just felt like a passenger.

IMHO, that is not worth the risk.

[cortex]

very happy with mine so far and i have tested it upto 1.2km. i couldnt even get it to go out of range on micro mode after walking the length of two football field next to water going infront of houses.

was just wondering what i should protect the antenna with? im using straws at the moment.

cheers

Cortex

[electricmick]

Cortex, are you using the ChainLink or the 459EzUHF? We had a bit of thread drift along the route.

[cortex]

Cortex, are you using the ChainLink or the 459EzUHF? We had a bit of thread drift along the route.

chainlink uhf m8  :D

[simondale]

Its just not worth the risk.  35MHz with a Corona RP8D1 receiver will give you up to a maximum of 1.5kms.  That's as far, or beyond, as far as the eye can see and therefore as far as you are allowed to FPV by law.

Simon, my experience of 35Mhz was not a plain sailing as this.

On two completely independent 35Mhz setups (Futaba/Corona) - ie. different Tx, Rx, Plane, motor, esc, battery -  the only reused things were my Vtx and GoPro, I had frequent twitching on all channels at all ranges, from sitting in front of me to 300m out where they became so intense I always turned back.  I found that dropping the radio voltage from 6V to 5V stopped the close range twitching, but instead I got mid range (200m) twitching on all channels and complete loss of signal fail safes at 500m for several seconds, nearly losing the plane twice.  Model was still within LOS and I just felt like a passenger.

IMHO, that is not worth the risk.

I wonder what was going on there.  I don't get any glitching on any of my 13 models with Corona RP8D1s in them and Futaba T7CP and T9CP transmitters.  Perhaps something in your aircraft gives off RF that caused your Corona's to get upset - possibly a brushless motor/ ESC giving off noise on 35MHz?  Or possibly there was some conductive interference going on from the ESC.

I had a weird problem which I thought was my receiver 6 months ago.  I lost control once.  After trying a couple of receivers I discovered that if I even touched the crystal holder the servos would chatter.  None of my other radios did that so I sent it in to Ripmax.  Basically I'd damaged the PCB inside, probably by carrying my Tx in a rucksack a couple of times. £40 repair and its good as gold again now.  And I won't ever carry it in a rucksack again!

All the best

Simon