PDA

View Full Version : No power to SBus receiver


thehatguy
12-23-2011, 05:07 PM
Bought a used SK720 and powered it up for the first time today.

Went through the wizard and all was well until step 18 - connect the Sbus receiver.

Nothing.

I thought it might be a defective SK-SB1 S-Bus adapter, but when I took the one off of my 550 and tried it... nothing.

Seems that there isn't any voltage out of the SAT REC port.

Anybody else had this issue?

John

georgi UK
12-24-2011, 12:29 PM
=] S-Bus selected in software? to eliminate connect the 550 s-bus to this unit.

curmudgeon
12-24-2011, 03:20 PM
Consider using a voltmeter to test the Power Bus

thehatguy
12-24-2011, 08:06 PM
Here's the current status.

Took the R6208SB receiver from the 550 and all is well.

The R6203SB still won't work. It was working fine when it was connected to the 3GX, but the Skookum doesn't seem to like the 3-channel R6203SB receiver.

Anybody else have/had this issue?

One figures an Sbus receiver is an Sbus receiver.

At least the SK720 is good.

John

mhoebrec
12-25-2011, 03:04 AM
I use a the 3-channel sbus receiver without problems on my sk720.

thehatguy
12-25-2011, 06:42 AM
Consider using a voltmeter to test the Power Bus

Not using a power bus on the 450. No place to put it.

John

thehatguy
12-25-2011, 06:44 AM
I use a the 3-channel sbus receiver without problems on my sk720.

So perhaps my 6203 is marginal when it comes to the SK720's lower power output???

John

herex
12-29-2011, 08:18 AM
Hi,
I use my R6203SB receiver without problems on my Trex500.
My conditions are:

BEC 5,4 Volts
functial SK Futaba SBUS cable (see SK manual for disconnecting + wire)
Extra power cable (servo extension cable) connectet between SK720 SW-A (unused port on my heli) and R6203SB channel 3/B.
SIGNAL wire must be disconnect on the extra power servo extension cable !!!
regards from Austria, Herfried

aarsevin
12-29-2011, 11:53 AM
I run a slave from my jive directly to the R6203SB. The output voltage from the sk is too low (3v) for the receiver to operate properly. 4.8 to 8v is required for the receiver.

herex
12-29-2011, 01:26 PM
Hi,
You are right. On SK720 side, the output Voltage on the two "SAT" connectors are to low for the R9203SB receiver by using the SK-SB1 S-Bus adapter. :mad:
Your way is one of some simple ways. :thumbup:
Remember I use 5,4 Volts BEC. And the same Voltage output is on SK720 - SW-A (free port) during powering the heli. This is a stable power source and I use it since long time. :)

Regards from Austria, Herfried

aarsevin
12-29-2011, 02:04 PM
I like that solution a lot herex. Especially on an esc that doesn't have a dedicated slave. Or if you are using a single lead bec.

thehatguy
12-29-2011, 03:13 PM
I run a slave from my jive directly to the R6203SB. The output voltage from the sk is too low (3v) for the receiver to operate properly. 4.8 to 8v is required for the receiver.

These are Futaba's specs on the 6203 and 6208.

R6203SB:

SPECS: Power Requirement: 3.7V or 7.4V battery or regulated output from ESC*
*output capacity must meet usage condition
Voltage Range: 3.5V - 8.4V

R6208SB:

SPECS: Power Requirement: 3.7V or 7.4V battery or regulated output from ESC*
*output capacity must meet usage condition
Voltage Range: 3.5 - 8.4V


I've got the 6208 in my 550 and the 6203 in the 450 both via the Futaba interface cable from the SK720.

According to your statement, neither one should work.
Or am I missing something.

John

aarsevin
12-29-2011, 03:25 PM
I can only speak from my experience with the 6203 on a 700e. My receiver would not function with only the sbus adapter via the sk. I have a 3gx that does power the 6203 on a 500. I would say if it works for you that's awesome.

thehatguy
12-29-2011, 03:32 PM
Now I'm concerned it is marginal and could fail.

Might need to give this more thought.

John

heathy
12-31-2011, 08:23 PM
Is this lead your using this 1 http://www.fast-lad.co.uk/store/skookum_sk720_s-bus_adapter_sk-sb1-p-13700.html ??

I thought that you just plugged this into the sbus and sk and thats it:confused:

Forgive me if i'm wrong, still in the process of deciding on a new TX and futaba are top of my list so far.

thehatguy
12-31-2011, 09:29 PM
That is the correct lead. I'm using it for both of the SK-720's.

Both are up and running. One with an R6203 and the other with an R6208. No power bus on either.

John

lhatton
01-08-2012, 05:38 PM
Just ran into this myself.

I have two ships with 6208s powered by the sbus adapter and no additional power jumper. Been flying both for over a year with zero problems.

Was converting a new ship to FBL and picked up a new 720, sbus cable and 6203.

It has been marginaly powering the reciever. I get removing the red power lead from the sbus cable to prevent the overloading the 720 with a servo plugged into the reciever, but what about this "don't hook up the signal wire" on the power jumper. What's the "official " word on powering a sbus reciever (yes, I've relooked at the manual)

This seems like poor implimentation of an sbus capable unit. I enen now worry about the two I've been flying. One's a quite large scale ship that surprises me it hasn't browned out with a penta head pulling on the power bus.

Les