DSMX/DSM2- zero range [SOLVED!!!]

Hi Cereal_Killer!! thanks for the reply!
How can I mesure if the diode is faulty? How I have to place the multimeter?
And what kind of diode is? To buy it..

Thanks again!

Hello,

First of all thanks for all the info and the good work.

I also tried the range mod by shorting the famous diode (which I think is a resistor) with no luck. I mean, the bridge is steady and works fine as per the multimeter but at full power I barely get coverage for ~150 meters.

I also modified the hardware.ini but no luck, seems like if the range mod is not working. I tested with a lemonrx sat and with orangerx 6xx (both dsmx).

By reading this thread I also tested if the diode was working ng or otherwise the voltage given to the module and seems fine. By the way the module is directly powered by the battery and the devo 7e can officially take a 2S battery so is fine to power up the mod with 7.2v. Anyway, voltage was fine (>5v).

I'm out of ideas and can not figure out why the range mod cant take more than 150m.

Any help will be appreciated. Thank you!

Hello there.

I have the same zero range problem, and did what Cereal_Killer did, but still have no range.
My Devo 7e has been used for NRF24L01 radio, and recently I got DSM2 and DSMX rx, so the problem is new and I have never successfully flown CYRF, any further than 20 feet

Problem:
OrangeRX R110xl Satellite receiver has no range(2~3meters / 8~9' max). Also R615X, and Redcon CM651 have same problem. So I guess it is TX problem.

Here's what I did:
- Increase range mod (long time ago)
- NRF24L01 +LNA + PA installed (long time ago, working fine)
- 2 x 2 switch mod (recently)
- Recently replaced CYRF antenna with RG316 to 2W wifi booster(which works fine with NRF24L01, but not CYRF)
- Pulling 5V from Jumper to CYRF 5V, although when I checked SOT-123 with multimeter, it gives 4.8xV, which is good.

What I think I'll do:
- Try to fix it, but first I need to figure out what the problem is
- Get a multi-module from banggood and hope it works

Any help is appreciated! Thank you!

Some pics to help
Devo 7e guts1
Devo 7e guts2

hyun wrote: - Get a multi-module from banggood and hope it works

How would that help anything if the problem is the CYRF module? You'd need a new devo module or a 4-in-1...


People need to stop trying the range mod until they have CYRF based receivers to immediately test their work (yes I was guilty of that too).
What did you use to short the resistor? A 0 ohm jumper of just a solder blob? Take the shield off and measure the resistance to make sure it's zero.

I'd also check your soldering of the antenna wire to the CYRF module if there are shorts between shield and center conductor. If that is ok I would remove the wire to the booster and test with a standard 2.4 ghz antenna cleanly soldered to the cyrf module.

Oops, wrong link!

It should be 4 in 1, not 3 in 1.

DIY 2.4G CC2500 NRF24L01 A7105 CYRF6936 Multi RF 4 IN 1 Wireless Module
banggood.app.link/cxddrDkhJv

Thanks for quick reply!

Yes that would be very reasonable from looking at kinda dirty soldering job, but I have already checked it and there was no contact from the shield and the center conductor. Also I checked the connections of the center conductors all the way up until the antenna and it was fine.

The problem has been there even before I replaced the antenna. Poor range was the reason that made me to replace the antenna..

ursus69 wrote: Hi Cereal_Killer!! thanks for the reply!
How can I mesure if the diode is faulty? How I have to place the multimeter?
And what kind of diode is? To buy it..

Thanks again!

Cereal_Killer do you know the exact diode specs?? I need to regulate the power. Batteries are just draining with the jumper.

I have come to a conclusion my cyrf module is dysfunctional. Ordered a replacement module for devo8 and waiting for arrival. I'll report after replacing it.

www.ehirobo.com/walkera-wk-devo-s-mod-de...search=Devo%20module

I did some research on the actual diode.

I zoomed in on the board and found the SL SMD code. It comes out to be a SOD-123 package and a 1N5819HW schottky diode which can be requested as a sample from Vishay, SL04-E3-08 / SL04-HE3-08

I am waiting on mine to arrive to see if this fixes the power regulation. I believe I uprated the voltage as well in order to regulate a LiPo up to 12VDC.

Cyrf module has arrived a couple weeks ago and finished installing it. Haven't done a full range test but on a quick test it performs much better than the original one. Will do a full range test in a couple of weeks and report.

BTW the voltage that goes into the module was proper 5v, so it wasn't a problem of low or no voltage.

I've received the uprated diodes. They are currently regulating the 2S LiPo I'm testing with, the voltage fluctuates I believe because of the multiple cells. Likely software can fix that.

Beyond that I am getting full range at full power 150mw. I actually have yet to lose range. I also have not changed my battery or recharged it in weeks. It's yet to go lower than 7.5 volts with full charge around 8.4 and I'd recharge at 7 or 3.5 per cell.

So far no issues at all with this fix.

I'm currently experiencing the same problem with my modded Devo 7e. I have NOT done the range mod yet and was hoping to be able to use it to fly a blade inductrix.

The Devo 7e with the latest nightly firmware has not problem binding, however I have only about 1 meter of range before it looses signal. I have the nrf24l01+ module installed to fly my toy grade quads and it works fantastic with them and I have a huge amount of range.

I did have some problems installing and I'm wondering if I possibly destroyed the default installed module. Or if I have to do the range mod to make it Usable for Dsm2/Dsmx. It seems unlikely to me that it's the diode preventing power mentioned before since the nrf24l01+ module seems to be working fine. and I don't have a way to test the voltage.

Any advice would be much appreciated.

Thanks.

theoriginaljosh wrote: . It seems unlikely to me that it's the diode preventing power mentioned before since the nrf24l01+ module seems to be working fine. and I don't have a way to test the voltage...

You're gonna a have to test that voltage, the NRF24L01 working tells you NOTHING because unlike all add-on modules which must be powered @ 3.3v the factory CYRF module is powered with 5v so again saying it must be fine cause the NRF24L01 is fine is not a thing...

Great thank you for the info. I'm sure one of the guy's I work with have a volt meter for me to test with.

Am I wrong in assuming that it's probably a bad diode in that case?

theoriginaljosh wrote: Great thank you for the info. I'm sure one of the guy's I work with have a volt meter for me to test with.

Am I wrong in assuming that it's probably a bad diode in that case?

Don't assume with electronics. Its not a faucet you can't see a leak without testing. Always test it. And its best to get the schematic of the board so you know what to touch. You don't want to cause a short and ruin everything else just from checking the wrong spots.

Most likely it is a bad diode but unless it looks burned you will not know until you check. The original diode is low rated and can't take the strain of the added modules well. In my opinion anyone with this mod will eventually have to replace the 3.3v diode. Its just not setup to take the amps pulled through it and eventually breaks down.

By this mod to do you mean the NRF24L01+ or the Range mod? I haven't attemtped the range mod yet. currently just using the stock module.

theoriginaljosh wrote: By this mod to do you mean the NRF24L01+ or the Range mod? I haven't attemtped the range mod yet. currently just using the stock module.

This mod meaning replacing the diode.

The diode is being tasked with more demand whether you do either of those mods. This diode regulates power. When you add either mod you mentioned, NRF24L01+ or Range Mod you are causing an increased power demand. The 7e was not setup from the factory for 150mW of power constantly.

This is a place that many people have ended up when they could not get range. I originally had great range then one day it just dropped off for no reason. The reason eventually was found to be a faulty diode that would fluctuate under load.

1. The Pa (T212) on the RF module is only capable of 20 dBm = 100 mW max.
2. The NRF 24L01+ incl./PA/LNA module is the module which takes the least power of all, exceptions are possible.
If the Transmiiter is configured correctly, two modules will never be up.

When will this bs of a diode instead of a resistor stop?

Edit: If there is a RFX 2401C on the NRF module, the consumption will be similar to the CYRF module, but with a RFX 2402 C it is more.

I believe software requests 150mW at full power for the stock CYRF module.

And the PA may not be active unless you are using a protocol on that module but the module itself is powered when you power on the radio. You can test and you will see voltage being pulled unless you put switches on your NRF and A7105 modules. Otherwise they are not on a switched power source besides the big switch for the entire radio.

The modules won't be pushing out anything but they are still powered. So that is really 100ma+, NRF no PA and A7105 this is why I believe the diode is burning up.

And a resistor could work but I believe the wasted energy as heat would or could eventually cause other issues. The diode does it more efficiently I'm guess at that current and voltage? Not sure don't quote me on that.