Range problem - Spektrum in CF hull

[zooma]

Using Spektrum DX4C transmitter and SR410 receiver. I know that the signal does not go through carbon fiber hull/deck, so I am using the external antenna tube. Total antenna length is 7", with 5 1/2" in the tube. So the little bare end is nearly 5" above the deck. As I travel around our small lake, the boat quits on the far side, only about 300 feet away. (took the measurement on Google Earth.) I release the controls, wave the transmitter up high, and after a few seconds, I can run the boat again. Sometimes I can pass that spot without losing signal, particularly if I'm going at full throttle. But, when I am slowing down to go around the buoy, she just quits. I have not had a chance to re-bind or try a different receiver yet.

Any ideas?

[NativePaul]

Someone had this problem recently, and solved by adding a second antenna tube to get them both out of the hull.

[zooma]

SR410 surface receiver only has one antenna.

BTW - I understand that Spektrum is discontinuing the MR200 dual antenna marine receivers.

[kfxguy]

I helped my range issue by issuing higher voltage aa batts. Along with running both antenna out the hull but that's not your issue. Note, I did both at separate times and the hv aa batts did help noticeably.

[zooma]

I helped my range issue by issuing higher voltage aa batts. Along with running both antenna out the hull but that's not your issue. Note, I did both at separate times and the hv aa batts did help noticeably.

What's a high voltage aa batt? I am running 1.5v alkalines. As far as I know, the fancier ones are just higher capacity.

[shua]

Spektrum is safe to use 2s lipo as well.

[kfxguy]

What's a high voltage aa batt? I am running 1.5v alkalines. As far as I know, the fancier ones are just higher capacity.

Do a search on eBay for nizn aa batteries. They are 1.6v each. Rechargeable

[AndyKunz]

This is not a voltage problem. The battery is dropped down to 3.2V internally in the receiver.

A range problem here is probably due to the installation in some way - CF, grounding, or such. Got photos?

The only part of the antenna that matters is the silver part, the last inch. You want that up and away from the carbon AND from the water. DSMR should give you about 500' on the water, farther over dry ground.

Andy

[Fluid]

My DX3R-PRO/MR3000 has the short antenna 5" above the deck and the long one taped along the underside of the deck. There is carbon fiber on the hull bottom (sport hydro). This gave me at least 950 feet (measured) on the water, does DSMR have less range or am I just lucky? Thanks Andy.



.

[kfxguy]

This is not a voltage problem. The battery is dropped down to 3.2V internally in the receiver.

A range problem here is probably due to the installation in some way - CF, grounding, or such. Got photos?

The only part of the antenna that matters is the silver part, the last inch. You want that up and away from the carbon AND from the water. DSMR should give you about 500' on the water, farther over dry ground.

Andy

Let me put it this way. I know that in one of my boats that's carbon fiber, I ran both antennas out the hull, both in the tube and that helped. And with no doubt whatsoever, I am absolutely sure that when I increased the voltage in the transmitter from 6v to 6.4-6.5v I stopped having it cut out on me. Say whatever you like, I run nothing but spektrum and I know that at a certain tree on the lake if I went past it, I was walking to the boat to get it to link again. When I increased the voltage, not only did it go past the normal spot, it would go further than I could see. That's a fact.

[tlandauer]

Using Spektrum DX4C transmitter and SR410 receiver. I know that the signal does not go through carbon fiber hull/deck, so I am using the external antenna tube. Total antenna length is 7", with 5 1/2" in the tube. So the little bare end is nearly 5" above the deck. As I travel around our small lake, the boat quits on the far side, only about 300 feet away. (took the measurement on Google Earth.) I release the controls, wave the transmitter up high, and after a few seconds, I can run the boat again. Sometimes I can pass that spot without losing signal, particularly if I'm going at full throttle. But, when I am slowing down to go around the buoy, she just quits. I have not had a chance to re-bind or try a different receiver yet.

Any ideas?

I asked this question back in May, here is the link to that thread. https://forums.offshoreelectrics.com/...hey-comparable

Then recently there was another discussion because newer tx is now not backwards compatible with MR200 and MR3000 because of some regulations in Europe. From the feed back I thought ( I have not used it since I have some MR series stashed away) the newer DSMR protocal should work even better than the MR series which operates on DSM-Marine protocol.
I have never had any problem with either MR200 or MR3000, a few of them are in partially CF layup hulls, always had one antenna out, in one case I pulled both out and in a custom tube, worked great.
I wonder if you have a bad unit?? As said, the only antenna section that counts is the silver section.

[zooma]

DSC05843b.jpg

Receiver is in the black foam sleeve, back at the transom. I will try another of the same SR410 receiver. If that doesn't improve the range, I'll pull an MR2000 from another boat. My DX4C transmitter is about 2 yrs old. It does not have a date label in the batt compartment. It does work with the MR receiver.

[runzwithsizorz]

[QUOTE=zooma;641571]SR410 surface receiver only has one antenna.

BTW - I understand that Spektrum is discontinuing the MR200 dual antenna marine receivers.[/QUOTE


Incorrect sir, see minute 14 in this video. https://www.youtube.com/watch?t=844&v=ELJ4XNwI-Pc

[runzwithsizorz]

DSC05843b.jpg

Receiver is in the black foam sleeve, back at the transom. I will try another of the same SR410 receiver. If that doesn't improve the range, I'll pull an MR2000 from another boat. My DX4C transmitter is about 2 yrs old. It does not have a date label in the batt compartment. It does work with the MR receiver.

Something I noticed in my instruction manual, the SRS4210 receiver, *does not like velcro.* Hmmmm Perhaps the SR410 receiver doesn't either, both are DSMR.
OOPS! my bad, re-read manual, they want you to use the provided double sided sticky foam to mound the SRS4210 receiver, as a anti-vibration inhibitor to make use of the ACTIVE VEHICLE CONTROL system.

[AndyKunz]

My DX3R-PRO/MR3000 has the short antenna 5" above the deck and the long one taped along the underside of the deck. There is carbon fiber on the hull bottom (sport hydro). This gave me at least 950 feet (measured) on the water, does DSMR have less range or am I just lucky? Thanks Andy.

You just got lucky, Jay. It could be related to the water surface (wave height) or your height above the water.

Andy

[AndyKunz]

And with no doubt whatsoever, I am absolutely sure that when I increased the voltage in the transmitter from 6v to 6.4-6.5v I stopped having it cut out on me. Say whatever you like, I run nothing but spektrum and I know that at a certain tree on the lake if I went past it, I was walking to the boat to get it to link again. When I increased the voltage, not only did it go past the normal spot, it would go further than I could see. That's a fact.

Post hoc, ergo propter hoc.

I'm glad you had great success. I run nothing but Spektrum too :)

Another fact, and why I say it's not the voltage:

BATTERY PACK ----> POWER SWITCH ------> VOLTAGE REGULATOR (3.2V) -----> ALL electronics.

That's how the transmitter is laid out. A receiver is like this:

BATTERY PACK/BEC ---> SERVO BUS ------> VOLTAGE REGULATOR (3.2V) ------> Receiver chip and control micro

The Servo Bus splits off the incoming voltage to the servos as well as the receiver stuff.

Andy

[AndyKunz]

I understand that Spektrum is discontinuing the MR200 dual antenna marine receivers.

That is correct. We must - Europe has a new standard for 2.4gHz systems, and DSM-Marine is not compliant with it. There are a few products with MR200's in them, but future production will be moved to DSMR. The good news is that DSMR is better on the water than DSM-Marine was.

Andy

[AndyKunz]

DSC05843b.jpg

Receiver is in the black foam sleeve, back at the transom.

I would add an inch to my antenna tube so that the active portion is inside the tube, and the tube is sealed. Water on the tip of the antenna will detune it dramatically and kill performance.

Andy

[runzwithsizorz]

Andy, how can a circuit board running at 3.2v provide 5.6+++v to servo(s), and other components? I is dumb.
Dumb confirmed, there are 3 wires to the servo, and 1 is the signal,

[AndyKunz]

Maybe I didn't explain it too well. It's hard using a variable-pitch font, but I'll try.



BATTERY PACK/BEC (5V) ---> SERVO BUS ------> VOLTAGE REGULATOR (3.2V) ------> Receiver chip and control micro
|
-------------------------> SERVO BUS ------> SERVOS (5V)


The radio chip is powered by a voltage regulator that takes a smidgen of power off the servo bus. It takes the 5V and gives 3.2V for the radio. The servos are still running on the input 5V (or 5.5V or 6V or whatever).

Andy

[tlandauer]

[QUOTE=runzwithsizorz;641687]

SR410 surface receiver only has one antenna.

BTW - I understand that Spektrum is discontinuing the MR200 dual antenna marine receivers.[/QUOTE


Incorrect sir, see minute 14 in this video. https://www.youtube.com/watch?t=844&v=ELJ4XNwI-Pc

I think you are correct that the "original" DSMR TXs were compatible with the MR series receiver, this video was published in Dec. of 2012, this changed in January of 2015, they had to comply with Europe, so now tx on this protocol is no longer backwards compatible. Here was the thread started by Darin:https://forums.offshoreelectrics.com/...DX2E-with-DSMR
I bought my DSMR tx DX4C in April of 2014, so mine is compatible with the MR series.
Here is what I would say to sport boaters: if you don't have to own a computerized TX, look out for a good-used DX3E, that was one hell of a TX, IMO it had more features than the later DX2E and I used it for three years without a hitch for my boats that run with the MR series rx.

[kfxguy]

Maybe I didn't explain it too well. It's hard using a variable-pitch font, but I'll try.



BATTERY PACK/BEC (5V) ---> SERVO BUS ------> VOLTAGE REGULATOR (3.2V) ------> Receiver chip and control micro
|
-------------------------> SERVO BUS ------> SERVOS (5V)


The radio chip is powered by a voltage regulator that takes a smidgen of power off the servo bus. It takes the 5V and gives 3.2V for the radio. The servos are still running on the input 5V (or 5.5V or 6V or whatever).

Andy

Well I've never had to hook up a servo to the transmitter so......


I'm still referring to giving the transmitter higher voltage. Not the receiver. I thought I was clear on that. Maybe he is having another issue but like I said my range improved noticeably when I added voltage to the transmitter.

[zooma]

I would add an inch to my antenna tube so that the active portion is inside the tube, and the tube is sealed. Water on the tip of the antenna will detune it dramatically and kill performance.

Andy

OK, that would have been nice to know. Is vertical orientation also very important? I was thinking that it was being blown back to horizontal. I have about 6 of the SR410 rx. Sometimes, on a new installation, I just let the antenna hang out through the hatch seal, and that has worked.

I have flown the small Spektrum receivers w/o satellites and Orange clones almost out of sight, with no problems. What makes the surface radios so much worse in range?

[AndyKunz]

I didn't show anything with hooking up a servo to the transmitter. That was the receiver side of things. Refer to the prior post, where I differentiated that.

In the transmitter, NONE of the electronics other than the voltage regular ever sees the battery voltage. The battery shows it, the switch passes it, the regulator drops it down to the proper level, and THAT'S what all the other electronics see. Unless you had dead cells below 3.5V output, putting new cells in your Spektrum transmitter will not make any difference to range.

Andy

[AndyKunz]

OK, that would have been nice to know. Is vertical orientation also very important? I was thinking that it was being blown back to horizontal.

Yes.

What makes the surface radios so much worse in range?

Water! In WW2 the Allies used new 2.4gHz radars to see German subs and snorkels. The water absorbed the energy, the metal reflected it.

Andy

[tlandauer]

Well I've never had to hook up a servo to the transmitter so......

I didn't show anything with hooking up a servo to the transmitter.

...............
Andy

[runzwithsizorz]

Maybe I didn't explain it too well. It's hard using a variable-pitch font, but I'll try.



BATTERY PACK/BEC (5V) ---> SERVO BUS ------> VOLTAGE REGULATOR (3.2V) ------> Receiver chip and control micro

|
-------------------------> SERVO BUS ------> SERVOS (5V)


The radio chip is powered by a voltage regulator that takes a smidgen of power off the servo bus. It takes the 5V and gives 3.2V for the radio. The servos are still running on the input 5V (or 5.5V or 6V or whatever).

Andy

Andy, I am still a little confused. Perhaps the SRS4210 receiver is different, for in this video at minute 8:00 from the technical director at Spektrum, he recommends feeding the receiver with over 6v, or even 2s????
If all a receiver does is pass on the voltage from the battery pack, why does he emphisize that the receiver be supplied with over 6.5v ??
https://www.youtube.com/watch?v=nERfl5gsgRI

[kfxguy]

I didn't show anything with hooking up a servo to the transmitter. That was the receiver side of things. Refer to the prior post, where I differentiated that.

In the transmitter, NONE of the electronics other than the voltage regular ever sees the battery voltage. The battery shows it, the switch passes it, the regulator drops it down to the proper level, and THAT'S what all the other electronics see. Unless you had dead cells below 3.5V output, putting new cells in your Spektrum transmitter will not make any difference to range.

Andy

Ok well maybe I have a defective radio. I don't mean to sound like I'm arguing with you. I am, however, politely disagreeing with you. Maybe I have a defective radio. I don't know. It does not go very far with fresh Duracell or energizer alkalines in it. If I put the hv batteries in, it goes further than I can see. I've changed batteries at the lake just to see. Unless the last couple sets of new alkalines were defective. It has also worked in my recovery boat. I've ran it out of range. As in I lose total control of it. Then I hurry up and steal the batteries out of my dx4s (hv ones) and regain control and go much further to recover the boat. I'm not making this up. I can video it to prove it. That's two radios that are spektrum that the higher voltage helps.

[AndyKunz]

Servo speed/responsiveness. That's especially important with AVC.

It has NOTHING to do with the reception of signals.

Andy

[AndyKunz]

I'm not making this up. I can video it to prove it. That's two radios that are spektrum that the higher voltage helps.

I'm not doubting that you are seeing different results. I only know that, unless you have bad cells, the batteries are not the answer. It could be that the low V cells you have are high-impedance (high internal resistance) and as a result they are not delivering the full power to the circuitry during transmission (which takes a burst of power). That is very possible. But that is defective CELLS, not a bad radio, and not a function of their output voltage.

If you have found that different cells make a difference, then don't use the bad cells. Cheap cells are usually bad by design or contamination.

Andy