Different countries have different laws pertaining to radio equipment. The Rx's have to be tuned according to the same laws that the Tx is in order for them to work together. Since his Tx is from a different country than the Rx's that he bought in his own country then they aren't communicating.

The real problem isn't Futaba though; it's an unscrupulous seller that the buyer had no way of knowing about. Maybe you can ask Futaba to exchange it for one for your region/country if it's never been used?

I've bitten the bullet mate & got 2 more 304 receivers..live & learn.

Just uncovered some interesting data after looking through the old RC Tech 4pks thread. Futaba said the 4PK Super was 3.3ms for it's response time IF you were using the R614 Fasst Rx in C2 HSR mode. That would put the PX at 2.14ms, it's quite a bit faster than what is typically reported. So if the data is accurate (right time frame and reference point for it to be) it finally looks like we have some solid numbers that we can determine from Futaba themselves on both the 4pksR (Tx was 5% faster) and the 4pX (Tx is 30% faster than pksR), instead of other company's claims of what the Futaba systems do. See post #503 at the link below:

http://www.rctech.net/forum/radio-el...l-4pks-34.html

Also, quick note: On that old 4PK Super thread it was noted by the Futaba lead engineer at that time that the "twice as fast as the 4PK" claim for the 4pk Super was a COMBINATION of both a Tx speed increase and a speed increase from the R614 Rx over the R604 of the time. Point is that unless Futaba states an increased speed percentage for the Tx itself, then it may be that they are referring to improvements with both the Tx and the Rx combined.

I am looking to update my older 4pks-r to the 4px and have a couple questions.

1) Is the grip vibrations on the 4px and better than the 4pk? The vibrations on my 4pk are very weak and really not even usable.

2) Does the voice output on the 4px work with the timer? I have been trying to find a video of the voice output and cannot seem to find one.

1. The grip vibration is very alerting. You will probably be quite pleased with it.

2. I have no ideas as I haven't tried to use the voice feature yet.

All this unverified $#!7 numbers that comes from manufactures is why I started testing the radios I have. And my friend just happens to have a 4PK and I have a 4PX on the way to test also. The results on the 4PK was uploaded today.

See my test thread here http://www.rctech.net/forum/radio-el...m-results.html

If the 4PKS is better I will look around and see if it is something I come across and verify.

What I can say is that the C1 and C2 method when using the 4PK with R604 and R614 is that the C2 receiver was about 1ms faster with the same radio. See the results on the wiki page linked in thread.

If you look at this R/C Tech Forums - View Single Post - Airtronics M11X It is clearly an advertising from Sanwa, but comparing the 4PK to the test I did the values are a bit off. The min value is close to the C2 mode in my test but the average is alot worse in my tests. And the maximum delay is also alot worse in my tests. They are probably only measuring somewhere in the radio parts and not whats coming out to the servo. Because the last part where you must wait for next message adds random delays because the signal to the servo is synced to the update rate. But if they are measuring inside and ignoring the last parts the values don't add up and they have cheated and present the 4PK as worse than it is.

Exampel 1:
If the avg value of 7.7ms in sanwas test is without the 2ms it takes to send the servo signal that is 2ms long. In my test the average of 10.3ms will be say 8.3ms and the fastest of 6.3ms in my test will be 4.3ms and not 6ms that sanwa claim. So here i suspect they are cheating and presenting the 4pk as worse than it is.

Example 2:
If the minimum value of 6ms in Sanwas test is correct and my min value of 6.3ms is close to that, then they have presented the avg and max values of futaba as better than they are in real life, why would you do that if you want to promote your sanwa product?
Or they have measured in strange ways and are probably hiding the bad max values in their own claims.

Also any data saying the 4PK has 3.3ms of delay or latency is not the latency but the loop time of the servo signal that runs every 3.3ms or 303hz.

AWESOME DATA!!!! Thank you!!! I'm really not surprised at your findings as I've suspected the research methodology and subsequent research approach and validity steps from Sanwa as well. I've read that the 4pX and M12S have the "same" chip somewhere, but that's an unsubstantiated claim. When people say they "feel" more 'connected' it is typically difficult to determine if it's due to latency, resolution, or framerate. If they do have the same 'chip' (CPU ?) then their framerates (clock cycles) are most like the same and locked in.

The 3.3ms from Futaba was for the 4pk-S. Futaba claimed it was UP TO twice as fast as the standard 4pK.

All futaba 4PK 4PKS 4PX etc probably have 303hz update rate on the servos as this is probably the highest rate you can go to with normal servos. So if you get the value 3.3ms in any context just ignore it because it is not the radio delay just the update rate. The update rate can not be faster because you must have at least 2ms to be able to send 2ms signal to the servo. And having 1.3ms resting between each signal to the servo is probably the lowest they dare to go and have servos working as expected and not glitching out.

The 4PX will arrive in my mailbox in 2 days time, stay tuned for results.

Ahhh, so that would mean that the fastest framerate (servo update speed) that a digital servo can handle and still have enough resolution for left/right range is 303hz? I've read that on a detailed servo discussion over on a helicopter thread on one of the rc airplane sites. So that would mean that the M12s wouldn't have any faster framerate as well then, right?
Thus we could only be talking about resolution at this point, and latency. With the Fasst Rx (and probably the new SR T-Fhss) the resolution should be equal to the Sanwa at 2024, or thereabouts. Thus we are only really dealing with latency at this point for the high end radios.

Looking at servos some say they can handle 333hz. If you calculate max from having 2100µs servo signal and reading some old data on ppm i think 500µs is the specified resting time you can have about 384hz. So yes, no other radio RX can have any faster speeds and use normal servos. But some have special servos that use shorter communications and might boost the update rate even more.

But the latency is having more impact than update rate when you have this fast update rates. The 4PK had up to 5 updates before the signal was updated to the latest stick input so I guess Sanwa radios if they claim they are fast that they have lower latency. They can have half the update rate but faster latency and it will probably be a better radio to drive with.

Understood. Once the resolution & frame rate factors are zeroed out (equal between brands) or beyond certain parameters, then latency will be the remaining key factor. Of course, as you've pointed out, if one brand is measuring their latency based upon the chip specs vs another measuring theirs at the servo's repeated movements you are going to get completely different specs.

Even if the M12-S is faster than a 4pX, it will be nice to see some independent comparative quantitative data so that we have a clearer picture of just how much faster it really is; that's IF it's really faster.

What does appear to be clearing up is that the "connectedness" that people feel probably isn't due to frame rates (which can affect servo torque if I'm not mistaken). It probably doesn't have anything to do with resolution either since the Fasst Rx (and upcoming SR T-Fhss rx) is at the 2024-2048 resolution level. Thus the resolution should be comparable to the Sanwa Fhss 4 Rx.

That leaves latency as the only real point of difference.

Stick to servo latency with the included receiver R304SB.

Avg: 5.3ms
Min: 2.2ms
Max: 17.9ms
Servo updaterate: 333Hz

Here is a histogram with 20000 data points so you can see distribution. Max values have a few points on the high side.

Interesting data and awesome work! Thanks!
So frame rate is 3.3 but this is already past useful because the servo can't update that fast.
Min latency is 2.2ms with average being 5.3ms.

We still have no idea what the M12/M12-S specs are with you test. We also have no idea if Sanwa's stated values are for minimum or average latency. Do we even know if their specs were tested at the component or the servo level?
It would be neat to see the following two things:
1) specs for M12S with your tests
2) spec of 4pX with a 614 Fasst Rx ( I assume it automatically links on C2 mode)