Originally Posted by jinxed

I just spoke to an Airtronics rep so let me clear few things up from this post made by several different people.The receiver with the mt4 (rx461) is an ssr receiver.When used with the SSR servos in SSR mode is just as fast as m11x with ssr receiver. It is capable of running the m11x ssr receiver also(rx451r). Difference between 2 is telemetry and the ability of the rx461 to run analog servos. The mt4 is just as fast as m11x when ran with SSR servos and a SSR receiver. M11X does have SSR mode(on radio it is SHR when used with SSR receiver) When they engineered the m11x they had not came up with SSR that is why it is not specifically in the menu. Since mt4 was made after SSR it is in the menu.

I run Airtronics radios I like them.As far as what radio to use it is up to you.Holding a radio in your hands and getting a feel for it is really one of the best ways to decide. My issue with spektrum is an issue that what was posted earlier by ntrain42.Why should I have to add anything( glitchbuster) to a receiver so it does not have an issue with some servos.If it is an issue fix it at the factory. Racers should not have to come up with a fix for their issues.

Originally Posted by BNiels707

Science disagrees with anyone having the ability to tell the difference between .011 sec., .007 sec., and .004 sec. The field of research is called mental chronometry. Studies have repeatedly shown that it takes around 0.190 sec. for young individuals to detect and formulate a response to a visual stimulus.

However, that isn't to say that response time isn't important. Assuming the response time of a radio is directly correlated to how often a FHSS system changes transmit frequency, a 'faster' radio will be less susceptible to narrowband interference than a 'slower' radio.

Lets say 15 frequencies a FHSS system are going to use one after another are compromised by interference (not entirely unlikely in an environment where many radios are in use at once and given the fact frequency choice is pseudorandom, meaning frequencies with interference may be used multiple times in a row).

For the slow radio:
.011 sec./hop * 15 hops = .165 sec.

For the fast radio:
.004 sec./hop * 15 hops = .06 sec.

This means, for the slow radio, it may be .165 sec. (or more, or less, depending on interference) between signals actually being accepted by the receiver. Certainly noticeable by the driver. However, the driver with the faster radio, while still being influenced by the interference, will not notice any difference.

Originally Posted by ntrain42

Key here is IF you use their SSR servos and rx. But are you running SSR servos(this is a generalized Q)?

Using a stabilizing voltage cap(glitch buster) regardless of brand is a smart move. They dont take up much space, but they regulate and stabilize the voltage for the rx system from heavy instantaneous current demands. Regardless of what brand of rx/tx I use, I would use a cap or 2 inline.

Originally Posted by ntrain42

After doing research on this matter, frequency hopping does not necessarily take x amount of time to switch from frequency to frequency. And the examples given by you in the elapsed time domain are definetly off in that regards, especially since we are talking about 2 different forms of frequency hopping, packet size transmitted etc.

I am not a expert in this field by any means, but the reality of the matter is that upgrading to a servo with a faster transit speed will make a much bigger difference than worrying about 2.4gig tx/rx response time. Over the last few weeks Ive played with a number of these 2.4gig sport and competition radios, and in reality they all perform pretty much on equal footing in terms of absolute speed in terms of real world response. I think the most important issue is what you get for features for your dollar spent. For me personally I couldn't see myself paying 125 bucks or more for an Airtronixs M11X or 200 plus dollars more for a Futaba 4PKS over the price I paid for the DX3R Pro. For me, if the prices were reversed I would have easily picked up or opted for the M11X or 4PKS if they ended up being priced better vs. the SPektrum Pro radio.

Originally Posted by BNiels707

I'm not an expert in the field either (not an RF guy by trade), but I have taken multiple classes in the field. Admittedly, the design of the systems we are using are not open, but the assumption that only a single 'packet' is transmitted before a hop (note that not all hops will actually result in a change in transmit frequency) is just as likely as not. Only a single value for each channel will be embedded in each packet and time between packets is directly related to latency. The number of packets lost to noise is just an approximation, but I've seen worse in a lab setting with artificial noise, I can imagine a noisy RF environment being similar. And, even with my approximations, if multiple packets are transmitted before a hop, noise will have an even greater impact, not less, leading to an even bigger impact on perceived latency (say 10 packets are transmitted between a hop, if there is narrowband interference, all of those packets will be lost).

That being said, I am interested in learning, and would love to see what you found that shows my assumptions to be erroneous.