IR - interference rejection?

[fishwater]

When you hit the IR button on the flasher, does it change the transducer waveform output? Or does hitting the IR just filter the input to reduce crosstalk interference? My guess is it only filters the input. Maybe it varies by manufacturer, some filter input only, others vary output and tune input reception to match?

I ask because you commonly hear people say when setting up multiple units, you should adjust them one at a time to keep from (re-)interfering with each other (due to changing outputs?)

Just wondering. Personally I think adjusting IR one at a time is total BeS and doesn't improve your chances of getting a clean signal.

[B-man715]

Hitting the ir button simply changes how fast your transducer sends out pings. The unit adjusts to accept the pings and forms them into a mark, but no matter how fast or slow 4 different flashers are sending out pings some will be picked up from neighboring units.

Try aiming your transducer at a hard surface a few feet away (like a wall/ceiling) and listen for a barely audible ticking sound. You can then hit your ir button and hear a definate change in speed with each click. I think my fl-18 has something like 10 different speeds it works with.

[OnAFly]

I always thought it was a fine adjustment of the frequency. This would let the unit expect to see signals at a certain frequency and this would reduce the amount of outside signal produced by other units at a slightly different signal.

This would make sense as far as the whole doing one at a time thing goes.

B-man go it first!

[fishwater]

I did some digging and read about one method that uses pings at a slight off-time from the synchronous ping to get a difference. That difference is then subtracted from the (dirty) signal in hopes it clears. This sounds plausible. I guess it isn't [PoorWordUsage] and I probably should start playing fair..

If that is the case, it seems that when you turn your unit on might possibly influence the interference? Shenanigans..