dirtmagnet

is there a difference in low band and hi band frequncies as far as equipment goes? in other words can i put a channel 18 crystal in the same receiver and transmitter as you i can a channel 50?

Rodney

In most cases, yes. The only place I know of that recommends either High or Low is some of the older Futaba systems. They would optimize the receiver sensitivity 1/4 of the way through the bandwidth and call it low band or optimize the receiver at 3/4 of the way through the bandwidth and call it high band. Most manufacturers optimize at the center of the bandwidth allowing changing of any of the frequencies even though those frequencies at either end of the spectrum would be a little less sensitive than they could be. Futaba gained a very slight advantage in range by doing this dual tuning setup. Of course if you now put a high band crystal in a low band receiver, you lose more range than normal and lose some selectivity (poorer noise rejection).

scale only 4 me

My Feedback: (158)

Depends on the Rx,, what make/model # is it?
Some Futaba RXs are tuned for high/low, some are wide range, so for those hi/low it's not recomended,, most other brands it's fine

jetmech05

In the US it is illegal to change transmitter chrystals without retuning the transmitter. It real life I doubt there are chrystal police. It can cause you to loose range and interfer with channels near yours

JohnBuckner

My Feedback: (1)

Yes it is illegal to change transmitter frequencys in the US but it is not illegal to change receiver frequencys. For receivers you may change frequencys within the band as you wish.

As noted by Scale and Rodney Futaba was the only one that center tuned to either the upper half or the lower half of the band on certain of their older model receivers. None of the other four majors at the time did this instead tunning to the center of the band making it practical to plug and play any of the frequencys within that band. Lets see the center of the band is channel 35 I think and that is the divisor between the hi and lo band on those certain Futaba receivers.

If one changed a Futaba receiver that is a hi/lo version from the top frequency in the hi end of the band to the lowest frequency in the low end of the band then its possible that you may experience reduced perfrormance (bad things).

John

Gray Beard

My Feedback: (-1)

I asked the same question to Tony Stilman of Radio South one day and he started laughing. He informed me that the high and low bands that Futaba was doing was just a marketing ploy and the RXs were exactly the same, nothing different from one to the other. I have been changing the crystals for years and there is no problem at all. The only difference was that little red dot they used to paint inside the slot for the crystal. Seems the ploy backfired on Futaba and people were buying Hitec instead. Hitec also sells a module you can use that you can change to any channel you like. I still have a couple of them, we called them dial a crash. They will work in either Futaba or Hitec radios. They work great but you can forget to switch them over once in a while and the results can be very ugly. Without going out to the shop and looking, I think they are called the Spektrum module.