Uk 40mhz Channel Frequencies Differ To Asia?

[lohr500]

I've managed to solve the problem, but interested to know if anyone has run into the same issue.

I recently bought a 40Mhz Futaba 4EX FM set from hong Kong seller dragonshophk on ebay.

It came with Channel 81 crystals.

I then ordered a second receiver from Technobot in the UK & to make it work with my existing TX, I ordered a Single conversion Channel 81 TX/RX crystal set.

The receiver wouldn't work when using the original Futaba TX crystal with the Technobots RX crystal.

On closer examination the original Channel 81 crystals that came with the Futaba set were marked 40.810

The UK standard for Channel 81, and the crystal supplied by technobots is 40.815

On swapping both TX & RX crystals for the Technobots set, and getting a second 40.815 RX crystal from Technobots, all is well.

Are the frequency steps different in different parts of the world, for the same nominal channel numbers.

All the UK websites selling Futaba crystals are 40.xx5. But the set came with 40.xx0

As I say, I solved it in the end, but is it common knowledge that I just didn't have

[terry.sc]

Yes, the UK uses different frequencies the the Far East in the 40mhz band. As you have found out every UK frequency ends in 5, every far east frequency ends in 0. The reason for the spacing is to prevent interference from adjacent frequencies, and the UK chose a different frequency to the far east.

Not much of a problem with crystals, you throw away the ones that come with the radio and fit UK ones to get it on to legal frequencies. The problem comes with the newer synthesised radios where the frequencies are adjusted on the transmitter and receiver instead of using crystals. No way of ever making them work on a UK legal frequency as not surprisingly the UK distributors aren't interested in retuning them for you.

[lohr500]

Thanks Terry. As I suspected.

Like you say, chuck away the crystals that came with it and start again!!