[cassat]

Originally Posted by DO335

Spoken from someone who recently sold his 7C, no it is not a module. It is a crystal.

The 9c which I have is with a synthesizer module.

For ye of little faith, here's a pic of the rear of the TX from page 13 of the official manual. Clearly, there is no module.

Thanks for the photo, this would explain why the 2.4 Ghz upgrade modules specify 9C but
nit the 7C models from Futaba.

[moo]

Originally Posted by Skidoo55

I am not sure if Futaba TX Crystals are the same as their RX Crystals

Transmitter xtals usually run on a harmonic of the transmit frequency
Receiver xtals are usually frequency minus 455 kHz or minus 10.7 MHz (single and dual conversion are different xtals)

The change from channel 11 to 60 is a very small percentage of the transmit frequency (1.35%), I've never noticed a loss of range changing xtals but I stay in the upper half of the band typically 39 - 60 (0.58% change).

Yes, I learned to design, build and tune radios back in college.

Yes, changing the transmitter xtal is illegal in the United States, not here.

Yes a 7C is a great radio for Hong Kong 2.4GHz conversion

https://www.rccanada.ca/rccgallery/sh...ry.php?cat=595

[moo]

Originally Posted by shinynewtoy

You can get away with moving perhaps two channels in either direction without compromising too much, but it's never a good idea. I know there will be guys here who tell you they've done it with no problems and that's fine. It's still not a good idea.

Math please. Not guesswork.

(72.990+72.010)/2 = 72.500

(72.500-72.010)/72.500 x 100% = ?

resistors installed on 7C transmitter board are what tolerance?

[d_orgera]

Originally Posted by moo

Math please. Not guesswork.

(72.990+72.010)/2 = 72.500

(72.500-72.010)/72.500 x 100% = ?

resistors installed on 7C transmitter board are what tolerance?

you call that math?....how can you explain away a non-linear function using simple ratios?

[jfckelly]

Anyone have a detailed step by step for the fry sky module install?

[moo]

Originally Posted by jfckelly

Anyone have a detailed step by step for the fry sky module install?

same as HK module, see previous post for link, also on RCGroups

[moo]

Originally Posted by d_orgera

you call that math?....how can you explain away a non-linear function using simple ratios?

So, you cannot estimate a percentage change, and you don't realize the significance of Futaba using 5% tolerance components? Is that what you are suggesting?