5 Digit Com Radios

[Kennair]

After reading Matt's review of the Cockpitsonic Avionics (a beautiful piece of kit and also well reviewed I might say), I noticed that the Com radio has 5 digits instead of 6 (2 decimal places not 3). Although here in Aus we don't use 3 decimal place frequencies other parts of the world do, so how do you overcome the shortcomings when sim flying with this radio of tuning a freq such as "132.125" with only 5 digits?

I know other versions such as Flight Illusion also produce 5 digit however companies such as Opencockpit produce their Com radio in 6 digit format. What exists in the real 737?

Thanks,

Ken.

[dnoize]

I know other versions such as Flight Illusion also produce 5 digit however companies such as Opencockpit produce their Com radio in 6 digit format. What exists in the real 737?



6 digits

CPflight also has 6 digit radios

Stef

[Michael Carter]

Old style analog Collins and Gables all used five digits too. Since the frequency band is based on 25 Khz spacing, you didn't need to worry about whether you were on the right frequency.

Your last digit was always a 5 or 0.

If they haven't already, Europe or at least the UK was supposed to implement a 8.33 Khz frequency spacing above FL245. I haven't heard much lately about this and don't know if it's in widespread use, if at all.

This would make most current US tranceivers obsolete.

[stabell]

yes, up until not many years ago, 25kHz-spacing made it unessecary for the sixth digit. The frequency "126.05" was with a leading "0" at the end. (050).
Or 127.75.
But now it is "126.055", (but I can't figure how this can be a 8.33 KHz spacing,
it sounds more like a 5KHz spacing to me.)
So when Fs11 or FS12 evolves, many cockpit builders have to add another digit to their radios.

[Michael Carter]

It's not just another digit that has to be added, the frequency step must also be changed.

[PascalHaldenstein]

Guys
don't know if this helps but here in switzerland or in general europe I often listen to the radar and there some frequencies have a sixth decimal. for example:Zurich tower: "american 55, contact departure on 135.675"

I think here in europe the sixth decimal is pretty often used. but I don't know about us territories.
....just an idea

[Michael Carter]

The whole frequency will always be stated, even if it's not visible on the radio head. .675 is still using a 25khZ spacing.

[skywatch]

8.33 Khz spacing is used extensively in the UK and French upper airspace regions. In fact the UK is currently making more use of it as more and more a/c are equipped with it as standard. It is necessary for commercial a/c to have this in these areas.

The 'channel' (as they are called) digits are rounded and so do not appear as 8.33 steps, but that is what they are.

hope this helps a little...

Skywatch