Frequency Spacing?

[Luke Bruce-Smith]

During my flight into the UK yesterday the controller was using 122.220Mhz to control, yet it way not possible to tune this frequency in flight sim?

 

I eventually found that FSINN would switch to the controllers channel if I tuned 122.225Mhz. However this may be quite confusing for new pilots etc.

 

Is this frequency spacing normal practice in the UK VATSIM region?

[Ernesto Alvarez 818262]

if i remember right, theres an option in FS to fix the radios going only to the .005's

[Sean Harrison]

Luke, I have had this irregularly even in the USA. As you said, FSInn seems to tune to it even though the actual radio is off slightly. I used to worry that I wouldn't be able to connect, however it's never failed to connect yet. It seems to be a case of "Close is good enough"

[Anthony Pavlak 1058071]

This is normal and the last digit is implied. Many General Aviation radios don't show three places past the decimal, but still tune these frequencies just fine. On newer radios, the last 5 may be displayed but it's not needed.

[Luke Bruce-Smith]

Should there be consideration for new pilots that may be confused when trying to select appropriate frequency?

 

It may be 'too hard' and the pilot may simply log off.

 

Would it be better to have a variation from real life in this instance and use selectable frequencies?

[Anthony Pavlak 1058071]

Maybe. But in the past when a new pilot has been confused about this, they've PM'd me to ask how to tune my frequency.

 

The frequencies are selectable, you just won't the .005 on the radio display.

 

For example, 126.125 is dialed in as 126.12 on radios that only go two places past the decimal. And in the U.S. anyway, this frequency is spoken as "One Two Six point One Two." The .005 is "silent" if you will, though it appears as "126.125" when printed on aviation charts. When tuning the frequency, it's not possible to tune 126.120 even if you have a radio that goes three places past the decimal. They just don't tune in those increments. As you turn the kilohertz dial the radio freqency will sequence as follows:

 

126.00(0)

126.02(5)

126.05(0)

126.07(5)

126.10(0)

126.12(5)

etc. The number in parentheses is only shown if you have a newer radio showing three digits past the decimal. But the frequency still tunes properly.

 

This confusion isn't limited to the online world either. I've had student pilots tell me they can't tune "126.12" because their radio only tunes "126.10" or "126.15." In many real aircraft, you have to pull the little radio knob "outward" (it's a two position knob) before it will tune in .025 increments. So even in real life, there is sometimes a need to explain this phenomenon to the uninitiated. I believe, though I am not sure, that some VERY VERY old aircraft radios are truly incapable of tuning in those increments period, and in that case they must then be given an alternate frequency. No aircraft in the sim has this issue though.

[Michael Pike]

This is normal practice in the UK - is it not everywhere? I believe it used to be necessary because of a limitation in FS when radios only displayed 2 decimal places and the frequency held internally also had only 2 decimals - it wouldn't tune to 122.225.

 

Is this still the case, or do current pilot clients overcome the problem? Can controllers safely set the final digit correctly now??

[Anthony Pavlak 1058071]

I do it in FSINN and it works just fine without the third digit.

[Johan Grauers]

As I've got it explained it's a problem more with the voice servers rather than the clients. I'm not sure why though, someone with more tech knowledge will have to explain that.

 

I would say though that it's a shame we can't use 8.33 spacing on vatsim. That would really make it a lot more realistic in terms of frequency allocation.

[Dave James 1018738]

This is normal practice in the UK - is it not everywhere? I believe it used to be necessary because of a limitation in FS when radios only displayed 2 decimal places and the frequency held internally also had only 2 decimals - it wouldn't tune to 122.225.

 

Is this still the case, or do current pilot clients overcome the problem? Can controllers safely set the final digit correctly now??

 

This is exactly how I understand it too Mike.

 

Using FS9 since joining Vatsim in 2007, I have never been able to tune a controller frequency that the controller sets with the third digit.

Example 118.625 vs 118.620. I believe FS9 will not recognise the 5.

 

A relevant example being EGKK_APP who is online now with a controller frequency of 126.820 set. The real world frequency is 126.825.

 

The controllers voice room and the server on which it is based (as far as I understand) is only joined "if" the pilot client is tuned correctly and firstly to the controllers set frequency (verbatim), in the Gatwick example, 128.62. Only then will the pilot client join the voice room. That voice room can be labelled "anything" that bares no resemblance to the frequency tuned, in this case "server"/egkk_app. not server/126.820.

 

Its a very interesting thread, but I do remember some years ago when controlling that there was a local UK thread with regards to using the third digit actively with a 5 instead of a 0 and the trouble that it caused for pilots.

 

If you look at it another way, what would happen (hypothetically) if two stations 123.470 and 123.475 were operating in close proximity to eachother, which one is the most likely to be tuned to with FS9, whereby stepping through the range the selectable frequencies are, 123.40, 123.42, 123.45, 123.47, 123.50......?

 

Using FS9, FSnavigator confirms this when a rogue frequency is entered into the comm box,

 

 

Food for thought perhaps ?

 

if i remember right, theres an option in FS to fix the radios going only to the .005's

Ernesto, could you expand a little more about this, would it be related to FSX only ?

[Ernesto Alvarez 818262]

Dave, not sure if its the same thing, i was thinking the 50khz fix applied by FSUIPC. i think that one only fixes the issue with some addons not being able to go from .20 to .25, etc.. tho

 

i remember seing an option in FS for something similar, dont see in FS9, maybe was with prior versions

[Dave James 1018738]

Thanks Ernesto.

 

Going back to Luke's original post, it is apparent that the controller was probably using 122.225 as can be done from my memory when using VRC, and Luke couldnt tune that frequency with FS using the normal nav/com selector buttons as in,

I eventually found that FSINN would switch to the controllers channel if I tuned 122.225Mhz.

It is interesting to note though that when entering the frequency using FSinn into the text bar (.com1 122.225 ) the frequency could be tuned exactly.

 

Would this statement be correct for FS9 users whereby the only prevention of tuning is in the com freq selector function of the stock aircraft and a few add-ons ?

 

Hopefully one of the more techy-type chaps will provide some insight

[Sean Harrison]

 

Would this statement be correct for FS9 users whereby the only prevention of tuning is in the com freq selector function of the stock aircraft and a few add-ons ?

 

Hopefully one of the more techy-type chaps will provide some insight

 

Not a techy-type, but I still use FS9 and FSInn and it tunes for me.

[Dave James 1018738]

Thanks Sean, could you elaborate a tad more ie. what is the controller frequency and what do you select in the FS com 1 window to tune please ?

[Anthony Pavlak 1058071]

For what it's worth, I would tune 122.22 and it works. This is with FSX and FSINN though. I didn't realize that FS9 did not always support this, or that it might be aircraft specific. My radio will just show 122.22 but it will tune and talk on 122.225 automatically.

[Luke Bruce-Smith]

The controller was obviously trying to replicate r/life by mimicing the r/life frequency selection.

 

If FSX and most aircraft add ons do not support anything other than 25k spacing, why use it online?

 

I worked out by cooincidence that you can tune to the next closest frequency and FSINN will allow the connection, but this is not publicised anywhere. You could understand how this arrangement is confusing for new pilots.

 

Why not make an exception from r/world procedure and use 25khz spacing? It's not like we are running out of frequencies on VATSIM

[Anthony Pavlak 1058071]

The controller was obviously trying to replicate r/life by mimicing the r/life frequency selection.

 

If FSX and most aircraft add ons do not support anything other than 25k spacing, why use it online?

 

I worked out by cooincidence that you can tune to the next closest frequency and FSINN will allow the connection, but this is not publicised anywhere. You could understand how this arrangement is confusing for new pilots.

 

Why not make an exception from r/world procedure and use 25khz spacing? It's not like we are running out of frequencies on VATSIM

 

In your example the controller was using 122.220 is that right? That's not a frequency any real radio would tune, and I don't think it should be used on the network. It should have been 122.225 and you would have tuned it just fine in an older radio by tuning 122.22 (using FSINN).

 

Real pilots (and I've even met some controllers) get messed up by these too, so it's not a big deal. But instead of wanting to change the system when it works ([Mod - Happy Thoughts]uming it does work for other people and not just me) why not learn how it is supposed to be done?

[Harry Williams 1141715]

To be quite honest, I almost always the give .005. Most pilots understand it, if you don't then ask..?

 

Equally, if the frequency doesn't work with one possibility you try the other. Simple as.

[Dave James 1018738]

From my own experience in the UK on Vatsim, controllers "voice" the frequency fully ie 118.625, 118.575 as per rw r/t. However, from my experience again looking at the controllers list in FSinn, it is extremely rare to see the frequencies as they are voiced, they are 118.620, 118.570 respectively. The frequencies expressed over r/t are purely realism related and fall in line with rw r/t phraseology.

 

An example of how using the .xx5 as oppose to the normal .xx0 in the controller client can mess up things for some - at Newcastle a few nights ago, the controller had set the .725. With only myself and another departing aircraft on the ground, using FS9 and FSinn, I was able to tune the primary and establish 2-way comms on voice and could see that the other aircraft wasnt getting any response from the controller on text or voice.

 

I received a pm from the other pilot asking if I had 2-way with the controller as he couldnt raise him on voice or text. I could see the text transmissions on the com1 box but nothing from the controller in response.

 

I called the controller and informed him that another aircraft was trying to call, but he stated that he had seen no text transmission or heard voice.

 

After PM'ing the chap controlling politely asking him to try an experiment as to which he agreed, he changed his primary to .720. The other pilot established 2-way on both text and voice and all was well.

 

This is the reason for this: Distinct lack of .xx5 for Gatwick.

 

 

......In your example the controller was using 122.220 is that right? That's not a frequency any real radio would tune, and I don't think it should be used on the network. It should have been 122.225 and you would have tuned it just fine in an older radio by tuning 122.22 (using FSINN).

Covered above Anthony

 

 

Interesting stuff.

 

David

[Paul Byrne]

Hi,

 

Was the other pilot using SB? I've had problems contacting .005 freqs before in the UK and I use SB.

 

Using .005 freqs may not be feasible on the network if SB doesn't accept them.

 

Cheers!

[Johan Grauers]

@Luke

 

We are already using 25khz spacing on vatsim. I would personally like to see 8.33 spacing implemented in the future though.

 

 

------

 

In the voice server list no frequencies may end with a 5. This is due to some technical limitation in the software, the details I do not know.

 

On R/T in general the frequencies will be pronounced they way the should be, this means a frequency can end in

.000

.025

.050

.075

 

In the frequencies list they will end in

.000

.020

.050

.075

 

How ever as this is unrealistic the R/T on vatsim is normally mimicing the real world pronouncing all 6 digits unless the last two digits are 0s. I personally do this aswell and rarely have any trouble with it at all.