Unable ATC frequencies with 25 KHZ seperation...

[el over dee]

I'll be ferrying an older A/C across the US and South America whose radios are unable to tune frequencies to three decimal places (eg PAL 126.875).
Looking over the charts for the route it appears that I'll often come across such frequencies (Depature/Appr./Cntr. etc).
As ATC guys do you see this as a major problem? or are there ways around this effectively NORDO situation?
What would be the proper flight plan phraseology to advise of this particular set-up?

[Scott Voigt]

Hi El;

If you are flying VFR, then the only problem that you may have is going to airports that have frequencies that you can't handle. If so, a phone call to that facility in advance to arrange a non radio arrival can be done ( not a busy facility please. ). If you are IFR, that could be a different subject. If so, there are some work arounds in some areas, but they are all area specific. In many areas, if you can't dial in the radio, you then can expect to go around that sector... It is hard to provide IFR separation services if you can't talk to someone. However, most areas can still take care of the old radios in the lower sector areas. Approach controls again my be a problem at the busy places.

regards

Scott

[2Donkeys]

This is a complete non-issue.

Most GA radios select frequencies to only two decimal digits. This is because, with the radios being 25 kHz spaced, the last digit is always implied.

Think about it.

118.00 = 118.000
118.02 = 118.025
118.05 = 118.050
118.07= 118.075
118.10= 118.100

etc etc

You only need two decimal digits to tune all of the 25 KHz frequencies.

A more pressing issue is whether the radio is 720 channel or 760 channel.

This refers to its ability or not to tune frequencies above and including 136.000 MHz. If you don't have 760 channel radios, then you will encounter some problems.

8.33 is something of a red-herring. It's use outside Europe is extremely restricted, and even in Europe it is only consistently an issue above FL190 or higher.


2D

[Aussie Andy]

Well said 2Donkeys, I was thinking the same...

However, I found the earlier posts on the 8.33kHz subject of interest as I hadn't yet heard how these channels will be communicated - and now I know!

Someone wanted the Eurocontrol 8.33kHz link? I just found it so here it is: http://www.eurocontrol.int/vhf833/

Andy

[el over dee]

Thanks Gentlemen for your responses.

Topupper infact I didn't properly identify the equipment in my first thread; The radios on board are even older than 'old 25kHz spacing' ones. (I'd gladly settle for ones with 25kHz spacing). They are infact only capable of 50 kHz spacing... uugggh.

And Scott thanks for the info, it looks like I'll be doing alot of calling ahead and zigzaging around problem sectors on my IFR route (CYYZ-KAKR-KMSY).
Cheers.

[2Donkeys]

I guess somebody ought to mention FAR 91.205 relating to the requirement to carry appropriate communications equipment on an IFR flight...

Its very questionable that your kit in appropriate with your intended flight regardless of any routing you may contrive. The need to be able to divert and/or the risk of being handed over to an unexpected or inconvenient Center Frequency will always be there.

Get a modern hand-held, some batteries and a headset adaptor - at the very least.

[el over dee]

Sound advice , thanks 2D.

[Scott Voigt]

2Donkeys;

Actually, you can fly in many areas in this country and still get buy on the old coffee grinder radios. We have a few folks who still have them and get by with them. A lot of the "new" frequencies are used in the high altitude areas as well as the many high density approach control frequencies...

regards

Scott

[411A]

Actually, some (most) of the older tube type GA comm radios (with 50kc spacing) have been illegal to use in US airspace since 1997, due to cross-channel interference during transmission.

FCC directive...$2500 fine, if caught.

Good luck...:sad:

[FWA NATCA]

el,

I would strongly recommend a good hand held radio, or rigging a temporary radio so that you don't run into any problems.

Nothing like flying around in bad weather with a bad radio.

Mike
NATCA FWA

[2Donkeys]

Scott

Is it really true that you can traverse large parts of the US IFR with just 118.0, 118.5 119.0, 119.5, 120.0 etc

Are you sure?

2D

[Timothy]

Handhelds have traditionally a very short range, particularly in transmit. This might be a little improved by an external aerial, but the power is still much less than in a rack mount.

I imagine that this short range could be quite a problem in the remoter parts of the two continents.

Would it not be possible borrow a rack mount 760 for the trip, and rig it up temporarily, with a ferry waiver from the authorities?

I have a couple of such boxes here in London, (one 760, the other 720) if that is of any help. I may have sold the 760, but that leaves the 720.

W

[bookworm]

Is it really true that you can traverse large parts of the US IFR with just 118.0, 118.5 119.0, 119.5, 120.0 etc

I think you've slipped a decimal place, 2D. el over dee said 50 kHz, not 500 kHz. As far as I can tell they're ordinary 360-channel VHF COMs.

[2Donkeys]

Bookworm - you are absolutely right. Must be the early morning :D

The question still stands though, even with the additional decimal shift.

2D

[411A]

The short answer is yes, in many circumstances.
However, transmitter frequency tolerance with older units may not permit same.

[Keef]

Without knowing what the 360-channel radio is, surely there's a low-cost 720 or 760 plug-in option?

I'd be highly unwilling to fly any distance with only a 360. I could see prosecution looming...

[Scott Voigt]

2 Donkeys;

I think that it has already been said, but his radio is capable of a lot more than what you have down. And the answer is still yes <G>.

regards

Scott

[FWA NATCA]

2Donkeys,

At my facility we use: 124.75 Clearance
121.9 Ground
119.1 Local/Tower
127.2 West Approach
132.15 Each Approach
135.325 Backup Freq
126.6 Remote Satelite
134.05 Remote Satelite
Plus 6 UHF frequncies and 121.5 & 243.0

Then the facilities around me use: (and yes I have to remember them all)

119.85
125.37
135.9
127.55
132.05
121.05
134.35
134.45
127.45
127.55
119.55
128.07
120.65
124.52
123.9

Mike
NATCA FWA

[lunkenheimer]

WCollins-
Actually, many of the newer handhelds have 5 watts output, same as a rack mount. Antenna issues are still a factor, though, as you point out.

An example is the ICOM A5...