Primarily for general aviation discussion, but other aviation topics are also welcome.
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#1567009
Long before 8.33, before even 25, Messrs Appleton and Heaviside were perplexed by the fact that little wiggles found themselves coming back to earth a considerable distance beyond the horizon. They thought this was silly because as any fule kno, radio waves travel in straight lines. Mr Heaviside concocted a wacky theory that something "up there" must be refracting the little wiggles back to ground and a while later Mr Appleton got a Nobel prize for demonstrating the existence of the Heaviside, or "E ba gum" layer, as it is known in Yorkshire.

Of course, having had the secret of radio revealed in an earlier posting, Forumites will now appreciate that the reason little wiggles get back to earth is because they want to get back inside a nice warm radio. Some of them just drift over the horizon a bit. Probably Brian's fault.
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By kanga
#1567042
I hope all Forumites passing through St John's (I hope I'm not the only one who has, several times :roll: ) take the trouble to pay due pilgrimage to Cabot Tower on Signal Hill, and even give it a respectful nod when flying nearby as many transatlantic aircraft do.

https://en.wikipedia.org/wiki/Cabot_Tower_(St._John%27s)

[There's also quite a lot of aviation history marked in displays at St John's Airport, the former RCAF Torbay, the first RCAF base outside Canada (Newfoundland then being a separate Dominion) in WW2.

https://en.wikipedia.org/wiki/St._John% ... al_Airport

It was the base of 125 Sqn RCAF during WW2, the only unit with depth-charge armed (Canadian-built) Hurricanes. Confusingly, 125 (Newfoundland) Sqn RAF operated only in UK

https://en.wikipedia.org/wiki/No._125_Squadron_RAF

St John's, indeed much of Newfoundland and Labrador, is a great place to visit]
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By Dave W
FLYER Club Member  FLYER Club Member
#1567053
kanga wrote:Confusingly, 125 (Newfoundland) Sqn RAF operated only in UK


Coincidentally*, 125 (Newfoundland) Sqn RAF, specifically Sqn Ldr Eric Barwell DFC & bar and his Navigator Flt Lt David Haigh DFC, shot down a Ju88 which impacted in our village on the night of 23/24 April 1944 sadly with the loss of one crewmember, Uffz. Helmut Trauwald who was a gunner. Whilst in its terminal dive, the Ju88 dropped incendiaries into surrounding fields, including what is now our airstrip.

Here's an MP3 of Barwell describing the Action.


*Well, it's a coincidence if you're reading this thread and you're me.
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By GlynneRees
#1572149
I need to check if my understanding is right here.
Old Sarum was operating 123.200. They are now operating on channel 123.205.
(the NOTAM says 123.205 MHz which I believe to be wrong. It should say Channel 123.205.
That is because 833 channels are not the actually frequency of operation.
If the actual frequencies were used they would have no natural pattern which would make setting on our radios much more difficult.
Instead a channel number is used always ending in a 0 or a 5.
The channel number is close to the frequency but usually not the actual frequency.
It so happens that 833 channel 123.205 actually has a frequency of 123.2.
So in fact the actual frequency that Old Sarum are using should be exactly the same as it always has been.
It's a bit odd though that for the last 20 years we have almost always got a "reading you 5" for our radios.
When I called for radio check I got a 4, with comment that we are a bit distorted.
So what could be actually going on?
By scottish_ppl
#1572263
I'd agree with your understanding.

Your transmitter frequency could be very slightly off, which is only apparent on the narrower receive filter used by the airports new 8.33 kit, maybe? Only likely if it is a very old radio.

Or maybe they just haven't got used to the new kit yet, and are giving everyone poor reports....
#1573526
Sorry I'm a bit late to this - been away.
GlynneRees wrote:I need to check if my understanding is right here...

Broadly correct. There is considerable confusion with 8.33kHz because, as you rightly say, the channel "frequency" is not the same as the actual frequency. Most people, when confronted with, say, 123.205 will think "Ahha! That's a frequency." It certainly looks like a frequency but it is really a channel description that is an approximation of the actual frequency. A massive opportunity to move to the use of proper channel nomenclature, e.g. "change to channel 41" was missed, despite this being a commonplace solution for virtually all other radio users.
...When I called for radio check I got a 4, with comment that we are a bit distorted.
So what could be actually going on?

Difficult to say. It could be that your transmitter is well off frequency but if it's a modern (say last 25 years) radio that is exceedingly unlikely. More likely is the reduction in audio bandwidth that 8.33kHz imposes. This will tend to make 8.33kHz channel audio sound muffled, with fewer higher frequency components. There is a common misconception that 8.33kHz will make radio communications quality better. It most certainly will not: at best people will notice no change, otherwise it can only make the audio sound worse.
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By Robin500
#1573530
The Westmorland Flyer wrote:Difficult to say. It could be that your transmitter is well off frequency but if it's a modern (say last 25 years) radio that is exceedingly unlikely. More likely is the reduction in audio bandwidth that 8.33kHz imposes. This will tend to make 8.33kHz channel audio sound muffled, with fewer higher frequency components. There is a common misconception that 8.33kHz will make radio communications quality better. It most certainly will not: at best people will notice no change, otherwise it can only make the audio sound worse.


A step backwards then!
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By neilmurg
#1573732
From the CAA web site:
From 1 January 2018 all aircraft operating in airspace that requires the carriage of a radio must have 8.33 kHz-compatable(sic) equipment...When your flight needs you to only communicate on 25 kHz frequencies, you will be able to continue to use your 25 kHz radio for a limited time period of 12 months (to 31 December 2018). However, when any ground station or service throughout your flight converts to an 8.33 kHz channel, you must only communicate on an 8.33 kHz capable radio.
On the plus side, you can use the EU rebate and Avionics shop visit to include the installation of a PAw in/behind the panel and have the option of EC and detection!
By Bob Upanddown
#1573758
GlynneRees wrote:
Old Sarum was operating 123.200. They are now operating on channel 123.205.

So in fact the actual frequency that Old Sarum are using should be exactly the same as it always has been.
It's a bit odd though that for the last 20 years we have almost always got a "reading you 5" for our radios.
When I called for radio check I got a 4, with comment that we are a bit distorted.
So what could be actually going on?



So what has driven Old Sarum to change? Are new airfields or ATC stations lining up to take the frequencies (sorry, channels) released by this change?

The only driving forces are regulations that no-one wanted and Government greed (Ofcom) as it can earn more from the same radio spectrum (watch future licence costs rise.....)

Totally pointless.
By Vtr1000
#1573801
As far as I am aware a 8.33 frequency costs much less per year than a .25 frequency as it occupies less bandwidth, hence why airfield etc may change for what appears no reason?
By chevvron
#1573834
Vtr1000 wrote:As far as I am aware a 8.33 frequency costs much less per year than a .25 frequency as it occupies less bandwidth, hence why airfield etc may change for what appears no reason?

Splitting hairs I know but you should refer to them as '8.33 compliant' frequencies because the notified frequency which you actually set won't change, just the bandwidth occupied by it's use.
#1573850
chevvron wrote:Splitting hairs I know but you should refer to them as '8.33 compliant' frequencies because the notified frequency which you actually set won't change, just the bandwidth occupied by it's use.

Splitting those hairs a little further, the occupied bandwidth is the same for 8.33kHz as for 25kHz but the channel spacing and, therefore, the guard space between the channels is (much) less for 8.33kHz.
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By Luscombe Flyer
#1573950
I think you need to take a look on the CAA website at charges for ground station fees.
Massive discount for the first year second year massive increase, Old Sarum would be paying around 1,200 pounds fee on 25 kHz change to 8.33 it could be 600.00 or lower, then the sting the following year 3,300
Its another nail in the box of General Aviation, why ?? who knows where the bright idea came from to change to 8.33 kHz but by heck General Aviation is paying a massive price for it, to gain what ??


Licence class Ground Stations

2015/2016 8.33 kHz 600.00 2017 onwards 3,300
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