One rarely discussed aspect of all this is that the equipment required on the ground to transmit 8.33 is expensive, so while the plebes in the sky are forced to upgrade, the old radios will remain effective for quite some time because of the lack of funds at airfields themselves. On Jan 1 2018, little in fact will change except for the fact that our old radios become illegal.
Perhaps ground based radios should also be disabled???
Anyone else seeing delays in delivery of new 8.33 COMs? I’ve been waiting over a month for my 225A.
Peter wrote:
any which is implemented with multiple transmitters which are offset slightly so as to not interfere with each other e.g. London Info 124.60 and other large area FIS
*That*’s how this is done. Interesting. Where can I read up on this?
There is an AIC which describes how this works – unfortunately it’s in the EAD system and the link below is likely to expire.
http://www.ead.eurocontrol.int/eadbasic/pamslight-085E3F942AF1FEEBA5716725F62A17D9/7FE5QZZF3FXUS/EN/AIC/P/072-2008/EG_Circ_2008_P_072_en_2008-08-14.pdf
If the link fails, the document is: AIC 72/2008, Compatibility of airborne VHF receivers with offset carrier systems
Go to http://www.ais.org.uk
Select IAIP from the ribbon menu
Then select Aeronautical Information Circulars from the sidebar menu
Choose Pink (P) – Safety related topics from
Scroll down to 2008 and locate: Compatibility of Airborne VHF RTF Receivers with Off-set Carrier Systems – 72(P144)/08
Unfortunately that Eurocontrol URL appears to have been dead for some years… I know they change the token monthly (presumably a crude attempt to prevent people creating links to the database) but even the PDF itself, while referenced variously on the www, appears to be gone. If anyone can find the PDF, please email it to me and I will insert it here.
@Peter – I will email you the PDF
That’s very weird. If I click on the link in my usual browser, I get the PDF. If I click on the link from another browser, I get a 404 error. Hmm.
As I know the Eurocontrol links to be unreliable, there is a manual option via the secondary route for which I provided instructions.
What is funny about the above map is how the UK is the top country for using offset carriers – for stuff like London Info. These cannot go to 8.33 because their operation needs the “more sloppy” receivers.
Peter wrote:
This popped into my email yesterday. Offset carrier (“climax” – what an unfortunate name ) usage in Europe
Anyone knows what these numbers mean ? Are these the number frequencies using offset carrier, or are these the offsets/number of base stations (thus the number of actual frequencies multiplied by 2, 3, 4…)
So it appears even after the “complete” switch to 8.33, dozens (or even hundreds) of 25khz frequencies willl remain in use. Quite a different story then i heard before, some people told me that very soon after 01/2018 all 25khz will be converted to 8.33 khz, only 121.5 will remain.
sugarcube wrote:
So it appears even after the “complete” switch to 8.33, dozens (or even hundreds) of 25khz frequencies willl remain in use. Quite a different story then i heard before, some people told me that very soon after 01/2018 all 25khz will be converted to 8.33 khz, only 121.5 will remain.Even if you don’t count the offset carrier channels, there are other exceptions. E.g. Sweden will keep twelve 25 kHz channels for club and school purposes for at least 10 years.
Sweden will keep twelve 25 kHz channels for club and school purposes for at least 10 years.
Since there is no detectable difference between using 125.000 on a 25k radio and using 125.005 on an 8.33 radio, why not?
) usage in Europe
