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CZYZ Toronto Center (Barrie) also has unlisted Timmins frequency


The Toronto Center (Barrie) feed lists only the "Toronto Center (Barrie Sector, East High), 134.575" frequency.
However, listening today, I discovered that it also has 121.225.  This frequency is listed in the (Currently Down) Toronto Center (Timmins) feed as "Toronto Center (North Bay High Sector), 121.225"

Proof of this can be found by listening to the Toronto Center (Barrie) Archive on 2021-08-03 from 0530Z to 0600Z.  Starting just before 31 minutes (i.e. at the very end), the controller can be heard switching EVA 031 over to his "other frequency".  (Note that EVA 031 incorrectly reads it back as 131.225 the second time).  It's clear that the frequency was actually switched, as the audio quality of EVA 031 is significantly better when he reads back the frequency the second time.

Can the listing for the "Toronto Center (Barrie)" feed be updated to include "Toronto Center (North Bay High Sector), 121.225"?
Also, is there any way for someone to check/ask how many other frequencies are included in the "Toronto Center (Barrie)" feed that are currently unlisted?  "Toronto Center (Timmins)" has a fair number of frequencies on it, and it's unfortunate that it's down as many of those frequencies would be nice to have access to.  (Maybe we have access to them through "Barrie" but we just don't know it as it isn't listed.)


--- Quote ---However, listening today, I discovered that it also has 121.225.
--- End quote ---

It varies depending on how they have the sectors configured. In off peak times 134.575, 124.675 and 121.225 are combined with the option to have the frequencies cross-coupled as required. With pre-covid traffic volumes the 3 sectors were usually split during the daytime shift, so you are not going to hear that all the time. I suppose for accuracy they could label the feed "134.575 cross-coupled with 121.225 and 124.675 as required".

Ah I see.  I wasn't familiar with cross-coupling until now.  I guess the frequency listing is honest then.

(I'm now somewhat curious on how this is actually done.  It's clear from the change in audio quality that the 121.225 receiver is geographically far from the cross-coupled 134.575 transmitter.  What's the physical layer of the cross coupling?  The internet?  A dedicated line?  Anyways, I digress.)

I'm sure that this sort of cross-coupling labelling difficulty happens all over the site.  I'm a small fish here and don't want to rock the boat.  I don't think any labelling change is needed, unless there's some unifying effort to list this sort of stuff all across the site in a consistent way.

I'll just keep this with my other "ATC quirks" notes.  Thanks for the info!

I did communicate with an ATC operator at Toronto Centre, about this same question.  The workload for these sectors, does vary.  North Bay - High level is "Killaloe" 121.225 MHz, where the transmitter is located.  The "Picton" transmitter is located in Coe Hill Ontario, on 124.675 MHz.  And the southern sector of this so-called "trio" is the Barrie sector, above Peterborough, Ontario.  That transmitter, for 134.575 MHz is at Pearson Airport (if I am not mistaken). Sometimes, all 3 sectors are "stand-alone", sometimes Killaloe will be stand-alone, and Picton/Barrie will cross-couple, or, Killaloe will cross-couple with Picton and Barrie is stand-alone.  I used to live in North Bay, from 1997 to 2004 and listened to the Killaloe sector.  The Killaloe sector, works with the Quebec sectors, such as the Ottawa Ontario NW region, the northern Laurentians, on 127.875 MHz, including the Sault-Ste-Marie High-Low sectors.  Killaloe also co-ordinates flights, going in to Pearson Airport, Detroit, Chicago and much more.

I have seen the digital Communication box at the Timmins Flight Service.  There is a row of settings for "Receive", "Transmit" as well as, Headset or Hand Mic.  Timmins FSS has 3 positions, Timmins, Moosonee and Muskoka.  The operators have access to all 3 airport profiles, on one screen.  If they are working 2 position in one, for example, Timmins/Muskoka, they set up a "toggle" switch, to go back and fourth between the 2 sites. 

The cross-coupling function, I forgot to ask how it works.  It does take about 5 seconds to set it up.  I did see an online posting for ATC cross-coupling, where a communications menu appears, and allows a "Transmit-receive frequency" to be enabled, onto the same button as another frequency.  For example, if Killaloe wants to cross-couple with Picton, the controller would most likely press "Cross Couple", then select "Tx/Rx 121.225 on the 124.675" button, then press XC enable.  And, repeat this same process for the "TxRx 124.675 onto 121.225. 


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