"San Francisco Radio San Francisco radio this is CH?? On 5.574 calling for a radio check from Minnesota." On HF? Really?

[northwoods]

About 02:49 utc heard "San Francisco radio San Francisco radio this is CH?? with a radio check from Minneapolis over." No reply. On 5.574 usb. Male white OP clear sounding voice. Well spoken in flight comms. Makes no sence as to who this was and why the heck on 5.574 out of Minnesota calling San Fran Collings Pacific aero Radio. At the time the unknown out of Minnesota was almost sounding airbourne? Background airbourne sounds. S- 01 noise. At the time San Fran Colllings Aero was S-3 with no noise. No mill aircraft above midwest at the time per ADS-B Exchange.

 

[motorcoachdoug]

Unless the Mill aircraft have their transponder turned off for some reason???

 

[ind224]

Here in Indiana I hear AC on San Fran ARINC 129.450 asking to do HF SELCAL checks often and they get directed to 11.342.
My guess is HF coverage area; I can hear NY radio evenings on 5520 5550 and 5598 but the airplane side is quite weak compared to the ground station w 100 miles more of distance.
ADSB Exchange requires info gleaned from a feed provider(s) so if they have coverage lapse be it RF(the actual ADSB) or internet probably no fix (plotting) for a period.

 

[northwoods]

Here in Indiana I hear AC on San Fran ARINC 129.450 asking to do HF SELCAL checks often and they get directed to 11.342.
My guess is HF coverage area; I can hear NY radio evenings on 5520 5550 and 5598 but the airplane side is quite weak compared to the ground station w 100 miles more of distance.
ADSB Exchange requires info gleaned from a feed provider(s) so if they have coverage lapse be it RF(the actual ADSB) or internet probably no fix (plotting) for a period.

Thank you very much. Now I understand.

 

[RidingDownUnder]

i noticed that you enjoy aircraft communications. I ve been listening to civil and military aviation ever since I was young.
Here’s a map that breaks up the aviation frequencies with their countries. You can see on the west coast of the US it shows CEP 1/2/3 (Central East Pacifiic) and shows the HF frequencies. And Australia shows SP (South Pacific) and the HF frequencies aircraft’s use when flying in that zone. NAT (North Atlanti) SAT (South Atlantic) SEA (South East Asia) and so on. 5574MHz is CEP 1.Also you see many frequencies to a area.. It all depends on what time of the day it is will use ã frequency which suits night time or daytime. Alot like ham radio.. When ã Countries aircraft radio centre gives ã aircraft a HF frequenc, they always give 2 ã primary and secondary.



Or for a clearer picture

https://swling.com/blog/wp-content/uploads/2015/09/MapasconFrecuenciasAereas.jpg

 

[RidingDownUnder]

Here in Indiana I hear AC on San Fran ARINC 129.450 asking to do HF SELCAL checks often and they get directed to 11.342.
My guess is HF coverage area; I can hear NY radio evenings on 5520 5550 and 5598 but the airplane side is quite weak compared to the ground station w 100 miles more of distance.
ADSB Exchange requires info gleaned from a feed provider(s) so if they have coverage lapse be it RF(the actual ADSB) or internet probably no fix (plotting) for a period.

Yes 5520 and 5550 comes under the CAR (Caribbean) boundaries. With ã foot print that covers New York, Cuba, Colombia and Mexico. Or all Central America. 5598 NAT A (North Atlantic) foot print covers from New York, Puerto Rico, Ireland and lower tip of Greenland.

 

[RidingDownUnder]

About 02:49 utc heard "San Francisco radio San Francisco radio this is CH?? with a radio check from Minneapolis over." No reply. On 5.574 usb. Male white OP clear sounding voice. Well spoken in flight comms. Makes no sence as to who this was and why the heck on 5.574 out of Minnesota calling San Fran Collings Pacific aero Radio. At the time the unknown out of Minnesota was almost sounding airbourne? Background airbourne sounds. S- 01 noise. At the time San Fran Colllings Aero was S-3 with no noise. No mill aircraft above midwest at the time per ADS-B Exch

DELETE.

 

[RidingDownUnder]

About 02:49 utc heard "San Francisco radio San Francisco radio this is CH?? with a radio check from Minneapolis over." No reply. On 5.574 usb. Male white OP clear sounding voice. Well spoken in flight comms. Makes no sence as to who this was and why the heck on 5.574 out of Minnesota calling San Fran Collings Pacific aero Radio. At the time the unknown out of Minnesota was almost sounding airbourne? Background airbourne sounds. S- 01 noise. At the time San Fran Colllings Aero was S-3 with no noise. No mill aircraft above midwest at the time per ADS-B Exchange.

It’s most likely Minneapolis Cetre calling SF for a radio check. I hear Brisbane Australia Centre calling SFO centre all the time.

 

[TerryPavlick]

It’s most likely Minneapolis Cetre calling SF for a radio check. I hear Brisbane Australia Centre calling SFO centre all the time.

Could also be aircraft maintenance doing HF system work on an aircraft and needing a radio check to confirm it works.
Military aircraft do that routinely on 11.175 most likely for the same reason.

When we were converting our aircraft to move to Europe (they were sold to another operator) - we installed HF systems in them. On lunch break - I used to go in the cockpit and tune around listening on the radio to see what I could hear.

 

[reconrider8]

Could also be aircraft maintenance doing HF system work on an aircraft and needing a radio check to confirm it works.
Military aircraft do that routinely on 11.175 most likely for the same reason.

When we were converting our aircraft to move to Europe (they were sold to another operator) - we installed HF systems in them. On lunch break - I used to go in the cockpit and tune around listening on the radio to see what I could hear.

thats a very valid point. i remember 3 or 4 years ago i would say before i had my own hf setup up and running, i was monitoring on a websdr and all of a sudden out of the static you hear one of the B-2 maintenace guys come across wanting a radio check and ive never heard so many stations try to check in with him at once

 

[RidingDownUnder]

Could also be aircraft maintenance doing HF system work on an aircraft and needing a radio check to confirm it works.
Military aircraft do that routinely on 11.175 most likely for the same reason.

When we were converting our aircraft to move to Europe (they were sold to another operator) - we installed HF systems in them. On lunch break - I used to go in the cockpit and tune around listening on the radio to see what I could hear.

A lot of ham ops and myself can tell you of hearing commercial pilots with a ham license using their aircraft’s comm’s system to work the ham band. I heard a United airlines pilot call CQ on I think it was 20meters and he made many copies. I unfortunately didn’t.

 

[northwoods]

It’s most likely Minneapolis Cetre calling SF for a radio check. I hear Brisbane Australia Centre calling SFO centre all the time.

I do not belive ill ever here Brisbane but you never know.

 

[northwoods]

It’s most likely Minneapolis Cetre calling SF for a radio check. I hear Brisbane Australia Centre calling SFO centre all the time.

Very cool. Thank you for the post. Now I understand.

 

[northwoods]

Thanks to all of you.

 

[northwoods]

It’s most likely Minneapolis Cetre calling SF for a radio check. I hear Brisbane Australia Centre calling SFO centre all the time.

Cool.

 

[AirScan]

I highly doubt it was Minneapolis Center on HF. I’d be very surprised to learn they have any operational HF equipment at the Center there. My guess would maintenance doing a radio check on an aircraft.

 

[northwoods]

Yes me to. There was no reply. Just a radio check checking the HF radio. Cool hit for sure.

 

[majoco]

When our domestic fleet had HF fitted to talk to company bases, we had to carry out an HF radio check when the aircraft was in for a weekly maintenance check. None of the company offices were manned late at night so I would often call Auckland on 8867 or 5643kHz but he was probably in the skip zone so didn't hear me. On a second call I would often get a reply from SFO on Hawaii and he/she would give me a selcal check without asking. One time I got a reply from a US ship - I asked him for his position and he said he was "bobbin' around in the wide blue nowhere".