R4002,
Excuse my delay but it seems that the web site was updated.
So these are likely South American in origin?
Yes, these service is very used by these argentinean cattle ranches and it was also used by the chilean army for link antartic military bases and the families of the soldiers in the continental chilean territory.
Which other frequencies have you monitored these transmissions on?
Check the follow frequencies commonly used by these services (in Argentina) (IN USB MODE):
BAHIA BLANCA: 2018, 4868, 7489.5, 10125 KHz.
BARILOCHE: 3167, 4478, 6845 KHz.
CATAMARCA: 2396, 4786, 7473 KHz.
COMODORO RIVADAVIA: 2322.5, 3804.7, 4563.5, 9077 KHz.
CORRIENTES: 2531.5, 3757, 3952.5, 5095, 7847, 1O330 KHz.
MENDOZA: 2039, 3841.5, 5851, 7711, 10345 KHz.
GRAL. PACHECO: 3808, 4920.5, 10107, 13567 KHz.
RIO GALLEGOS: 2575, 3893, 4458.5, 7542 KHz.
2237,0 KHz
2039,0 KHz
3841,5 KHz
5851,0 KHz
7711,0 KHz
10345,0 KHz
4028,0 KHz
5352.0 KHz
7480,2 KHz
10193,5 KHz
What's the official title of it in Spanish?
SERVICIO RADIOTELEFONICO TERRESTRE RURAL.
If these are remote Argentine cattle ranches, are they operating a crude telephone patch system?
According what I know this service is also used in Mexico but in Argentina are private companies who administrate this network, as I was telling you before (in the other answer to this post) is possibe to hear the conversation in a unique channel and not in two different as duplex communications do, so I really don't know what is the equipment used by the "telephonic service".
The proced for solicite a link between farms or communicate with a cellphone of the "normal/common" network is calling to the radiotelephonic central on the "call channel", the central answer to your call and then the client solicite the type of service (talk with other farms or talk directly to a common cellphone), then the central OP ask you the cell number that you want to call or the callsign of the farm that you need to link, you wait while the company link you to the other farm/cellphone, after that you are allowed to talk with the other person.
I'm not beeing very exact but in the follow link you'll find a lot of information (in spanish):
http://arieldx.tripod.com/manualdx/variantes/utilitarios/telrural.htmIf you have problems for understand what the google translation says just send me a message with your questions.