por Mago31 » 21 Feb 2013, 20:34
Hola yoarturo38:
Perdona compañero es 139.900. Pero lo que te quiero decir con la frecuencia 139.900 y 338.475 es que sevilla militar emite a la vez tanto en estas dos frecuencias como en la de 379.250 cuando habla con los cazas, en cambio el avión solamente lo hace en una de ellas.
Aqui os pongo un ejemplo de radios militares utlizadas por los aviones.
23.2 VHF/UHF AND MIDS COMMUNICATION SYSTEM
The aircraft has two voice communication radios which can be either two ARC-182, two ARC-
210(RT-1556), one of each, or one ARC-210(RT-1556) and F/A-18C/D AFTER AFC 269 one ARC 210
DCS (Digital Communication System). The ARC 210 DCS is only installed as a comm 2 radio. The
VHF/UHF radios, comm 1 and comm 2, provide air-to-air/air-to-ground voice communications, and in
conjunction with Automatic Direction Finding (ADF) equipment, provide a DF function. The radios
can be operated in a plain mode, an anti-jam (Have Quick) mode (ARC 210), a secure mode (KY-58 or
DCS), and a relay mode, in either normal or secure voice. An additional function is generation of a 1,020
hz tone by either comm 1 or comm 2 that serves as an ident tone for weapon release. With AFC 270,
the Multifunctional Information Distribution System (MIDS) is installed. MIDS, a joint service
system, provides secure, jam resistant voice and data communications utilizing spread spectrum,
frequency-hopping, and error detection/correction techniques. In addition, MIDS provides the
functionality of the AN/ARN-118 TACAN.
The comm 1 and comm 2 radios operate in fixed frequency plain, fixed frequency/secure, Electronic
Counter-Countermeasure (ECCM), or ECCM/secure mode. Comm 1 and comm 2 radios operate in the
frequency bands listed below and, when enabled, integral guard receivers continuously monitor the
emergency guard channels for each frequency band:
ARC-182
Frequency Band(MHz) Modulation GuardChannel(MHz)
30 to 87.975 FM 40.5
*108 to 155.975 AM 121.5
156 to 173.975 FM 156.8
225 to 399.975 AM/FM 243.0 (AM)
*Cannot transmit on 108 thru 117.975 MHz
ARC-210(RT-1556 and DCS)
FrequencyBand(MHz) Modulation Guard
Channel
(MHz)
30 to 87.995 FM
*108 to 135.995 AM 121.5
136 to 155.995 AM/FM
156 to 173.995 FM
225 to 399.975 AM/FM 243.0 (AM)
*Cannot transmit on 108 thru 117.995 MHz
Transmission and reception of amplitude and frequency modulated signals (AM and FM) occur in
the respective frequency bands on spaced channels of 100 kHz (aircraft 161353 THRU 161705), 25 kHz
(aircraft 161706 AND UP with ARC-182) or 5 kHz (ARC-210). Twenty channels in the 30 to 400 MHz
band may be pre-set to assigned frequencies as a convenience in the rapid selection of operating
frequencies.
When the Guard receiver (GRCV) is enabled, comm 1 or comm 2 is able to continuously monitor the
243.0 MHz AM Guard frequency while the radio is operating in the UHF band. When the radio is tuned
in the VHF band, 121.5 MHz is monitored.
The ECCM modes are Have Quick (HQ) I, II, and Single Channel Ground/Airborne Radio System
(SINCGARS). HQ I, an anti-jam (AJ) voice communication system, uses a single Word of Day (WOD)
and operates in UHF AM mode using frequency hopping techniques. HQ II is an extension of HQ I
operation that has multiple WODs and the capacity to store six multiple WODs. SINCGARS is also a
jam-resistant voice communication system that operates in VHF FM mode.
Secure voice operation is accomplished using the KY-58 system or DCS. With the ARC-210
(RT-1556) during secure operation, the radio provides a Baseband/Diphase (BB/DP) control signal to
the KY-58 to switch from BB to DP or vice versa. Diphase is the encrypted audio for the VHF/UHF
FM mode. With the ARC 210 DCS a secure voice capability is integral and does not require a KY-58
speech encoder.
Comm 1 and comm 2 may be operated in a relay mode, in either normal (plain), secure (cipher), or
ECCM operation. In this mode, the voice signal received by one communication set is retransmitted by
the other communication set on a different, pre-assigned frequency, provided the two frequencies are
spaced a minimum of 10 MHz apart. Cipher relay in Diphase mode is performed if and only if the
Diphase option has been enabled for comm 1 or comm 2.
Un saludo.