This is the reception conversion part for the basic function of the relay station at ISDB-T Digital Terrestrial Broadcasting system. It receives one specified channel, removes unwanted signal, –amplifies with AGC, adjusts output level and converts into the IF signal.
The SAW filter is mounted on the IF part by one section for the re-elimination of upper and lower adjacent waves.
Because one main body of 50mm in height can mount two units, one is for the operation line, and another is for the standby line, the mounting space can be saved.
Main body (TX20SR/RX20SR) mounting type
External size: 214.6(W)×49(H)×405(D)mm (Excluding protrusions.)
Mass: 3.0kg or less
| Input | Frequency | Specified channel of UHF band |
| Level | -47dBm±20dB | |
| Impedance | 50Ω/TNC type (Unbalanced) | |
| Output | Frequency | 37.15MHz (Center frequency) |
| Level | -10dBm | |
| Impedance | 50Ω/BNC type (Unbalanced) | |
| Standard reference signal input (Applies to RC20U1.) |
Frequency | 10MHz |
| Level | -10dBm | |
| Impedance | 50Ω/PO51 type (Unbalanced) | |
| Power supply voltage | DC＋48V±15% or less | |
| Power consumption | 20W or less | |
| Use conditions | Continuous use | |
| Environmental requirements | Temperature | -10°C to 45°C (Range for in-spec) -20°C to 60°C (Range for spec restorable) |
| Humidity | 45% to 90%RH (Without dew.) | |
| Local oscillation frequency deviation | ±0.4Hz or less (When locked to external standard signal) |
| Frequency characteristic | 1.0dBp-p or less at fc±2.79MHz |
| Group delay characteristic | 100nsp-p or less at fc±2.79MHz |
| AGC response range | -10dBm±3dB or less IF output fluctuation to change of UHF input -80dBm to -27dBm |
| Standard reference signal pull-in range | Rated value ±10dB or less |
| Input squelch function | Able to set within the range of UHF input -80dBm to -67dBm |
| Noise figure | 2.5dB or less (when full gain of AGC) |
| IM | -55dB or less |
| Spurious characteristic | -63dBc or less (without IM) against the average output. |
| Phase noise | Equivalence C/N＝50dB or more (10Hz to 1MHz) |
| Input return loss | 20dB or more (at input frequency ±3MHz) |
| Output return loss | 20dB or more (at 37.15MHz±3MHz) |
| Monitor output level | -20dB±1dB or less against the output level. |
| Local oscillation monitor level | -10dBm±2dB or less |
| Device delay time | 8µ sec or less |
Alarm monitoring item:
Power failure/ Abnormal output level /PLL unlock / Squelch / Abnormal standard reference signal/SW alert /AGC voltage
Alarm interface (At mounting on TX20SR):
Non-voltage contact output, Contact rating DC24V, 0.1A or less (ALARM), DC voltage (AGC), D-sub 15S M2.6 type
This is the reception conversion part that coverts inputted UHF signal to IF signal (37.15MHz) in the relay station of ISDB-T Digital Terrestrial Broadcasting system.
Because of mounting two units in the main body (TX20SR), it is possible to correspond to the relay broadcasting system of dual line (operation and standby) system.
This structure adopts the rack mounting type of JIS 1H and a half size unit construction, therefore, It contributes to the miniaturization, and It has the flexibility of the right and left division of the first system and the second system when the rack is mounted.
It provides with the monitoring and the control operation in accordance with "Transmission equipment commonness specifications for the Digital Terrestrial Broadcasting" (Orange Book), and it is possible to connect it with the basis part switch control device, the PA switch control device, or etc. Moreover, it has the function to output the AGC voltage for the monitoring of the reception level.
This corresponds to UHF all channels, and can do the channel change easily by exchanging the crystal oscillator units.
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