HF Antenna Multicouplers 2-32 MHz frequency range 20 kW average, 40 kW peak power rating Natural air convection cooling 50 ohm coaxial input impedance 1.2:1 maximum insertion VSWR 3.0:1 allowable load VSWR 97% efficiency 30 dB port-to-port isolation (with matched load) -40°C to +50°C ambient temperature General Description The transmitting multicoupler connects two HF transmitters to a single broadband antenna, allowing each transmitter to operate simultaneously without significant insertion loss. Each transmitter operates as though the other were not in circuit-one performing in the lower portion of the antenna’s frequency range and the other in the upper portion. A narrow “guard channel” of unusable frequencies separates the two channels. A multicoupler consists of two bandpass filters and an output crossover network. Each filter is a network of passive, fixed-tuned elements which are permanently adjusted to pass all frequencies within the particular channel and to reject all frequencies allocated to the opposite channel. Consequently, the transmitter frequency can be freely shifted within its respective channel without retuning the multicoupler. Applications The use of transmitting multicouplers in a communication network makes possible the use of full capability of modern broadband antennas. When receiving stations lie a differing distances within the direction pattern of a single antenna, the use of multicoupler permits simultaneous use of a “long-distance” and a “short- distance” frequency, accommodating a second HF communication circuit on the antenna. The Model 520F, intended for shipboard applications, is in all respects electrically identical to the Model 520G. For new installations, consideration should be given to use of the Series 3000 SPIRACONE antenna which permits transmissions simultaneously on highand low-angle modes without frequency restriction. 1 HF Antenna Multicouplers Characteristics Multicouplers may be cascaded to permit the use of more than two transmitters with one broadband Their power ratings may be intermixed to obtain the lowest cost for a system. Type Number 579 520G 557 Power per Channel Average 2.5 kW 10.0 kW 20 kW Crossover Band* Peak 5 kW 20 kW 40 kW 16.5% 16.5% 16.5% Std. Connectors In 7/8” 1-5/8” 1-5/8” Out 7/8” 1-5/8” 3-1/8” * Upper limit of the lower channel must be at least this percentage below the lower limit of the upper channel. Ordering Information Typical Ranges of Lower and Upper Channels* 2.5 kW Type Nos. 579-21 579-54 579-71 579-91 579-113 579-141 579-150 579-187 579-231 579-314 Lower Channel 2.0 to 3.50 MHz 2.0 to 5.15 MHz 2.0 to 6.00 MHz 2.0 to 7.00 MHz 2.0 to 8.10 MHz 2.0 to 9.50 MHz 2.0 to 9.95 MHz 2.0 to 11.80 MHz 2.0 to 14.00 MHz 2.0 to 18.15 MHz Upper Channel 4.20 to 32.0 MHz 6.20 to 32.0 MHz 7.20 to 32.0 MHz 8.40 to 32.0 MHz 9.75 to 32.0 MHz 11.40 to 32.0 MHz 11.95 to 32.0 MHz 14.15 to 32.0 MHz 16.80 to 32.0 MHz 21.75 to 32.0 MHz 10 kW Type Nos. 520G-1 520G-7 520G-10 520G-6 520G-2 520G-9 520G-8 520G-3 520G-11 520G-5 520G-4 520G-15 20 kW Type Nos. 557-1 557-7 557-10 557-6 557-2 557-9 557-8 557-3 557-11 557-5 557-4 557-15 Lower Channel 2.0 to 3.5 MHz 2.0 to 4.75 MHz 2.0 to 5.55 MHz 2.0 to 7.30 MHz 2.0 to 8.15 MHz 2.0 to 9.55 MHz 2.0 to 11.25 MHz 2.0 to 12.5 MHz 2.0 to 12.85 MHz 2.0 to 13.4 MHz 2.0 to 18.35 MHz 2.0 to 14.1 MHz Upper Channel 4.2 to 32.0 MHz 5.7 to 32.0 MHz 6.7 to 32.0 MHz 8.8 to 32.0 MHz 9.8 to 32.0 MHz 11.45 to 32.0 MHz 13.5 to 32.0 MHz 15.5 to 32.0 MHz 15.4 to 32.0 MHz 16.1 to 32.0 MHz 22.0 to 32.0 MHz 16.9 to 32.0 MHz * Other frequencies are available on special order. HF Receiving Multicouplers ASC Signal offers a range of passive multicouplers which simply divide the signal; the resultant 3 dB loss for each split is in no way significant, since the limiting atmospheric noise from the antenna is also reduced. Ordering Information Characteristics Frequency range, MHz Input Impedance Insertion loss (add 3 dB for each 2-way split) Model 356-1 Model 356-2 Model 356-3 Output Isolation Input VSWR Phase/Amplitude Balance 2-32 (usable 1.65-32) 50 ohms unbalanced, input/output 0.5 dB 0.7 dB 0.75 dB 30 dB 1.3:1 maximum 1°, 0.1 dB maximum Bulletin 1533A 05/08 Data subject to change without notice. Number of Outputs 2 4 8 2.0-32 MHz Freq. Range (1.65-32 Usable) Type No. 356-1 50 ohm 356-2 BNC 356-3 Connectors 2 ASC Signal Corporation • 606 Beech Street West • Whitby, Ontario, Canada • L1N 5S2 • t. +1 (905) 668 3348 • f. +1 (905) 668 8590 • www.ascsignal.com