Item Details:
Telewave TWPC-1008-1, TWPC-1008-2 Bandpass Cavities
The Telewave
TWPC-1008-1 and
TWPC-1008-2 are bandpass cavity filters with a diameter of 8 inches and a quarter wavelength, high "Q" and superior selectivity. These filters are designed to reject all frequencies except for a narrow pass band, which reduces transmitter sideband noise and protects receivers from desensitization. They cover the frequency range of 88-108 MHz and can be tuned to either 50 or 75 ohms upon request.
The cavities are tuned to specified frequencies before shipping, and a positive locking mechanism allows for quick field re-tuning if frequency changes are needed. These cavities feature calibrated adjustable coupling and insertion loss that can be easily set from 0.5 dB to 2 dB or more for increased selectivity, optimizing cavity response to any operating environment. For densely populated sites, the
TWPC-1008-2 dual cavity filter provides even greater selectivity with minimum insertion loss. Multiple cavities can be used for a wider passband when necessary, and mounting rails are provided for all multiple-cavity filters.
To achieve excellent frequency stability, a specially machined compensator and Invar rod are used, making the pass frequency temperature stable from -30°C to +70°C. Telewave Ground Loop technology places the center conductor of each coupling loop at DC ground potential for lightning protection and noise reduction.
Heavy-duty materials are used throughout each cavity to ensure high performance and long life. Cavity top plates are machined from 1/4-inch aluminum and are heliarc welded to the cavity body at the high current point, improving conductivity and strength. This allows Telewave cavities to handle up to 350 watts, depending on insertion loss.
The tuner assembly is supported by rigid foam inserts, allowing for vertical or horizontal mounting. Similar metals and alodined aluminum are used to prevent galvanic corrosion. Silver-plated tuners and beryllium copper finger stock provide non-corrosive, low loss contact, ensuring reliable long-term performance.
Specification:
Tuning frequency range: |
88-108 MHz |
Nominal impedance: |
50 ohms (75 ohm opt.) |
VSWR at resonance (max): |
1.5:1 |
Input power (max) vs. insertion loss: |
0.5 dB - 350 watts, 1 dB - 250 watts, 2 dB - 150 watts |
Temperature range: |
-30°C to +70°C -22°F to +158°F |
Cavity electrical length: |
1/4 wavelength |
Outer conductor, end plates: |
6061-T6 aluminum |
Inner conductor, coupling loops: |
Silver plated copper |
Tuning rod: |
Threaded Invar |
Contactors, fingerstock: |
Beryllium copper |
Cavity dimensions (Diam. x H): |
8 x 36 in. (13 x 91 cm) |
Connectors: |
N or UHF female (opt.) |
Finish: |
Gray acrylic enamel |