Item Details:
Telewave TWPC-0310-1, TWPC-0410-1 Bandpass Cavities
The Telewave TWPC-0310-1 and TWPC-0410-1 are bandpass cavity filters with a 10" diameter and high "Q" values that provide superior selectivity by rejecting all frequencies outside a narrow pass band. These cavities decrease transmitter sideband noise and protect receivers from desensitization. The TWPC-0310-1 covers 30-40 MHz, while the TWPC-0410-1 covers 40-50 MHz. The cavities have a tuning range of approximately ±2.5 MHz from the center frequency and are tuned to specific frequencies before being shipped. The positive locking mechanism enables quick field re-tuning if frequency changes become necessary.
The cavities are designed with calibrated adjustable coupling that enables insertion loss to be set from 0.5 dB to 2 dB or more, resulting in increased selectivity. This feature allows cavity response to be optimized for any operating environment. The 0310/0410-2 dual and 0310/0410-3 triple cavity filters provide even greater selectivity with minimal insertion loss at densely populated sites. Multiple cavities can also provide a wider passband when required, and mounting rails are provided for all multiple-cavity filters.
The use of a specially machined compensator and Invar rod results in excellent frequency stability, with the pass frequency being temperature stable from -30°C to +70°C. Ground loop technology places the center pin of each coupling loop at DC ground potential.
Each cavity is constructed with heavy-duty materials to ensure high performance and long life. The cavity top plates are machined from ¼-inch aluminum and are heliarc welded to the cavity body at the high current point for improved conductivity and strength. Telewave cavities can handle up to 350 watts, depending on insertion loss.
The tuner assembly is supported by rigid foam inserts that allow 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 and ensure reliable, long-term performance.
Specification:
Nominal impedance |
50 ohms |
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 |
-22°F to 158°F -30°C to +70°C |
Cavity electrical length |
1/4 wavelength |
Outer conductor, end plates |
6061-T6 aluminum |
Inner conductor, coupling loops |
Silver plated copper |
Tuning rod |
Invar |
Contactors, fingerstock |
Beryllium copper |
Connectors |
N or UHF female (opt.) |
Finish |
Gray acrylic enamel |