Item Details:
Telewave TWPC-4504 Bandpass Cavity Filters
Telewave TWPC-4504-1, 4504-2, and 4504-3 are 4" diameter, ¼-wave high-Q bandpass cavity filters with excellent selectivity. They pass a narrow 400–512 MHz band, rejecting all else to cut transmitter sideband noise and shield receivers from desensitization.
Factory-tuned; no adjustments needed. Positive locking allows fast field retuning. Adjustable coupling sets insertion loss from 0.5 dB to 4 dB for optimal selectivity. The 4504-2 and 4504-3 offer higher selectivity with low loss in dense sites. Combine cavities for wider passbands; up to four fit on one 19" x 5.25" panel.
Temperature-stable (-30°C to +70°C) via machined compensator and Invar rod. Ground Loop tech grounds loop centers for lightning protection and noise reduction.
Rugged construction: ¼" aluminum top plates heliarc-welded at high-current points; handles up to 350 W (loss-dependent). Alodined aluminum, silver-plated tuners, and beryllium copper contacts prevent corrosion and ensure low-loss, long-term reliability.
Specifications:
| Tuning range: |
400-512 MHz |
| 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: |
¼ wavelength |
| Outer conductor, end plates: |
6061-T6 aluminum |
| Inner conductor, coupling loops: |
Silver plated copper |
| Tuning rod: |
Invar |
| Contactors, fingerstock: |
Beryllium copper |
| Cavity dimensions (Diam. x H): |
4 x 8 inch (10 x 20 cm) |
| Connectors: |
N or UHF female (opt.) |
| Finish: |
Gray acrylic enamel |