Item Details:
Telewave TWNC-8604 Notch Cavity Filters
The Telewave TWNC-8604-1 is a 4-inch diameter, quarter-wave notch cavity with an adjustable coupling loop, designed to reject a specific frequency when used with pass or pass/reject cavities. It provides very low loss outside the notch band and can have its notch response tilted to position the notch close to a pass frequency without affecting performance.
The cavity covers 800 to 960 MHz and is factory-tuned to the specified frequency, requiring no further adjustments, though a positive locking mechanism allows quick field retuning if needed. The adjustable coupling is calibrated for easy optimization of selectivity in any operating environment. At sites with high interference, a dual-cavity configuration increases selectivity while keeping insertion loss minimal, and multiple cavities can create a wider notch when necessary. Mounting rails are included for all multi-cavity filters.
Frequency stability is maintained across -30°C to +70°C using a machined compensator and Invar rod. Telewave Ground Loop technology grounds the center conductor of each coupling loop at DC potential for lightning protection and noise reduction.
The cavity is built with heavy-duty materials, including quarter-inch aluminum top plates heliarc-welded to the body at the high current point, silver-plated tuners, beryllium copper finger stock, and alodined aluminum to prevent corrosion and ensure reliable long-term performance. It handles up to 350 watts continuously.
Specifications:
| Tuning range: |
800-960 MHz |
| Nominal impedance: |
50 ohms |
| VSWR at resonance (max): |
1.5:1 |
| 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 6 inch (10.2 x 15.2 cm) |
| Connectors: |
N female |
| Finish: |
Gray acrylic enamel |