VHF & UHF Cavity Filters
Hi-Tec Aerials cavity filters are 150 mm coaxial resonator filters that clean up transmitter noise and protect receivers from strong nearby signals at busy VHF and UHF repeater and base station sites. They’re made in New Zealand and tuned to your frequency.
- CAVITY-VBP: VHF band pass, 75–80 and 138–170 MHz
- CAVITY-UBP: UHF band pass, 400–510 MHz
- Insertion loss options: 0.5, 1.0 or 1.5 dB
- Up to 250 W, N jack connectors
- Aluminium cavity with invar rod temperature compensation and contactless tuning
Cleaner signals on crowded sites
On a shared hilltop, strong signals from other transmitters can desensitise your receiver, and your own transmitter's wideband noise can affect others. A band pass cavity filter only passes a narrow slice of spectrum around your channel and rejects everything else, cutting interference in both directions.
Built for stability
Each 150 mm cavity is aluminium, with an invar tuning rod that compensates for temperature to within 5 ppm from −30 to 50 °C. Contactless tuning avoids sliding contacts that wear or become noisy over time, so the filter holds its tune for years.
Choosing a filter
Choose the VHF (CAVITY-VBP) or UHF (CAVITY-UBP) model, then the insertion loss. Lower loss (0.5 dB) handles up to 250 W with a wider passband. Higher loss (1.5 dB) gives a sharper filter for tighter sites, up to 100 W. Specify your frequencies when ordering and we'll supply the filter tuned. Band reject (CAV-VBR, CAV-UBR) and combined band pass/band reject (CAV-VBPBR, CAV-VBRBP, CAV-UBPBR, CAV-UBRBP) models are also available on request.
Complete the site
Use cavity filters with a VHF duplexer, Sinclair isolators, Procom filters and lightning protection. Signals NZ designs, installs and services repeater sites across New Zealand.
Specifications
| Model | CAVITY-VBP | CAVITY-UBP |
|---|---|---|
| Frequency range | 75–80 & 138–170 MHz | 400–510 MHz |
| Passband bandwidth at −14 dB | 50 kHz | 300 kHz |
| Insertion loss | 0.5, 1.0 or 1.5 dB | |
| Impedance | 50 Ω | |
| Return loss / VSWR | < −14 dB / 1.5:1 | |
| Maximum power | 250 W @ 0.5 dB IL / 100 W @ 1.5 dB IL | |
| Connector | N jack | |
| Temperature range | −30 to 50 °C (5 ppm) | |
| Cavity diameter | 150 mm | |
| Weight | 4 kg | 2 kg |
Additional information
| Weight | N/A |
|---|---|
| Brand | Hi-Tec |
| Band | UHF, VHF |
| Model | CAVITY-UBP (UHF 400–510 MHz), CAVITY-VBP (VHF 75–80 & 138–170 MHz) |
| Insertion Loss | 0.5 dB, 1.0 dB, 1.5 dB |
| Connector | N jack |
