- The BPBR 2/4… and the BRBP 2/4… are 4-cavity pass-reject filters, which pass one frequency or frequency band and reject another in immediate vicinity of the pass frequency.
- The filters are delivered in two basic models: The BPBR-types have the reject range on the high side of the pass frequency and the BRBP-types have the reject range situated on the low side of the pass frequency.
- These filter types can be used to protect a receiver against interference from a nearby transmitter. The filters are tuned to reject the interfering signal. Pass-reject-type filters are applied when the spacing between the utility signal and the interfering signal is so small, that the slope steepness of normal band-pass filters or notch filters are not sufficient enough to provide adequate rejection.
- These filters are primarily intended to pass and reject two single frequencies, but the filters can also be tuned to pass and reject several single frequencies or to having a certain pass and reject port bandwidth. In these cases, factory-tuning is recommended.
- Both the BPBR 2/4… and the BRBP 2/4… are delivered in a high-band and a low-band version tunable within 136 - 154 and 152 - 175 MHz, respectively. These models are again divided into submodels, each dedicated to work with a certain spacing between the pass frequency and the reject frequency. See “Ordering information” below.
- The filter has very small physical dimensions owing to the use of high-Q, temperature compensated helicalresonators.
- The housing is made of extruded aluminium, the chassis of passivated steel, and teflon insulation has been applied in the rigid coaxial cables and in the connectors.
- The filter is black vinyl coated to prevent corrosion.
Pass/Reject FiltersBPBR 2/4 / BRBP 2/4
Band-Pass/Band-Reject Filters for the 2m Band
Description
Specifications
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Ordering Designations
| Model | Product No. | Description | Frequency | |
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| BPBR 2/4 L-4/6 | 200001349 | SPACING: 4 - 6 MHz | 136 - 154 MHz | |
| BRBP 2/4 L-4/6 | 200001474 | SPACING: 4 - 6 MHz | 136 - 154 MHz | |
| BPBR 2/4 L-6/8 | 200001350 | SPACING: 6 - 8 MHz | 136 - 154 MHz | |
| BRBP 2/4 L-6/8 | 200001478 | SPACING: 6 - 8 MHz | 136 - 154 MHz | |
| BPBR 2/4 L-8/10 | 200001351 | SPACING: 8 - 10 MHz | 136 - 154 MHz | |
| BRBP 2/4 L-8/10 | 200001479 | SPACING: 8 - 10 MHz | 136 - 154 MHz | |
| BPBR 2/4 H-4/6 | 200001345 | SPACING: 4 - 6 MHz | 152 -175 MHz | |
| BRBP 2/4 H-4/6 | 200001468 | SPACING: 4 - 6 MHz | 152 -175 MHz | |
| BPBR 2/4 H-6/8 | 200001328 | SPACING: 6 - 8 MHz | 152 -175 MHz | |
| BRBP 2/4 H-6/8 | 200001463 | SPACING: 6 - 8 MHz | 152 -175 MHz | |
| BPBR 2/4 H-8/10 | 200001337 | SPACING: 8 - 10 MHz | 152 -175 MHz | |
| BRBP 2/4 H-8/10 | 200001465 | SPACING: 8 - 10 MHz | 152 -175 MHz |
Typical response curves @ 4.5 MHz Duplex Spacing


Ordering Information
If pass and reject frequencies are stated when ordering, the filters are delivered factory-adjusted. Ordering example : BRBP 2/4…, LOW : 149.5 MHz, HIGH : 154.0 MHz. In this case, further information is not required.
When ordering untuned filters please use the model selection table above to select the appropriate ordering designation for the desired filter type.