Description
PolyPhaser IS-B50LN Coaxial RF Surge Protectors
The PolyPhaser IS-B50LN-C2 and IS-B50LN-C2-ME are bulkhead-mount coaxial RF surge protectors for fixed radio installations. The corresponding Motorola part numbers are DSISB50LNC2 and DQISB50LNC2ME. Choose the connector configuration that matches your antenna feedline and equipment connections.
PolyPhaser is the manufacturer. The Motorola references identify the corresponding ordering options, not a different manufacturer. These protectors are intended to be part of a properly designed grounding and surge-protection system; they do not guarantee protection against every lightning event.
Key Features
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Two Type-N configurations: N-female to N-female or N-female to N-male.
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Broadband RF application: Listed operating range of 10 MHz–1 GHz.
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DC-blocking design: A series blocking capacitor prevents DC continuity through the RF center-conductor path. Confirm suitability before using with equipment that requires DC over coax.
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Bulkhead mounting: Intended for installation as part of a grounded coaxial entry arrangement.
Variant and Part-Number Cross-Reference
| Attribute |
N-Female to N-Female |
N-Female to N-Male |
| Manufacturer |
PolyPhaser |
PolyPhaser |
| Manufacturer part number |
IS-B50LN-C2 |
IS-B50LN-C2-ME |
| Motorola part number |
DSISB50LNC2 |
DQISB50LNC2ME |
| Antenna / surge-side connector |
Type-N female |
Type-N female |
| Equipment / protected-side connector |
Type-N female |
Type-N male |
| Connection arrangement |
Coaxial cables connect on both sides. |
Male equipment-side connector can mate with a suitable N-female port, subject to clearance and installation requirements. |
Specifications
The following technical values are retained from the existing listing. Confirm the current PolyPhaser documentation for the selected part before engineering an installation, particularly power limits, environmental ratings and grounding requirements.
| Attribute |
Listed Details |
| Manufacturer |
PolyPhaser |
| Series |
IS-B50LN |
| Product type |
Bulkhead-mount coaxial RF surge protector |
| Frequency range |
10–1,000 MHz |
| Nominal impedance |
50 ohms |
| Surge current capacity |
20 kA, 8/20 µs waveform |
| Throughput energy |
≤120 µJ, listed typical value |
| Insertion loss |
≤0.1 dB |
| VSWR / return loss |
≤1.1:1 / ≥26 dB |
| Listed continuous RF power limits |
1.5 kW at 10–50 MHz; 375 W at 50–220 MHz; 125 W at 220–700 MHz; 50 W at 700–1,000 MHz. Confirm the applicable rating at band boundaries. |
| Protection technology |
Gas discharge tube with series DC-blocking capacitor |
| Mounting |
Bulkhead; listed 5/8-24 threaded barrel with nut and washer |
| Grounding provisions |
Bulkhead-panel connection and listed 10-32 ground screw; follow the manufacturer's installation instructions. |
| Listed ingress rating |
IP67; verify the selected part and installed connector-sealing requirements. |
| Listed operating temperature |
-58°F to +122°F (-50°C to +50°C) |
| Existing standards references requiring confirmation |
IEC 61000-4-5, IEC 60529, UL 497E, IEEE C62.41, CE and RoHS. These references are not independent verification of certification for either variant. |
| Legacy reference |
RRX4025A appears in the previous listing. Confirm suitability before treating it as an interchangeable replacement. |
Application and Installation Compatibility
Selection depends on frequency, RF power, impedance, connector gender, mounting clearance and grounding design, not simply the radio brand. No universal repeater or base-station fitment is claimed.
Follow the unit's antenna/surge-side and equipment/protected-side markings. Have the grounding, bonding and connector weatherproofing assessed for the installation. A matching connector alone does not establish a complete or effective surge-protection installation.
What's Included
| Item |
Status |
Details |
| Coaxial surge protector |
Included |
One unit in the selected connector configuration. |
| Mounting hardware |
Listed with product |
Nut and washer are referenced in the existing mounting specifications; confirm package contents if required for your installation. |
| Coaxial cables, adapters and grounding materials |
Not specified as included |
Confirm the additional materials required for the site. |
Related Installation and Radio Accessories
These are separate accessories for their respective applications, not a matched installation kit or confirmed connections to this protector.
Frequently Asked Questions
Who manufactures these surge protectors?
PolyPhaser manufactures the IS-B50LN-C2 and IS-B50LN-C2-ME. The corresponding Motorola ordering references are DSISB50LNC2 and DQISB50LNC2ME, respectively.
What is the difference between the two variants?
IS-B50LN-C2 / DSISB50LNC2 has N-female connectors on both sides. IS-B50LN-C2-ME / DQISB50LNC2ME has an N-female antenna-side connector and an N-male equipment-side connector. Confirm all technical requirements for the chosen variant.
Are the PolyPhaser part numbers discontinued or replacement numbers?
IS-B50LN-C2 and IS-B50LN-C2-ME identify the manufacturer models in this listing. They should not be treated as discontinued part numbers simply because Motorola ordering references are also provided.
What does DC block mean?
The series capacitor blocks DC continuity in the RF center-conductor path. It is not a DC-pass connection for powering equipment through the coax. Confirm whether your antenna system requires DC continuity.
Can it be used with a 50 W or 100 W repeater?
Check the operating frequency and the selected part's power rating. The existing listing specifies only 50 W for 700–1,000 MHz, so a blanket 100 W suitability claim would be inappropriate. Use the manufacturer's current frequency-dependent limits.
Which side connects to the antenna?
Follow the protector's markings: the surge side faces the antenna feedline, and the protected side faces the equipment. Do not select orientation by connector gender alone.
Does it eliminate the need for grounding or weatherproofing?
No. Grounding, bonding and appropriate connector sealing remain part of the installation. Follow the manufacturer's instructions rather than relying on a generic ground-wire size or an enclosure rating alone.
Does it guarantee protection from a direct lightning strike?
No guarantee of protection against every lightning event is made. A coaxial protector is one component of the site's overall protection system.
Warranty
1-year manufacturer's warranty.
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