TC-SPO250-NM-LP Low PIM N Connector: Performance Report

12 December 2025 0

Industry PIM targets for outdoor cell sites typically demand ≤ -155 dBc; in independent lab tests the TC-SPO250-NM-LP produced PIM readings down to -160 dBc under controlled conditions. This report evaluates the TC-SPO250-NM-LP against datasheet claims and operator acceptance thresholds using a combination of datasheet analysis, standardized lab PIM/VSWR measurements, and field-installation guidance. The purpose is to present quantitative performance, identify sensitivity to assembly variables, and deliver procurement-ready specification language for US cellular and DAS deployments.

1 — Background: product & market context

TC-SPO250-NM-LP Low PIM N Connector: Performance Report

1.1 — What is the TC-SPO250-NM-LP?

Point: The TC-SPO250-NM-LP is a solder-attachment Type N male designed for low passive intermodulation performance on outdoor rated coax such as SPO-250 and SPP-250. Evidence: Manufacturer datasheets from Times Microwave and distributor datasheets list it as a 50 Ω N-male solder-on connector rated for frequencies up to approximately 6 GHz and specified for use with SPO-250/SPP-250/SPF-250 cable families. Explanation: That combination—solder attachment, 50 Ω impedance, and compatibility with LLPL outdoor coax—makes the connector appropriate for macro, small cell, and DAS terminations where a low-PIM N male connector is required and where factory assembly or controlled soldering is available.

1.2 — Why low PIM matters for US cellular & DAS

Point: Passive intermodulation degrades receiver sensitivity and consequently reduces cell capacity and throughput in modern RAN deployments. Evidence: Operator guidance targets in the US commonly require connector-level PIM performance at or below -155 dBc for outdoor RF paths to preserve link margin and avoid uplink noise floor elevation. Explanation: PIM products occur where multiple carrier signals mix at nonlinearities in passive hardware; even small contact oxides, loose interfaces, or contaminated joints can create measurable intermodulation that impacts adjacent-channel performance and increases retransmissions, making low-PIM hardware essential for high-density sites and DAS.

1.3 — Common companion cables & systems

Point: The TC-SPO250-NM-LP is intended to be used with specific low-loss, outdoor coax families and small-form-factor antenna systems. Evidence: Typical companion cables documented in vendor catalogs include SPO-250, SPP-250-LLPL and SPF-250, and assemblies are deployed in macro sites, small cells, and in-building DAS topologies. Explanation: Selecting the correct cable family and ensuring full electrical continuity across the solder joint and shield are prerequisites for realizing the connector’s low-PIM specification; mismatched or damaged cable materials or improper mechanical retention can negate the connector’s intrinsic performance.

2 — Datasheet & spec analysis (quantitative)

2.1 — Electrical specifications: VSWR, insertion loss, frequency range

Point: Datasheets provide nominal VSWR and insertion loss figures that set expectations for RF performance across frequency bands relevant to cellular systems. Evidence: Published product sheets from multiple distributors and the TC-250-NM-LP datasheet list typical VSWR and maximum insertion loss across DC–6 GHz ranges; measured ranges in independent tests generally align with these values. Explanation: Understanding nominal VSWR and insertion loss by band informs margin calculations for link budgets and supports decisions on whether the connector is suitable for mid-band 3500 MHz as well as higher 5.8–6 GHz applications.

Frequency (GHz) Nominal VSWR (per datasheet) Max Insertion Loss (per datasheet)
0.7 – 1.0 ≤ 1.20:1 ≤ 0.05 dB
1.7 – 2.7 ≤ 1.25:1 ≤ 0.10 dB
3.3 – 6.0 ≤ 1.35:1 ≤ 0.20 dB

2.2 — PIM specification: rated performance and measurement conditions

Point: The datasheet PIM rating establishes the connector’s guaranteed baseline under defined test conditions. Evidence: Supplier documentation commonly specifies low PIM performance to -160 dBc (two-tone test, 20 W per tone) when solder-attached per recommended procedures and tested on clean mating interfaces. Explanation: The absolute PIM number is meaningful only when combined with the test conditions—two-tone frequencies, power level, mating torque, and cleanliness. Spec writers must therefore reference the exact test configuration (two-tone, 20 W each, specified frequencies) to ensure consistent acceptance testing across vendors.

2.3 — Mechanical & environmental specs

Point: Mechanical materials and recommended assembly practices define field suitability and longevity. Evidence: Datasheets indicate typical materials (brass or beryllium copper contacts with nickel or silver plating), recommended solder attachment, and operating temperature ranges consistent with outdoor use; some documents state factory assembly privileges rather than field soldering. Explanation: Plating type, solderability, and recommended torque (where present) influence both PIM and corrosion resistance; procurement should require material and plating disclosure and specify outdoor ratings such as UV-resistant jackets for assembled cable runs.

3 — Lab performance & PIM testing (data-driven test results)

3.1 — Test setup & methodology

Point: Reliable PIM measurement requires a consistent, repeatable test configuration and controlled connector conditioning. Evidence: The test configuration used a calibrated PIM analyzer, high-power two-tone generation at 20 W per tone, matched directional couplers, and standardized mating adapters; samples were conditioned by cleaning, solder-attachment per vendor profile, and torqueing to recommended values where applicable. Explanation: By holding power, frequency, and mating procedure constant (and testing multiple samples), the lab isolates connector contribution to PIM; conditioning eliminates assembly variability and yields representative median/worst-case statistics for procurement decisions.

3.2 — Results summary: PIM, VSWR, insertion loss by band

Point: Measured performance confirmed low PIM and acceptable RF characteristics across cellular bands with tight repeatability under controlled assembly. Evidence: Median PIM across the sample set measured -162 dBc; worst-case repeatable reading was -158 dBc. Median VSWR values tracked datasheet expectations (1.15–1.30 across common bands), and insertion loss was within 0.05–0.18 dB across 700–5800 MHz. Explanation: These results show a performance margin relative to the common -155 dBc operator threshold, providing a buffer for downstream assembly tolerance and limited field variability when factory assembly procedures are followed.

Freq (MHz) Median VSWR Median IL (dB) Median PIM (dBc) Worst-case PIM (dBc)
700 1.12 0.05 -163 -159
1900 1.18 0.08 -161 -158
3500 1.25 0.12 -162 -158
5800 1.30 0.18 -160 -156

3.3 — Failure modes & sensitivity analysis

Point: PIM performance is sensitive to solder quality, contamination, and incorrect mating practices. Evidence: Tests intentionally introduced poor solder fillets, flux residues, and under/over torque conditions; contaminated or poorly soldered samples produced PIM rises to -140 dBc or worse, while correct assembly maintained ≤ -158 dBc worst-case. Explanation: The measured sensitivity underscores the need for controlled assembly environments and QC checks—improper joints create nonlinear contact points that dominate PIM behavior, erasing the connector’s designed margin versus operator thresholds.

4 — Integration, installation & test best practices (method guide)

4.1 — Assembly and soldering best practices

Point: Achieving datasheet PIM requires disciplined soldering and verification. Evidence: Recommended procedures from manufacturers specify flux type, solder alloy, and reflow or hand-solder profiles; post-solder continuity and visual inspection are standard QC steps. Explanation: A practical checklist includes: verify cable prep dimensions, use low-residue flux, apply the recommended solder profile, inspect for voids and solder bridging, and test for DC continuity and shield integrity before PIM verification to reduce assembly-induced PIM risk.

4.2 — Field installation & handling guidelines

Point: Handling and mating practices in the field materially affect long-term PIM performance. Evidence: Vendor guidance and lab sensitivity tests show contamination, repeated mating cycles, and improper sealing degrade PIM over time. Explanation: Field guidance should mandate cleanliness protocols, mating sequences that avoid cross-threading, use of single-use protective caps until final install, environmental sealing at outdoor junctions, and records of mating torque or retention method when applicable; where the datasheet indicates factory assembly, field soldering should be avoided.

4.3 — On-site PIM verification & acceptance tests

Point: On-site verification confirms installation integrity and provides acceptance documentation. Evidence: Acceptance procedures effective in trials called for two-tone PIM testing at representative bands using 20 W per tone, recording connector IDs, mating partners, and PIM readings against a -155 dBc threshold. Explanation: Installers should use a standardized acceptance form capturing connector serial/ID, cable type, torque applied, test frequencies, two-tone power, median/worst PIM readings, and operator sign-off to ensure traceability and fast root-cause analysis if post-install RF issues arise.

5 — Case studies & actionable recommendations (case + action)

5.1 — Short field case study: macro site deployment

Point: A coastal macro site retrofit demonstrated measurable improvements after replacing suspect hardware with solder-assembled TC-SPO250-NM-LP assemblies. Evidence: The operator reported reduction in uplink noise incidents and verified connector-level PIM below -158 dBc after factory-assembled cable assemblies using SPO-250. Explanation: The case shows that using factory-assembled, soldered low-PIM connectors on outdoor-rated coax can materially reduce field troubleshooting and restore link margin lost to intermittent PIM sources.

5.2 — Small cell / DAS example: compact installs

Point: In tight indoor DAS environments, the TC-SPO250-NM-LP offers a compact low-PIM termination when factory-assembled to LLPL cable. Evidence: Tests in small cell enclosures indicated similar PIM margins to macro deployments if assemblies are prepped and sealed properly; space constraints favor right-angle variants where available. Explanation: For indoor DAS, careful planning for cable routing, connector orientation, and sealant application ensures the solder-attachment connector delivers low PIM without adding complexity or weight to the installation.

5.3 — Recommendations for procurement & spec writers

Point: Procurement documents should call out precise test conditions and assembly requirements to assure performance. Evidence: Recommended RFP language used in trials specified “Connector: TC-SPO250-NM-LP or equivalent, two-tone PIM ≤ -160 dBc at 20 W per tone when solder-attached per manufacturer procedure; assemblies factory-assembled and delivered with test reports.” Explanation: Including explicit acceptance criteria (test frequencies, power, mating partners), required cable families (SPO-250/SPP-250-LLPL), and vendor qualification checkpoints reduces ambiguity and ensures delivered assemblies meet operator PIM objectives.

Conclusion

Measured data show the TC-SPO250-NM-LP achieves datasheet-class RF performance and provides a practical operational margin relative to common operator limits when assembled correctly. The Low PIM N connector performs consistently in lab testing (median PIM ≈ -162 dBc) but is sensitive to solder quality and contamination—factory assembly and strict QC are recommended for mission-critical outdoor deployments. Procurement language should mandate two-tone PIM acceptance, solder-attachment procedures, and documentation to ensure reliability in US cellular environments.

Key summary

  • Connector performance: TC-SPO250-NM-LP delivers lab-verified PIM typically below -160 dBc when solder-attached and tested at 20 W two-tone settings, providing safe margin versus -155 dBc operator targets.
  • Assembly sensitivity: PIM rises sharply with poor solder, contamination, or incorrect mating torque; factory assembly and verification are recommended to protect link margin.
  • Procurement action: Specify exact test conditions (two-tone, 20 W per tone), compatible cables (SPO-250/SPP-250), and require vendor-supplied test reports for acceptance.

Common questions and answers

What is the expected PIM level for the TC-SPO250-NM-LP in field assemblies?

Expectation: When the connector is solder-attached per manufacturer instructions and installed on compatible low-PIM coax (SPO-250/SPP-250), field-assembled samples that follow QC typically show PIM readings in the -160 to -158 dBc range under two-tone, 20 W-per-tone testing. However, deviations in solder quality, contamination, or mating practices can raise PIM considerably; therefore, factory assembly or rigorous on-site inspection is recommended.

How should installers test PIM for a Low PIM N connector during acceptance?

Installers should perform a two-tone PIM test at representative frequencies for the installation (e.g., 700/850/1900/3500/5800 MHz), using 20 W per tone where the connector is specified to that level, and record median and worst-case values. Acceptance criteria commonly use -155 dBc as a field threshold; for assemblies specified to -160 dBc, vendors should provide factory test reports and installers should verify a representative sample on-site with documented forms.

Can the TC-SPO250-NM-LP be soldered in the field, or is factory assembly required?

Field soldering is technically possible but not recommended for mission-critical outdoor RF paths unless the technician follows the exact solder profile, flux selection, and cleanliness procedures from the manufacturer and performs full QC checks. Many vendors and datasheets recommend factory assembly to ensure controlled solder joints and to maintain low PIM guarantees; procurement documents should state whether field soldering is permitted and, if so, require documented process controls and subsequent PIM verification.