RF Line Sweeps
Anritsu Site Master line sweeps - Return Loss, VSWR and Distance-to-Fault - with clean, carrier-grade sweep reports for every cable run.
- In-house Anritsu sweeps - no third-party scheduling
- Carrier-grade RL / VSWR / DTF reports
- We find the real fault, not just the symptom
- Reports labelled and close-out ready
A line sweep verifies a tower's transmission line system end to end - connectors, jumpers, the main feeder coax and the antenna - so you know the run is healthy before it goes into service, and so a carrier will accept it. Broadband Tower Services runs its own sweeps with Anritsu Site Master analyzers and hands you the reports directly. No third-party scheduling, no waiting on a sub.
What we measure
- Return Loss (RL) - how much signal is reflected back toward the radio instead of reaching the antenna. Measured across the actual operating band, in dB; higher is better.
- VSWR - the same match expressed as a ratio (1.0:1 is perfect). The headline pass/fail number on most acceptance specs.
- Distance-to-Fault (DTF) - locates exactly where a problem sits along the run, so a bad connector, a kink or water ingress can be found and fixed instead of guessed at.
- Cable loss - confirms a long feeder is intact and within spec for its length.
Acceptance thresholds we report to
We sweep to clear pass / marginal / fail criteria and call out anything that doesn't meet spec - always checking your carrier's spec first. The chart below is a real BTS sweep:
Real BTS sweep - catching a failing surge protector
| Measurement | Pass | Marginal | Fail |
|---|---|---|---|
| VSWR | < 1.3:1 | 1.3 - 1.5:1 | > 1.5:1 |
| Return Loss | > 17.7 dB | 14.0 - 17.7 dB | < 14.0 dB |
| DTF (any point) | < 1.2:1 | 1.2 - 1.5:1 | > 1.5:1 |
Finding the real fault
Most sweep failures trace to a handful of causes: water in a connector, a loose or under-torqued connection, a crushed cable past its bend radius, or a failing surge protector at the base of the run. A surge protector shows up right at the test port on a DTF trace - we bypass and re-sweep to confirm it, so you replace the part that's actually the problem. Every trace is calibrated at the test port before the job and labelled with site, sector, band, cable and date.
The deliverable
One clean PDF per cable run showing Return Loss across the band and the DTF trace, labelled and ready to drop straight into a carrier close-out package. For carrier acceptance work we can also scope PIM (passive intermodulation) testing.
FAQ Common questions
Good to know
What counts as a passing sweep?
It depends on the carrier's spec, but as a general guide we treat VSWR under 1.3:1 (Return Loss better than ~17.7 dB) as a pass, 1.3-1.5:1 as marginal, and worse than 1.5:1 as a fail. We always confirm the customer's required threshold before sweeping.
What's the difference between Return Loss and DTF?
Return Loss tells you whether the whole run is good or bad across the band. Distance-to-Fault tells you where along the cable the problem is, so it can be located and fixed. We typically run both.
What equipment do you use?
Anritsu Site Master handheld analyzers, calibrated at the test port before every job, with the correct cable type and velocity factor set so fault distances are accurate.
Do you do PIM testing?
Line sweeps are our standard test and cover most acceptance needs. For carrier work that requires passive intermodulation (PIM) testing we can scope that as well - get in touch with the site details.
More Related services
Other work we do
Tell us about your tower.
Send the details and we'll come back with a clear, itemized quote - no vague ballparks. For urgent or emergency work, call us directly.