Cablesoft Engineering


The above sample waveforms depict the following:

Upper Left            Composite 2nd Order distortions in a HFC cable television plant.

                                    Green trace, beats at +/- 1.25 MHz above each luminance carrier.

Upper Right          A spurious beat under a 256-QAM carrier (carrier turned off to capture the beat).

                                    Beat with marker shown on green trace.

Lower Left            Signal leakage in the 700 MHz band. Markers on visual & aural carriers 'leaking'

                                    from local cable television plant.

Lower Right          Sporadic interfering carrier captured with RTA 'signal mask' feature.

Cable Television FCC Proof of Performance testing, with all FCC mandated tests (analog and QAM) performed during testing. All downstream QAM carriers are tested to ANSI/SCTE 40 2016 specifications. A sample FCC POP report is available on the ‘Downloads’ page.

Technical Due Diligence testing for cable system sale and acquisition.

Cable Television Reverse Path Proof of Performance testing, using an injected upstream high symbol rate QAM carrier from HFC plant ‘line ends’, with complete analysis of the ‘condition’ of the entire return path and remedial action recommendations where necessary.

RF Spectrum Analysis and Testing from 9 kHz to 3.2 GHz. Services provided (to 6.2 GHz unless noted otherwise) include calibrated field strength measurements; interference analysis and location (including TI interference at TVRO installations); digital carrier measurements including QAM, OFDM, TDMA, LTE & WiMax; and scalar measurements [to 3.2 GHz] including gain/loss, frequency response, and isolation. See the Downloads page for measurements on various CATV and satellite components, including frequency response, isolation and return loss.

High Definition ATSC (8-VSB) receive site testing including antennas, downleads, decoders, and full analysis of the 8-VSB signal with a dedicated 8-VSB spectrum analyzer. A computerized signal survey level projection program is utilized (CSE’s in-house survey program) is correlated with receive site measurements. Services also include the locating of optimal alternate receive sites; where the existing site is prohibitive to good off-air reception. See the Download page for an article on 8-VSB theory, reception, plus actual measurements.

General Engineering and Design Services for Broadband Networks including headend FDM combiner design (downstream & upstream) and testing (including the ability to test headend components or ‘combiner sections’ for frequency response and isolation); and outside plant RF/AC design including BOM and map creation. Map printing services are provided, with sample maps available on request.

Refurbishing, calibration, and repair of older Avantron/Sunrise Telecom AT2500 RQv series spectrum/ QAM analyzers, and we are now adding repair services for the older Rohde Schwarz FSH 3/6 series spectrum analyzer. See the Repair Services page for detail.