Inaaprubahan ng purchasing ang mas murang coaxial cable dahil mukhang tama ang outer diameter at kasya ang connector. Pagkaraan ng ilang linggo, nagpapakita ang EVT ng dagdag na 1.8 dB loss, hindi pala tugma ang cable sa totoong bend path, at wala ring matibay na ebidensiya ang supplier para sa shielding o compliance. Doon nagiging sanhi ng delay ang isang mukhang simpleng cable.
Ang datasheet ng coaxial cable ay dapat basahin bilang risk document. Tingnan ang:
- Characteristic impedance: 50 ohm o 75 ohm
- Capacitance: pF/m
- Velocity factor: porsyento
Total cable loss (dB) = datasheet attenuation × actual installed length
Kung 0.62 dB/m sa 1 GHz at 2.4 m ang aktuwal na haba, humigit-kumulang 1.49 dB na agad ang loss ng cable pa lang.
| Field | Ano ang i-check | Magandang senyales | Risk |
|---|---|---|---|
| Impedance | eksaktong 50 ohm o 75 ohm | may tolerance | nominal lang |
| Attenuation | dB sa totoong frequency | kumpletong table | isang marketing number lang |
| Velocity factor | epekto sa phase/delay | malinaw ang porsyento | wala |
| Shielding | foil/braid/coverage | malinaw ang construction | malabong claim |
| Bend radius | mechanical fit | may static at repeated value | walang data |
| Temperature range | totoong environment | malinaw ang min/max | generic |
| Compliance | RoHS, REACH | may declaration | walang ebidensiya |
Para sa finished assemblies, humingi ng connector series, plating details, VSWR o return-loss data, at reference sa MIL-STD-348. I-check din ang REACH, tolerances, at traceability.
FAQ
Ano ang pinakaimportanteng linya?
Ang attenuation table sa totoong frequency.
Maaari bang ipagpalit ang 50 ohm at 75 ohm?
Hindi.
Bakit mahalaga ang velocity factor?
Nakaaapekto ito sa delay, electrical length, at phase.
Kailan dapat tanggihan ang datasheet?
Kapag kulang ang attenuation table, impedance tolerance, bend data, shielding detail, temperature range, o compliance declaration.
References
- Coaxial cable fundamentals: Wikipedia: Coaxial cable
- PTFE material background: Wikipedia: Polytetrafluoroethylene
- Connector interface standard background: Wikipedia: MIL-STD-348
- Safety certification context: Wikipedia: UL (safety organization)
- Chemical compliance background: Wikipedia: REACH
Ipadala ang drawing o cable route, BOM, target quantity, operating environment, target lead time, compliance target, frequency range, allowable loss budget, at connector family. Magbabalik kami ng technical review at quote sa aming quote request page.
