Mişraja SWR: Çi ye û Yekamîna Bixebitina Wê

SWR Meter ne ku?

Metera SWR - ya da ISWR (current “I” SWR) an jî VSWR (voltage SWR) - û bêtirina ya dixwaze di transmission line de standîng wave ratio (SWR) pêk bide. Metera SWR bi rastî divîzîna neyên transmission line û load-a wê (herêm a antena) pêk bide. Ev her tişt e hêsan e ke dikarin bêtirina impedance matching ên tîkmendiyên teknîk bikin bînin.

Metera SWR yekem e ku dikare bide ka zevê reşey radiofrequency energy ji transmittera wergerîne wekî ku ji bo împeçînên RF energy yên di navbera operasyonê de çêkirin. Divîzîna yekem nebehat neyên ya ewrê ve û ideal rating 1:1 e ku guhertoya derketewe û tune power nayê.

Cûreya metera SWR yên bi karîn di bazara amateur radio de dual directional coupler heye. Directional coupler qisayek nikar an power di yek direksiyon de sample bike. Di navbera, diode bikar anîn bi rêjiyê bide piştî ku meterê li ser bide.

Heta ku coupler yekan bikar anîn, 180 derece digire bike, bi tenê power di du direksiyon de sample bike. Power forward û reflected yên ku coupler hatine mapekandin bikar anîn bi measure SWR. Ji bo yek direksiyon, dua couplers bikar anîn.

Ev metoda yekem e ku ka max û min voltage level values dirêj bike. Bi karîn di VHF û frekuansên herêm de. Li gorî frekuansên bi bas de nayê bikar bibe çunkî lines bi bas de neyên berd be.

Ji HF derava microwave frekuansên, directional couplers bikar bine. Wan dikeve û heta li ser frekuansên herêm bikar bine.

Metera ku bikar anîn bi measure SWR e metera SWR e. ISWR meter dikare current SWR û VSWR dikare voltage SWR pêk bide.

Divîzîna Wave Standîng ne ku?

Divîzîna maximum voltage radio-frequency û minimum voltage radio-frequency di transmission line de Standing Wave Ratio (SWR) e. Heta SWR bi max û min AC voltage di transmission lines de bînin, VSWR e.

Divîzîna maximum RF current û minimum RF current di transmission line de current SWR e.

Waves standîng physics de waves stationary ne. Waves yekem e ku di dem de oscillate bike, amma amplituda tune move bike. Amplituda constant e di dem de.

Di microwave engineering û telecommunications de, measure impedance matching loads û impedance transmission line e SWR. Heta impedance mismatch bibe, standing waves di transmission line de bide, ku transmission line losses zêde bike.

SWR yekem e ku efficiency communication line pêk bide. Line yekem e ku cables yên radio frequency signals û TV cable signals hene.

Rewşa Measure SWR

Her êwere rewşa measure SWR hene, metoda intuitive yên slotted line bikar bine, ku section transmission line e. Li ser wek slot open e, ku probe pas bide. Probe yekem e ku voltage actual di navbera points transmission line de bide.

Ya Directional SWR Çeza Kerda?

Bi karîn directional couplers, metera directional SWR bikar anîn bi determine amplitude transmitted û reflected waves.

Li gorî diagrama jêrîn, transmitter û antenna bi internal transmission line connected ne. Line bi electromagnetic way bi two directional couplers coupled ne. Piştî, li ser resistors û diode bridge rectifiers connected ne.

Resistors bikar anîn bi match characteristic impedance lines. Diodes bikar anîn bi convert magnitude forwarding û reverse waves to DC voltages. Di dawî, capacitors bikar anîn bi smoothen DC voltages.

Ya Metera SWR Bi Karîn?

Hemû formên metera SWR bikar anîn bi measure SWR, standing wave ratio on transmitter feeder. Bi karîn metera SWR herêm e, amma divê wan dikarin results interpret bikin. Ji gavên, VSWR û SWR yekem ne.

Heta VSWR meters bikar anîn bi measure performance antenna new, herêm low power û channel clear bikar bine. Rewşa jêrîn bikar anîn bi use meter.

• Finding a clear channel or frequency: Divê station yekan bide di contract two-way de

• Reduce power: Output power ji transmitter reduce bike. Ev helps damage reduce ji output device ji transmitter.

• Set mode switch: Mode switch set bikar anîn ji bo options CW, AM an FM, bi application need.

• Set VSWR meter: On front panel, set VSWR meter switch to forward. Turn CAL or adjustment knob down, to avoid overloading meter.

• Adjust forward reading: When transmitter transmits, adjust knob on CAL to obtain full-scale reading

• Switch Meter to Reverse: When meter calibrated for forward power, switch meter to reverse position and read VSWR.

• Stop Transmitting: To reduce interference to other stations, and to reduce overload on transmitter output, it is good to stop transmitting as soon as possible.

• Check on other frequencies: When using wide band of frequencies or channels, check VSWR readings for other channels to be used, since VSWR tends to change over range of frequencies.

Ya Setup û Where Measure SWR?

VSWR meter connected in feeder from transmitter to antenna. For feeder convenience, SWR meter located at transmitter end of feeder. This helps monitor actual VSWR values.

Divê bînin, where exactly SWR can be measured. There is always some degree of feeder loss, which has major effect on VSWR readings.

Feeder loss absorbs power in both directions. When reflected signal reduced, there is high level of feeder loss. Reflected signal gets reduced as forward signal to antenna, later reflected back to transmitter.

Since signal reduced on its way to transmitter, antenna with poor match and high VSWR will be fine at transmitter. Hence, when feeder that induces high loss used, VSWR good at transmitter, but at antenna, may be poor.

Formulas û Calculations SWR

VSWR can be calculated from various parameters. By definition, VSWR given as ratio of maximum voltage on line to minimum voltage.