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R.L. Drake W-4 Directional Coupler Serial number 7914, 1.8-54 MHz SO-239 in Excellent Condition

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MPN:
W-4
Condition:
Used
Shipping:
$8.00 (Fixed Shipping Cost)
  • R.L. Drake W-4 Directional Coupler serial number 7914 excellent condition for W-4 Wattmeter 1.8-54 MHz SO-239 The R.L. Drake W-4 is a directional through-line RF wattmeter covering 1.8–54 MHz (HF plus 6 meters). It features selectable scales of 0–200 W and 0–2000 W for both forward and reflected power, accuracy of ±5% of reading +1% of full scale (or similar published figures), 50-ohm impedance, low insertion VSWR (≤1.05:1), and continuous 2000 W capability. The sensing element (directional coupler) is remotable via a multi-conductor cable so the meter head can sit at the operating position while the coupler is placed near the transmitter or amplifier output. The W-4 coupler uses SO-239 connectors.⁠Qrzcq The companion WV-4 covers 20–200 MHz (VHF), with lower power scales (typically 0–100 W / 0–1000 W), and normally uses Type-N connectors on its coupler. Far fewer WV-4 units were produced than W-4 units.⁠Qrzcq Serial-number data compiled from surviving units place early W-4 examples in the low hundreds (1967–1968) and later production continuing into the high 20,000s–low 30,000s by the late 1970s. Serial 7914 falls comfortably inside the documented W-4 production span and is well above the low-thousands range typically seen on surviving WV-4 examples. Combined with the user’s description of an SO-239 coupler for the W-4, this confirms the unit is the HF W-4 directional coupler, not a WV-4 part.⁠Wb4hfn The coupler itself is a compact metal box containing a toroidal current transformer, capacitive voltage sampler, rectifiers, and calibration adjustments. It is designed to be placed in the transmission line and connected to the W-4 meter head.
  • R.L. Drake W-4 Directional Coupler serial number 7914 excellent condition for W-4 Wattmeter 1.8-54 MHz SO-239 The R.L. Drake W-4 is a directional through-line RF wattmeter covering 1.8–54 MHz (HF plus 6 meters). It features selectable scales of 0–200 W and 0–2000 W for both forward and reflected power, accuracy of ±5% of reading +1% of full scale (or similar published figures), 50-ohm impedance, low insertion VSWR (≤1.05:1), and continuous 2000 W capability. The sensing element (directional coupler) is remotable via a multi-conductor cable so the meter head can sit at the operating position while the coupler is placed near the transmitter or amplifier output. The W-4 coupler uses SO-239 connectors.⁠Qrzcq The companion WV-4 covers 20–200 MHz (VHF), with lower power scales (typically 0–100 W / 0–1000 W), and normally uses Type-N connectors on its coupler. Far fewer WV-4 units were produced than W-4 units.⁠Qrzcq Serial-number data compiled from surviving units place early W-4 examples in the low hundreds (1967–1968) and later production continuing into the high 20,000s–low 30,000s by the late 1970s. Serial 7914 falls comfortably inside the documented W-4 production span and is well above the low-thousands range typically seen on surviving WV-4 examples. Combined with the user’s description of an SO-239 coupler for the W-4, this confirms the unit is the HF W-4 directional coupler, not a WV-4 part.⁠Wb4hfn The coupler itself is a compact metal box containing a toroidal current transformer, capacitive voltage sampler, rectifiers, and calibration adjustments. It is designed to be placed in the transmission line and connected to the W-4 meter head.
$28.99
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Description

R.L. Drake W-4 Directional Coupler Serial number 7914, 1.8-54 MHz SO-239 in Excellent Condition. It also is for the Drake C4 Console.

R.L. Drake W-4 Directional Coupler serial number 7914 excellent condition for W-4 Wattmeter 1.8-54 MHz SO-239

The R.L. Drake W-4 is a directional through-line RF wattmeter covering 1.8–54 MHz (HF plus 6 meters). It features selectable scales of 0–200 W and 0–2000 W for both forward and reflected power, accuracy of ±5% of reading +1% of full scale (or similar published figures), 50-ohm impedance, low insertion VSWR (≤1.05:1), and continuous 2000 W capability. The sensing element (directional coupler) is remotable via a multi-conductor cable so the meter head can sit at the operating position while the coupler is placed near the transmitter or amplifier output. The W-4 coupler uses SO-239 connectors.

The companion WV-4 covers 20–200 MHz (VHF), with lower power scales (typically 0–100 W / 0–1000 W), and normally uses Type-N connectors on its coupler. Far fewer WV-4 units were produced than W-4 units.

Serial-number data compiled from surviving units place early W-4 examples in the low hundreds (1967–1968) and later production continuing into the high 20,000s–low 30,000s by the late 1970s. Serial 7914 falls comfortably inside the documented W-4 production span and is well above the low-thousands range typically seen on surviving WV-4 examples. Combined with the user’s description of an SO-239 coupler for the W-4, this confirms the unit is the HF W-4 directional coupler, not a WV-4 part.

The coupler itself is a compact metal box containing a toroidal current transformer, capacitive voltage sampler, rectifiers, and calibration adjustments. It is designed to be placed in the transmission line and connected to the W-4 meter head.

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