874-VQL
The General Radio 874-VQL is a "voltmeter detector" with two GR-874 connectors for the signal, and an GR-874 for the rectified output. It was introduced in Catalog R (1963) and remained available through Catalog 1973, after which only the 874-VQL version with locking connectors remained in the catalog.
The 874-VQL is used in frequency-response measurements with a 1750-A Sweep Drive and 1263-A Amplitude Regulating Power Supply. An 874-VI Voltmeter Indicator can be used for calibrated measurements from 0.1 to 2 V.
It contains a 1N23B diode and a mica capacitor.
The 874-VQL is similar to the 874-VR Voltmeter Rectifier, but omits the latter's 50 Ω series resistor, and includes matching elements to compensate for the discontinuity caused by the diode capacitance.
Key Specifications
- Frequency range: 500 kHz to 2 GHz ("in limited application" up to 7 GHz)
- Maximum input: 2 V
- VSWR: ≤1.1 @ 1 GHz, ≤1.2 @ 2 GHz; rising rapidly above 2.5 GHz
- Resonant frequency: 3.6 GHz
