Practical field-strength measurements call for an analyzer that is portable yet powerful. The model 3290 RF Field Strength Analyzer from PROTEK Test and Measurement (Allendale, NJ) is a handheld instrument that contains not only a full-featured spectrum analyzer capable of measurements from 100 kHz to 2.9 GHz, but also a sensitive frequency counter, a host of demodulators, and the choice of operating on batteries, AC, or vehicle DC power.

The analyzer (see figure) features a basic data-entry keypad and on-screen menu. The 3290's backlit 192 × 192-pixel liquid-crystal-display (LCD) screen provides a spectrum display or bar graph with large readout of marker frequency and smaller readouts of center frequency, reference level, span, and step size.

Based on a temperature-compensated crystal oscillator (TCXO) and phase-locked-loop (PLL) tuning, the 3290 provides ±3 PPM reference-oscillator frequency accuracy and displayed measurement accuracy of ±25 PPM. The instrument offers ­117 dBm sensitivity, handles maximum input voltage of 5 V RMS, and can display levels in units of dBmV, dBµV, or dBm. It features versatile demodulation capabilities with narrowband and wideband frequency-modulation (FM), amplitude-modulation (AM), and single-sideband (SSB) demodulators. In narrowband FM mode, the 3290 operates with a 3-dB bandwidth of approximately 12.5 kHz while in wideband FM mode, the 3-dB measurement bandwidth is approximately 180 kHz. In AM/SSB mode, the 3-dB bandwidth is approximately 2.4 kHz.

Narrowband FM mode detects levels from ­70 to ­20 dBmV (­10 to 40 dBµV) from 300 to 1800 MHz and ­60 to ­20 dBmV (0 to 40 dBµV) from 1 to 300 MHz and from 1800 to 2900 MHz. Wideband FM mode allows level measurements from ­60 to ­10 dBmV (0 to 50 dBµV) from 300 to 1800 MHz and ­50 to ­10 dBmV (10 to 40 dBµV) from 10 to 300 MHz and from 1800 to 2900 MHz. Resolution and level accuracy are 0.5 dB and ±3 dB, respectively, in both modes.

The 3290 analyzer, which is ideal for testing cellular systems, wireless-local-area-network (WLAN) systems, cable-television (CATV) systems, wireless medical-telemetry systems, and satellite-television systems, supports sweeps with step sizes of 5 kHz to 9995 kHz in multiples of 5 and 6.25 kHz. The instrument boasts a scan speed of 125 channels/s. P&A: $2700. PROTEK Test and Measurement, 40 Boroline Rd., Allendale, NJ 07401; (201) 760-9898, FAX: (201) 760-9888, e-mail: sales@protektest.com, Internet: www.protektest.com.