Panoramic SPA-3/25 Spectrum Analyzer 200 CPS-25 MC w/ PS-19 Power Supply

Panoramic SPA-3/25 Spectrum Analyzer 200 CPS-25 MC w/ PS-19 Power Supply

The Panoramic SPA-3/25 is a vintage vacuum-tube sweep spectrum analyzer manufactured by Panoramic Radio Products, Inc. of Mt. Vernon, New York. It covers a frequency range of 200 CPS to 25 MC (25 MHz) and displays the spectrum on a round CRT with a calibrated graticule. The unit is housed in a self-contained portable gray cabinet and includes its matching PS-19 Power Supply Unit, which provides the necessary operating voltages from a 115V AC line.

Specifications & What's Included

• Model: Panoramic SPA-3/25
• Manufacturer: Panoramic Radio Products, Inc., Mt. Vernon, N.Y.
• Frequency Range: 200 CPS to 25 MC (25 MHz)
• Display: Round CRT with calibrated graticule (Scale Illum control)
• Amplitude Scale: LOG / LIN / PWR selectable
• IF Attenuation: 0 dB / 20 dB switch
• IF Bandwidth: Continuously variable (Min to Max front-panel knob)
• Input Attenuator – Continuous: 0 dB to Max (front-panel knob)
• Input Attenuator – Step: 0 / 20 / 40 / 60 / 80 dB
• Sweep Width: Continuously variable (front-panel control)
• Sync Amp and Cal-Sync Selector: CAL / LINE / EXT
• Video Filter: switchable (Off and on)
• Sweep Rate: variable front-panel knob
• A BAL and S BAL controls on front panel
• Marker Amplitude control (OFF to full)
• CRT controls: Focus, Brilliance, H POS, V POS
• Center Frequency tuning dial on front panel
• RF Input connector: BNC
• Probe connector: 5-pin circular military-style (blue)
• Power Supply Unit: Panoramic PS-19
• Input Voltage: 115V AC
• Power Consumption: 180W
• Technology: Vacuum tube (thermionic valve) chassis
• Form Factor: Benchtop/portable self-contained cabinet
• Includes: SPA-3/25 analyzer unit and PS-19 Power Supply Unit
• Does not include: manual, probe accessories, or external cables

Applications

The Panoramic SPA-3/25 dates from the late 1940s to mid-1950s era of vacuum-tube RF test instrumentation — a period when Panoramic Radio Products was one of the leading American makers of spectrum display and panoramic adapter equipment. Instruments in the SPA series were widely used by military, government, and commercial radio laboratories for monitoring and analyzing the RF spectrum in the HF and low-VHF ranges. The swept-frequency display allowed technicians to visualize signal occupancy, check transmitter sidebands, measure IF passband shapes, and identify spurious emissions — tasks that previously required tedious point-by-point measurement with a signal generator and meter. The SPA-3/25's 200 CPS to 25 MC coverage made it well suited for shortwave, AM broadcast, and early VHF communications work. Today, instruments like this are sought by vintage test equipment collectors, radio historians, and those restoring or maintaining period radio equipment. The tube-based design, military-style connectors, and Panoramic nameplate make this a historically significant piece of mid-20th century American electronics.