Welcome to
Azur Electronics

HP 415E SWR METER
I bought this Meter, complete with an original paper Manual, just to find out what it can do! The original cost was $875 in 1980.

Front view
Rear view
"The 415E SWR Meter is a low noise, tuned amplifier-voltmeter calibrated in dB and SWR for use with square law detectors. It is an extremely useful instrument for measuring SWR, attenuation, and gain directly from metered scales, or as a tuned amplifier for driving an X-Y recorder when making RF substitution measurements. The 415E responds to a standard tuned frequency of 1000Hz. This frequency is front panel adjustable over a range of 7% for exact matching to the internal 1kHz modulation of the signal source being used. Amplifier bandwidth is also adjustable from 15Hz to 130Hz. The narrow bandwidth allows maximum sensitivity at CW frequencies while the wider bandwidths enable swept tests to be displayed on an oscilloscope or X-Y recorder. A precision 60dB attenuator with an accuracy of 0.05dB/10dB assures high accuracy in making substitution measurements. An expand-offset feature allows any 2dB range to be expanded to full scale for maximum resolution. Linearity is ±0.02 dB on expanded ranges and is limited only by meter resolution on normal scales. This performance, together with the inherently low noise figure, allows maximum measurement range with exceptional resolution and linearity. The 415E operates with either crystal or bolometer detectors. Both high and low-impedance inputs are available for crystal detectors. Precise bias currents of 4.5mA and 8.7mA (200Ω) are available for operation with bolometers as selected at the front panel. This bias is peak limited for positive bolometer protection. Both ac and dc outputs located on the rear panel allow use of the 415E as a high-gain tuned amplifier or for X-Y recorder operation. In addition, the 415E can be operated with an internally mounted battery pack (Option 001) for completely portable use." [HP Catalogue 1980]


May 2008

Cleaned-up and the 415E is in very good condition with only a few scratches and marks from labels. The serial number is 1750A indicating that it is circa 1977 manufacture. Powered-up on a Variac 230V at 5mA ac, indicator lights and meter moves slightly. Performance tests to be done.

Top and bottom views
Left and right hand side views
April 2011

The 415E has been in store for 3 years and still not had time to test it!