URM-32 meter

URM-32 Frequency Meter

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General Description

The URM32 measures frequencies in the range 125kHz to 1000MHz. It can also be used as a signal generator which provides a choice of modulated or unmodulated signals for testing and calibrating radio equipment. The frequency meter was introduced in 1957 as an item of US Army and Air Force equipment.

The meter has the following frequency ranges:

Band A0.125 - 2.5MHz
Band B2.5 - 65MHz
Band C65 - 1000MHz

The URM-32 was obviously a replacement for the BC-221 and its VHF and UHF counterparts, enabling one unit to cover all versions of the earlier equipment.

Technical Data

Output Voltage Range

Sensitivity: With an RF input signal of .1 volt an AF output of .05 mw is obtained.
Accuracy: .01% (-40F to 125F)
Radio Frequency 100uv minimum across an external 50 ohm resistive load.

Power Input:
6 volts dc 1A
180vdc 25mA
Number of Valves 5
Weight 27lb (12.3 kg)

The unit had 2 power sources available - either batteries (2 x BA-419/U and one BA412/U) or power unit PP-1243/U (115/230vac) The power sources were fitted in the lower section of the case, behind the calibration book.

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Illustrations of the set

View of the front panel and calibration chart. URM-32-panel URM-32 calibration chart

Views of the range switch and top. URM-32 range switch URM-32top view interior

The spares and identification plate. URM-32 spares URM-32 name plate

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© Ian O'Toole, 2009. Page created: 29/01/05 Last updated: 11/12/2009