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Azur Electronics

The HP 8447D Amplifier is a general purpose wideband pre-amplifier with a frequency range of 100kHz to 1.3GHz. This cost $765 in 1980. A Manual was downloaded.

Front view
Gain is 26dB ±1.5dB with a maximum output level of +7dBm. 50Ω input and output impedance and a maximum dc input voltage of ±10V.

Other versions were also available:
8447A 100kHz to 400MHz, 20dB gain, >+6dB output;
8447C 30MHz to 300MHz, 30dB gain, >+17dB output;
8447E 100kHz to 1.3GHz, 22dB gain, >+15dB output.
Also the 8447F which is a D and E version in one case.

Rear view with cover removed
Top view with cover removed
The Amplifier consists of a power supply and a thin film hybrid integrated circuit amplifier which is hermetically sealed. This has low noise, low distortion, flat frequency response, long term stability & reliability. Front Panel BNC input and output connectors.

July 2007

The 8447D is in good condition and just needed cleaning. Powers up ok and a quick test shows that it is amplifying without any obvious distortion. Performance tests need to be carried out.

June 2020

After another 13 years, finally got round to testing this pre-amplifier. Performance tests carried out ok.

The 8447D is useful for amplifying low level signals, typical maximum input is in the -30dBm region with a typical maximum output level of 0dBm, although +7dBm is specified.

Rarely used, but a useful addition to the Workshop.