Older DMC Modules

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Power Amplifier 110123

Small signal gain for the modules that I tested was 7 dB at 24 GHz. I could get about +14dBm of DATV out of them.

Cable Connections:

Colour Voltage Function
Black 0 Ground
Yellow +4.5 Unknown
White +0.1 O/P Level Monitor
Orange +8.0 Unknown
Red +8.0 Supply
Green +4.5 +5 supply
Blue -5 Unknown
Mauve -5 -5 Supply

Voltages shown enable the "A" input. One of the +4.5V lines needs to be dropped to 0v to enable the "B" input.

LNA 110124

Gain approx 20 dB to each output. Both outputs are driven and seem to be reasonably well isolated.

Cable Connections:

Colour Voltage Function
Black 0 Ground
White +0.1 O/P Level?
Red +8.4 Supply
Orange +8.4 Supply

Up Converter 110125

LO input needs about +5 dBm at 23.6 GHz. IF needs about + 5dBm at 432 MHz. The gain of the post-filter amplifier is approximately 10 dB at 24 GHz. Max output about +11 dBm.

Cable Connections:

Colour Voltage Function
Black 0 Ground
White +0.1 O/P Level?
Red +8.4 Supply
Yellow 0  ?

Down Converter 110126

The downconverter has 2 modules. The upper module has an input filter, a diode mixer and a 1542 MHz IF amplifier. The lower module has a diode mixer, a 1612 MHz LO and 70 MHz IF amplifier.

The Lower module was discarded and the upper module modified for a 432 MHz IF by applying the modifications linked here http://www.eb3frn.net/?p=130.

Cable Connections:

Colour Voltage Function
Black 0 Ground
Grey 0 AGC: 0v for max gain
Red +8.4 Supply to upper module
Yellow 0  ?
Orange +8.4v Supply to lower module

Local Oscillator 110127

This is a free-running DRO operating in the range 22.5 GHz to 23.5 GHz depending on the specific version number. Output level is approx +7dBm from each output. The DRO is tuned by removing the top screw in the adjustment thread and then tuning the bottom screw; screwing in (clockwise) raises the frequency. The top screw is then replaced to lock the bottom screw. The DRO has 2 outputs and needs -5v and +8.4v supplies. The +8.4v does not appear to be critical as it feeds a 7805 regulator inside the unit. The BNC connector on the case is not connected internally.

Cable Connections:

Colour Voltage Function
Yellow 0.5v  ?
Mauve -5 -5 Supply
White 0  ?
Grey 0  ?
Red +8.4 Supply
Black 0 Ground