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8-Port BNC Video Distribution Amplifier

Front Panel
Front Panel

Time for another eBay special: this time it’s an 8-port video distribution amplifier, with BNC connections designed for commercial/industrial equipment. Not much on the front panel above, apart from the power switch & LED.

Rear Panel
Rear Panel

The rear panel has all the connectors, input is on the left, while the outputs are in the centre. Power is supplied through the barrel jack on the right, 9v DC in this case.

Data Label
Data Label

Not much in English on the data labels, there’s also an authenticity label on the left to make sure you don’t get a fake.

Amplifier Board
Amplifier Board

Taking the lid off reveals a very small PCB, taking up less than a third of the aluminium case! The input stage is on the right, composed of a pair of SOT-23 transistors to buffer the incoming signal. There’s an KST812M6 PNP & an S9014 NPN Epitaxial. The signal is then fed to the output stages, all individual S9014 NPN transistors to the output ports.
The power LED is just poking in the general direction of the hole in the front panel, so this isn’t likely to work very well – it’s going to illuminate the inside of the case more!

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Pringles Speaker Modifications

USB Charging Port
USB Charging Port

These speakers are available free from Pringles, with two packs bought. Normally running on 3x AAA cells, I have made modifications to include a high capacity Li-Ion battery & USB charging.

18650 Battery
18650 Battery

New battery is 3x 18650 Li-Ion cells in parallel, providing ~6600mAh of capacity. These are hot glued inside the top of the tube under the speaker, with the charging & cell protection logic.
The battery charging logic is salvaged from an old USB eCig charger, these are single cell lithium chargers in a small form factor ideal for other uses. Charging current is ~450mA.

Amplifier Board
Amplifier Board

The cells are connected to the same points as the original AAA cells, with the other pair of wires going into the top of the device to connect to the MicroUSB charging port.

The amplifier in this is a LM4871 3W Mono amplifier IC, connected to a 6Ω 1W speaker.
The other IC on the board is unidentifiable, but provides the flashing LED function to the beat of the music.