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Labgear PSM114E/S 12v Conversion

Onboard the boat we have a small issue with a weak TV signal, and this coupled with a 60′ long run of coax is an issue. Due to the loss in the coax, we’ve lost most of the already weak signal.
To try & solve this issue, I’m fitting a masthead amplifier unit.

These amplifiers are fed power down the same coax that’s carrying the RF signal, and a special power supply is supplied with the amplifier for this. However it’s only 240v AC, no 12v version available.

Here’s the power supply unit, which fits into the coax between the TV & the antenna.

Amplifier Supply
Amplifier Supply

Luckily the 240v supply is easily removable & here has been replaced with a 12v regulator.

New Supply
New Supply

There’s not very much inside the shielding can, just a few filter capacitors & an RF choke on the DC feed, to keep the RF out of the power supply system.

The original cable is used, so the supply doesn’t even look like it’s been modified from the outside.

More to come on this when I get the amplifier installed along with the new coax run 🙂

73s

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Ericsson GA628

Front
Front

Here is a phone from the mid 90s, the Ericsson GA628. Here visible is the front of the unit with keypad, & single line monochrome LCD for number display.

Battery & Rear
Battery & Rear

Here the battery is removed from the phone, showing the SIM card socket. At the top under the antenna stub is the socket for an external antenna.

Front Removed
Front Removed

Here the front is removed from the phone, PCB on left, rear of keypad on right. Microphone is at bottom of keypad, with speaker at the top. Top right of the PCB is the ringer buzzer, left is shield for RF amplifier.

Main PCB
Main PCB

Here is the back of the main PCB, RF sections on left & centre. Processing & memory on right.

Battery
Battery

This phone had a Ni-Mh battery, before Li-Ion batteries were introduced.

LCD
LCD

The LCD from the front of the phone is shown here. A simple dot matrix single line unit.