These units are used to broadcast local audio, such as from a public address system or local microphone. They accomplish this by producing a modulated magnetic field that a hearing aid is capable of picking up. Not many controls on this bit of equipment. A bi-colour LED for status indications,
I’ve had a couple of viewfinder CRT modules for a while, & haven’t done much with them, so I decided to make a very small B&W monitor. I ordered a small transparent ABS box when I made a large order with Farnell, that turned out to be just about the
One bit of my equipment that I’ve never looked into is my scanner, a handheld Uniden unit. I got this when Maplin Electronics had them on special offer a few years ago. Here’s the scanner itself, roughly the same size as a usual HT. Here the back cover has been
Following on from my review, here are some internal views & detail on the components used in this radio. Below is an overview of the main PCB with the top plate removed from the radio. Most visible are these MOSFETs, which are Mitsubishi RD70HVF1 VHF/UHF power devices. Rated for a
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. New battery is 3x 18650 Li-Ion cells in parallel, providing ~6600mAh of capacity. These are hot glued inside the
For convenience, a pair of USB ports have been fitted to the wearable Pi, which open on the bottom of the unit. These will be hardwired into a 4-port USB hub which will also support the wireless adaptor for the mini-keyboard that is to be used with the device. The
Here are a few details of a valve amplifier I am building, using the valve related parts from a 1960’s reel to reel tape recorder. This amplifier is based on an a Mullard ECL82 triode/pentode valve, with an EM84 magic eye tube for level indication. Here the first components are
Continue readingDIY Valve Amplifier – Part 1 – Amplifier Section
Here is an old XM2000 marine VHF tranciever. Here is the casing split, with the main CPU board & display on the right, & the RF tranciever board on the left. View of the main CPU board, with the mic & loudspeaker on the right hand side. The channel display
Here is a Sanyo tape recorder, with built in voice activation. Takes standard audio cassettes. Here visible is the speaker on the left, microphone is on the right of the tape window. The tape counter is at the top. Back cover removed from the unit, showing the PCB & the
Here is a PSP Slim that recently died. For those that are interested, here is the ID label, this is a PSP-2003. Here the front of the unit has been removed, showing the first internal components. Here is the unit with the LCD removed, here the mainboard is partially visible.
This is an old cordless landline phone, with dead handset batteries. Here’s the handset with the back removed. Shown is the radio TX/RX board, underneath is the keyboard PCB with the speaker & mic. All the FM radio tuning coils are visible & a LT450GW electromechanical filter. Radio PCB removed
Here is a more modern phone, the Motorola V360v. Features include Dual screens, 640×480 VGA camera, full col our TFT Main LCD, SD-Micro slot. Here on the back the grey scale LCD can be seen, with the camera lens to the right of the Motorola logo Here the phone is
Another phone from the mid 90s. This is the nokia 7110. Here the slider is open showing the keypad. Here the battery is removed, a Li-Ion unit. The battery cell & protection circuit removed from the casing. This is the rear of the PCB removed from the housing. Data &
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. Here the battery is removed from the phone, showing the SIM card socket. At the top under the antenna stub is