Slimline USB Charger for tiny ham Radios

The recent trend to smaller and smaller handy talkie (HT) transceivers is approaching the limits of the human interface. Sure, engineers could probably continue shrinking the Baofeng and Wouxun HTs further, but pretty soon they’ll just be too small to operate. And it’s getting to the point where the accessories, particularly the battery charging trays, are getting bulkier than the radios. With that in mind, [Mads Hobye] decided to slim down his backpacking loadout by designing a slimline USB charger for his Baofeng HT.

Lacking an external charging jack but sporting a 3.7 volt battery pack with exposed charging terminals on the rear, [Mads] cleverly capitalized on the belt clip to apply spring tension to a laser-cut acrylic plate. A pair of bolts makes contact with the charging terminals on the battery pack, and the attached USB cable allows him to connect to an off-the-shelf 3.7 volt LiPo USB charger, easy to come by in multicopter circles. YMMV – the Baofeng UV-5R dual-band HT sitting on my desk has a 7.4 volt battery pack, so I’d have to make some adjustments. But you have to applaud the simplicity of the build and its packability relative to the OEM charging setup.

This isn’t the first time we’ve seen [Mads] on Hackaday. He and the FabLab RUC crew were recently featured with their open-source robotic arm.

Improve Your HT Ham Radio by Adding a Counterpoise Antenna Wire


We found an interesting tip that might just improve the performance of those small affordable handheld ham radios called a “Handy Talky” or HT for short in ham vernacular. [RadioHamGuy] posted an interesting video on adding a counterpoise antenna wire to an HT. He claims it will noticeably improve both transmit and receive by making a quarter-wave monopole into a makeshift dipole antenna system.

Per his instructions you basically add a short wire to the antenna’s outer ground connection or to an equivalent case screw that’s electrically connected to the antenna’s ground side. Apparently this can be referred to as a Tiger Tail and does make it look like your HT has a tail. You would construct a counterpoise antenna wire 11.5 inch for VHF, 6.5 for UHF and about 19.5 inches for an OK performing dual band VHF/UHF radio.

Normally with a handheld radio the counterpoise (ground) is your own body as you are holding the HT. This is because the capacitance of your body makes a good counterpoise under normal conditions. It would be interesting to hear what others find for performance when adding a counterpoise antenna wire.

You can watch [RadioHamGuy’s] full construction tutorial video for multiple radio types after the break.

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DIY Slingbox

[David] took some interesting steps to put together his own Slingbox-ish setup. He used a Mac mini running Quicktime Broadcaster to capture the stream from a Firewire video camera which his cable/satellite receiver is plugged into. You’ll have to use an OS X machine, but that’s not too difficult these days. Broadcaster is about the simplest way to capture from Firewire and stream. We’re using it in our own office to multicast the signal from a Canadian satellite box.

LCD projector repair

[Kieth] picked up an Infocus projector only to find that it needed some repair. The polarizer on the blue light path was toast. When he parted out an Optoma projector he scored a polarizer that was just about right for the repair. It’s a good read even if you don’t have a projector in pieces at the moment. He ended up bending the mounting bracket a bit to hold the filter and got his projector fully up and running again.