rotator

5 Articles

Broadcast TV Simulator Keeps The Nostalgia Flowing

September 26, 2024 by 40 Comments

Watch out, Gen X-ers — there’s a nostalgia overload heading your way, courtesy of this over-the-air TV simulator. And it has us feeling a little Saturday morning cartoon-ish, or maybe even a bit Afterschool Special.

[Shane C Mason]’s “FieldStation42” build centers around a period-correct color TV, and rightly so — a modern TV would be jarring here, and replacing the CRT in this irreplaceable TV would be unthinkable. Programming comes via painstakingly collected sitcoms, dramas, news broadcasts, and specials, all digitized and stored on disk and organized by the original networks the programs came from. Python running on a Raspberry Pi does the heavy lifting here, developing a schedule of programs for the week that makes sense for the time of day — morning news and talk, afternoon soaps, the usual family hour and prime time offerings, and finally [Carson] rounding out the day, because that’s all we had for late night.

As for switching between stations, rather than risk damaging the old TV, [Shane] really upped his nostalgia game and found an old antenna rotator control box. These were used to steer the directional antenna toward different transmitters back in the day, especially in fringe areas like the one he grew up in. He added a set of contacts to the knob and a Pi Pico, which talks to the main Pi and controls which “channel” is being viewed. He also added an effect of fading and noise in the video and audio between channels, simulating the antenna moving. The video below shows it in action.

For those who missed the Golden Age of TV, relax; as [Shane] correctly surmises after going through this whole project, Golden Ages only exist in your mind. Things were certainly different with 70s mass media, a fact which this build captures neatly, but that doesn’t mean they were better. Other than Saturday mornings, of course — those were objectively better in every way.

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Start Tracking Satellites With This Low-Cost Azimuth-Elevation Positioner

November 26, 2017 by 28 Comments

Tracking satellites and the ISS is pretty easy. All you really need is an SDR dongle or a handheld transceiver, a simple homebrew antenna, and a clear view of the sky. Point the antenna at the passing satellite and you’re ready to listen, or if you’re a licensed amateur, talk. But the tedious bit is the pointing. Standing in a field or on top of a tall building waving an antenna around gets tiring, and unless you’re looking for a good arm workout, limits the size of your antenna. Which is where this two-axis antenna positioner could come in handy.

While not quite up to the job it was originally intended for — positioning a 1.2-meter dish antenna — [Manuel] did manage to create a pretty capable azimuth-elevation positioner for lightweight antennas. What’s more, he did it on the cheap — only about €150. His design seemed like it was going in the right direction, with a sturdy aluminum extrusion frame and NEMA23 steppers. But the 3D-printed parts turned out to be the Achille’s heel. At the 1:40 mark in the video below (in German with English subtitles), the hefty dish antenna is putting way too much torque on the bearings, delaminating the bearing mount. But with a slender carbon-fiber Yagi, the positioner shines. The Arduino running the motion control talks GS232, so it can get tracking data directly from the web to control the antenna in real time.

Here’s hoping [Manuel] solves some of the mechanical issues with his build. Maybe he can check out this hefty dish positioner for weather satellite tracking for inspiration.

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Shop-Made Fixture Turns Out Dream Welds

November 10, 2017 by 14 Comments

You can tell a lot about a person by the company they keep, and you can tell a lot about a craftsman by the tools and jigs he or she builds. Whether for one-off jobs or long-term use, these ad hoc tools, like this tubing rotator for a welding shop, help deliver results beyond the ordinary.

What we appreciate about [Delrin]’s tool is not how complex it is — with just a motor from an old satellite dish and a couple of scooter wheels, it’s anything but complicated. What we like is that to fabricate some steering links, each of which required three passes of TIG welding to attach a threaded bung to the end of a rod, [Delrin] took the time to build just the tool for the job. The tools slowly rotates the rod, letting the welder keep the torch in one position as the workpiece moves under it. The grounding method is also simple but clever — just a wide strap of braid draped over the rod. The result is some of the prettiest and most consistent welds we’ve seen in a while, and with an order for 28 steering links, it ought to be a huge time saver.

It may be time for a little more TIG welding love around here. Sure, we’ve covered the basics of oxy-acetylene welding, and even talked about brazing aluminum. Perhaps your humble Hackaday writer will take the plunge into a new TIG welder and report from a newbie’s perspective. You know, for science.

[via r/welding]

Antenna Rotation Arduino Style

August 31, 2016 by 12 Comments

Back in the days when you didn’t pay for your TV programming, it was common to have a yagi antenna on the roof. If you were lucky enough to have every TV station in the area in the same direction, you could just point the antenna and forget it. If you didn’t, you needed an antenna rotator. These days, rotators are more often found on communication antennas like ham radio beams. For terrestrial use, the antenna only needs to swing around and doesn’t need to change elevation. However, it does take a stout motor because wind loading can put a lot of force on the system.

[SP3TYF] has a HyGain AR-303 rotator and decided to build an Arduino-based controller for it. The finished product has an LCD and is able to drive a 24 V motor. You can control the azimuth of the antenna with a knob or via the computer.

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Track Satellites With A 2-axis Antenna Positioner

January 20, 2016 by 22 Comments

Ham radio operators are curious beasts. They’ll go to great lengths to make that critical contact, and making sure their directional antennas are pointing the right way can be a big part of punching through. Of course there are commercial antenna rotators out there, but hams also like to build their own gear, like this Raspberry Pi-controlled 2-axis rotator.

[wilho]’s main motivation for this build seems to have been the sad state of the art in commercial 2-axis rotators, which seems firmly mired in the 90s. Eschewing the analog pot sensors on DC brushed motors that seem to dominate the COTS market, [wilho] went with steppers and stout gearboxes for the moving gear. Feedback on the axes comes from 10-bit absolute encoders, and an MPU9250 9-axis IMU makes sure he knows exactly where the antenna is pointing with respect to both compass heading and elevation. A mast-mounted Rasp Pi controls everything and talks through a REST API to custom software that can return the antenna to custom set-points or track the moon, satellites, or the ISS. It’s a very impressive bit of kit that’s sure to drive your home-owners association bonkers.

For another 2-axis antenna positioner, check out 2015 Hackaday Prize finalist SATNOGS.

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