Es’hail-2: Hams Get Their First Geosynchronous Repeater

In the radio business, getting the high ground is key to covering as much territory from as few installations as possible. Anything that has a high profile, from a big municipal water tank to a roadside billboard to a remote hilltop, will likely be bristling with antennas, and different services compete for the best spots to locate their antennas. Amateur radio clubs will be there too, looking for space to locate their repeaters, which allow hams to use low-power mobile and handheld radios to make contact over a vastly greater range than they could otherwise.

Now some hams have claimed the highest of high ground for their repeater: space. For the first time, an amateur radio repeater has gone to space aboard a geosynchronous satellite, giving hams the ability to link up over a third of the globe. It’s a huge development, and while it takes some effort to use this new space-based radio, it’s a game changer in the amateur radio community.

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EBay Modules And Custom PCBs Make A Plug And Play Ham Transceiver

Many of us have fond memories of our introduction to electronics through the “200-in-1” sets that Radio Shack once sold, or even the more recent “Snap Circuits”-style kits. Most of eventually us move beyond these kits to design our circuits; still, there’s something to be said for modular designs. This complete amateur radio transceiver is a great example of that kind of plug and play construction.

The rig is the brainchild of [jmhrvy1947], who set out to build a complete transceiver using mostly eBay-sourced modules. Some custom PCBs are used, but those are simple boards that can be etched and drilled easily. The transceiver is only for continuous-wave (CW) use, which would normally mean you’d need to know Morse, but thanks to some clever modifications to open-source apps like Quisk and FLDigi, Morse can be received and sent directly from the desktop. That will no doubt raise some hackles, but we think it’s a great way to learn code. The rig is QRP, or low power, transmitting only 100 mW with the small power amp shown. Adding eBay modules can jack that up to a full 100 Watts, which also requires adding a 12-volt power supply, switchable low-pass filters, a buck-boost converter, and some bandpass filters for band selection. It ends up looking very experimental, but it works well enough to make contacts.

We really like the approach here, and the fact that the rig can be built in stages. That makes it a perfect project for our $50 Ham series, which just kicked off. Perhaps we’ll be seeing it again soon.

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The $50 Ham: Getting Your Ticket Punched

Today we start a new series dedicated to amateur radio for cheapskates. Ham radio has a reputation as a “rich old guy” hobby, a reputation that it probably deserves to some degree. Pick up a glossy catalog from DX Engineering or cruise their website, and you’ll see that getting into the latest and greatest gear is not an exercise for the financially challenged. And thus the image persists of the recent retiree, long past the expense and time required to raise a family and suddenly with time on his hands, gleefully adding just one more piece of expensive gear to an already well-appointed ham shack to “chew the rag” with his “OMs”.

Not a $50 ham. W9EVT’s shack. Source: QRZ.com

As I pointed out a few years back in “My Beef With Ham Radio”, I’m an inactive ham. My main reason for not practicing is that I’m not a fan of talking to strangers, but there’s a financial component to my reticence as well – it’s hard to spend a lot of money on gear when you don’t have a lot to talk about. I suspect that there are a lot of would-be hams out there who are turned off from the hobby by its perceived expense, and perhaps a few like me who are on the mic-shy side.

This series is aimed at dispelling the myth that one needs buckets of money to be a ham, and that jawboning is the only thing one does on the air. Each installment will feature a project that will move you further along your ham journey that can be completed for no more than $50 or so. Wherever possible, I’ll be building the project or testing the activity myself so I can pursue my own goal of actually using my license for a change.

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This Satellite Finder Can Watch Amateur TV

Setting up satellite dishes can be a finicky business. To aid in the alignment of these precision antennas, satellite finders are often used which can display audio and video feeds from the satellite while also providing signal strength readouts for accurate adjustment. However, these devices can also be used in interesting ways for more terrestrial purposes (Youtube link).

Using the DMYCO V8 Finder, [Corrosive] demonstrates how to set up the device to pick up terrestrial amateur streams. Satellite reception typically involves the use of a low-noise block downconverter, which downconverts the high frequency satellite signal into a lower intermediate frequency. Operating at the 1.2GHz amateur band, this isn’t necessary, so the device is configured to use an LNB frequency of 10000, and the channel frequency entered as a multiple of ten higher. In this case, [Corrosive] is tuning in an amateur channel on 1254 MHz, which is entered as 11254 MHz to account for the absent LNB.

[Corrosive] points out that, when using an F-connector to BNC adapter with this setup, it’s important to choose one that does not short the center pin to the shield, as this will damage the unit. This is due to it being designed to power LNBs through the F-connector for satellite operation.

By simply reconfiguring a satellite finder with a basic scanner antenna, it’s possible to create a useful amateur television receiver. If you’re wondering how to transmit, [Corrosive] has that covered, too. Video after the break.

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Lime SDR (and Pluto, Too) Sends TV

If you have experienced software defined radio (SDR) using the ubiquitous RTL SDR dongles, you are missing out on half of it. While those SDRs are inexpensive, they only receive. The next step is to transmit. [Corrosive] shows how he uses DATV Express along with a Lime SDR or a Pluto (the evaluation device from Analog Devices) to transmit video. He shows how to set it all up in the context of ham radio. An earlier video shows how to receive the signal using an SDR and some Windows software. The receiver will work with an RTL SDR or a HackRF board, too. You can see both videos, below.

The DATV Express software has plenty of options and since SDR if frequency agile, you ought to be able to use this on any frequency (within the SDR range) that you are allowed to use. At the end, he mentions that to really put these on the air you will want a filter and amplifier since the output is a bit raw and low powered.

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Using AI To Pull Call Signs From SDR-Processed Signals

AI is currently popular, so [Chirs Lam] figured he’d stimulate some interest in amateur radio by using it to pull call signs from radio signals processed using SDR. As you’ll see, the AI did just okay so [Chris] augmented it with an algorithm invented for gene sequencing.

Radio transmitting, receiving, and SDR hardwareHis experiment was simple enough. He picked up a Baofeng handheld radio transceiver to transmit messages containing a call sign and some speech. He then used a 0.5 meter antenna to receive it and a little connecting hardware and a NooElec SDR dongle to get it into his laptop. There he used SDRSharp to process the messages and output a WAV file. He then passed that on to the AI, Google’s Cloud Speech-to-Text service, to convert it to text.

Despite speaking his words one at a time and making an effort to pronounce them clearly, the result wasn’t great. In his example, only the first two words of the call sign and actual message were correct. Perhaps if the AI had been trained on actual off-air conversations with background noise, it would have been done better. It’s not quite the same issue, but we’re reminded of those MIT researchers who fooled Google’s Inception image recognizer into thinking that a turtle was a gun.

Rather than train his own AI, [Chris’s] clever solution was to turn to the Smith-Waterman algorithm. This is the same algorithm used for finding similar nucleic acid sequences when analyzing genes. It allowed him to use a list of correct call signs to find the best match for what the AI did come up with. As you can see in the video below, it got the call signs right.

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The Return of RadioShack?

We’ve been following the ups and downs of Radio Shack for a while now, and it looks like another chapter is about to be penned in the storied retailer’s biography – and not Chapter 11 bankruptcy this time.

According to the ARRL website and major media reports, up to 50 of the 147 US locations of HobbyTown, the brick-and-mortar retailer of RC and other hobby supplies, will soon host a “RadioShack Express” outlet. Each outlet will be up to 500 square feet of retail space devoted to electronic components that would be of use to HobbyTown’s core customer base, as well as other merchandise and services.

HobbyTown locations in Mooresville, North Carolina, and Ontario, Ohio, will be among the first stores to get the RadioShack Express treatment. Current employees of the franchisees will staff the store-within-a-store, which will be stocked with RadioShack merchandise purchased by the store. Stores with Express outlets will have special RadioShack branding inside and out to attract customers. There’s talk of the deal being extended chain-wide if the pilot program goes well.

Back from the Ashes?

This is obviously great news for the beleaguered electronics retailer that was once a neighborhood fixture. True, its parts selection was often less than complete, more so in recent years than in the chain’s heyday in the mid-1970s and early 1980s. And it’s true that prices were often astronomical compared to buying online. But on a Sunday afternoon, The Shack was a lifesaver for that last minute part needed to finish a project, and the premium was well worth the convenience. Watching the decline of the chain and seeing stores disappear one by one was a slow, sad process, so that makes this seems like an unqualified positive development.

But is it? On the face of it, there’s a lot of synergy between the HobbyTown offerings and what could be stocked in a RadioShack Express. I’ve never actually visited a HobbyTown myself — I plan to fix that now that I know I’ve got an outlet nearby, even if it doesn’t appear to be on the list of 50 early Express locations — so I can only go by what I see listed online for merchandise. But a store that sells every conceivable part for RC cars and planes, drones, model rockets, and STEM-related toys and kits seems a likely place to find customers for RadioShack’s offerings.

It won’t be clear until someone sees one of these Express kiosks first hand and reports back, but it seems like we might see something like the old “cabinet o’ components” that was found in the back of the most recent incarnation of RadioShack retail stores, along with a few shelves full of things like solder, wire, and tools. There may also be some items in the Arduino-Pi space, which would be really exciting, although that might run afoul of existing HobbyTown offerings. Still, one-stop shopping of everything from servos to MOSFETs would be a huge win for electronics hobbyists.

Not the Cell Phones Again!

But there may be cause for concern. Reports are that RadioShack Express locations will also offer services such as cell phone repairs. Dipping a toe into the cell phone market seemed to be the beginning of the end for RadioShack the first time through, and by the time it was clear to everyone that the chain was on death’s door, it was hard to go into a RadioShack store without being bombarded by cell phone sales pitches. To be brutally frank, I don’t take the early inclusion of cell phone repairs as an encouraging sign of the long-term viability of the RadioShack Express concept. Do we really need another place that fixes cell phones? The areas that HobbyTown stores tend to locate are rife with places that fix phones already, so I just don’t see the point. And it just smacks of the bad old days of RadioShack.

Still, I’m cautiously optimistic that this is a positive development for RadioShack, and I think it’s a win for electronics hobbyists overall. I’ll be keeping my eye on my local HobbyTown for the return of that iconic RadioShack logo, and looking forward to the day that I can pay a buck for a resistor again. Until then, if any readers happen to be near one of the combined locations when they open next week, we’d love a boots-on-the-ground report. Post your observations in the comments below, and pix or it didn’t happen.

[via r/amateurradio]