Tag Archives: VHF

First Amateur Radio in Geosynchronous Orbit Will Aid Disaster Communications

Could it be we will have a true geosynchronous satellite for Amateurs in 2017?! I hope so, and we will not need an antenna this big to use it!

This was first reported in Wireless Design Magazine

Researchers at the Ted and Karyn Hume Center for National Security and Technology are preparing to send an amateur radio transponder into a geosynchronous orbit in 2017.

“Seven days a week, 24 hours a day, 365 days a year, a new ham band will be available for the Americas,” said Robert McGwier, a research professor in the Bradley Department of Electrical and Computer Engineering and the Hume Center’s director of research. “It will allow rapid deployment to disaster areas and support long-haul communications for first responders.”

This would be the first amateur or “ham” radio payload in a geosynchronous orbit, and would significantly enhance communications capabilities for amateur radio operators, in particular following natural disasters or other emergency situations. The Hume Center team met with Federal Emergency Management Agency Administrator Craig Fugate in September to discuss the project.

The full article may be found following this link.

I have really been enjoying trying to catch the satellites and the International Space Station as I am able, but it really is catch as catch can due to orbiting times and changing horizon points. A geosynchronous orbit satellite means we could plant an antenna pointed directly at the satellite and find it there day or night. I for one am ready!! I might even dedicate an inexpensive dual-band radio to it assuming typical satellite repeater protocol is used.

I will post more details as I find out additional information. Cheers! Robert

Robert Gulley, AK3Q, is the author of this post and a regular contributor to the SWLing Post. Robert also blogs at All Things Radio.

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Using the RTL2832U $20 SDR for HF & trunk-tracker scanning?

3 Replies

In response to our post on inexpensive SDRs based on the RTL2832U, Jeff Benedict writes:

Here’s a website that has a lot of info on cheap SDR gear. They have a write-up on an external board which adds HF capabilities. I have one but haven’t done anything with it yet.

http://www.hamradioscience.com

Jeff KB7AIL CN88

Thanks, Jeff! Has anyone tried HF with any success? I’m curious how well this über-cheap receiver will cope with adjacent signals and blowtorch stations within the HF spectrum.

Meanwhile Neil, blogger on Fofio, commented:

I have an RTL-SDR system up and running. I have done 2 demonstrations for my local Ham Radio club. One on the basic setup and use of the dongle, using both SDR# and HDSDR. The other presentation showed the remote receiver capability using a Raspberry Pi as the receiver with the dongle attached and a remote SDR# computer decoding the stream over a network connection. Once I compensate for some minor frequency discrepancies it’s a pretty good receiver. The only issue I have noticed with mine (one of the early E4000-based models) is a tendency to overload in the presence of a strong signal. We have a pretty powerful 2 Meter repeater less than a 1/4 mile from our home, and when it’s active it causes some strange results with the RTL-SDR setup.

I have yet to try one of the HF converters they make for these. I hope to do that soon.

Another project I was reading about today that I may try out is using 2 of the dongles at once to create a trunk-tracker scanner.

Wow! Two $20 USB SDRs and a little PC magic could yield a trunking scanner? I want to hear more about this. Trunking scanners tend to be both expensive and complicated. If a web-updated database could be downloaded and used to control this sort of rig, the possibilities would be most impressive!

Neil, keep us informed!

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A very inexpensive Software Defined Radio based on the RTL2832U

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Many thanks to Benn (AK4AV) for passing along this article from the IEEE which describes how a $20 USB digital TV antenna tuner can be transformed into an impressive, flexible software defined radio:

http://spectrum.ieee.org/geek-life/hands-on/a-40-softwaredefined-radio

The article incldes the following embedded video from the IEEE:

Here is another informative video via YouTube:

This year at the SWL Winterfest we had a presentation on the topic of $20 SDRs configured like those above. Some scanner enthusiasts had used them to receive satellite and many other VHF/UHF communications. I’ve heard of some devices being nearly plug-and-play easy to install and configure; others may take some minor tweaking. All of the SDR applications and drivers are either open source or free.

This page contains a wealth of information on the topic of RTL2832U based SDRs–it makes for a great starting point.

If you have experimented with thRTL2832U USB SDR, please comment below.

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