Category Archives: Aviation

Video tour of the E-4B NAOC Doomsday Plane

An Air Force E-4B National Airborne Operations Center aircraft sits at the international airport in Bogota,Colombia Oct. 3, waiting for Secretary of Defense Robert M. Gates. U.S. Air Force photo/Tech. Sgt. Jerry Morrison)

Many thanks to SWLing Post contributor, Jason Whiteley, who shares a video tour of the E-4B NAOC Doomsday Plane and notes:

This is a pretty interesting video of the inside of the flying Pentagon or Doomsday Plane. There is a lot of radio equipment on board including a radio antenna that can fly out of the back of the plane:

Click here to view on YouTube.

This is very cool, Jason! It’s amazing how much technology they’ve crammed into this Boeing 747-200. The 747 is a large aircraft, but when loaded with so much technology and support staff, there’s no room to spare.

With a video this detailed in the public domain, I can’t help but think there may already be a replacement for the E-4B.

Thanks for sharing!

Video: Air traffic on the HF bands

Many thanks to SWLing Post contributor, Dan Hawkins, who writes:

Air traffic bands on VHF is well-known.

Not so well-known are the shortwave (HF) communications networks that must be operated by transoceanic flights.

This is an ARINC station for San Francisco, California. I am located about 70 miles inland from this station. I assume ARINC is using a directional antenna system beamed westward toward the Pacific Ocean.

I recorded this video of an ARINC station late last night for my YouTube channel.

Click here to view on YouTube.

Many thanks, Dan!

I enjoy monitoring air traffic on VHF and often forget that when I’m outside the range of an airport’s tower, I can still hop on HF and often hear international traffic. Thanks again!

Photos of a B-17G Radio Operator Position

I had the pleasure of visiting the Champaign Aviation Museum recently and examining their under-restoration B-17G, “Champaign Lady”. Actually, the term “under-restoration” is incorrect. In actuality, the Champaign Aviation Museum is effectively building their B-17G nearly from scratch—quite an undertaking but one that the volunteers are performing skillfully and enthusiastically.

Being an amateur radio operator, shortwave listener, and would-be WWII-radio restorer, I was was pleased to see that Champaign Lady already has a nearly-complete radio-operator position installed, between the bomb-bay and the waist-gun section of the airplane. As a B-17G would have had during the war, Champaign Lady features a BC-348 liaison receiver and morse-code key mounted on a desk on the port (left) side of the bomber and a stack of AM/CW Command Set transmitters and receivers racked on the starboard (right) side of the bomber. In the photos, the top Command Set boxes are the transmitters and the bottom three Command Set boxes are the receivers. Of course, the BC-348 and the Command Set transmitters and receivers are fully tube-type, semiconductors having not yet been invented. During the war speedometer-type cables would connect the Command Set receivers to controls in the cockpit, allowing the pilot and co-pilot to control the Command Set receiver frequencies; electrical cables would have carried the receivers’ audio to the pilot and co-pilot and would have allowed them to change volume-level. The radio operator could transmit using the Command Set transmitters and could also switch the pilot or co-pilot intercom microphones to any of the Command Set transmitters to allow the pilot or co-pilot to broadcast to other bombers in the formation.

"Champaign Lady" radio operator position

B-17G “Champaign Lady” radio operator position; BC-348 liaison receiver on the port (left) side and Command Set transmitters and receivers on the starboard (right) side.

"Champaign Lady" BC-348 receiver

B-17G “Champaign Lady” BC-348 liaison receiver and morse-code key.

"Champaign Lady" Command Set transmitters and receivers

B-17G “Champaign Lady” Command Set transmitters and receivers on the starboard side of the radio room

During the war, the B-17G radio operator was an enlisted man, typically a sergeant or higher in rank. If in an earlier version of the B-17G, the radio operator was also responsible for manning a .50 caliber machine gun located in his section of the airplane. In all versions of the B-17G, the radio operator assisted the navigator by providing position reports based on radio fixes of beacons or radio stations. Additional information about the role of the B-17G radio operator can be found on the B-17 Queen of the Sky website.

And, for those interested, here is what Champaign Lady’s nose-art looks like:

B-17G "Champaign Lady" nose-art

B-17G “Champaign Lady” nose-art, starboard side; the port side features a mirror-image version of the same design

The Champaign Aviation Museum has a beautifully restored B-25J, “Champaign Gal”, in flying condition. Unfortunately, I’ve not been able to see if Champaign Gal features a restored radio operator position.

I have a BC-224, which is the 12-volt version of the BC-348 liaison receiver to put back into service as well as a BC-696A Command Set transmitter that I hope to eventually put back onto the air in the 80-meter amateur band. It would be wonderful if I had a B-17G in which to install these items—or even just room to build a replica B-17G radio operator position!


Eric McFadden, WD8RIF

ADS-B for SDRplay RSP1 and RSP2 now available

I was very happy to see the following message from Jon Hudson at SDRplay this morning:

“ADS-B for both RSP1 and RSP2 is now available for the Raspberry Pi 2 & 3 – you can get the software from downloads –

If you are an RSP2 user, make sure you use Antenna Port B when running ADS-B.”

This is great news as I’ve had a number of readers ask if the RSP series SDR was compatible with the DUMP1090 ADS-B system.

The SDRplay RSP2

If you have an RSP1 or RSP2 and either a Raspberry Pi 2 or Pi 3, this will be an easy, accessible way to experiment with ADS-B.

In the long run, however, I’d never devote an RSP as a dedicated ADS-B feeder. Why? The RSP is a very versatile, full-featured SDR and I wouldn’t want to tie it up with such a relatively routine, simple task.

Instead, I’d give ADS-B a try with the RSP, and if I liked it, I’d purchase this inexpensive FlightAware RTL-SDR dongle with a built-in 1090 MHz bandpass filter for $18.95.

Click here to read my recent article about setting up a FlightAware ADS-B feeder.

I’m always so happy to see such active application development from “Mom and Pop” companies like SDRplay and AirSpy. Just more ways to put your SDR to work for you!

Dan’s take on ADS-B with the Raspberry Pi B model

Many thanks to SWLing Post contributor, Dan Srebnick (K2DLS), who recently posted a detailed overview of his ADS-B installation on his blog:

Monitoring NextGen ATC (on the cheap!)

A key component of next generation air traffic control is Automatic Dependent Surveillance – Broadcast (ADS-B). The current FAA mandate is for all included aircraft to output ADB-B transmissions no later than January 1, 2020. But you don’t have to wait to receive and map ADS-B. There is a lot of air traffic to be seen.

[…]I decided to use a spare older RTL-SDR stick based on the RTL2832U and R820T chips. This USB device comes with a small antenna that I hoped would be good enough to get me started. It is not in any way optimized for the 1090 MHz signals that are used by ADS-B and is roughly 19 parts per million (ppm) off frequency. It cost a bit over $10 at a hamfest a couple of years ago. The designs have improved since the early models were offered. Newer models include a TCXO (thermally compensated crystal oscillator) for stability and accuracy.

I needed software to take signals from the RTL-SDR stick and plot them on a map. That software is “dump1090”, originally written by Salvatore Sanfilippo. I added an install stanza to the Makefile, along with a systemd service file, for a smooth system install. I also needed to install the RTL-SDR USB drivers. The complete installation runs “headless”, meaning no monitor, keyboard or mouse need be connected. Remote management can be done via ssh.[…]

Continue reading on Dan’s blog…

This is fantastic, Dan! Thank you for taking the time to share all of the code snippets you needed to do the installation on the Raspberry Pi B as well. Post Readers: if you have an older Raspberry Pi and RTL-SDR sitting on a shelf, use Dan’s guidance to turn them into an ADS-B feeder!

Click here to read my ADS-B feeder tutorial based on the Raspberry Pi 3.