Hello
I work at an aviation museum dealing with a fantastic collection of static and flying ex military aircraft. We have been fortunate to secure the navigational beacon transmitter (NDB) from the local airfield for use as a static exhibit having been made redundant. To enhance the display, I want to add in aircraft hardware that would have been required by this system. In particular, I am chasing a suitable circuit that would generate the ground station identifier in Morse, in this case SCN and have it auto loop back and repeat every 5 or 10 seconds. This would be connected to a speaker so visitors could get a good appreciation of how the pilot interfaced with this system.
Thanks kindly
Blue VK2CBN
I see a few possible solutions DIY solutions to the scenario. 1. record the station identifier signal as an MP3 (audio) file (I can only assume that you can gain access to such a signal for a little while so you can record it on file) and put it on a little (Micro SD) memory card, Then use an arduino style memory card shield to interface with an arduino board and with (few lines of code) would program it to playback that file every few seconds (and obviously the output would be hardwired to a little audio amplifier). 2. recreate the same signal (as a synthetic reproduction of the same signal) and play it back with just using code ” some special libraries are needed” (but I doubt it would sound as good as a proper MP3 file). 3. get yourself a basic run of the mill MP3 file player (such as those using a USB stick or a microsd card or similar and connect it to an audio amp. then record the signal you wand as MP3 file and build a simple Timer circuit (such as 555 or something) and connect it to the play button of the mp3 player so it triggers the play button every few seconds. There are also other ideas….sky is the limit :))
Well thought through, any of these solutions would work great!
Woodb180
Another solution that would give you flexibility and is not too complex is a an Arduino with speaker. Here is one that has LED’s also. You could delete the LED’s and related code, or just build it as shown. You can program the code for SCN. It will repeat. Only potential issue is whether the sound quality will match the transmitted NDB signal in tone and quality. Here is the Arduino link:
https://www.instructables.com/Arduino-Morse-Code/
Your museum seems intriguing. Slightly unrelated to your specific request, but directly related to the importance of NDB Morse code identifiers, is an article I wrote a few years ago, as a pilot. It is regarding the cause of the crash of a SAR B-17G in 1952 in the Buckhorn Wilderness area of the Olympic Peninsula. We live nearby and backpacked into the site. I concluded that the official accident report could not have been correct. My article goes in depth into the four course radio range system, NDB’s, and IFR procedures, routes and systems in use in 1952. I was able to determine what actually led to that crash. I gave the ATC Historical site non-exclusive rights to publish the article. I would do the same for your museum if interested. It is a deep dive into the specific incident, but includes an in depth discussion of these historical systems and how they worked. Directly on point is that one of the most serious of the several errors made by the crew, was their failure to listen to, and identify the Morse code identifier of a critical NDB marker beacon. Because they did not do this, they wrongly assumed they were over a specific NDB when they made a turn, when in fact they were over a different NDB at a different location. If you would like to communicate directly my email is paulinsunriver2@netscape.net. Here is a link to the article on the ATC History site. Click on the page to go to the article:
https://www.atchistory.org/analysis-of-the-1952-b-17g-aircraft-crash-by-paul-eisenberg/
One other comment on the Arduino approach. If you do this, suggest you use the code posted by mrhenry1876 in the comments on that site. It has more characters, some corrections, and cleaner than the original version. Coding and compiling code to an Arduino is pretty easy once you get the right software and follow the instructions.
@pauleisenberg Wow… quite a story about that accident then. Tnx. for sharing the historical facts.
Blue VK2CBN; where are you located? I see “Blue Aviation” in Kuwait? I do not find any active or deactivated radio beacon with identifier SCN in any list I’ve searched. As a pilot I’m curious about your aviation museum, and wondered if you had interest in the article I wrote about the consequences of failing to use the Morse code ID of a beacon. Do you have a website?
@ovi4 It was interesting researching this. Several sites about it, some with family connections to the crew. None seemed to really want to know the true cause, so after reading all their information and the official military accident analysis, I decided to figure it out myself. As a pilot I’ve read a lot of accident reports with the idea of putting myself mentally into the situation, and learn from others mistakes. When I did that with this one, it just did not make any sense at all. Now it makes complete sense, and is typical of the compounding errors and confirmation bias that leads to so many pilot error accidents.
@pauleisenberg A little more about the Arduino approach. I did it a couple of years ago using an ATTINY85 which costs
under a dollar at Aliexpress. If you have an Arduino hobbyist available – or can do it yourself, it’s easy! Ed
Australia would be my guess as VK2CBN is an Australian call sign.Blue VK2CBN; where are you located? I see “Blue Aviation” in Kuwait? I do not find any active or deactivated radio beacon with identifier SCN in any list I’ve searched. As a pilot I’m curious about your aviation museum, and wondered if you had interest in the article I wrote about the consequences of failing to use the Morse code ID of a beacon. Do you have a website?