Multi-channel ALE Decoder: Listing and Logging

Chris Smolinski’s Black Cat Systems ALE Decoder has changed monitoring ALE messages which are widely used onf HF to provide an automatic link establishment. It has set the standard not only by its unsurpassed sensitivity and the option to decode up to 24 channels in parallel, but also with its look-up table for “translating” cryptic ALE callsigns into stations and locations of flesh and blood. Tahnks to this, the usual decoded message of just
- 7527.0 [Frequency in kHz] USB [mode] 2021-11-10 22:54:24 [date/time] 16 [BER] TO TSC TIS K62
turns into:
- 7527.0 USB 2021-11-10 22:54:24 16
TO TSC COTHEN Technical Service Center Orlando FL USA
TIS K62 USGC MH-65D/E Short Range Recovery Helicopter Dolphin #6562 USA
This blog entry provides a description of the system as well as a list of 3’200+ ALE callsigns as a First Aid Kit.
How Callsigns come into Life
This feature is a major achievement in DXing. And it is, too, that innovative that we have to set our sails into unchartered sea. [Do you remember the completely blank OCEAN-CHART. in Lewis Caroll’s “The Hunting of the Snark” from 1876? You are here!]
The general idea of the software is to look-up each decoded callsign in a list of tab-separated information where you already had collected metadata like organization, station, location, country – anything you consider important.
The software then looks up each callsign – as above TSC and K62 -, introduces all the information in a neat way and prints it all together in the window. Even more, as the software automatically fills a logfile with all this for later inspection, edition and further processing by spreadsheet or database. Smart! And unique!
The callsigns’ document and its quality (extent, reliability, consistency …), of course, plays a pivotal role, see following illustration – shit in, shit out.

Whatever format your Reference Database may have, it will and must put out a simple tab-separated textfile.
It helps if you think of different type of data (organization, location, country …) as of different fields or cells, each separated by a TAB from each other – see an example with just one entry below.
All data fenced in by TAB can contain arbitrary characters, such as spaces, brackets, commas etc.
ALE Call | Organization | Name | Location | Type | … | ITU |
HNC | USCG | Harriet Lane | Portsmouth VA | WMEC-903 | … | USA |
Different output Formats for different Tastes
The decoder may present the same decoded message plus the same information from your callsign file in different ways, controlled by the “Settings” menu of the decoder:

Let us now decline the different Message Formats for a simple message of LNT calling J10 on November 6th, 2021 at 22:19:59 UTC, with data from “ale_callsigns”, see lines 16 to 18 :

The sources for e.g., line 42 are marked in colors:

Divide and conquer
The look-up table(s) must be saved in a directory called “ale_callsigns” (lower case!) in the Documents directory for your user account.

Above you see not only one callsigns’ file, but many. There is a reason for that: If you have a large callsign file, undoubtedly some one and the same callsign will be valid for two or several stations. If the software detects this case, it prints (original decoded message):
- 03 5732.0 USB 2021-11-10 22:29:03 31 TWAS J51 Ambiguous – multiple entries
This is because the list contains (in this case) two entries under callsign J51, namely:
- J51 Royal Moroccan Armed Forces MRC
- J51 USGC MH-60T Medium Range Helicopter #6051 USA
You can evade this ambiguity by defining different jobs with matching callsigns lists. If you want to check the channels of USCG/COTHEN, you should query your database for USCG only, save this set and invoke just this reduced set of callsigns instead of the complete bunch – divide et impera. This technique in most cases reduces the problem or even avoids it at all.
There maybe also the effect of a “false positive”: if a callsign doubles on two different stations, but you have listed only one under this callsign, being this the wrong one for the given case.
Basic Reference List: Database or Spreadsheet
I keep my data in a very simple FileMaker database with each entry carrying an individual number ALE_ref.

Then you can query the list: “Tell me all USCG entries located in Alaska!”, getting this window out of your database. This must be exported as TAB-separated file (“USCG_ALS”) and put into the “ale_callsigns” folder of your “Documents” directory.

Of course, you may use any type of spreadsheet and/or database.
You can see the content of folder “ale_callsigns” in the dropdown menu “Callsigns” of the decoder. There you have the choice to select one, two or many files or even “all”.

Callsigns: A First Aid Kit, 3’000+ entries
To become a bit acquainted with this new function, I prepared a list of callsigns containing only very few basic data. It must, of course, contain the callsign for looking up. I then provided fields for the organziation (USCG), the station itself, its location and the ITU 3-letter code. All fields/cells mut be separated by a TAB. For each field which is left empty (i.e., if you don’t know the location), you must insert a TAB instead. Otherwise, the other data may be wrongly allocated in your log. I also tried to keep a balance of streamlined data and the obvious desire not to have be a Rear Admiral of the Navy to understand all the acronyms. The list works perfect for the decoder, plus as sink and as source for your by far more flexible reference database/spreadsheet.
I plan to extend the list as well as to correct the mistakes. Your support is welcome!
The list is a first approach in format and content. It surely works fine. As all work in this field, it combines information from many different sources, contributors to UDXF must be named first. The list is also flavored with my own monitoring log of more than 11000 entries, being all different in call/frequency. In addition, there is a lot of information around in the web – surprisingly often from the organizations themselves, but also from flight spotters, vessel spotters etc. I am sure that all information used is “open”, as otherwise I couldn’t had no access to it … got it?
You can download the zipped list here:
If this doesn’t work, drop me a line under dk8ok_at_gmx.net.
Nils. I am getting perfect copy with the ALE decoder HOWEVER,,although I have the file ale_callsigns in my Documents folder I still can’t get the ID’s decoded in full. I am doing something wrong with the ale_callsign file but can’t figure out what as I can’t seem to gett smaller text files shoing up when clicking the “callsign” tab (ie. Cothen.txt,USAF_HFGCS.txt etc. ). Could you please help.
Tank you in advance
73 Paul VE3HFQ
Hi, Paul – thanks, and fine that the decoder works as expected. Would you mind to post me a screenshot of your setup? (It maybe possible that I mixed up Configuration files with Callsigns files?!) 73 Nils, DK8OK – dk8okgmx.net
Thank you Nils. My mistake was not setting up an ale_callsigns folder under documents. All working fine now. Best 73 Paul VE3HFQ
Great to see it working right now, Paul! Good DX: Nils, DK8OK
I tried with SDRC record some waw files and than send to sdrRewind (following this tutorial https://www.radiohobbyist.org/blog/) , which prepares files for BlackCat ALE. Recently I got this from BC Ale
[01 5836.6 USB 2022-04-27 20:39:50 36] TWAS S6H , presume that it’s just one portion of the message, where can i find more about this message, who send/receive this
… thanks Robin. Callsign S6H maybe a „false positive“, i.e. noise or interference wrongly interpreted as a callsign. This is the result of a delicate balance between sensitivity and reliability. For DX, I prefer sensitivity, manually weeding out some false positives afterwards. 73 Nils, DK8OK
Thanks Nils.