My old copy of ACP 131 is divided by tab markers for easy reference. It's version B, with Changes 1-5, and is dated in 1976. It provides both encode and decode for both Q and Z Signals. The Q-Signals are for civilian use and the Z-Signals for military use.
I’ve had this old document for decades. It’s an older version with Changes 1 – 5, with Change 5 dated 28 April 1976, which was just before I went into the Air Force, so I’m presuming I got it then. I put it here for its historical value, because it reflects current usage back then. The most up-to-date version can be found here at the DoD DTIC website.
I’ve organized this the same way my book is organized: using tabs. Also, accessing the book a little at a time makes each section download more quickly. Clicking on a link brings up the section in another browser tab. Once you close that tab, you should come back here.
Note that although this is a nice, clear, sharp scanned copy, the text is selectable and copyable.
INTRODUCTION
Q-SIGNALS DECODE
- QAA – QBZ
- QCA – QDZ
- QEA – QFZ
- QGA – QHZ
- QIA – QJZ
- QKA – QLZ
- QMA – QNZ. Please note that amateur radio operators have created their own set of QNx signals for net operation. You can see these by going here at the ARRL site and scrolling down toward the bottom.
- QOA – QQZ (reserved for the maritime services)
- QRA – QSZ
- QTA – QUZ
- QVA – QZZ (reserved)
Z-SIGNAL DECODE
- ZAA – ZBZ
- ZCA – ZDZ
- ZEA – ZFZ
- ZGA – ZHZ
- ZIA – ZJZ
- ZKA – ZLZ
- ZMA – ZNZ
- ZOA – ZPZ
- ZQA – ZRZ
- ZSA – ZTZ
- ZUA – ZVZ
- ZWA – ZXZ
ENCODE
- Search and Rescue
- Radio Navigation
- Direction Finding
- Aeronautical and Sea Operations
- Meteorology
- Communications Equipment and Circuits Adjusting and Testing
- Circuit Discipline and Net Control. See also the ham-radio-specific list of Q-signals used for net control here at the ARRL site (scroll down toward the bottom).
- Message Handling
- Security and Cryptographic
- Visual
- Exercise and Miscellaneous
- Miscellaneous Abbreviations and Symbols (Both Decode and Encode)
- Series ZYA – ZZZ (Reserved for intra-nation, intra-service, or intra-command use)
- Designation of Emissions [Note that this section is way, way out of date!]
- List of Effective Pages [Through Change 5]
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ZZO ZWH when I was in the Navy as a Radioman stated to “rephase and try again”. I understand it later went to “ZYR-1 ZWH. I believe we use to have a US SUPP to the ACP 131. Been retired almost 22 years so not sure what it is now.
As i recall ZZO was “try again”. As in “Rephase and try again” ZWH ZZO
Hi Tom, I’m wondering if ZZO was an “informal” signal, as the book lists no codes starting with ZZ. I looked in the updated ACP131 and found nothing there either.
I have looked at a lot of the ACP 131 listings and wonder if I have really lost it!?
I seem to clearly remember ZZO# An inexperienced operator is about to send signals using###
It looks like ZDL is not used for a question, but rather only as an “Answer, Advice, or Order.” It looks like it’s simply a “confirmation,” much like hams use “QSL” today. ZDL with the number 1 means “was omitted,” and ZDL 2 means “differs from text.” I can see how it could easily have been used as you describe.
What happened to “ZDL 1 and 2. USAF in late 60s and early 70s used ZDL2 for “Unable to xmit pictures?
You forgot:
INT ZZZ – “Are you asleep”. Or, at least, that’s what we in the U.S. Navy translated that to when someone on the other end couldn’t “get it”.
Thanks for the post. Brought back some good memories.
Lupe Torres
RMCS USN (Ret.)