The purpose, use, and importance of the exchange of a matching set of "73" codes as the final salutation of each party in a conversation (QSO) between Amateur Radio Operators (AROs aka HAMs) has been the varied opinion. This is especially true of digital modes such as FT8 where great effort has been made to shorten the already diminutive 1.75 minute length of a QSO from its initial call or "CQ" to the final and mutual "73" codes. This has led to oft-times contentious debates about the need for sending the final "73" by *both* parties.
Monitoring of QSO habits suggests 3 types of AROs - those who:
- seek a full and proper logging of a QSO to its respectful and full conclusion resulting in a mutually agreed to confirmation of transmission (QSL). Call them "ProFormas".
- are interested in contesting or DXing and seek the fastest way to QSL in contests with time limits or heavily sought-after "DXpeditons" to rare locations. Call them "Contesters".
- treat QSLing as a casual activity and do not care about a full and proper exchange that assures the certitude of both parties of a QSL status. Call them "Casuals".
ProFormas: The 1st group are those who seek complete and diligent QSLs with each party doing their best to assure the other that the QSO was properly confirmed and logged. For them, a log is a careful record of activity and achievement than can entail 1,000s of hours and decades of effort.
Contesters: The 2nd group is more concerned with maximizing the QSLs made in a fixed time period (contesting) or to deal with DX operators being sought ("Fox") by 10's of AROs ("Hounds") every second. In both cases, participants are willing to forgo certitude for increased QSL rates.
An important aspect of both ProFormas and Contesters/DXers is that they operate within a well-defined set of rules. Even when special events may shorten the message train, it is, nonetheless, a formalized ad hoc protocol that participants need to abide by for an acceptable QSL.
Casuals: The 3rd group doesn't care about certitude,
mutual assistance, or protocol. For them, QSLing is a casual
pastime wherewith they prefer to do the minimum to enjoy sporadic
contacts. Much like dropping by a pub to share a few rounds with
strangers who seem to share some interests but aren't inclined to devote
any time to - unless chemistry intervenes.
QSO Protocol's "Message Train" format.
The following "message train" maps an entire transmission sequence from the train's opening message, through multiple data messages, and on to the final closing "73" message. In modern digital FT8 QSOs, only a single pair of mutual signal strength reports are in the train.
To help understand the value of "73", let's start by looking at the minimum set of QSO message types for a digital QSL - from the
initial (directed call) or "CQ" to the final "73".
As with nearly all modern communication transactions, there are multiple levels in a hierarchy with different levels of scope. However, as per the diagram above, the hierarchy is not readily apparent and simply appears as a linear stream of message exchanges.
To help understand the value of "73", let's start by looking at the minimum set of QSO message types for a digital QSL - from the
initial (directed call) or "CQ" to the final "73".
The next diagram below uses some example variations to help clarify the hierarchy and highlight some methods of reducing the number of messages while adhering to the protocol. In those examples a single data message transfer occurs between the outer start and end messages of the train.
1. Outer communication's message train. Includes From/To Call Signs, Ends with mutual 73's.
See BLUE messages in examples below.
2. Individual messages. One or more messages, each ending with RRR or RR73.
See GREEN messages in examples below.
For this example, let us use the popular FT8 mode which, by design, distills the essence of a complete QSL transmission to the least number of messages - 7 to be exact - each of which is transmitted within synchronized alternating 15 second time intervals, buckets, or packets. That's 7 x 15 which is 105 seconds or 1m 45s. That assumes the digital software modem (e.g., WSJT.) is set to auto message sequencing, all messages are received without repeats, and all are transacted without errors.
FT8 QSO examples of the full protocol that is robust, proper, and respectful.
Table 1a: CQ call's 7-steps/formats for a digital FT8 QSO on to final QSL
| # | Message Format | Example | Remark |
| 1 | CQ Oper1 Grid | CQ KT1TK FN42 | KT1TK/Grid FN42 calling anyone. |
| 2 | Oper1 Oper2 Grid | KT1TK WD4HIP EL96 | Hi KT1TK. I am WH4HIP/Grid EL96. |
| 3 | Oper2 Oper1 SigDB | WD4HIP KT1TK -04 | Hi. Your signal's -4db, what's mine? |
| 4 | Oper1 Oper2 SigDB | KT1TK WD4HIP R+02 | Yours is +2db. Good to end message? |
| 5 | Oper2 Oper1 RRR | WD4HIP KT1TK RRR | Got Report. Ready. Waiting your 73. |
| 6 | Oper1 Oper2 73 | KT1TK WD4HIP 73 | All good. Best wishes. Waiting your 73. |
| 7 | Oper2 Oper1 73 | WD4HIP KT1TK 73 | Got your 73. QSL. Best wishes. Out! |
The essential and respectful aspect of
this exchange is that both parties ensure the other has what they
need with their matching 73's. This is not only good telecom practice and social
etiquette, it also fulfills the mandate of AROs to help others and spread goodwill - a fundamental tenet of their
licensing. Remember your licensing studies and exam questions?
Table 1b: Directed call needs only 6-steps/formats for a digital FT8 QSO.
| # | Message Format | Example | Remark |
| 1 | Oper2 Oper1 Grid | WD4HIP KT1TK FN42 | KT1TK/Grid FN42 calling WH4HIP. |
| 2 | Oper1 Oper2 SigDB | KT1TK WD4HIP -04 | Hi. Your signal's -4db, what's mine? |
| 3 | Oper2 Oper1 SigDB | WD4HIP KT1TK R+02 | Yours is +2db. Good to end message? |
| 4 | Oper1 Oper2 RRR | KT1TK WD4HIP RRR | Got Report. Ready. Waiting your 73. |
| 5 | Oper2 Oper1 73 | WD4HIP KT1TK 73 | All good. Best wishes. Waiting 73. |
| 6 | Oper1 Oper2 73 | KT1TK WD4HIP 73 | Got your 73. QSL. Best wishes. Out! |
Concatenated message code "RR73" eliminates one step.
Can the number of messaging steps be reduced even further whilst maintaining proper protocol, etiquette and respect? Yes, but carefully. Later versions of the digital protocols allow the sending of a combined "RRR" and "73" in the form of a "RR73". See note further down on how to set up WSJT to sent "RR73" rather than "RRR". As shown below, this eliminates one cycle (a) without sacrificing etiquette or integrity of the QSL certification, (b) reduces the cycles to 6 and (c) incidentally changes who sends the final "73".
Table 2a: Shorter 7-step CQ call by using concatenated response, "RR73"
| # | Message Format | Example | Remark |
| 1 | CQ Oper1 Grid | CQ KT1TK FN42 | KT1TK from Grid FN42 calling anyone. |
| 2 | Oper1 Oper2 Grid | KT1TK WD4HIP EL96 | Hi, this is WH4HIP from Grid EL96. |
| 3 | Oper2 Oper1 SigDB | WD4HIP KT1TK -04 | Hi. Your signal's -4db, what's mine? |
| 4 | Oper1 Oper2 SigDB | KT1TK WD4HIP R+02 | Yours is +2db. Good to end message? |
| 5 | Oper2 Oper1 RR73 | WD4HIP KT1TK RR73 | Got Report. Ready to QSL. Waiting 73. |
| 6 | Oper1 Oper2 73 | KT1TK WD4HIP 73 | Got your 73. QSL. Best wishes. Out! |
Using "RR73" reduces even further the already shortened cycle of a "directed call" (one initiated to a specific call - not a CQ to "anyone"), dropping the cycles to 5.
Table 2b: Reducing 6-step directed call to 5 by using concatenated response, "RR73"
| # | Message Format | Example | Remark |
| 1 | Oper2 Oper1 Grid | WD4HIP KT1TK FN42 | KT1TK from Grid FN42 calling WH4HIP. |
| 2 | Oper1 Oper2 SigDB | KT1TK WD4HIP -04 | Hi. Your signal's -4db, what's mine? |
| 3 | Oper2 Oper1 SigDB | WD4HIP KT1TK R+02 | Got your signal report, yours is +2db. Good to end message? |
| 4 | Oper1 Oper2 RRR | KT1TK WD4HIP RR73 | Yes, Got your signal report! Ready to QSL? Waiting for your 73. |
| 5 | Oper2 Oper1 73 | WD4HIP KT1TK 73 | Got your 73. QSL, "73" (We're done). |
A point I hope the reader gleans
from the preceding examples is that each QSO message, as in any respectful exchange, is NOT about what it means to you but what it mean to the other party.
Example: If
your "73" is first in a QSO, the QSO is not over till you
receive acknowledgement of its receipt via your receiving their final "73". If you don't get one, you don't know if they got yours. So, it is incumbent upon you to
repeat your "73" a number of times until you do. If you still don't receive the final "73", then the band died, the other party is inexperienced,
they had an emergency or they blew a fuse. In such cases, I often send a "NO 73 NO LOG". In many cases, that seems to strangely and immediately improve band conditions as the final "73" miraculously appears.
Setting up WSJT to send "RR73" instead of "RRR"
The messages sent by WSJT's auto-sequencing relies on the contents of the text boxes whose labels are "Tx1" through "Tx6". For those who haven't studied the WSJT manual, double-clicking the label "Tx4" will toggle the value of the message to be sent between "RRR" and "RR73". Unfortunately, when "Tx4" is set to "RRR", WSJT stops the sequencing and doesn't try to send the much needed final "73". That leaves it to the ARO to manually one or more "73" to get the ARO who sent the "RRR" to send their final "73". If they don't, we never know if they got our final "73".
The simple solution that reduces the message count and also makes it clear the other party is concluding, is to send "RR73" instead of "RRR". Problem solved. The protocol is complete!
To log or not to log - what is a log?
Logging is a topic unto itself and deserving of a complete separate treatment.
However, in the case of this article on "73", the topic rears its head. To wit: Should we log an incomplete
digital QSO? In so much as our mandate (albeit no longer the law) is to
record *all* our uses of the airways, then should we not log all incomplete QSOs? That gets a little hazy with the extreme brevity of
digital modes whose sole purpose is to log a QSL - not carry on a
prolonged conversation. Conversely, with the advent of fast and painless logging options like QRZ.com or PC-based logs like ACLog, HRDLog, et
al, logging every transmission could not be easier.
I
admit, excluding incomplete QSOs enticed me as it makes my
logbook tidier, more compact, and just prettier.
However, my desire to achieve the highest level of compliance steers
me back to the fold. After all, the percentage of
incomplete digital QSOs is much less than 2%. So there is no
contest. An incomplete entry's lack of a confirmed flag as well as my own
comment in the log entry such as "Incomplete" makes the entry's status clear while adhering to proper logging practice.
Enjoy ... 73
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