How to distinguish when a DXpedition uses FT8 Fox/Hound (F/H) mode and when it uses Multistream (MSHV)

IMPORTANT: The information shown in this page is only valid for old implementations of the Multistream in MSHV. For the new implementation read this.

I often see questions of many operators in the chats, mailing lists, WhatsApp groups, etc. requesting whether a certain DXpedition is using FT8 in Fox/Hound or using the Multistream feature provided by MSHV.

Unfortunately I also often see many answers from other operators that are not correct !

The fact is that distinguishing both modes is very easy, just paying a little attention to the messages that the DXpedition is sending. Just read the following and you will also be able to do it yourself without having to ask.

The most noticeable difference between the two modes is that in Fox/Hound the DXpedition (the Fox) will transmit two different messages to two different stations at the same time and in the same audio frequency, something that does not happen in the multistream signals of MSHV. So, just pay attention to the messages sent by the DXpedition and you will see it.

If you are using WSJT-X you will see something like this:

As you can see in this example, 7P8RU is transmitting two streams, one on the audio frequency of 381 Hz and another on 321 Hz, but the stream on 321 Hz contains two different messages, one sending RR73 to N5OK and another sending the signal report to W3FOX. Because of this, there is no doubt at all that 7P8RU is using Fox/Hound.

Notice that in WSJT-X the two different messages on the same audio frequency are shown in a single line, one beside the other.

If you are using JTDX you will see something like this:

In this example you can see 7P8RU transmitting three streams, on the audio frequencies of 381, 321 and 441 Hz, but the stream on 321 Hz contains two different messages, one sending RR73 to WD6EIW and another sending the signal report to KS3F. Because of this, there is no doubt at all that 7P8RU is using Fox/Hound.

Notice that in JTDX the two different messages on the same audio frequency are shown in different lines, one after the other, but you can clearly see in the "Freq" column that they are both on 321 Hz.

Another thing to keep in mind is that in Fox/Hound mode the DXpedition (the Fox) can only transmit in the even periods (seconds 00 and 30), while in multistream it can transmit in both odd and even periods. In other words, if the DX transmits in the odd periods (15 and 45 seconds) we can be sure that it is NOT in Fox/Hound mode. On the contrary, if it transmits in the even periods then it will be necessary to see if whether transmits two messages on the same audio frequency or not, as explained above.

So is it better for DXpeditions to use the WSJT-X in Fox mode or to use the MSHV in multistream mode?

The answer is not simple and depends on each case. Let's discuss the advantages and disadvantages of each: