The new digital mode FT8 created by the WSJT-X development team has taken the amateur world by storm. Officially only released in July, the characteristics of this mode are still being studied by the global amateur radio community. The 15 second cycle time and 90 second QSO time while decoding signals down to -20dB in the 3kHz AWGN channel make it very attractive for DXPeditioning as even under difficult band conditions, contacts can be maintained at roughly 20-30 an hour (a far cry from the 10-15 on JT65). While not as good as RTTY (where 60/hour is possible) in terms of QSO rate, its weak signal performance make it a serious contender.
So, in preparing for my trip to Niue to run E6AG, I have been spending quite a bit of time from VK working FT8, especially under congested band conditions at the other end of the circuit, trying to get a feel for how it will react. It is clear that it has one significant issue and that is if you are subject to pileups on your transmitted audio frequency. The result in that circumstance is that you will see signals in the waterfall at this end but will decode nothing! How to tackle this I wondered? I’ve tried several techniques over the past few weeks and have developed the following guidelines to help people work E6AG successfully.
Intra-Channel Split Working Method
- Make sure you are using the latest version of the WSJT-X software (currently candidate release 1.8.0-RC2. This release has some new QSO handling features designed to reduce QRM in pileup scenarios. You can download the software from (here).
- If you see E6AG calling CQ repeatedly and not answering, it is likely too many stations are calling back on the same frequency. When you see this, you should do the following:
- Stop transmitting, then
- Select elsewhere on the waterfall in a clear frequency for your transmit frequency (click in the waterfall on a clear spot)
- Deselect the “Lock Tx=Rx” checkbox
- Finally, Hold down the “Alt” key and then double click back on my last CQ Call
- This will tell your station to call me using FT8 in “split mode” within your waterfall. You then are transmitting on one audio frequency (say 1726Hz) and E6AG is transmitting back on another (eg 1127Hz). At that stage, please just wait your turn. I will see the call and generally will try and answer people in the order I first decoded them in the protocol sequence order dictated by the software.
Futther Operating tips after Week 1
I have seen WSJT-X 1.8-RC2 decode 2 stations in the same 50Hz but not many more than that so this split mode of operation is a must when calling popular stations. Further, when I see the pileup form, you are likely to also see me send “E6AG SPLIT UP” as free text as an alert to your end. That is a positive indicator for you to follow the procedure outlined above!
A few people may be disappointed that they are not in my FT8 logs. Some of the issues I am seeing are as follows:
- Make sure you are using WSJT-X v 1.8.0-RC2 – there are fixes there that help ALOT!
- If you call me on SPLIT, and then when I answer you QSY to my TX frequency you are likely to be swamped by signals from others calling me. I have lost a lot of contacts because people did that.
- If I dont hear a reply after 3 slots I will cancel the cycle and call CQ – you will need to start from scratch again in that case
- IMPORTANT: Please do not put free text in your 73 message. The software is picking up the first text you enter, and is putting that in the far station callsign field. If you send “GRANT TU 73” instead of VK5PO E6AG 73 I found the software logging the contact under GRANT instead of VK5PO – this will make for a lot of broken contact records to fix later…..
- MOST IMPORTANT: If I see you send me an R[Signal] and I reply with RRR, if you do no reply with the 73, I WILL STILL LOG YOU! I consider seeing R[sig] and my sending [RRR] enough to constitute a valid contact. Check the clublog records to confirm if you made it this way!
Follow these tips to maximise your chances of working me on FT8! de Grant E6AG
Alternate FT8 Frequencies (Not being used Currently)
I had considered before the trip that it would be wise to QSY away from the main channels. Whilst here and watching the channels live I havent felt it necessary to undertake this final drastic step. I leave the following here for reference however as something that I might try in the future.
I am also very conscious that as an expedition station being called by a pileup I could take a lot of channel resources away from everyone else. This of course is most impolite. To overcome this, if I see more than 3-4 frequency slots being taken by people calling me, I will likely QSY to an alternate VFO Dial frequency on my radio and call CQ FT8 there on a dedicated frequency. To work me on that frequency you will then need to
- go into File > Settings > Frequencies and enter one of the listed frequencies below using the following steps:
- QSY your radio to the expdeition FT8 frequency
- follow the procedure outlined in the Intra-Band Split working section above (for working SPLIT within the new dial frequency audio passband) and make your call.
I will make free text announcements on the primary FT8 frequencies prior to QSYing like “E6AG QSY14094″ so that those on channel can QSY, and I will ask that if you see me do that that you please spot me on the DXCluster so that people know where to look too!
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With luck these procedures will help many to successfully work this new FT8 DXCC entity for the first time!