Skip to main content
14 votes
Accepted

What does CQ NM mean in FT8?

Now that I've seen a few other 2 letter abbreviations, I've figured out it means they're looking for a contact in New Mexico.
xxpor's user avatar
  • 331
11 votes
Accepted

How is FT8 modulated with both upper side band and FSK?

Remember that, theoretically speaking, a USB transmitter just takes a signal, shifts it up in frequency, and amplifies it. That means that if you take a 50Hz wide 8FSK signal centered at 1500 Hz, and ...
hobbs - KC2G's user avatar
  • 12.5k
10 votes
Accepted

Am I really receiving FT8 signals from 12,000 km away on 144 MHz?

I'd say these are simply corrupt. Take for example: 210113_163545 144.174 Rx FT8 -17 1.3 1247 J06NQY A68ITS/R R QM30 A68ITS doesn't seem to be a real call, ...
Phil Frost - W8II's user avatar
9 votes

Am I really receiving FT8 signals from 12,000 km away on 144 MHz?

210115_114630 144.174 Rx FT8 -17 -1.6 685 SIDE LOBE This is probably the one real one of the bunch, actually! The odds of random noise decoding as a freetext message with sensible English, ...
hobbs - KC2G's user avatar
  • 12.5k
9 votes
Accepted

FT8 callsign/maidenhead compression encoding

You can find the code in packjt77.f90. Callsign encoding (for "standard" callsigns that don't require hashing) is in function pack28. A quick summary: ...
hobbs - KC2G's user avatar
  • 12.5k
8 votes

Can the IC-7300 be connected straight to a computer and use WSJT-X for FT8?

Yes, you only need a USB2 A to B cable. The IC-7300 already has an integrated sound card, for audio signal transmission, and an integrated serial port for remote control, both of which are ...
AndrejaKo's user avatar
  • 2,893
8 votes

How is FT8 modulated with both upper side band and FSK?

FT8 is just FSK. However, most legacy transceivers don't support direct digital to FSK modulation (and FSK to digital), but do support SSB modulation and demodulation (from and to audio). So these ...
hotpaw2's user avatar
  • 13.5k
7 votes
Accepted

Should I add call signs with /R suffix to the logbook?

FT8 decoding can use a technique called a priori (AP) whereby it uses naturally accumulating information for the purposes of increasing apparent sensitivity by about 4 dB. There is an increased chance ...
Glenn W9IQ's user avatar
  • 18.6k
7 votes
Accepted

What does exclamation mark mean in FT8 CQ calls in WSJT?

That is something that is activated by "Show DXCC entity and worked before status" (selectable on the "Settings" > "General tab"). From the manual: When this option is checked WSJT-X appends some ...
Pablo Fernandez's user avatar
6 votes
Accepted

What does retain mean in the logging of WSJT-X 1.8.0?

When those boxes are checked, the values entered will be retained as the defaults for the next QSO to be logged. Unchecked, the fields will revert to blank.
Phil Frost - W8II's user avatar
6 votes
Accepted

Can someone without privileges on a band operate FT8 on it using the callsign of a ham who does and is present?

Apparently, yes. See Part 97, Amateur Radio Service Rules: 97.3.a.47 and 97.115.b. The FCC does not appear to make a distinction as to whether the third party is licensed or not. https://www.ecfr.gov/...
timetraveller's user avatar
6 votes
Accepted

What does <...> mean in FT8?

From the WSJT-X documentation: Angle brackets imply that the enclosed callsign is not transmitted in full, but rather as a hash code using a smaller number of bits. Receiving stations will display ...
Peter Bagyinszki's user avatar
6 votes

Why is SNR for FT8 defined using the noise power in the 2500 Hz channel containing the FT8 signal?

Matter of opinion, but it's kind of a "level playing field" thing. Say you want to compare the SNR required to have a successful QSO across SSB, conversational-speed CW, QRS(S) CW, and ...
hobbs - KC2G's user avatar
  • 12.5k
5 votes
Accepted

What dot means in JTDX FT8 received messages?

Found on the JTDX groups.io (link won't work without login, unfortunately): sybmol • - this operator loaded his log into LoTW symbol ° - this operator loaded his log into LoTW and this is Hint ...
hobbs - KC2G's user avatar
  • 12.5k
5 votes
Accepted

If WSPR can go further than FT8, why do I only see local WSPR signals?

My guess, looking at WSPR reports, is that, on average (median), WSPR beacons are transmitted at power levels maybe in the range of 10 to 30 dB lower than the median of FT8 transmissions. e.g. 20 dBm ...
hotpaw2's user avatar
  • 13.5k
5 votes
Accepted

Long callsigns in WSJT-X?

For the current "77-bit" versions of FT8 and MSK144 (as supported by wsjt-x version 2.0, released in late 2018, and newer), you can use these callsigns without doing anything special. Any combination ...
hobbs - KC2G's user avatar
  • 12.5k
5 votes

What is the minimum equipment necessary to get on the air with FT8?

Without getting into specific product recommendations, I believe the simplest way is as follows: Obtain a license. An amateur license is required for using amateur bands. I am not aware of any non-...
Chris K8NVH's user avatar
  • 1,042
5 votes
Accepted

Unidentified signals on FT8 frequencies

The fact that they align properly to the FT8 15-second period, and have 8 tones (the same as FT8) is a sign that these may be distorted FT8 signals, caused by AF harmonics in the transmitter or the ...
hobbs - KC2G's user avatar
  • 12.5k
5 votes
Accepted

wsjt-x problems with windows 11

With windows 11 there is a new feature "enhanced audio" Windows 11 provides additional features to improve the sound quality with more bass, virtual surround, room correction, and loudness ...
Paul Brennan's user avatar
4 votes

Only noise, no signals whatsoever on HF

There is a lot you haven't told us about the current situation that could be helpful. Since your dad lives so close, perhaps you can make various substitutions to identify the problem. For example, ...
Brian K1LI's user avatar
  • 7,878
4 votes

Can someone without privileges on a band operate FT8 on it using the callsign of a ham who does and is present?

Yes, but keep in mind that it takes slightly more than "physical presence"; as the control operator, you're the one responsible for the operation of the station. That means being attentive ...
hobbs - KC2G's user avatar
  • 12.5k
4 votes
Accepted

Linux Alternative Time Sync-ing for JS8 or FT8

Yes. Chrony is an NTP client which is particularly good at offline behavior (better than ntpd in this regard, and infinitely better than systemd-timesyncd, which is only an SNTP client and not a true ...
hobbs - KC2G's user avatar
  • 12.5k
4 votes
Accepted

Help implementing FT8 crc check in Rust

I had also reached out the the author (VK3JPK) of the paper that I was referencing in order to write this code. He pointed out what turned out to be my error. You specify your message using a 128-bit ...
JohnRudolfLewis's user avatar
3 votes
Accepted

FT8 etiquette when no reply after responding to CQ?

There are a few things to have in mind. First, be reasonable. :) If there is no response, there's nothing wrong with trying again. There could have been interference that you cannot hear or the ...
David Hoelzer's user avatar
  • 1,053
3 votes

WSJT-X V2: How to identify stations already logged?

Set your "New Call" to one color and your "CQ in message" to a different color. My new call CQs are green and my "CQ in message" are light red. The light red indicates that I have worked the station ...
Cecil - W5DXP's user avatar
3 votes

Unidentified signals on FT8 frequencies

Both marked signals follow an 8 tone MFSK pattern. The one on the left is about 125 hertz wide while the one on the right is about 100 hertz wide. The signal on the left appears to follow the ...
Glenn W9IQ's user avatar
  • 18.6k
3 votes

Can only use WSJTX in sudo

I would guess that your user is not in the dialout group. You can fix this with: sudo adduser your_user_name dialout Then log out and back in.
user3486184's user avatar
  • 1,957
2 votes

Only noise, no signals whatsoever on HF

QRM is extremely common nowadays due to a great increase in switch-mode power supplies that tend to desensitize nearby receivers, hence the reason why many Hams put up a shack away from the house. ...
pappad's user avatar
  • 71
2 votes

Should I add call signs with /R suffix to the logbook?

I agree with Glenn's answer about AP decodes since this V0 is an invalid callsign, but I'd like to add that in general /R on a callsign typically means it is a "Rover", or a mobile station ...
John's user avatar
  • 156
2 votes

How many HF (FT8/JT65/BPSK/RTTY etc) amateurs are active in Canada?

If there is any merit to your claim, consider that Canada has ~ 69,000 hams while the US has ~800,000 hams according to Wikipedia. With less than 10% of the number of hams in Canada compared to the US,...
Glenn W9IQ's user avatar
  • 18.6k

Only top scored, non community-wiki answers of a minimum length are eligible