What is JS8Call? - Craig's Simple guide (hopefully!)

Here you can discuss Datamodes for all bands (PSK31, FT8, JS8Call, etc), Software Defined Radio topics & General Radio Software or apps
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MrWeetabix
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What is JS8Call? - Craig's Simple guide (hopefully!)

Post by MrWeetabix »

I have recently been experimenting with a new Datamode called JS8Call, I may have mentioned it a few times on the boards. The most common question I get is what is it, so this is my attempt to explain it and how it works.

Now, you may be familiar of the FT8 Datamode which took the Ham bands by force in recent years, basically it allows very weak signals to be exchanged between stations when voice just wouldn’t get through, allowing for contacts to be made on apparently closed bands.

FT8 is somewhat of a ‘marmite’ mode with some hams loving it whilst others loathe it. This is because FT8 can be ran in near autonomous mode, with stations churning away day and night without any operator interaction and certainly without any chit chat or personality.

Js8call is underpinned by the same weak signal technology that FT8 uses, but has a messaging layer added to it, allowing for direct typed messages between stations in real time. The JS8Call software is heavily derived from WSJT-X and shares more than a striking resemblance to it.

This is a typical interface, showing the waterfall where contacts are show, as well as the list of heard and called stations.

JS8Call_Interface.jpg

One of the many things that make JS8Call unique is the automatic HeartBeat (HB) transmissions, and the ability to put your station on automatic mode. In this mode, your station can act as a relay for messages to be sent to other stations, meaning messages could relay through a number of stations to reach a station which is currently out of range, with replies coming back via the same path, which is pretty cool if you ask me!

Now, the real reason I love this mode is that there is a growing number of enthusiasts who are using it on 11m, using EU ch25 (27.245 USB). JS8Call will also report into PSK Reporter, so not only can you make contacts, but you can also see where you have been heard around the world, which can be pretty addictive.

JS8Call_PSKreporter.png

Now, interfacing with a regular CB radio can be tricky, but you can get setup for RX very easily, simply download the JS8Call software HERE , set it up and feed your radio’s audio from your extn speaker output directly into your PC or Laptop sound card via the line-in port. I use an external USB Sound card for this, cost me less than £10 delivered. You can then feed your own spots into the network and be part of things. If you dabble on HF you can also find JS8Call QSOs going on over all HF bands too (all freqs are in the software).

Transmitting is very different ball game. If you use a modern HF radio on 11m then likely you can set that radio up as a soundcard in itself to do this and JS8Call also has a list of radios build in which it can connect with. If you don’t have a HF Radio then perhaps your radio has VOX on it. Again, you can feed the audio from your radio via the ext speaker jack, but your audio from the computer will need fed direct into your mic socket. Now this isn’t for the faint hearted, but it is bespoke to you and your radio.

Even if you don’t have VOX, you could simply key your mic next to your pc speaker when you are transmitting, although this is quite cumbersome and hit-and-miss, but whatever your setup it is a fun exercise to install the software, start decoding and then work your way up to transmitting. This is the basic concept of how I have wired my President McKinley up using it’s rear VOX mic jack. I have since added some line isolators to add a little protection for the radio.

simple_plan.png
(Other president radios which feature this vox jack are the Jackson II and the Grant II, all pictured.)

I am more than happy to share my own experiences and help you get up and running with this interesting mode and hopefully grow the JS8 11m community further.

For more information on JS8Call, please see the links below and I look forward to hearing your comments on this post. Thank you. Best 73 de Craig, 26TM175 and I hope to see you on the waterfall

http://js8call.com/

https://miscdotgeek.com/js8call-getting-started/

https://www.k0pir.us/js8call/
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26TM175. OP: Craig. QTH: Gateshead. Also 163TM175 when mobile in Wales 8)

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MrWeetabix
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Re: What is JS8Call? - Craig's Simple guide (hopefully!)

Post by MrWeetabix »

Despite some popular misconceptions around the use of Datamodes on 11m the impact that this particular Datamode has on voice users is minimal.

JS8Call can be described as a very "thin" mode (just like FT8). JS8Call only uses 1500 hz. The best way to picture this in your mind (if you don't have a fancy radio with a waterfall) is if you imagine each CB channel to be the width of your finger. Using that as a size guide js8 is the width of a few strands of hair in comparison. Someone using FM on the same frequency would barely even notice that the JS8 signal is there. Even in terms of Voice users on USB, JS8 still has a very small footprint and often a QSO would still be possible.

Another big bonus for JS8Call (as with FT8, the shoulders on which JS8Call was built) is that it can utilise extremely weak propagation and paths to make DX contacts. If we're talking in tangible terms it is estimated that JS8Call only needs 20% of the conditions needed for a comparable voice DX contact to make the trip. So on a day when the 555 is dead and all you have is the local muppets playing gash music or chatting amongst themselves on the calling freq, why not have a play with JS8Call and see what contacts you can hear? The band may seem closed, but if there's any sniff of lift, JS8Call comes alive!

The JS8Call community is growing, but we need new users to get involved and become active to really help cement it as the sociable Datamode which FT8 just isn't. JS8Call is also used beyond 11m and again we're looking for more people to take part to grow its use on HF, as well as UHF and VHF.

166857331_1335212926852127_1217264508892874755_n.jpg

Remember, to receive JS8call and most other Datamodes it really is as simple as downloading an app and feeding your radio's Speaker output straight into your PC. You can then start to decode and also contribute as a monitoring station, adding spots to PSK Reporter automatically. If you don't know what PSK Reporter is, its a website which collects information from HAM, SWL and 11M radio users around the world, detailing what stations they are working, or can hear along with their station info and modes in use. The data is then collated into a simple map for anyone to browse, free-of-charge and follow your own spots, those of others or even by mode or band. Try it now at the link below.

https://www.pskreporter.info/pskmap.html

If you have any questions please feel free to reply to this thread or inbox me. There are also Telegram and Facebook groups to promote the mode if you want to get involved, again you can hit-me-up for the info.

Best 73 all and I hope to catch you all on JS8 soon.
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26TM175. OP: Craig. QTH: Gateshead. Also 163TM175 when mobile in Wales 8)

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