So … it’s been a while. I tried (and failed) to get into portable operations by purchasing a Xiegu X1M a while back. I quite enjoyed activating my first summit with a borrowed FT-817 and decided the X1M was going to be my personal entry. It seemed like the ideal compromise of weight, price, power and bands.
Sadly, the X1M wasn’t to be. After building & testing a link dipole it started developing a nasty noise on TX. It seemed to kick in if I overmodulated and then, later, it didn’t require any prompting. The receive side worked very well & I used it for SWL for a bit until it stopped doing that as well. Not being particularly dextrous I decided not to poke around the two circuit boards too much in case I made things worse.
Fast-forward a couple of years and it was time to think about this whole portable thing again. The FT-817 seemed to be the best option as I had developed a fondness for the borrowed version. Scarce as hen’s teeth second-hand it looked highly likely that the new FT-818 was going to be it. Saved money here & there until & got close until, unfortunately, the local retailer upped their price. That was it! I ducked onto the VK classifieds and found a FT-857 for sale locally … and right in my price range. The next day I was a proud owner. It’s a little bit heavier but still ultimately portable.
Let’s step back about 18 months or so. It’s solar-minimum-ish time & 10 watts just ‘aint cutting it (I’ve tried to learn Morse but it’s still a work in progress). I had been following the developments of WSPR for a while and now there was a new mode FT8 that operated on the same principles as WSPR. I was able to listen and spot but the license restrictions on Foundation callsigns were such that I could look but not touch. I was good with that. That was the whole idea of the way the licenses were tiered. It was great incentive to upgrade and further oneself. Just didn’t have time to get in and do it. The dream of a Standard call will remain just that for the time being.
Fast-forward to 2019/2020 and the WIA has successfully advised the ACMA to allow F calls to use digital modes and that it wouldn’t be bad thing. This caused a flurry of research into audio isolation interfaces, modulation, drive & methods of connecting radios to computers. All of a sudden my 10 watts was going to take me places. I had a play around with FT8 but it seemed a little too automated and, although I was assured by the manuals that I could, I wasn’t able to see how it would easily accommodate a good rag-chew. Sure enough, the vast majority of FT8 traffic is, while technically speaking, QSO’s, there’s no, “How’s things, haven’t heard you on for ages, how’s the weather over there?”, sort of thing. Enter JS8.
I had been following Julian, OH8STN, for a while on a couple of different social media platforms. He has an amazing amount of experience in portable operations and his preferred digital mode is JS8Call. Jordan Sherer, KN4CRD, had re-purposed the FT8 codec and made it more QSO-friendly. JS8 is a very lightweight programme that can reliably decode digital signals down as far as -20dB SNR in 4 speeds between 8 & 40 words per minute (depending on conditions). After seeing Julian’s videos on JS8 development and use, I was hooked.
JS8 and FT-857
Finally got my audio interface to work. It’s a very basic circuit that isolates the TX side. I used an old PS2 mouse cable and a surplus 3.5mm – 3.5mm stereo cable that comes with a lot of PC & KVM extender kits. Also seen in the pic below is my well-dodgy QRP dummy load. The image on the screen is a VNC session from the shack laptop. I was listening to the shack radio (IC-718) through the dummy load.
The next steps will be sorting out portable power for the FT-857. A fantastic reference for this is Andrew’s (VK1AD) blog. He’s done a lot or research into ‘857 power requirements as well as creating some great resources for portable equipment users generally. I don’t think my idea of a second-hand 7AH SLAB is going to cut it somehow.
Thanks to the online resources of the above-mentioned, Ian (VK5CZ) who’s semi-regular contacts keep me inspired & motivated and VK6AXB for the constant leg-ups and astounding knowledge of all things radio.