First posted 6/26/2021
Update 7/11/2021: Turns out I had an antenna issue, after getting that squared away, I was able to get many FT8 contacts off my balcony! Full story is now at https://kd9cpb.com/10m-ft8
You may have noticed it’s been a full quarter year since my last ham radio post, and that’s because I’ve been working on a few big project ideas! Well, sadly one of these ideas didn’t really turn out the way I hoped it would, but I learned a lot in the process. After reading all about FT8 recently, figured it’s about time I hop on the bandwagon. Instead of getting the slick “Making FT8 contacts with only a technician license and sub-$100 used 10m radio” article I originally was hoping this post would be, today you’re going to get hear about all my 10m problems instead. Can’t win ’em all 
What I tried
About a month ago, I decided to buy the cheapest 10m transceiver I could find, a basic 10m whip antenna and a Signallink USB sound card with the intention of getting FT8 contacts off the condo balcony. Since I can do 10m FT8 with my Technician license, figured this would be the perfect way to get my feet wet with HF before studying for the general exam and dropping big bucks on an all-mode transceiver. Here’s a bit more color as to why I chose this exact set of gear:
Realistic HTX-100 Transceiver
Originally, I wanted to buy a new 10m radio such as the President Lincoln II or Anytone AT-5555. After digging through various ham radio forums and google searches, I decided not to spend the $200+ on something new, taking a gamble on the cheapest 10m SSB ham radio I could find instead: a Realistic HTX-100.
Why did I go with this old radio that’s around as old as I am? Well, long story short you can still find a Realistic HTX-100 or its slightly newer cousin (Radioshack HTX-10) for dirt cheap on eBay, and they’re well regarded as a decent 10m option to this day. I picked up my HTX-100 for $75 plus shipping, which is about one-third the cost of a new 10m SSB transceiver This was a gamble; even though the manual is available online and the auction listing said the radio powered on, you just never know what you’re going to get off eBay. Overall I think my gamble paid off as I was able to transmit & receive some FT8, but I’m fairly certain the microphone is broken. Fortunately thanks to the next item on my gear list, the broken microphone is a non-issue
Signallink USB sound card
Other than the little bit of tinkering I’ve done with my SDRPlay Duo and Nooelec GQRX Raspberry Pi setup , I haven’t done much with getting audio from a transceiver into my computer. So I decided to spend a little extra on a Signallink USB sound card given it can handle all the “press the PTT button when I want to transmit FT8” stuff for me. Although you can do similar things with the Raspberry Pi’s GPIO ports like VK3IL does with Direwolf, I didn’t want to add extra complexity this time around.
Normally I’m all for doing things as cheap as possible on the Raspberry Pi, but I didn’t feel like spending lots of time making a custom cable to the HTX-100 considering Signalink has the exact prebuilt 8pin adapter cable I need. But that above link to VK3IL’s blog about Direwolf looks fascinating, perhaps I’ll give that a shot someday. In the meantime, I must say the Signalink + HTX-100 combo does look quite photogenic:
MFJ-1610T 10M Antenna
It would be really hard to try 10m FT8 without an antenna that can do 10m, so I went with this MFJ-1610T whip antenna as it looked like the best fit for the condo balcony. If I had more space for antennas, something much larger and supporting all the HF bands would have been a better idea. But I don’t want to push my luck becoming a big antenna eye-sore on the balcony, and I don’t want to buy an antenna tuner yet either, so the MFJ will have to do for now.
How it went
After reading SDRPlay’s guide to decoding FT8, Signalink setup guide for Windows 10 and Tigertronic’s WSJT-X instructions, I felt like I had everything all set for getting lots of FT8 contacts off the Balcony! With only minimal trial & error, I quickly got my first FT8 transmission out on 28.074mhz, and it felt great to see it come across in WSJT-X via my SDRPlay radio with longwire antenna a few meters away!
Not only did I see my transmission on my own SDR gear, but I also was able to see a few folks reporting into hamspots.net were able to copy my signal! I can’t believe all of this is possible with my technician’s license and the same amount of transmit power as my Anytone 568 on UHF/VHF, this was the highlight of the project for me:
This was fantastic, but I wasn’t able to receive anything back on the 10m band. Even in the middle of June 2021’s ARRL Field Day, I only saw a little bit of band activity coming from both the Signalink hooked into the HTX-100 with MFJ-1610 antenna and the SDRplay Duo with longwire antenna listening to 28.074mhz:
I’m not sure if I pushed my power supply to the limit or if I just wore out the HTX-100 after many transmissions, but eventually when I’d try to reply to the 3 stations I saw on the WSJT-X band activity, I’d see nothing on the SDRPlay waterfall for 28.074mhz. I figured this was a sign that getting a FT8 QSO just wasn’t in the cards, even on field day, so I stopped attempting to transmit. On the bright side, all of these QSO attempts did light up my search results at hamspots.net, so at least I have some neat results from there to show off:
As much as it’s cool to see the 10m band activity and see my call on hamspot.com, it’s just not as cool as the massive amount of 40M FT8 traffic I can pickup from seemingly nothing but noise every night off the SDRPlay longwire antenna. Technicians having access to 10m is great, but I must admit it’s a tiny fraction of the band activity I can see on 40m from the condo:
And on that note, I think I’m going to give my 10m FT8 ambitions a break for a bit. The fact that someone from Florida picked up a signal from my condo balcony is super cool, even if I couldn’t pull off a full QSO on field day. However, given that 40m has multiple times the amount of band activity as 10m, I think I’m going to bite the bullet and get that general license instead of going down the 10m technician path long-term for FT8 fun.
Lessons Learned
Time.is truly is your friend
Time synchronization is important for FT8, ideally you want to be within a handful of milliseconds away from a perfect timesource like time.nist.gov or GPS-based time. It’s possible to spend large sums of money getting nanosecond-level accuracy time sync on your PC. But unless you’re really serious about time sync, I’d recommend using time.is to quickly determine if your machine’s time is good enough for FT8. I didn’t know about time.is until starting to play with FT8, and I’ll be using this quite heavily at my IT support dayjob going forward!
Keep the transmit volume super low in WSJT-X and in your sound card settings
Last week, I was convinced the HTX-100’s transmitter was garbage and the radio itself was the sole reason I wasn’t able to make FT8 QSOs. So I decided to swallow my pride and ask the internet strangers of reddit why my SDRPlay waterfall looked so funky when observing transmissions from the HTX-100. Sure enough, thanks to advice from the comments, I learned the problem was 100% my fault from sending too much volume into the microphone input. I’d imagine many others doing FT8 have made the same mistake, so I definitely wanted to make it known here. Just like many problems for us IT support people, sometimes the issue ends up being between keyboard and chair, not the radio’s fault
I kind of wish I spent my time getting the general license + a 40M FT8 setup instead of spending time on all the 10M FT8 tshooting
Although it felt good to get familiarity with FT8, to be perfectly honest, I kind of wish I skipped trying to get the cheap used transceiver working on 10m and went straight to general license studies for 40m FT8. I think I might sell off the HTX-100 and get a full-blown general license with all-band radio now that I’ve gotten a taste of HF. All of the Solar cycle 25 press is great, hopefully the ten meter band gets more users as a result of better solar weather, but the truth is FT8 looks far more interesting to me on the lower bands. Therefore, I think I’m now of the opinion that anyone who wants to do FT8 should “go big or go home”, much like the words of wisdom found in this reddit comment.
Finding the time for truly understanding the general exam content (not just cramming the minimum to pass) is a uphill battle though, especially with the weather getting warm here in Chicago. All things considered, I learned a lot from this 10m project and I’m looking forward to my friend N9AAC stopping by the condo soon to deep dive into 40m possibilities with his rig. Until then, please let me know if you have any thoughts on Twitter or in the comments about all this 10m FT8 attempt stuff. Hope everyone had a happy field day as well!
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