|
Yesterday my QMX got its maiden voyage in full kitted-out form.? Went to US-3715 here in GA (Cartersville).? It's been out in the field before, but with other radios till I was confident this one would be a good primary, and I wasn't disappointed this time.? My kit is not a micro, SOTA-up-on-a-peak kit, but still very small and fits in a backpack with plenty of room for other stuff.
Even though I had fine internet, I wanted to use the QMX to spot myself, so I didn't use internet for anything other than verifying.? I have KM6LYW's Digipi set up?on a Pi 0 2w.? Added a GPS dongle to pull time off gps satellites (pi doesn't have an rtc), so once i got a gps fix and the time was locked, and chrony sets the pi's time from it, fired up WSJTX.? With SotaMAT on my phone and the Georgia parks + CW on several bands configured, I found a good clear 20m CW freq.? I set that freq up in SotaMAT, copied the POTA spot string from SotaMAT into the CQ message line in WSJTX, tuned over to 14.074 in digi mode, and let er rip.? Watched on the pota spot page that I was spotted and sure enough, was spotted the first time within seconds.
Switched back over to CW and the freq I spotted myself on, and got to work.? Activated on 20, switched to 30 and got a few there.? Didn't get to work any 40.
I've done both FT8 and JS8Call on the pi02w with the QMX before but didn't here.
QMX CW thumps?? Yes.? Bad enough I can't work?? No.? I have AGC on (I will not turn this off now that it's available, anyone who's used the QMX before AGC knows this well), sidetone relative, I forget what volume, I also forget what freq somewhere between 550 and 600, I like it low.? Volume not up loud, I have earbuds in so hear it very well.
In the kit:
QMX rev 2 (qrp labs assembled, i had to replace the rx mux ic that I blew out by unknowingly using it without the diode fix which i've since done)
Talentcell 6000 mah battery - (can't see it, it's under the tuner) this is way overkill but it's the same size as the tuner so kit-wise it just made sense.? I like that it has both a 12v DC port (for the QMX) and a 5v USB port (to run the pi).
ATU 10-0A - as cheap as they come, but man it just works.? hard to beat for $30
Pi Zero 2W and a case, headers, and all the fun stuff like the screen
---
Glonass gps dongle - i dunno, some cheap one, works fine
3d printed paddles - i've made several of these and have used them a long time but don't care for them, got boards for VK3IL's pressure paddles coming which will work much better for the kit
Retractable 3.5mm cable for the paddles
Retractable 3.5mm earbuds
Couple right angle bnc adapters
A few inches of rg174 stub between tuner and QMX
A few inches of DC cable with 2.1mm right angle barrel ends for power
~16' rg174 feed
External speaker I usually don't even use
Right angle 3.5mm adapters
USB necessities to power the pi and data to the qmx
JSVer hard case
---
Antenna is a homebrewed 20+30+40 tapped coil (22ga bntechgo)
Coil is sitting on an unbelievably small camera tripod. Of all the things in the kit, that tripod makes me the giddiest.
Whip is the Elecraft kx1 replacement whip which collapses to 6".
I pressed in a 1/4-20 rivnut into the bottom of the coil, but the 1/4-20 camera stub on the tripod wasn't long enough to reach the threads so I had to add an extra coupler and some allthread to finish the mount
2 different radials - 13' 22ga bntechgo silicon for 20m, 33' for 30 and 40m (30 is wound in to 20-25', I haven't found the perfect sweet spot yet).? They each have a fork and get clamped to the pvc tee with a screw+wingnut you can't see
---
The antenna fits in the case underneath the QMX in a cardboard case I custom fit
---
And after left open only a few minutes, enough pollen to choke a honeybee.? Yep, it's March in Georgia.
|
Nice post. Beautiful pix. Thanks for all the info. Great job!??
Yesterday my QMX got its maiden voyage in full kitted-out form.? Went to US-3715 here in GA (Cartersville).? It's been out in the field before, but with other radios till I was confident this one would be a good primary, and I wasn't disappointed this time.? My kit is not a micro, SOTA-up-on-a-peak kit, but still very small and fits in a backpack with plenty of room for other stuff.
Even though I had fine internet, I wanted to use the QMX to spot myself, so I didn't use internet for anything other than verifying.? I have KM6LYW's Digipi set up?on a Pi 0 2w.? Added a GPS dongle to pull time off gps satellites (pi doesn't have an rtc), so once i got a gps fix and the time was locked, and chrony sets the pi's time from it, fired up WSJTX.? With SotaMAT on my phone and the Georgia parks + CW on several bands configured, I found a good clear 20m CW freq.? I set that freq up in SotaMAT, copied the POTA spot string from SotaMAT into the CQ message line in WSJTX, tuned over to 14.074 in digi mode, and let er rip.? Watched on the pota spot page that I was spotted and sure enough, was spotted the first time within seconds.
Switched back over to CW and the freq I spotted myself on, and got to work.? Activated on 20, switched to 30 and got a few there.? Didn't get to work any 40.
I've done both FT8 and JS8Call on the pi02w with the QMX before but didn't here.
QMX CW thumps?? Yes.? Bad enough I can't work?? No.? I have AGC on (I will not turn this off now that it's available, anyone who's used the QMX before AGC knows this well), sidetone relative, I forget what volume, I also forget what freq somewhere between 550 and 600, I like it low.? Volume not up loud, I have earbuds in so hear it very well.
In the kit:
QMX rev 2 (qrp labs assembled, i had to replace the rx mux ic that I blew out by unknowingly using it without the diode fix which i've since done)
Talentcell 6000 mah battery - (can't see it, it's under the tuner) this is way overkill but it's the same size as the tuner so kit-wise it just made sense.? I like that it has both a 12v DC port (for the QMX) and a 5v USB port (to run the pi).
ATU 10-0A - as cheap as they come, but man it just works.? hard to beat for $30
Pi Zero 2W and a case, headers, and all the fun stuff like the screen
---
Glonass gps dongle - i dunno, some cheap one, works fine
3d printed paddles - i've made several of these and have used them a long time but don't care for them, got boards for VK3IL's pressure paddles coming which will work much better for the kit
Retractable 3.5mm cable for the paddles
Retractable 3.5mm earbuds
Couple right angle bnc adapters
A few inches of rg174 stub between tuner and QMX
A few inches of DC cable with 2.1mm right angle barrel ends for power
~16' rg174 feed
External speaker I usually don't even use
Right angle 3.5mm adapters
USB necessities to power the pi and data to the qmx
JSVer hard case
---
Antenna is a homebrewed 20+30+40 tapped coil (22ga bntechgo)
Coil is sitting on an unbelievably small camera tripod. Of all the things in the kit, that tripod makes me the giddiest.
Whip is the Elecraft kx1 replacement whip which collapses to 6".
I pressed in a 1/4-20 rivnut into the bottom of the coil, but the 1/4-20 camera stub on the tripod wasn't long enough to reach the threads so I had to add an extra coupler and some allthread to finish the mount
2 different radials - 13' 22ga bntechgo silicon for 20m, 33' for 30 and 40m (30 is wound in to 20-25', I haven't found the perfect sweet spot yet).? They each have a fork and get clamped to the pvc tee with a screw+wingnut you can't see
---
The antenna fits in the case underneath the QMX in a cardboard case I custom fit
---
And after left open only a few minutes, enough pollen to choke a honeybee.? Yep, it's March in Georgia.
|
Is it possible to share details for your antenna? Measures etc.
Thank you. 73 DE DK4BN
|
hi Jason, great stuff, the talentcell I have too, my tuner is the pocket transmatch by Kanga, tiny paddles and a very cheap speaker. simply have a look at the following: my /p setup
|
Udo: I really like your setup!? Is that the smaller 3000mah talentcell?? I struggled between it and the larger 6000 that I ended up getting.? I figured the larger one would let me have it operational for considerably longer, though tbh I'm not sure I'll ever need it off grid for as long as it'd allow me to be.? But, with the Pi and its screen working off the battery too, I felt better with the extra capacity assurance.? And it's the same footprint as the tuner which was another plus.? I may end up also getting the 3000 to use with the QMX alone with a resonant antenna (tuned efhw or dipole) separate from this loadout.? I like your paddles - n6ara right?? I have boards coming for vk3il's pressure paddles that'll replace these, they'll be much smaller (or, thinner anyway) and let me space out stuff and not need to cram all the bits in the corner.
DK4BN:?I just took the antenna out for the first time on this trip as well.? It is not finished and I haven't done good tests with it yet, but here it is.? It is built on 1/2" PVC (0.839" OD, or 21.3mm) with 22ga BNTechgo wire off Amazon (my measurements: insulated dia 0.027", 0.6858mm, and uninsulated 0.0253", 0.6426mm) and 4' whip (actually 46-3/8").? Top of former has a m4 bolt to accept the Elecraft whip.? The tap screws are m3, and spacing between coils is (or, was) whatever dia the m3 washers are - this GREATLY affects the inductance as it breaks up one coil into multiple.? I don't bother with the math on this, since I'm going to have to do trial and error on the coil winds anyway?(though there's a multiple coil inductance calculator that can be used).? I tuned it there in the park before getting on the air with it (except for 40m).? Here is a closeup of the coils if you'd care to count winds.? Note there's a length of wire (2-3" running from the bnc connector to the bottom of the former through that hole to the first coil.? Bottom is 20m - I had to remove 5 or 6 winds to bring it up from about 11MHz to 13.7MHz hence all the slack.? Removing another wind and keeping the coil tight would have taken it too far above 14 so I spread the winds out to decrease inductance a little and now it's spot on 14.0, and to tweak it to higher in the band I can just pull the whip in a small amount.? Bottom+Middle is 30m and where it is is just right, with pulling the whip in a small amount.? Bottom+Middle+Top is 40m, which I have not tried yet other than observe on the nanoVna and it does not have a nice dip.? My guess is there is not enough coil and I need to add more, but I'm out of space with this former and I'll probably rebuild and move this all to a slightly longer one (it's not glued yet).? But, where it is I get ~3.5:1 SWR on 40 which is tunable (and did in fact tune to ~1.1:1) with the atu-10.? Once I get it all where I like it I'll wrap in heat shrink leaving holes for the taps.? I hope this helps
|
Beautiful setup. I can see some future directions for antenna experimentation in my future! Thanks!
|
Jason,
As others have said, great post and photos.? Really a tremendous set-up and love that home-brewed antenna assembly.
Please pardon my ignorance, but for what is the Pi Zero 2W w/screen used?
Thanks for sharing this amazing set-up.
Eric (KC5JEV)
|
Eric:
For this setup (with the QMX), I'm using the Pi for FT8 and JS8Call.? There are probably other modes in FLDigi that can be used but I'll likely never touch them.? When SSB gets implemented on the QMX I'll go to town with SSTV, and probably 30m APRS will also be useful for various things.
The screen is not that useful for this setup except for one thing, to clue me in that it's booted up and ready.? It does show the url for ft8 and js8 web-based vnc, but (to me) that's not that useful as I can either get to it from the main web interface or (the one i actually use) realvnc which is on a fixed port (5901).? So, it'd work just fine without the screen and probably save a few mWh.? But it looks neat.? A 2 pack of them cost like 25 bucks so it didn't set me back much just to fool around with them.
A bit larger screen (think, size of a full size pi 4) could show wsjtx right on it, and with a mouse connected be able to use it and not need a phone/tablet vnc'd in.? I've not tried this but it sounds like an amazing approach.
For another setup with the 705 (and anything else the digipi is connected to that's 2m/dual band), the screen shows live APRS traffic which is pretty useful.
I hope that answered your question.
|
yes Jason, it's the 3000 and yes, the paddle is by N6ARA :) in my setup the 3000 only feeds the QMX, the trekstor 2in1 is powered? by the LogiLink solar bank .... that's enough for several days? :)
73s de Udo DF4BJ?
|
I am attempting to use Digipi with my QMX and am intrigued with your set up. I noted that you use the Rpi02W with a GPS dongle. I have some technical questions if you don¡¯t mind my asking.
How did you connect the dongle? My Rpi0 only has the two microUSB ports which I¡¯m using one to power it and the other to connect for CAT control to the tsncvr. Also, you run Conky for updating time with the GPS dongle. Is this a separate program you¡¯ve loaded to the Rpi0 or is it integral with Digipi? Finally, when you spot yourself on POTA, are you spotting yourself first as a FT8 mode activator or going for CW mode to begin with?
|
Could use a usb hub. If that's an option it's probably the best way. But in my setup I'm not. Instead I plug in the gps and let the time fully sync first, then when that's happened I unplug it and then plug in the qmx. Once the time is sync'd I don't really need the gps anymore. Time won't drift any significant amount while I'm running the pi. While I have the gps plugged in it also gives location including grid square if I need it.?
?
Yes it's loaded in digipi.? The most recent digipi update looks to have better handling for the gps.? I open up a ssh term to do what I need to do, but the latest update looks like you can do it from the main browser ui.? I haven't loaded the newest update to check, just watched his recent video on it.?
?
I mostly just spot from either the website or via sotamat. I'll try and setup a scheduled activation if I think I'm not going to have internet, so either cw or ft8 will auto spot me. If I have internet though I'm just going to spot whichever mode I'm working.?
?
Good luck,?
Jason KO4NDP?
|
I wonder why I can't see the pictures posted in this thread. I read content online like a forum, rather than getting emails, perhaps that is related? Still, I normally DO see photos posted here and in other groups. Odd, perhaps only emails get attached content?
?
As someone who has built a QCX+, two QDX and just ordered a QMX+ kit, I'd love see Jason's setup!
?
Cheers es 73,
Larry KC6WOG
?
|
A photo might be 10000 times larger than the text of a message in this forum.
To keep the archives at a reasonable size, the forum is configured to remove post attachments after a few days.
Attachments deemed important can be stored elsewhere and pointed to in the post, perhaps in the files section of this forum.
?
Jerry, KE7ER
?
On Sat, Apr 19, 2025 at 12:48 PM, Lawrence KC6WOG wrote:
I wonder why I can't see the pictures posted in this thread. I read content online like a forum, rather than getting emails, perhaps that is related? Still, I normally DO see photos posted here and in other groups. Odd, perhaps only emails get attached content?
|
|
|
Nice description Jason.
?
Can you detail or link the diode fix please?
?
Thanks
|
Bruce,
It's a fix described on the QMX page right below the Documentation header.? Here's a link directly to it
It's been a while since I posted this, so the fix may not apply to most folks by now.? My understanding is that just pre-2024 rev 2 boards need it.?
?
Sorry about the photos, yeah they don't last for long on groups.io.? I've revamped my qmx kit since this post, and doing it again now to fit in a WB2CBA Pocket Tuner I'm trying to build into an Altoids tin, a kind fellow member on this board (thanks Eric) hooked me up with a PCB.? Condenses the kit size considerably.
?
?
?
?
|
Udo Die?elberg DF4BJ
Todd W2TEF
Randy KO4WTM
Lawrence KC6WOG