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Almost forgot -- in order to do this APRS stuff you need some JS8 stations set up to forward (via the internet) any received JS8 messages that contain the APRS flag.? I don't know how many JS8 stations do this now (you need an easy-to-get APRS password), but I have three 24/7 JS8 30-meter receive-only?APRS gateway stations up and running: WB6CXC/6 in northern California, WB6CXC/7 in Washington state, and WB6CXC/FIN in Finland. You can usually see these on pskreporter.? The station uses a RPi, an RTL-SDR, and a few other bits, and the cost (less antenna) was under $100.? Details here:
--
Paul Elliott - WB6CXC

Again, this is an older topic, but with JS8 you can do way more than APRS position reports.? You can send arbitrary telemetry data, not only to the APRS network, but you can use the APRS email and text message capability to send your arbitrary data wherever you want.? It's a pretty powerful mode, way more flexible than WSPR or FT8.
--
Paul Elliott - WB6CXC

I'm afraid I've tried this. The calibration is now set to Step 01, Time 060, but the step size was larger initially. The frequency has more or less stabilized to 26,998,733 which should be about right.


--
Sverre

?

LA3ZA, http://la3za.blogspot.com

One other thing, are you using the gps to calibrate the u3s? The OCXO oscillates at a lower frequency, maybe the OCXO is set correctly and it's working it's way to its settled point.
I use a big calibration step and 240 seconds on first start up after the Argo setting up then once it's settled down to around 26.998 mhz or so it rarely needs calibration and after around 20 mins warm up time rarely shows a drift on wsprnet.?
Hope you sort it soon,
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.

Love what Andreas, DM5MU did with those plug-in modules !
Very nicely-done six-band QCX rig, Andreas !
Tnx & 72 / 73,
Bill, N4QA

When I was using the plain old Si5351A synthesiser module (no GPS correction) I was getting drift reports of 0 or 1 - it was very stable. My U3S is in the aluminum case but I have a LM7805 voltage regulator on a little board with a large heat sink (converting 13.8V to 5V) which is probably keeping the heat very constant in the case.
--
John, WB5THT

Thank you, Alan...I'll have a look !
72 / 73,
Bill, N4QA

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Bill,

There are a couple of reports of multi band builds here on the web / forum, a search should find a few different ideas / implementations.

One such build is also shown in the builders gallery ? towards the end of the list (6-band QCX by Andreas DM5MU)

Alan

Hello Nigel.
Thank you for your kind comments !
Sounds like your QCX-30 will be a very handsome rig !

Looking at the? QCX schematic, I am considering lifting one end each of C27 & C28, and jumpering the C29 end of L3 to the rf connector end of L1.
That would facilitate using an external low-pass filter which could be home-brewed or purchased for the band of interest, .
Additionally, I would be very interested in seeing ideas/designs for a band-switched version of the QCX receiver's band-pass filter & phase-splitter circuits !
Or...wait a minute..how about removing T1 and replacing it with small terminals to which one could temporarily attach a specially terminated? 'T1' of choice !?

72 / 73,
Bill, N4QA

Hi Andy,
Thanks for the reply. Yes, I set up just like you describe. But I am still afraid that I didn't quite hit the sweet spot because of the drift I am seeing.?

The fact that I am seeing negative values for drift, seems to indicate that my 27 MHz clock is not at the minimum frequency. And since the setup for the OCXO specifically looks for the minimum, I am afraid that I am not at that sweet spot. But before I tear it apart to redo the calibration, I thought I would look for some confirmation of that and other advice as well.

--
Sverre

?

LA3ZA, http://la3za.blogspot.com

DOH! What a dummy.

I forgot to change the calibrate step time on this U3S kit - I did go through this on U3S #1 but completely forgot on #2. Now we are calibrating and the reference frequency is changing. Can't believe I missed this. Thank you Hans for the help.
--
John, WB5THT

?I received my QCX kit it a couple of weeks which I ordered on 3-16. But the extra QCX programmed ATMEL chip which was ordered on 3-18? hasn't left Turkey
or shown any movement since 3-22

Joe

Greetings from sunny South Africa Bill :-)?

VERY interesting report back from your QCX adventures! Many thanks for sharing - I for one sincerely appreciate, thank you.

Sooooooo, I have yet to start construction of my QCX - 30 for a number of reasons including collection of all hardware and metal bashing I have planned for the enclosure (which is a di-cast aluminium case). Reading your posts I am now wondering if perhaps could be of value to purposely make change to intended filter (switched maybe? Need to revisit schematic) and include a selectable output filter / atu arrangement (case has space as intended to include internal batteries)? Having a MULTI band QCX is VERY appealing <BIG smile>.

Will appreciate your (and any one else who cares to chime in) feedback / ?comments as I suspect will many others...

Keep the feedback coming, it is making for an interesting read :-)?

73

Nigel ZS6RN ex G8DEV?

Hi Sverre,?
I have built 4 of the OCXO, how did you set the OCXO up? Mine are all inside a qrp-labs.com case with no issues.?
I used Argo software and a FT 817ND as receiver with a lead from spk out on the 817 to mic in on laptop, set u3s to tx fskcw as stated in manual and watch the signal frequency in Argo drop then stabilise. At some point it will rise, this is too far,back off a touch and you will be fine. My OCXO u3s don't drift although sometimes a spot may say -1.
Good luck?
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.

I had the same problem with my 30m QCX.
--
73
Richard
G4TGJ

I just assembled an OCXO and have had it running for a few days with the U3S at 18 and 14 MHz. The U3S is in the QRPLabs enclosure. It turns out that I need to have the lid off in order to reduce drift to 0. Otherwise I will get drift in the -1,-2,-3 range. This seems to indicate a heating problem, could it be that it gets too hot with the lid on?

And how should I interpret the drift? Does it mean that the 27 MHz reference is drifting down in frequency during the transmission with about 27/14 times the reported drift? Could it be that I haven't found the proper sweet spot for the setting of the OCXO?

--
Sverre

?

LA3ZA, http://la3za.blogspot.com