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I've read from past posts that even though you have a fresh start with a new build, that a factory reset can cure a bad sweep display.?
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73
de Roy - KI0ER
Littleton, Colorado USA

Hello Roy,

It's drawing 212 mA powered up and idle, which is high!

Indeed. Around 100 mA here.

Have you checked the status of the buck converters? The 3V3 converter is working and the status is SMPS (Terminal - Hardware tests - Diagnostics)?
During the QMX start 3.3 V is produced for 0.25 sec by an analog voltage regulator causing a higher current. After the buck converter is working the analog regulater should be disabled (see schematics page 1). So far as I know it should be checked as ok before the start procedure of the QMX is finished, but maybe ...

Sweeps are not bad except Image @ 20 m. Please try again. Sometimes sweeps are not correct but after a second run or later ok.

Yes, output is (to) low. How did you measure these values? I don't know the real SWR of this dummy. But if the SWR is this bad (12 m and higher) and you measured the voltage the bad SWR causes larger errors in calculated power. Did you read the SWR from the QMX or from an externel SWR meter?

But Power @ 20 m with a good SWR = 1.09 is also to low.

TX current here is
580 mA @ 20 m and 3.5 W
600 mA @ 17 m and 3.7 W
870 mA @ 15 m and 5.1 W
700 mA @ 12 m and 3.1 W
770 mA @ 10 m and 3.7 W

For higher frequencies the current is higher for the same output.

Maybe something is wrong with the PA? The PA voltage looks ok. Could you check the signal at both inputs of T501 using an oscilloscope? Both are symmetrically?

73, Ludwig

I just finished may QMX.? Everything checks out except the RF sweeps.?

The radio seems to work fine in all modes and passed all the diagnostics except the rf sweeps all look like noise and the level is low compared to the?
published sweeps in the manual.

Did I miss something running the test?

I'm considering re-winding T407 just as some path forward.??
I don't have the case installed in case that makes a difference.

Your thoughts are much appreciated.

Traces:



Kindest regards,
Tim W8TWF

I just completed my 3rd QMX build, this being my first High-Band QMX. It is a 12 Volt 2023 Rev 2 board with 3 modifications done by me, the addition of the diode (surface mount) for potential parasitic oscillations, and the jumper for the PTT Out grounded functionality, and 3) replaced the power socket with a power cable with power-poles. It is running the _17 firmware with AGC enabled.

Everything appears to work correctly and it appears to be receiving OK ... except that I'm getting about half the power out that I should be expecting. What should I be looking at that I may have done wrong, or that should be adjusted? What other tests can I perform to determine the issue?

Here's my data while the QMX is connected to a QRP-Labs dummy load:

It's drawing 212 mA powered up and idle, which is high! And it feels warm (I'll look at it w/ infra-red camera next). My low-band QMX draws around 93 mA at idle.
When transmitting (CW key down) on:
20M drawing 716 mA
17M drawing 775 mA
15M drawing 833 mA
12M drawing 740 mA
11M drawing 760 mA
10M drawing 755 mA



--
73
de Roy - KI0ER
Littleton, Colorado USA

Hi,

Is there any way to key the CW transmitter via CAT?

I experimented with sending "TQ1;" but it doesn't output any RF. I
simultaneously sent 50 Hz tone via the sound card interface and it does
output RF, but only in digi mode. In CW mode is doesn't seem to do
anything (but the mode, queried with "TQ;", is switched to 1 = TX).

What worked was:

- sending MD6; to switch to digi mode
- sending TQ1; to enable transmitter
- sending tone via sound card interface
- sending TQ0; to disable transmitter
- sending MD3; to switch to CW mode

It works, but:

- it looks very hacky to me (and I'm worried about timing stability,
but I didn't test it)
- frequency is different from the one emitted when I press the paddle
by the frequency I send via the sound card interface
- there's no audible sidetone
- probably there's also no envelope (I didn't test it -- does the QMX
apply envelope for signals transmitted in the digital mode? I doubt, but
maybe?)

Second point could probably be solved by sending "FA;" to read the VFO A
frequency, sending another FA to lower it by the frequency emitted via the
sound card interface (for example 1 kHz less, and emit 1 kHz to the sound
card), and then send another FA to increase it again when keying up, but
it's even more hacky this way.

Is there any other way to programatically send CW with QMX?

Alternatively: is there any way to use the paddle port for a paddle, with
QMX's keyer, and any other port (PTT port) as a straight key input? This
way I could do some hardware to just toggle PTT via another port.

Basically, what I need is to be able to transmit CW both from a PC and
from a paddle, at the same time. Before Saturday, as SP DX Contest is on
Saturday...

I think that bending the device lead without supporting it between the bend and the body was the cause of the cracked encapsulation.
Hold the lead close to the body with tweezers or fine needle-nosed pliers and use another tool to bend the lead.? Don't exert any force on the FET body.?
If you break the device open you will see that the lead does not protrude very far into the encapsulation, thus has limited strength.

Those solder blobs on the ground pad were caused by someone's tinned soldering iron touching the pad.
73, Don N2VGU

I have the same problem - bad AF, RF, image sweeps (10m-20m) on kit QMX rev 3.? I just checked the 4 voltages (VrefL, VrefR, VcomL, VcomR) on PCM1804, they are all in the neighborhood of 2.5V.? I did have problems earlier with T507 and was putting out almost 10W on 11.9V battery.? My bad.? I fixed and re-installed the T507.? Now I only get 1W-1.2W.? As I hold the "t" key down in the diagnostic mode in PuTTy the wattage decreases slowly.? Otherwise audio "sounds" great with dummy load and straight key.? AGC seems to work great too.

Any ideas for next step?

I spent several hours under a microscope looking for solder bridges and cleaning flux.? And checking for decent solder joints.? Checked all toroids installation for continuity, all this looks good.

Thanks!

Frank
K8FXG

Antarctica on WSPR, attached.

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- 73 de Andy -

On Wed, Apr 3, 2024 at 08:17 PM, Da Amazin' man G0FTD wrote:

There's a German supply ship / monitor down there.
DP0POL and another one to look out for.

DP0POL and DP0GVN.
?
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- 73 de Andy -

On Wed, Apr 3, 2024 at 05:09 PM, Ron VE8RT wrote:

As to my knowledge there are no WSPR monitors in the interior of
Antarctica, the expedition may not see longer DX than this as they're
approaching the north geographic pole.

There's a German supply ship / monitor down there.
DP0POL and another one to look out for.
I often get spots from down there using 400mw on just about any band and wet noodle.
Even done on indoor loops / hamsticks.
?
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- 73 de Andy -

Corrected distance reasoning, the maximum WSPR distance should be half of the circumference with a maximum error of one grid square if both the sending and receiving stations were at the borders of the grid square nearest to each other. Does that sound correct. A bit OT no doubt.

As best I know there is no way for WSPR Spots to calculate long path,
then I suppose WSPR does not represent propagation distance but the
distance between the grid square of the sending and receiving
stations. Maximum WSPR spot distance then is one grid square less (if
the reference point used for the calculation is the centers of the two
grid squares) than half of the circumference along the widest axis,
likely near the equator.

In that case the record distance may be between a WSPR equipped
nautical vessel and any antipodal station along the equator.

As the earth has a "squished spherical shape" is it flat at the
poles :-) ?

Thanks Hans, enjoying the QCX+, and wondering about how many WSPR
stations of your design will contributing to the data collection during
the North American total solar eclipse.

Ron VE8RT

On Wed, 03 Apr 2024 10:03:54 -0700
"Daniel Walter via groups.io" <nm3a@...> wrote:

Actually, you can have about 24,000 miles propagation distance. Long path that's just outside of ground wave and too close for skip.
--
73, Dan? NM3A

--
Ron VE8RT <ve8rt@...>

As best I know there is no way for WSPR Spots to calculate long path,
then I suppose WSPR does not represent propagation distance but the
distance between the grid square of the sending and receiving
stations. Maximum WSPR spot distance then is one grid square less (if
the reference point used for the calculation is the centers of the two
grid squares) than half of the circumference along the widest axis,
likely near the equator.

In that case the record distance may be between a WSPR equipped
nautical vessel and any antipodal station along the equator.

As the earth has a "squished spherical shape" is it flat at the
poles :-) ?

Thanks Hans, enjoying the QCX+, and wondering about how many WSPR
stations of your design will contributing to the data collection during
the North American total solar eclipse.

Ron VE8RT

On Wed, 03 Apr 2024 10:03:54 -0700
"Daniel Walter via groups.io" <nm3a@...> wrote:

Actually, you can have about 24,000 miles propagation distance. Long path that's just outside of ground wave and too close for skip.
--
73, Dan? NM3A

--
Ron VE8RT <ve8rt@...>

Thanks, Dan !?

Thanks, Ron. That raised circle along with the dimple had be over-thinking it.?

Hi Rob,
I agree fully, hoping that Hans will find a solution. This is a crazy nice small radio, I love it. Would be a pity if there would be no solution.

BR
Heinz, DK4EZ??

Actually, you can have about 24,000 miles propagation distance. Long path that's just outside of ground wave and too close for skip.?
--
73, Dan? NM3A

The question as to whether this is a record is because greater
distances are possible and may have been achieved along the equator.

The success of this endeavour speaks to the quality of the design and
components in a QCX+, mobile whip antennae are not necessarily good
matches to a 50 Ohm transmitter, the GPS receiver (also from QRP Labs)
works at extreme latitudes, there have been no software crashes. When
the QCX+ is shut down (when they stop and sleep) upon powering up it
picks up again without operator involvement.

No part of the system is expensive purpose built ruggedized gear. It
worked beyond hopes and expectations. Holding a record would be a
bonus though :-)

Ron VE8RT

On Wed, 3 Apr 2024 12:19:06 -0400 (EDT)
"Mike Besemer - WM4B" <mwbesemer@...> wrote:

Yes... I don't believe there are any monitors in the interior of Antarctica either. There is one that I hit pretty regularly that is located on the Northern periphery, but that's the only one I'm aware of.

Mike
WM4B

On 04/03/2024 12:09 PM EDT Ron VE8RT <ve8rt@...> wrote:


Our local 200mW VE8CK beacon, but on a long wire antenna is also heard
at those distances. A challenge to record setting between the poles is
that the Earth is not a perfect sphere, the circumpherence along the
equator being greater than through the geographic poles. Also I
believe that the WSPR distances are calculated between the grid squares
and not actual positions and are not precise. the online calculator
gives 11,133 miles as the equivalent of 17,917 km.

As to my knowledge there are no WSPR monitors in the interior of
Antarctica, the expedition may not see longer DX than this as they're
approaching the north geographic pole.

Ron VE8RT

On Wed, 3 Apr 2024 11:42:54 -0400 (EDT)
"Mike Besemer - WM4B" <mwbesemer@...> wrote:

That's roughly 11,000 miles, or pretty close to the distance from my QTH to Western Australia. I routinely get reception reports from Oz/NZ running 100 mW into a random piece of wire laying in my attic which I'm very certain has negative gain.

Antipode distances are about 12,427 miles on a long circle path, so the record could not exceed that distance.

Now if you're taking miles/watt, that's another story.

Mike
WM4B

On 04/03/2024 11:17 AM EDT Ron VE8RT <ve8rt@...> wrote:


Are there records for longest WSPR DX, and if so are they online?

Yesterday a distance of 17,917 km was reported under spots, the TX is
a QCX+ on 40M using a Hamstick antenna.



Ron VE8RT VE8TEA FP5EK

--
Ron VE8RT <ve8rt@...>

--
Ron VE8RT <ve8rt@...>

Yes... I don't believe there are any monitors in the interior of Antarctica either. There is one that I hit pretty regularly that is located on the Northern periphery, but that's the only one I'm aware of.

Mike
WM4B