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On Sun, Jul 14, 2024 at 01:41 PM, M0WAS wrote:

Hi all,

Firstly, thanks Hans for a well designed kit, I've been waiting for a large qmx that I can actually build. I built this over the weekend, probably about 10-12 hours all in at a relaxed pace.

Most frustrating bits of the build were the 160m toroids. Kept losing count and then counting the turns was a challenge in and of itself. The 38 turn one must be at about the limit of turns possible? About 20cm of each enameled wire left over and 2324 capacitor cutoffs. The RWTS thingy wasn't necessarily difficult, but it was hard to feel confident in it. I think a few more pictures of it from a few angles would have inspired more confidence.

Only other point of note, my laptop track pad became very unresponsive when I plugged it into the QMX+ for the firmware install. It was connected USB c to USB c and it's an HP Envy X360.

Very very happy it turned on without issues.

Just wondering if I should be concerned about these power levels, specifically 40m and 30m. I.e. concerned enough to refrain from using the 40m band (or even tx in general) without fixing it.

160m 5.5w
80m 4.7w
60m 3.8w
40m 1.4w
30m 0.25w
20m 2.9w
17m 2.9w
15m 4.0w
12m 2.8w
11m 3.6w
10m 2.4w
6m 0w (my power meter isn't rated below 30MHz so hopefully that's why this is 0...)

What areas would I need to look at to check soldering, I assume the bands specific toroids, anything else?

Also are there any tips around the toroid spacings to increase power output? I know there was a tips and tricks for the QCX+ I built which got it from 4W to just a bit over 5W. I run a compromised antenna so every watt counts.

Generally looks good. I would check the 40/30 m toroids for proper windings number. Ifthey are correct then play with turn spacing.

6m is more concerning- it should show something even if the meter is not designed for or accurate at 6m. There I would suspect a bad solder joint.
?
--
73, Dan? NM3A

My QMX and I have a date with a nearby (NJ) POTA or WWFF entity on 28 July: Bumblebee #77!

Thanks for organizing, Jody!

G'Day Greg
Using the Hardware TX Diagnostic Test - the TX Bargraph is a steady switch on/ switch off (The result is what I expect)
Having gotten totally confused - I have gone through this morning logically retesting everything that I can think of..

Using WSJT-X & JS8Call on both my laptop (Panasonic CF-31) & Tablet (Panasonic FZ-G1) produces the "pulse" at the start of the transmissions.. this is occurring on BOTH the Hi & Low Band QMX's
It is there regardless of which USB socket or cable I use. Sometimes the very 1st transmission is a clean switch on. (No pulse)
Occasionally - rarely, & not at repeatable intervals the LOW Band QMX does not complete a full TX cycle on the on 20M Band (Dummy Load or antenna makes no difference).
This morning I watched every Transmission (I think) for a full hour & it didn't drop out once - Frustration..!!
It has probably always done it & I haven't noticed. When it does drop out, it transmits normally for around 3 to 4 seconds then the bargraph drops to zero & no power output. The switch to Rx & next cycle are fine.

QRZ tells me I have worked 210 QSO's through 42 Countries since May - so the QMX's are working - It is just a minor glitch that I am trying to get my head around...!!
Though the occasional Tx failure after 3 - 4 seconds is obviously not right.
I have attached a short 5 sec video showing the "Pulse" at the start of the transmit sequence.

Rob
VK5ZIK

Flight of the Bumblebees is 2 Weeks Away.? ??July 28^th will soon be here.??

?

Bumblebee Number requests are still coming in.? As of today, there are 120 Bumblebees signed up to go out and operate portable in some fresh air location. ?The Bumblebees will be everywhere from Maine to California and Florida to Washington.? Not in every state, but pretty darn close.? We will also have Bumblebees in Canada, and at least one in a DX location.? They will be operating from mountain tops, parks, beaches, local fields, back yards, etc.

?

Let me address this to the Home Stations (Especially those who use q QCX or QMX at home):

?

Your challenge is to work as many of these Bumblebees as possible using 5W CW.? On as many bands as possible.? You have the advantage of having better permanent antennas, but you may encounter pileups since Home Stations will outnumber Bumblebees.?

?

You can work the same Bumblebee once on each band – each band will count as another Contact and another Bumblebee worked.?? While you can also work other Home Stations from your Home Station, the scoring is weighted toward working Bumblebees.

?

Let me give you an example:

-????????? Working 1 Bumblebee and 9 other Home Stations results in a Total Score of 30?

-????????? Working 10 Bumblebees results in a Total Score of 300

Not everyone will be in it for the Score, but it is always nice to have bragging rights.

?

Of course propagation will not support it, but with 120 Bumblebees, and 5 bands available (10-15-20-40-80), a Home Station theoretically has 600 Bumblebees out there to find and work.? Chasing Bumblebees will easily fill up the whole 4 hours of this event.

?

Good Luck.? And have fun.

?

Adventure Radio Society – Rules are at :

?

73,

Jody – K3JZD

My QDX doesn't change tune rate of RIT. After pressing and holding tune encoder, it jumps to the VFO frequency and varies tune rate of VFO, 500, 100 etc. normally. The At the same time, the RIT tune display disappears. If I double click select it comes back with the RIT value still there. I've tried lots of key combinations. I'm running FW 20 and have tried other FWs and done resets. No joy.

It did pass all the hardware checks.

This is not a big deal, I'm just looking for help resolving the functionality and some pointing in the right direction. All else works fine.

I'm planning on taking it apart and looking over the control board and resolder.

Thanks,
Tim W8TWF

I'll be placing an order for one of these units next week. The intended use will be primarily shack, but I will also be taking it mobile occasional for field days or on camping trips. do not have a mobile set up now, and this radio will be my first foray into this aspect of amateur radio. I suspect that since my laptop will also be involved, I will need to plan on having a source of power at a remote site. For the most part, we camp at sites with amenities such as having a power outlet. My thinking is that I need to have some form of power supply that will clean up the power and deliver nice and stable DC power. Is this as easy as using a 9v wall-wart or will I need something far cleaner? Is there an advantage of 12v over 9v?

I do not know what I do not know, so any advice in this area will be greatly appreciated.


--
Jason
KI5UMG

Thanks Jim.
I assumed it was an update problem as I installed #20 on Friday.
So please report if it disappears!
You will really like the new firmware especially if you use presets.
73,
George
k3GK

Thanks David. I hate to try again and just fry another board.
I was going to oder some more power supply boards. My jumber for the power at the GPS is very low to the board and doesn't appear to be touching and I have no short to ground when measuring resistance between VDD and ground.
What amazed me was how fast the overload came on. I literally dropped the file onto the flash drive and it was nearly instant. Before dropping the firmware file into the flash drive (meaning the drivethat shows up when loading the inital firmware) there was no current draw to speak of. In fact I was so suprised to see the flash drive show up - I wasn't sure what to do or even where the firmware was. LOL. I though I was home free when the flash drive showed up.
And then all heck broke loose. Sigh.
I'm at that point were I just don't know what I want to do next.
I have one of those DROK chinese power boards but I don't think I'm setting the current correctly.

--
Dan Reynolds -- KB9JLO
<><

George - In the QCX+ Message menu both Interval and Repeat are set to zero. Another interesting bit...this issue only impacts Message 2. For other stored Messages (e.g. Message 1, Message 3, Message 4) each plays and does not cause other messages to automatically play subsequently. The issue seems to be with Message 2 somehow, but I have no idea what is triggering it to play Message 1 after it completes its own message.

It's not a big deal, just a quirk to work around. Maybe when I update to FW ...20 it will resolve.

————————-
Jim?
N7RCS
Palm Bay, FL

Hi all,

Firstly, thanks Hans for a well designed kit, I've been waiting for a large qmx that I can actually build. I built this over the weekend, probably about 10-12 hours all in at a relaxed pace.

Most frustrating bits of the build were the 160m toroids. Kept losing count and then counting the turns was a challenge in and of itself. The 38 turn one must be at about the limit of turns possible? About 20cm of each enameled wire left over and 2324 capacitor cutoffs. The RWTS thingy wasn't necessarily difficult, but it was hard to feel confident in it. I think a few more pictures of it from a few angles would have inspired more confidence.

Only other point of note, my laptop track pad became very unresponsive when I plugged it into the QMX+ for the firmware install. It was connected USB c to USB c and it's an HP Envy X360.

Very very happy it turned on without issues.

Just wondering if I should be concerned about these power levels, specifically 40m and 30m. I.e. concerned enough to refrain from using the 40m band (or even tx in general) without fixing it.

160m 5.5w
80m 4.7w
60m 3.8w
40m 1.4w
30m 0.25w
20m 2.9w
17m 2.9w
15m 4.0w
12m 2.8w
11m 3.6w
10m 2.4w
6m 0w (my power meter isn't rated below 30MHz so hopefully that's why this is 0...)

What areas would I need to look at to check soldering, I assume the bands specific toroids, anything else?

Also are there any tips around the toroid spacings to increase power output? I know there was a tips and tricks for the QCX+ I built which got it from 4W to just a bit over 5W. I run a compromised antenna so every watt counts.

Mine including the proto have been in use and testing while working just fine.
Its proven to be very durable despite my abuses. I have not noted any fragility
in the QRPL design.

Part of the reason for that is at 10W the devices are being run at less than half
their capability. That makes for reliable operation.

--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.

Hi Adrian,

That is great news. It's good to know there's nothing wrong with my build. The birdies (new word to me) don't really bother me, other than a slight worry that maybe there was a defect in my QMX.

Thans!
VA2WLM -- Willem

Hi the Bias is a stabilised switch supply, the two IFR FETs will have a different turn on voltage hence two pots. They are on a bit of a knife edge.

These are cheap transistors pressed into service to form a good RF amplifier, however, only a few manufacturers will work correctly as not all IRF 510 have the same spec

They are switching transistors normally switched hard on or off in a switched mode power supply, however, as they have a low capatance they are ideal for a general purpose RF transistor. They are cheap less than ?1.

Most Transmitters have power control which throttlies back the drive when you have a mismatch, to save them from high voltages. The QRP LAB design does not, so they are vulnerable.

You must have a matched load to use them.

You could use a multi turn pot to set the Bias, or a very steady hand, they also will run away with heat as well.

It is a PA on a Budget, having said that mine has been working for 10 years with carful handling.

I build a second unit with a SWR bridge and the reflection port throttlies back the drive, this makes it very robust.

RF power transistors are very expensive ?25 each.

Make sure you are using the original make supplied with the kit. Vishay not sure how it it is spelt.

73

Andrew

Hello Willem,

What you are hearing are internal "birdies" generated by the SMPS. It is a known issue, and it's on Hans list.
There was a discussion some time ago, please see this post.

Regards,
YO3GFH
op. Adrian

On my QMX (mid-band), I can hear a constant tone on some frequencies, as if someone is tuning up an antenna, but it just stays. It also doesn't make a difference if I have an antenna attached or not, so it's not an actual signal, but seems to be internal to the QMX. In a way it behaves as if it's an actual received signal, in that it shows on the S-meter. For example, on 14,074,80 I have a pretty loud one, showing 4 bars. But in another way it's not like a received signal, because when I tune slightly away from it, the tone disappears instead of changing in pitch. For example, the "signal" on 14,074,80 is completely absent on 14,074,79 and 14,074,81. I'm powering it from a battery, so it's not power supply noise.

Also, I can change the frequency of where I hear the tone by changing the CW offset. For example, when changing the CW offset from 700 to 800, the tone mentioned above moves to 14,074,90.

The tone I hear has a pitch of 820 Hz (measured with an app on my phone).

Has anyone experienced this, or know what could be causing it?

To add to Bojan's comments a bit.
Using a radio like the U3S, which creates the "data" through direct frequency control, you set the frequency to the actual Tx frequency.
? In Bojan's example 14.097130 MHz
NOTE: some software picks the center tone, others pick an edge tone, but they are only a few Hz apart.

When using a radio in SSB tone and a computer application like WSJT-X that injects a "Tone" into a mixer with a suppressed carrier, the tone is between 1400 and 1600 Hz.
? So the radio displays 14.095600 MHz (in SSB - usually USB). WSJT-X shows a bar in the waterfall between 1400 and 1600 Hz (the WSPR window).
WSJT-X injects a audio Tone of 1530 Hz - seen on .
The actual signal is 14,095,600 Hz + 1530 = 14,097,130 MHz. => 14.097130 MHz.

To verify this, put the receiver in CW mode and set the waterfall to look for the signal.
The using the typical 800 Hz offset (or tone), your radio would be set to 14,096,330 or 14,097,930 depending on CW or CW-R setting to be on frequency.

I hope this helps!
-------
Rob KB8RCO

On Sun, Jul 14, 2024 at 08:50 AM, ajparent1/kb1gmx wrote:

I make it a point of using separate relays to get better isolation and often its
a mechanical convenience as well.

Thank you for that very practical tip, given how low cost these little relays are, it's probably best to carry out that seperation as you suggest - I;ve never built an RF amplifier before, so all these tips are most helpful

Thank you, 73

Peter - GM8JCf

One area is that input and output must not be close as in using the same relay.
If isolation is not enough oscillation can be a unwanted result.
I make it a point of using separate relays to get better isolation and often its
a mechanical convenience as well.


--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.

On Sun, Jul 14, 2024 at 07:20 AM, Timothy Fidler wrote:

Put colour coding via Red and blue heat shrink on the Two cables which have the common BNC connectors and a red and blue spot adjacent to the bulkhead connector at the amp. Viz J2 and J5.

Useful tip, thank you

Peter - GM8JCF

On Sun, Jul 14, 2024 at 07:20 AM, Timothy Fidler wrote:

Use a contact from Relay one ?as a the input controller for the RF use a contact from Relay 2 as the output controller for RF out. ?Currently you have RF in and RF out in the same relay. Some ?Chinese boards do that (RF in and RF out in the same relay housing ) but it is not good practice.

?

Tnx for the tip

Peter - GM8JCF