Re: The $200,000 Question
Just to close this out, I wound up winding for 12V after (almost literally) flipping a coin.
On Sun, Sep 15, 2024, at 08:39, Michael - WD0OM wrote:
Trigger cables? Not so far. I suspect another noise source.
On Sun, Sep 15, 2024, at 06:35, Bob KB1TEK wrote:
Have you found these cables to be noisy? ?I have one and it¡¯s terrible. I guess it could be the power bank.?
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Re: QDX and QMX+ (soon at least) what is the max safe swr?
On Sun, Sep 15, 2024 at 10:15 AM, Sandy wrote:
Very simple. 1:1 is the max safe SWR. I use a 4 state tuner to get nearly there and then fine tune while broadcasting until the SWR indicator on the QMX reads a perfect 1:1.
I use the same tuner and have an MFJ.? I suspect I may have some issues with both that I have not yet had the time to look into further.? I also have a Rigexperts antenna analyzer, but I can't always get all the way to a 1:1.? My 4SQRP seems to make my SWR on 20M worse.? I think I can get it less that 2:1, but I finally put the analyzer on my antenna clean (no tuner) and am about 1.2:1 so I figure that is okay.
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As I have said several times, I know 1:1 is best.? My QDX and my QMX+ (when built) are both for 9V for what that may matter.? And I can check my SWR several ways, but just wanted to know how far off of 1:1 was redlining.? So far the only answer I got was 1.5:1 should be okay.? Would like to know if 2:1 is okay (knowing that it is NOT optimal).? Just want to avoid having to replace finals... but may have to just play till I blow a set.
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Bob
KG5GTE
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I expect someone's already asked this, but I can't find any reference here.
Has anyone converted a QMX+ to operate on 70 instead of 50MHz?
73 Mark G?OIW
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#bug #qmx QMX SWR protection not working when QSK is enabled?
#bug
#qmx
Hello all,
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Since a few FW versions ago, I kept my QMX on 30m band, on a doublet tuned with a manual Z-match. Today I felt like doing 20m and I retuned the antenna. To my surprise, the SWR protection didn't trip - although the S was displayed on the screen and the sidetone gone silent, the QMX happily countinued to emit RF. Being on 027 firmware, I proceeded to scratch my head in order to ascertain what new feature could cause that, since I'm positive that SWR protection worked ok some versions ago.
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First thing that came to mind was the QSK and, sure enough, after disabling it, SWR protection worked as intended. I had QSK on "auto" before.
I searched the group for similar occurences and haven't found anything, but, in all fairness, I didn't give it too much time either. Has anyone else observed this?
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Regards,
YO3GFH
op. Adrian
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Re: QDX and QMX+ (soon at least) what is the max safe swr?
Dan,
Similar experience here. I suspect the majority of people with QRP Labs equipment have seen the same. With reasonable care to minimizing SWR mismatch and duration of the mismatch, risks are low for magic smoke exit.?
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73, Dan? NM3A
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Re: QDX and QMX+ (soon at least) what is the max safe swr?
I'm with Mike.?
The nanoVNA is such an incredibly useful tool, I wonder how I survived without one. It also pinpointed a feeder break to the centimeter, just one of the many magic tricks it contains.
I've also been pretty careful since I bought the QCX classic and all the radios from QRP Labs that inevitably followed. So far my spare pack of finals has remained unopened.?
73s Ted?
2E0THH?
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Re: Short USB cable for QMX to reduce RFI pickup
I had run into a similar situation. And this solved it:
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Although a better solution is to be sure to add a 17 foot (for 20 Meters) or longer (for longer than 20 M) counterpoise wire when tuning a single long wire. It connects to the other post on the antenna tuner and can just run out along the ground. Remember that all circuits need somewhere for electrons to travel to, which is why we have 2 wires to connect pretty much everything. Antennas are no different, 2 wires are needed, but if only one is supplied, the other needed "wire" is sought out by the RF circuit causing havoc.
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When operating a hand-held walkie talkie, for example, your body becomes that "other wire".
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--
73
de Roy - KI0ER
Littleton, Colorado USA
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Re: QMX+: The trifilar toroid torture test
Michael,
Good advice from others to follow. I used three different color wires to make my transformer, but marking them with colored markers would work just as well.?
As far as inserting them in the proper holes, leaving the wires long and using tweezers does work well, but the best method is to cut them all different lengths from front to back. Then you can guide them in one at a time without having prior wires pop out. See Hans description of how to assemble the QRP Labs dummy load (in the manual) for a great description with photos.?
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73, Dan? NM3A
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DDS VFO Synth display choice?
Hello all,
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Some while ago I built the DDS VFO and I can say it works very nicely! Only change I mad was to use a green/black LCD module, then I did not need the backlight. Good for QRP /P operations.
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I am thinking of connecting the DDS into my new homebrew TXVR that I am building for backpack portable using.
But here is my problem. The LCD display module is 70mm X 24mm and the mounting board even bigger.
That takes up lots of space on the front panel of my small TXVR! And to be honest I do not need all the two lines of characters. Just need the frequency display
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I really want something smaller. I have searched and all the Hitachi HD44780-compatible displays are this large size.
Is there any way to use a smaller display? Even if I loose some info. As above i just want the frequency digit.
Does not have to be pin compatible because I can make wire connection adjustments.
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Any ideas?
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Re: QDX and QMX+ (soon at least) what is the max safe swr?
I meant QRP Labs ...
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73, Dan - W2DLC
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Re: QDX and QMX+ (soon at least) what is the max safe swr?
I'm not particularly careful at all. I have an MFJ-971 which I tune for max noise, then a short transmission to get as close as possible to 1:1, which I almost never achieve on either my balanced dipole, or my EFW. I've also used MFJ 949E, and QRP Guys mini tuners. I've been using QRL Labs transceivers for almost 5 years and never blown a final. I have an original QCX, two QCX minis, a QDX, and a QMX. I built them all from kit form, and I keep a bag full of BS170s in the shop just in case, because of all the horror stories I've heard here. I don't know what I may be doing differently, but I've had a lot of success with BS170s withstanding some fairly high SWRs. I suspect it may be because I don't stress myself with trying to squeeze the last milliwatt out of these transceivers.?
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73, Dan - W2DLC
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Hi Thomas?
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You could try if usb powered in the terminal from the command line?
Run Tracker?
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The U4B does not run from USB power without a terminal (computer) ... usb power tells the radio that it is connected to a computer and so it runs the usb connection program? . I always check using? battery power before a flight or in text edit/ debug/r which should also work
in Basic make sure there are no extra spaces at the beginning or end of your lines and if you are using 2 digit line numbers make sure the starting number is on the far left and the first line is at the very top of the page. Make sure you compile after any change and wait a second after compiling.
Dave VE3KCL
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Re: QDX and QMX+ (soon at least) what is the max safe swr?
I try to minimize the stress I put on the finals of my radios, so I use a nanoVNA to check/tune my antennas before connecting a radio.? At about $60 and smaller than a battery pack, it's a great tool for home or portable use.
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73,
Mike, KL7MJ
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Re: Connector Source Assistance
Wayne Carpenter KN2Z @minicowman
On Sun, Sep 15, 2024 at 08:53 AM, ND6P wrote:
Have you considered using traps instead of quick connections??
No, I really hadn't. But you know what, that is very good idea. I will see what that might entail. I don't mind winding coils. Thanks!
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Re: New Build but can¡¯t get firmware to load
On Mon, Sep 16, 2024 at 12:55 AM, <N4uav@...> wrote:
Lots of measurements and I KNOW it¡¯s a solder issue.
At which place?
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Indeed, the problem should be at PCB#2. It looks like the values are from the pin header, right?
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In this state (analog regulator) VDD at the pin header comes from the 78M33. Because different current across D102 and D103 the voltage is a bit below 3.3V.??? 2.96 V is ok here.
We don't see VDD produced by the SMPS. But we have ADC_3V3 produced from the SMPS VDD by the voltage divider R110 and R112. ASSUMING (!) this divider is correct the SMPS VDD is around 2.3 V. In one of your former posts Diagnostics show 2.58 V. I think in this operational state the voltage shown by Diagnostics are a bit higher than real (see VCC = 4.96 V measured by DMM and 5.52 V shown by Diagnostics).
PWM_3V3 = 1.19 V is the mean value from the switching pulses. With 2.9 V for ON (see voltage of the signal PWR_HOLD at ON from the controller) the Duty cycle should be around 41 %. In your former posts 42% and 43% were shown, this fits.
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To find the problem at PCB#2 you should test this board off line (see QMX QMX_Plus Power supply test Process). For step No. 3 reduce the input voltage below 1 V and set a current limit of around 50 mA!!! Doing 3.1 increase the input voltage slowly and check the input current and VDD. Question: How much input current at which input voltage? Do you have a sudden current increase or is this linear to the voltage?
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73, Ludwig
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Re: Surprising invoice from FedEx
I shouldn't say this non a qrp-labs forum, but I ordered a Venus sw-3b.? When the customs forms were completed they made a mistake and as such calculated the customs duty to be double what it was. Over ?100 on a ?180 radio.... they would not release the radio to me unless I paid the fee. Over a year later I'm still fighting with them to get my money back. They agreed that it was a mistake at their end but will only offer a credit against my account... like I import things every day... for the life of me I can't get fedex to issue an actual refund.?
Hate fedex with a passion. Dhl only for me.?
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Re: Surprising invoice from FedEx
Nice to read a quote from Robert A. Heinlein's Novel, "Time Enough for Love".?
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Re: A ¡°pluggable¡± firmware architecture?
Hello Matthew
All ideas are indeed welcome, even bad ones ;-)?
I think your ideas are interesting?but, I think it is likely to be impractical?on a small scale system like QMX. The architecture?to be able to include or exclude or include functionality?modules is probably itself?too large an overhead to contemplate on such a small system, both in hardware, software and human terms (development and support).?
I think and hope?that a better way to proceed has been and will be, to keep the code efficient?and the processor future-proofed enough. Right now only about 1/3 to 1/2 the CPU and Flash memory is utilized; I hope and suspect that the resources of the processor will suffice to allow all planned future development in a single firmware version.?
I understand why and fully support the fact that QRP-Labs firmware is not open source.
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This idea is for a capability to pick from a ¡°menu¡± of options enabling the user to tailor the firmware on their device.
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For example; on every radio I own, I¡¯ve disabled the CW decode capability. It would be cool to be able to free the code space occupied by the decoder function to make room for some other, more compelling feature.
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Maybe SSB pushes the firmware to the limit and you want remove FSK capability to make room.
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et cetera.
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This is NOT a feature request. I can think of a lot of reasons why this could be a bad idea.
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- Firmware ¡°versions¡± don¡¯t have a clear meaning anymore.
- It could become a support nightmare. User: ?¡°Hey, my thing doesn¡¯t work!¡± Support: ¡°What combination of modules do you have in your firmware?¡±
- Module X doesn¡¯t play nice with module Y.
- Cost of re-architecting the firmware code base.
- Cost of UI/infrastructure to put this into the hands of customers.
- Opportunity cost.
Why even mention this if it¡¯s not a feature request and is such a bad idea? Even ¡°bad¡± ideas should be heard, maybe it helps ¡°good¡± ideas to be uncovered.
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Re: QDOS vs Python vs c vs ...
Hello Allison
QDOS =? QRP Labs Disk Operating System
What I called the U4B OS with BASIC, FIle manager, Command Line, Debugger, Text Editor. With all due apologies to former proper users of the "QDOS" ;-)?
73 Hans G0UPL
On Fri, Sep 13, 2024 at 7:33?PM ajparent1/kb1gmx via <kb1gmx= [email protected]> wrote: When I see QDOS two things come to mind.
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QDOS a z80 clone of CP/M-80.. didn't get a large following.
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QDOS? Seattle Computing Corp, Quick and dirty OS for the 8088/8086
which was bough by Microsoft as IDM DOS V1.
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There is no reference I know of QDOS as a language.? Send me a clue?
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As to Basic, its widespread, its been ported to just about every
processor/platform.? Its an acceptable language for solving
problems.? My only beef with most versions is speed as its usually
an interpreted language.
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--
Allison
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Post online only,?
direct email will go to a bit bucket.
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Re: QMX+: The trifilar toroid torture test
For ease of assembly?
Cut the wires to different lengths?
pre scrape /tin the connection area?
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For ease of identification
Use the insulation off a reel of silicone wire (18AWG sometimes or 22? / 28 AWG more typically) to make tiny ¡®slide on tightly¡¯ markers.
(As I use these wires all the time the off cuts are easy to re stock ?)
This way also survives the assembly process to provide a sanity check in any later fault finding ?(pic from a 10W amp but applies generally)?
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Mark Palmer
Ted 2E0THH
Daniel Conklin
VE3KCL
Bruce Akhurst