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Re: #QMX first powered test -- is this right?
#qmx
On Fri, Feb 23, 2024 at 05:54 PM, Eric W. Hansen wrote:
I set my bench supply to 6.8V with a very low current limit.Be aware you need around 160 mA to start the QMX. |
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Thank you so much, Hans, for the reply. I really appreciate your customer care and especially your responsiveness to your vast? market. Charles K5KXJ
On Friday, February 23, 2024 at 09:27:43 AM CST, Hans Summers <hans.summers@...> wrote:
Hi Charles, all To be clear: ***NO*** QMX Rev 3 will have a Q202 problem. 100.0% of all the 1,000 in the batch, the Q202 will be changed by us, to the Nexperia BSS84AK I sourced. It should be noted also that it's a precautionary measure. Even with the factory assembled BSS84 it works fine... But it is a little vulnerable if you didn't observe good ESD practices, and this is why we are changing it. I didn't want to introduce a new increased failure probability mechanism.? 73 Hans G0UPL On Fri, Feb 23, 2024, 6:11?PM C R Murrell via <crmurr=yahoo.com@groups.io> wrote: Hans, |
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Re: #QMX first powered test -- is this right?
#qmx
On Fri, Feb 23, 2024 at 05:54 PM, Eric W. Hansen wrote:
ViFly ShortSaver 2Which current if you remove the power connector from the QMX? How much power consumption by the ViFly ShortSaver 2? 73, Ludwig |
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Rotary encoder problem
#qmx
#rotaryencoder
Hi,
sorry if this topic was discussed before but I couldn't find it. Yesterday I finished my second QMX (20 m - 10 m). I found problems related to the right rotary encoder. When dialing the frequency sometimes after one step the same frequency is shown. It looks like the step is done and in the same moment the step is removed (same value shown again.) In the menu mode around 10 ... 20 % of the steps bring the wrong submenu (e.g. "Audio - Presets - Audio" or "Audio - Audio - Presets - ... - Digi interface - Beacon - Beacon - Beacon - Display"). Sometimes going backwards one Submenue is skipped (e.g. "Protection - Beacon"). Using my first QMX I have simular effects but considerably rare. In the moment I dislike to swap the controls between the two QMX, both are in the enclosure. Are there any information about this? May be debounce is a little bit to tight and for most of encoders are sufficent but for some are not? Ludwig |
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#QMX first powered test -- is this right?
#qmx
I finished construction of high-band QMX rev2 (2024), 9V version.? Checked and rechecked all my soldering under magnification and probed for shorts with an ohmmeter.? Time to apply power and do the smoke test.
I set my bench supply to 6.8V with a very low current limit.? I'm passing the power through a ViFly ShortSaver 2 (per recommendation on this forum), but since the current limit on the power supply is set well below 1A, I don't expect the ShortSaver to actually function as a circuit breaker right now.? When I turned the bench supply and the ShortSaver on, the meters on the supply read 6.8V and 40mA.? I stopped there, and did not press the rotary encoder to power up the radio.? Before I do, I want to know if things are OK so far (after all I've read on this forum, I really want to be careful not to blow the QMX up.)? Should there be a quiescent power-off current draw? Thanks, Eric |
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Re: QMX Rev 1 Watt & SWR meter problem
#transmitpower
#troubleshoot
#troubleshooting
#qmx
Firstly please don’t drill the holes out.
It’s a multi layer board and there may be inter-layer connections, I don’t know for sure but just saying. I soldered a capacitor in the wrong place on one of my kits and managed to successfully remove it and get the holes cleaned out. I used solder wick with a little flux, but I first added some fresh solder to the holes to give the solder wick something to grab on. I had to do it a couple of times on one hole, trying from both sides, but it worked. Another way is to not clear them but to introduce the fresh wires whilst heating the pad/hole (preferably and easier from the top side if access allows). Hold the wire relatively close using some fine forceps and push the wire in and through when the solder is wet. Then follow up again with your iron and a dab of fresh solder to re wet the joint. Or, if you need, solder the new wires to the top side, I did that to one toroid on my QCX Mini 40M, where I was changing turns to optimise power. Though could be difficult to get to all on that transformer. 73. Rowan. |
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Re: QMX Rev 1 Watt & SWR meter problem
#transmitpower
#troubleshoot
#troubleshooting
#qmx
I have cleared solder holes by simply heating the pad and displacing the solder with a toothpick.? Sometimes it helps to whittle the toothpick to the right diameter. 73, Bob W7DIT |
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Re: QMX Rev 1 Watt & SWR meter problem
#transmitpower
#troubleshoot
#troubleshooting
#qmx
Have decided to remove T507, rewind and reinstall. Now I must ask HOW did you clear the through-holes of solder?
I have a hot iron solder sucker but it is way too big. Have also solder wick and have used to clean up the pads but still have thru-holes with solder in them. I will wait to see your answers before I drill out the holes.... -- 73 Karl KI4ZUQ |
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Hi Charles, all To be clear: ***NO*** QMX Rev 3 will have a Q202 problem. 100.0% of all the 1,000 in the batch, the Q202 will be changed by us, to the Nexperia BSS84AK I sourced. It should be noted also that it's a precautionary measure. Even with the factory assembled BSS84 it works fine... But it is a little vulnerable if you didn't observe good ESD practices, and this is why we are changing it. I didn't want to introduce a new increased failure probability mechanism.? 73 Hans G0UPL On Fri, Feb 23, 2024, 6:11?PM C R Murrell via <crmurr=yahoo.com@groups.io> wrote: Hans, |
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Re: QMX on a stick - a minimalistic SOTA activation
#qmx
@DL2ARL
Thanks for pointing this out. Seems I have been lucky so far...and if I think about it, its probably by chance. Routinely, I connect my trigger board first to the powerbank and then I connect the transceiver. By this time, voltage negotiation seems done and the QMX does not see the 5 V to 12 V step anymore. Unfortuantely, I can't edit my initial thread to highlight that this sequence may be important to not kill anything. So for everyone who is still reading: If you plan to use USB-PD to power your QMX, first connect the trigger board to the powerbank, wait some seconds until voltage negotiation is done, then connect the QMX. @N6HAN Correct, it's a BNC connector for RG58. It's drilled open (a little) to match it with the 6 mm brass tube + heat shrink (to isolate the whip from ground). That's basically the base of the antenna. In the meantime, I played around with the coil "design". Because it worked so well on 30m, I wanted to have the option to switch coils and operate on 20m, 30m as well as 40m. Below a picture with some comments. I did another short SOTA activation with the QMX this morning on 20m, and again it worked amazingly well. 12 QSOs in 15 minutes. And with the new firmware 017 I did not experience any glitches at all. Smooth CW operation. Thumbs up, Hans! For sure many more QMX SOTA activations will follow. Best, Matt |
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Hello AD5MO! Tangential to topic, but, I am working on three similar go-boxes and I am very interested to incorporate two Inovato Quadra systems.? My plan includes water resistant power outlets on two of these.? I ordered two Quadra and two 10.1" monitors that were?each engineered to support Raspberry Pi.? The third case has a 12V PC and monitor.? There are three transceivers here to box up.? I am thinking to put Yaesu FT 891 and a QDX together. I want a 2M/70cM go-box for who knows what's coming. So, maybe I will likely use the third case for solar, a battery, and for antennae and connectors.? Your set-up is a different but welcome inspiration. I appreciate your photo!? A member of a local ham club made one that included an MFJ UTC/Local clock, a white board, band plan, LiPoFe4 battery, I liked his that was easy to set up and take down in less than 5 minutes.? I want to include my QDX, an azmithal map and carry the battery separately.? Other members of this same local club use a go-box to contain systems that they set up on site rather than have mostly packed with connections already made like yours.? I am thinking about putting connections under a sheet of scrap Lexan.? Yours seems easier.? Thanks for your go-box photo. 73 KY4XJ Paul ? ?
On Thursday, February 22nd, 2024 at 2:03 PM, mordan42 via groups.io <mordan42@...> wrote: Hello all, looking for assistance with my POTA to go box, which consists of QMX Rev 1 low band, a screen, an Inovato Quadra box, and a morse key paddle in an Apache case. WSJTX works great on decoding, but when the QMX tries to transmit, I get one dot under VFO indicator and a brief flash of power out meter, then everything reverts not no dots under VFO and AGC meter (Firmware 17 is running). I would include a picture but it happens so quickly, I can't really get it. |
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Re: 10W HF Linear PA kit
I'm on my 5th build.? All work and the latest partial SMT and works the same as the others.
My curves are different than Guidos.? I never measure output impedance,? However the? gain I get is flatter to 30mhz.? I used a 50mW into an attenuator so the source sees a flatter load.? Fixture line up used was a Rigol815T, Qbit block amp, step attenuator(HP set to 10db), DUT(the amp), 30DB Narda?power attenuator, Kaye step attenuator to Rigol input.?? The Qbit amp is a class A video amp flat from .5Mhz to 100Mhz with max undistorted output of 27dbm.?? Test is done at 9W to avoid saturation . for the amps I have and built 1db compression? varies from 12W to 13.5W at 13.8V at it terminals.? The amp will oscillate if the wiring is poor that being th einput coax and output coax to LPF and load.? Your dealing with 26-28db of gain. -- Allison ------------------ Post online only,? direct email will go to a bit bucket. |
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Hi Hans. Glad your problem is (painfully) solved.? I can;t tell you how many times I've got bitten over the years with:
1. early CMOS chips that had no input protection.? They would get damaged if you looked at them the wrong way.? From where I live, I had ab expression, "CMOS loves the summer, CMOS hates the winter."? In anything I design for my own use, I always make sure devices have built-in ESD protection to the extent available. 2. I learned not to get too clever taking advantage of of a device's unusual internal structure that may not be there from multiple vendors.? I once minimized chip count for a 5 v to 10 v level shifter by taking advantage of a 5V CMOS device that could handle 10 volts on its output via a pullup resistor to 10 volts. This was confirmed by the vendor as acceptible use. I was happy for awhile, then I became unhappy when the vendor stopped making the part.? No problem. I said to myself. There are several other vendors making the part.? But it turned out they were all only 5V compatible on their output. So I had to do a redesign with considerably more parts and was considerably unhappy. -Steve K1RF ------ Original Message ------
From "Hans Summers" <hans.summers@...>
Date 2/23/2024 4:36:53 AM
Subject Re: [QRPLabs] #qmx #shipping update
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Chris / W2BPL
Rick Williams - VE7TK
Karl
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