Re: Release of version 1.2 of ABS solution for QMX+ (Automatic internal antenna tuner, internal battery and internal speaker with audio amp)
#ABS
#ATU
#PSU
#QMXplus
On Wed, Dec 18, 2024, at 07:39 AM, Roland OE5ARN wrote:
I?m not a technician, but I made some measurements with help of the video from NA5Y.
The result: all is okay until minute 9:30.? The voltage on L10 should be abt 14 V in RX and close to ground on TX. This is not the case (only 0.25 V RX and TX). The following measurements are also incorrect. For instance R13 always shows 14 V (RX and TX). So I stopped testing.
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Merry Christmas, Roland,
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I went back and read your first post.? ?We may be looking in the wrong area.? The incorrect voltages on L10 suggest that there is a problem with the T/R switching circuit.? This could be Q4 or one of the components L10, L1,? L2, R10, or R11.? ?I would bet on R10 or L10 being open as those are the source for the receive 12volts on L10.? The next potential culprit is Q4 being open, as there is no voltage on L10 when in receive mode.? This would cause a failure to turn on D1 and D7, which connect the input and output RF to the amplifier stage.
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Can you verify the voltage on the gate and drain of Q4?? This is a P-channel MOSFET, so the device is on when the gate voltage is lower than the source.? This happens when Q6 turns on.
Thank you to everyone in the group!! And hope you all have a merry christmas!! I just realized that farther back in this thread, I?said that I would submit audio and RF sweeps and I still have not done it yet. Been very busy lately. I have reviewed this thread several times away from the shack and in solitude, lol when i get it, to absorb all the info i have been given. What I documented is this.... Low pass filter sweeps were good on the lower to mid HF bands (160m thru 20m), and not so good on higher bands like 6m Audio sweeps all bands -100db,**** RF sweeps all bands 90 to 120 db below with no detectable center frequency?on any bands, Image sweep , no bands above -90dbSWR sweep very chaotic due possibly to the low power output. As I previously promised, I will try to submit some actual?screen shots of my sweeps. Just received my new QMX mini kit today from Hans and?I want to wait to figure?out?my problem with?the?QMX+ before I?start that project. I cannot handle multiple?unfinished projects around the house. Again, I want to say thanks, Merry Christmas and a Happy new year!! Will be back again with the screenshots.
On Mon, Dec 16, 2024 at 7:39?AM DH8WN via <DH8WN=[email protected]> wrote:
On Mon, Dec 16, 2024 at 11:47 AM, Chris wrote:
The gate of Q507 should be high (+12V) in receive
Yes and no. In RX mode the voltage to the PA (BS170) is switched on again to reduce the D-S capacity of the BS170. There is a parameter in the Advanced config (see operations manual).
I believe the 10 watt kit requires a very low input power level.?
I've had good results with the 50 Watt Amp kits for 15 and 20 meters, powered at 12 volts,? with the bias set to produce only about 10 - 12 watts out for that bit of extra punch on FT8 when conditions are crappy.?
On Wed, Dec 25, 2024 at 8:22 AM, terompet via groups.io
<terompet@...> wrote:
Depending on band conditions, a few db of gain can make a difference.? I am looking at the 10 watt amplifier kit. I'm wondering if I might be able to use the case of the QMX+ as a heat sink.? But that might be a project for the new year.? Happy holidays everyone...
I've assembled, successfully, a QMX HB, a QDX LB, 2 QMX+ units, three 50W amps, numerous, small SWR/Power Meters, 2 QRPOmeters, an Elecraft dummy load and a slew of plugs, jacks, and RC aircraft connectors with a WEP 882D station. The hot air gun is very useful for shrink tubing.?
I purchased an extra basic set of tips for the WEP and a set of long, 0.5mm conical tips for touchup of small IC pins. Almost all the work done with the 1mm conical tip and the 3mm screwdriver tip for really throwing heat quickly to large tabbed jacks and such.?
400 degrees C has worked fine for me with MAX for big tabbed stuff. ( Much less for the low temp SMD solder pastes if/when you practice or rework on the real units. See the recommendations in the instructions on the ChipQuik offerings. See below for more on that).
I like Kester 63, leaded solder and have also used some Austor brand from Amazon. Those are the 0.8 mm size. I use 0.015 inch, Radio Shack solder with Silver for really fine work too. It's back and made in the USA again. Bit pricey but a little goes a long way.
I use ChipQuik brand liquid flux and practiced SMD soldering and removal on several cheap practice boards I got off Amazon with their low and high temp solder pastes. I practiced with the hot air gun here? before using it on Q units. Was able to easily replace the PA control IC on the QMX HB when I glitched the PAs doing something stupid. What helped me the most to build confidence for SMD work was watching Mr. Solder Guy videos. The guy is skilled !?
Harbor Freight has an inexpensive magnifying head band. A bit clunky but worked fine for checking component markings and general fine soldering and inspection work.
For SMD work I also got an inexpensive USB microscope. Not a lot of work room under it, but doable.?
Two thumbs up for 2.5mm and 1.5mm solder braids.
Squirt some ChipQuik flux on it. Works much better.
I also use an old Weller Stained glass soldering iron or a YiHua temp control soldering iron with a really broad tip for removing wire enamel for toroids and such. Google 'solder blob technique for removing wire enamel' and think about what you see on the videos and written explanations. You won't regret it. I did find that some of the larger wire in the kits needs a few quick scrapes with an XActo knife to give the solder blob some copper to bite on before the enamel will burn off.?
I do solder outdoors in the garage now and have a simple small desk fan to blow away the magic flux smoke.?
Take heed of the recommendations about needing to sink extra heat on component leads on the 6 layer boards in the Q series! Check connections with a simple DMM ohm meter as you go and be sure to probe on the pad areas and not the wire ends where applicable.?
A cheap, simple PC board holder is like a miracle.
Do use a grounded solder mat or simple aluminium foil covered board with a 1M ohm resistor to ground along with a proper grounding wrist strap!!!! A small purchase you won't regret.?
Have fun. You'll be amazed at the capabilities of these fine kits.
On Wed, Dec 25, 2024 at 3:38 AM, KJ7RBS via groups.io
<jadonerenda@...> wrote:
Oh boy do I have some opinions
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The Pinecil is the neatest thing I've ever seen and is top 3 best value items you can spend money on.
? $25 gets you an self-contained smart iron (with Bluetooth app) that is powered off USB-PD or DC jack 12v-21/24v (18v drill batteries work great)?
? I've done SOT-23 SMD work and 6AWG solder cup cannon plugs with the same iron (quick change tips)
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Kester #44 67/33 eutectic solder? I'm more a sticker on the eutectic mix than the brand I've not heard any reasons 60/40 is better, And lead free is mandated trash and should be avoided at all cost.
? ? Thin solder is necessary for small components but works fine on larger stuff just a pain to feed in 6 inches at once. The $11 tube of .031 off amazon is very nice and decent all around to use. Solder-paste is genius for SMD components and kinda OK to help tin stuff I guess.
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RMA flux is very cool and makes things a dream to solder compared to using just flux core solder. I got that amtech stuff Louis Rossman recommends but know nothing more about flux than that.
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I would add a roll of MG chemicals de soldering braid, 2.5mm and 6mm. NTE blue label is what Ive always used but they are out of business so probly won't find that
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TLDR;
Iron: buy the Pinecil and the fine tips set
Solder: kester 44 .031?
Flux: Amtech NC-559-V2-TF or other recommendations?
Depending on band conditions, a few db of gain can make a difference.? I am looking at the 10 watt amplifier kit. I'm wondering if I might be able to use the case of the QMX+ as a heat sink.? But that might be a project for the new year.? Happy holidays everyone...
Merry Christmas, and Happy Holidays to all from Upstate New York, USA. May your Holidays be filled with peace and love, family, and ham radio friends from afar.?
As many more have said: NO!? The real difference between 3w and 5w is virtually indiscernible.? FAR MORE depends on your antenna, the propagation characteristics of any particular day, and the receiver's ears.
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Let this sink in:? 3.6w on 10m using a TW2010 antenna.
The Villages, FL to KL7AC in North Pole, AK, about 3712 miles (1,030 miles/watt)
There should be a diagnosis title for that condition: seeing what one THINKS one is seeing…. I have had that disease since childhood and it gets me in trouble frequently with my XYL.
On Dec 24, 2024, at 12:44?PM, Andy via groups.io <andy.mm0fmf@...> wrote:
?On 24/12/2024 16:58, terompet via groups.io wrote:
I guess I should have had 3 watt expectations when I ordered. C'est la vie.
Maybe read the description carefully and ensure you understand what it says next time.
Not that I think Hans' descriptions are misleading or designed to confuse. You just need to make sure you know what it says and not what you think it says.
Hi all, may I wish you all a happy new year and say a big thank you to all you builders who post questions on this site. I look forward to the daily digest each morning to read the queries, it starts my day with a smile, sometimes a full blown laugh.
Just think about the efforts people do to have 2 db more gain with antennas...
Peter,
Yes, 2dB will make a contact that is just missed without it. Add 2dB and then an extra 2dB will make a contact that is just missed without it. And so on until you have more dB than anyone else.... By then QRP is abandoned:-)
As others have said the QMX+ could most likely be tweaked to give 5 Watts on 20m at the expense of what else is on the same LPF. And, as others have said maybe the PA will last longer with 3 Watts. The QMX is not an expensive complex rig where everything is calculated to the last fraction of a dB.
No, don’t worry. Be Happy! ?You can fiddle with the toroids and mess up a great radio or be satisfied with those power output readings…. Anything over 3 watts is excellent and the ham at the other end won’t know the difference. ?If you are concerned build a 10 watt amplifier or even a 50 watt one. You will have to reduce your output power so you don’t blow up the amp though. ?
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My QRP Labs built QMX+ runs a little lower in output on some bands but it’s fine in my book. ?
On Dec 24, 2024, at 10:23?AM, terompet via groups.io <terompet@...> wrote:
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My new assembled QMX+ showed up on my doorstep yesterday and I was very excited!? Everything checks out fine, but I find that I am disappointed in the reported power output levels: 160m 5.7w, 80m 4.8w, 60m 4.1w, 40m 3.9w, 30m 4.5w, 20m 3.3w, 17m 3.1w, 15m 4.5w, 12m 3.2w, 10m 3.8w, 6m 3.1w.? I am most disappointed with 3.3w on 20 meters since that is my goto qrp band.? I guess that I was expecting power output numbers on all bands to be closer to 5 watts.? Should I be disappointed?
The best investment I ever made is the Donegan Optical Loupe. ?I had two from my medical practice. They are worth the money (the Donegan brand) but like everything else the Chinese knockoffs are good also. Here is one that is recommended and looks like my original ones: ?
I also use frequently the add on flip down loupe:
This is a Donegan product and I found it quite useful. ?It fits on the front of the head loupe.
Also this lighting system has been useful for years:
?Worth the extra money.
I bought my originals from Micro-Mark but they seem to be out of stock on a lot of these items. ?My Donegan units are 30+ years old and still working and holding up well. I can’t vouch for the Chinese items but they are cheaper. The Donegan OptiLoupe runs about $70 for the basic head unit with one lens. ?I use the 2x lens 99% of the time but you can figure that from any “readers” you usually use. I use 2.5 x readers for reading and for shack close uo work but keep a set of 2.75, 3, 4 x readers in construction booth. ?
As for soldering stations I have used the Solomon brand from Amazon for years too.
This is a newer version. I use two of them, one for a fine tip and one with a heavier tip for larger items that require more heat like BNC and power connectors.
As for solder, I use Kester 60/40 that I buy from Steve, The Solder Man at Dayton. Easily available. ?Do NOT use lead free solder.
On Dec 24, 2024, at 3:15?PM, Curt wb8yyy via groups.io <wb8yyy@...> wrote:
?
Dave
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You don't need a boatload of equipment. Also note focus is through hole construction. Don't need paste, just quality solder. I see plenty of nice enough gear out there. Definitely temperature regulation. Some swear by Hakko but others may be good enough. You may want a stand magnifier. All this should easily be in your budget.?
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Oh I built my K2 with a plain soldering iron, but I suggest a modest investment in a soldering station.?
My new assembled QMX+ showed up on my doorstep yesterday and I was very excited!? Everything checks out fine, but I find that I am disappointed in the reported power output levels: 160m 5.7w, 80m 4.8w, 60m 4.1w, 40m 3.9w, 30m 4.5w, 20m 3.3w, 17m 3.1w, 15m 4.5w, 12m 3.2w, 10m 3.8w, 6m 3.1w.? I am most disappointed with 3.3w on 20 meters since that is my goto qrp band.? I guess that I was expecting power output numbers on all bands to be closer to 5 watts.? Should I be disappointed?
I checked the PCB for solder bridges with a sharp knife.
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I'm not sure if I made a mistake in former measurements. But now resistance between R2/3 and D1 is 28,5 ohms. No matter, if C3 is installed or removed. C3 is okay (1.02 uF).
I have bought a few months ago a JBC BT-2BQA soldering station with a few different tips. With this 140W soldering iron it was convenant to solder the QMX+. A simple and good tool for electronic soldering.?
The Pinecil is the neatest thing I've ever seen and is top 3 best value items you can spend money on.
? $25 gets you an self-contained smart iron (with Bluetooth app) that is powered off USB-PD or DC jack 12v-21/24v (18v drill batteries work great)?
? I've done SOT-23 SMD work and 6AWG solder cup cannon plugs with the same iron (quick change tips)
?
Kester #44 67/33 eutectic solder? I'm more a sticker on the eutectic mix than the brand I've not heard any reasons 60/40 is better, And lead free is mandated trash and should be avoided at all cost.
? ? Thin solder is necessary for small components but works fine on larger stuff just a pain to feed in 6 inches at once. The $11 tube of .031 off amazon is very nice and decent all around to use. Solder-paste is genius for SMD components and kinda OK to help tin stuff I guess.
?
RMA flux is very cool and makes things a dream to solder compared to using just flux core solder. I got that amtech stuff Louis Rossman recommends but know nothing more about flux than that.
?
I would add a roll of MG chemicals de soldering braid, 2.5mm and 6mm. NTE blue label is what Ive always used but they are out of business so probly won't find that
?
TLDR;
Iron: buy the Pinecil and the fine tips set
Solder: kester 44 .031?
Flux: Amtech NC-559-V2-TF or other recommendations?
I use fldigi on occasion - with flrig to control the QMX.
In flrig, you set the config to talk to the QMX - there is even an entry for it in their 'rig' selection:
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Note that it is good to set the polling interval up as high as it will go - the QMX firmware is not expecting rapid polling.
The 'update' button by the com port selection re-scans the computer com ports, which is useful if you start the program before your QMX has been cabled and powered on.? Press the 'init' button to connect after you select the port.? I have seen the 'connected' indication get stuck at green when it is not connected, so keep that in mind.? You can tell it is connected back in the main flrig window because it will update the frequency display, A/B, and PTT buttons will work.
One more flrig config window I played with:
I reduced the number of controls it would try to poll for.
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In fldigi itself, you need to select the rig control and soundcard:
Rig control needs set to 'flrig'.? I tried Hamlib, but was having problems, so I switched to fldigi.
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Under soundcard select the QMX in and out devices.? If you don't see these, restart the QMX and this program, and also make sure the QMX does NOT have I/Q Mode enabled (that disables the soundcard devices).
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Also, in the bottom-right corner of the fldigi window, to the right of the received signal indicator, is a "TX Level Attenuator" control.? That should be set to 0, so a maximum signal level goes out on TX.
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You also must disable the fldigi TxID feature, because the timing of the TxID preamble fools the QMX data detection routine, and it will only transmit the few milliseconds of the preamble then cut out.? Alternately, you can set the QMX digimode rise and fall thresholds to zero, which works ok, but disables the cleaning the QMX normally does on its output waveform, so the signal start/stop won't be as clean.? At some point this may get fixed in the firmware - it's on Hans list.
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That's about it, other than to remember it will only currently work on CW, RTTY and MFSK modes - ones that transition between single tones.? It will not work properly on any of the phase-shifting (PSK) modes.? I have used it on MFSK and RTTY.
The difference between 3W and 5W is -2 dB, or 1/3 of an S-Unit. In the real world, there's no perceptible difference between 3W and 5W under normal conditions.