Hi there,
I've run some tests now.
Measured the output power with almost 5W at input voltage of about 9.1V into a dummy load.
I tested for continuity on all the coils. The soldering here seems to work fine.
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I post some pictures of the test-screens...
Hopefully these pictures lead to the problem somehow
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LPF
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image sweep
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RF filter
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audio filter
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test ADC I/Q
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On Wed, Dec 25, 2024 at 12:43 PM, stan timmerman wrote:
But probably - when no one is looking - you will pull out the 60/40 (lead) solder you have been hiding from the goverment.
Or even better, 63/37 (eutectic) alloy with RMA flux core.
73, Don N2VGU
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Re: WSJT-X on Raspberry PI 3B and QMX+ unstable
It could be a faulty USB cable, but I would check your antenna from end to end and the transmission line first. I was having some strange issues recently and discovered my counterpoise had fallen into the snow.
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73, Dan - W2DLC
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WSJT-X on Raspberry PI 3B and QMX+ unstable
The setup of this combination has been working just fine with FT8 and WSPR for a while. All of a sudden, tx stopped working while rx still works, including bandhopping. After resetting and restarting sometimes both tx and rx work, then. again suddenly tx quits. Any advice? Could it be a falty USB-C cable?
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Hiroki AH6CY
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I would not agree to the statement that it won't work with lead free solder.
You should use a soldering station anyhow for the multilayer boards and with a good alloy there is no problem.
I'm using Stannol HS10 Sn95,5Ag3,8Cu0,7 which is so far the best lead free solder I used and I tried quite a few.
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If you use a low cost alloy without silver it makes things more complicated.
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KR
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Dirk
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The water spec is common for what's also referred to as deionized water in industrial applications. We had a plant at pppl.gov that made thousands of gallons, since we used it to cool a number of? of high power devices like 8974 2.5 MW tube amplifier modules...
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While that NASA soldering spec dates from 2006, SN60/SN63 remains to this day in the NASA supply chain. Aerospace material suppliers still sell it. SAC305 (tin-silver-copper) is the current recommended replacement, at 4-5 times the cost.
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Re: QMX and FLDigi - MFSK modes
Has this been fixed or are these the same modes that work? Is there a way to do RTTY?
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Hint for new builders:
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If you? build with lead free solder your radio will probably not work.
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Maybe if you? have a lot of experience and? very nice equipment you could make lead free work.
But probably - when no one is looking - you will pull out the 60/40 (lead) solder you have been hiding from the goverment.
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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
If anyone is building more than 1 and is willing to sell the other one, I'd love to volunteer! Interested in the full monty — the board with ATU, battery, and speaker. 73, Merry Christmas,
Randy K7RAN
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Re: Should I be disappointed?
On 25/12/2024 11:04, David Wilcox K8WPE via groups.io wrote: There should be a diagnosis title for that condition Now then Dave, a chance for you to write a scholarly article about this and submit it to The Lancet or such. As a doc, you have the qualifications. Maybe they'll publish it and it can become known as Wilcox Syndrome. ;-) Andy
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Happy Holidays to all and may 2025 be happy and prosperous to all.
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Re: Should I be disappointed?
On 25/12/2024 13:22, terompet via groups.io wrote: a few db of gain can make a difference.? I am looking at the 10 watt amplifier kit. As Greg says the QRP Labs 10 Watt amplifier is not suitable without modifications to reduce its gain. Basically that is best done by removing most of its circuitry. (Or the QMX PA.) And, following the theme 3 Watts to 10 Watts is just over 5dB, maybe worthwhile but you will want more and more. On the other hand if you don't feel you will live long enough to do it with 3 Watts go for 1.5KW and then give up radio:-) 73 Alan G4ZFQ
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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
How do I sign up for this group buy?
I? will commit to this buy
Will
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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.
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73
Evan
AC9TU
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Re: QMX+ No transmit or receive
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.
73s Joel MacNeill VY2KW
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).
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73 Ludwig
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Re: Should I be disappointed?
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...
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Re: Soldering Station Recommendations
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.
73 GREG KI4NVX?
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?
Also: MG chemicals de-soldering braid 2.5mm & 6mm
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Re: Should I be disappointed?
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...
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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.?
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73, Dan - W2DLC
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Re: Should I be disappointed?
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)
more at:
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72 de N4REE, Bob Easton - QRP CW forever
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Donald S Brant Jr
Daniel Conklin
Dirk
Chuck AI7SY
Randy K7RAN
N4REE - Bob
