QMX+ Kit - Capacitor Marking
My new QMX+ kit arrived in Virginia today, only 7 days after the 'shipped' notice from QRP Labs. Amazing considering that includes a weekend.?
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Checked the contents and everything is there BUT ..
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The Capacitor for C402 is labeled '33K' instead of '330' or '33J'. It measures out pretty much at 33 picofarads, but the'K' apparently? may indicate a 10% tolerance vs others in the BOM that have the 'J' designator.
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Is it good to use?
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Thanks in advance.
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73 GREG KI4NVX?
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Re: QRP Labs Turkey Workshop?
I would definitely be interested, however I have as yet renewed my passport, I could plan for next year with the XYL. I would love to explore those ruins.
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Here's the proper link to the USB cable that I use between my QMX and PC.
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As I recall from other discussions on this topic within this group, the shield of the USB cable is not, by spec, supposed to connect to the ground side of both connected devices, which is surprising to the uninitiated. But many cable manufacturers do make that connection.
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--
73
de Roy - KI0ER
Littleton, Colorado USA
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Re: QRP Labs Turkey Workshop?
Hans,
why must you tempt us, so?! :-D
Sadly, I
think I'd need a lot more lead time to plan a trip like that from
Minnesota! But that doesn't mean I didn't at least peek at
flights...
/m
On
Mon, Sep 23, 2024, at 13:54, Hans Summers wrote:
Hi
all
We would like to see if there is
interest in arranging a workshop here in Dalyan, Turkey. Location is
25km from Dalaman international airport (about 25 minutes' drive) with
direct low-cost flights from many European destinations including
Austria, UK, Slovakia, Ireland, Germany, Belgium, Netherlands,
Switzerland, Poland and of course,
Turkey.?
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Re: QRP Labs Turkey Workshop?
Oh man! I wish I could. I’ve traveled a lot of Turkey but not your region. Always beautiful country and great food.?
Ken/NO4D Wishing and Daydreaming ?
toggle quoted message
Show quoted text
On Sep 23, 2024, at 2:55?PM, Hans Summers via groups.io <hans.summers@...> wrote:
? Hi all
We would like to see if there is interest in arranging a workshop here in Dalyan, Turkey. Location is 25km from Dalaman international airport (about 25 minutes' drive) with direct low-cost flights from many European destinations including Austria, UK, Slovakia, Ireland, Germany, Belgium, Netherlands, Switzerland, Poland and of course, Turkey.?
The area is a few km inland from the sea with access via river estuary to the beautiful Iztuzu beach, which is also a protected nature reserve for nesting sea turtles. The ancient ruins of the city of Kaunos () is within a few km walking distance.?
The weather at this time of year is very nice, averaging?+26C midday in October without about 75% chance of pure?blue sky sunny days. The weather is still warm enough for comfortable swimming in the sea and?pool, and many tours and trips are still available as it is not yet the end of the summer season.?
For the XYLs there?are many activities?possible including natural thermal springs mudbaths, boat trip tours and local markets. For the radio amateur you are welcome to buy and assemble some of your favourite kits here in QRP Labs HQ complete with testing and alignment?while here, all equipment will be provided (test equipment, soldering irons). There are lots of hiking areas and mountains in the area so if portable operations are your thing, there's plenty of opportunity for that too (regrettably Turkey is not yet a member of SOTA but POTA does operate here).? - Shared villa accommodation ?50/night - self-catering with 5 ensuite rooms, pool and barbecue, 5 minutes walk from town center restaurants, bars and shops - and 2 minutes' walk from QRP Labs ;-)
- Airport transfer?and return ?35 each way
- Boat trip to Iztuzu beach including lunch ?35
- Many other possible activities (trekking, climbing, safari)
As it is approaching the end of the holiday season we have villa availability in October so dates can be flexible. Please let me know if you are interested and we can set it up.? <dalyan-kings-rock-tombs.jpg> <villa5.jpeg> <villa4.jpeg> <villa1.jpeg> <villa2.jpeg> <villa3.jpeg> <area.png>
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QRP Labs Turkey Workshop?
Hi all
We would like to see if there is interest in arranging a workshop here in Dalyan, Turkey. Location is 25km from Dalaman international airport (about 25 minutes' drive) with direct low-cost flights from many European destinations including Austria, UK, Slovakia, Ireland, Germany, Belgium, Netherlands, Switzerland, Poland and of course, Turkey.?
The area is a few km inland from the sea with access via river estuary to the beautiful Iztuzu beach, which is also a protected nature reserve for nesting sea turtles. The ancient ruins of the city of Kaunos () is within a few km walking distance.?
The weather at this time of year is very nice, averaging?+26C midday in October without about 75% chance of pure?blue sky sunny days. The weather is still warm enough for comfortable swimming in the sea and?pool, and many tours and trips are still available as it is not yet the end of the summer season.?
For the XYLs there?are many activities?possible including natural thermal springs mudbaths, boat trip tours and local markets. For the radio amateur you are welcome to buy and assemble some of your favourite kits here in QRP Labs HQ complete with testing and alignment?while here, all equipment will be provided (test equipment, soldering irons). There are lots of hiking areas and mountains in the area so if portable operations are your thing, there's plenty of opportunity for that too (regrettably Turkey is not yet a member of SOTA but POTA does operate here).? - Shared villa accommodation ?50/night - self-catering with 5 ensuite rooms, pool and barbecue, 5 minutes walk from town center restaurants, bars and shops - and 2 minutes' walk from QRP Labs ;-)
- Airport transfer?and return ?35 each way
- Boat trip to Iztuzu beach including lunch ?35
- Many other possible activities (trekking, climbing, safari)
As it is approaching the end of the holiday season we have villa availability in October so dates can be flexible. Please let me know if you are interested and we can set it up.?
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Re: Still no output on QMX
On Mon, Sep 23, 2024 at 02:18 PM, Paul - AI7JR wrote:
In general, how do changes in input voltage affect the efficiency of a typical buck/boost supply?
I am not a power supply expert, but from what I have seen, the efficiency seems to be more related to load current, with a broad peak and a shallow falloff, and fairly insensitive to input/output ratio, but typically above 90%.
73, Don N2VGU
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Re: Removing flux. Is it necessary? Yes/No
On Mon, Sep 23, 2024 at 01:12 PM, Steve H wrote:
2. The sooner you clean the board after soldering, the easier it is to remove the flux.
3. Flux which has not been overheated and burned will come off much easier, too.
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Re: Still no output on QMX
If he built for 9V and ran from a "13.8" V supply, would that
affect conversion efficiency? In general, how do changes in input
voltage affect the efficiency of a typical buck/boost supply?
(Thanks for the info, too!)
73, Paul -- AI7JR
On 9/23/24 05:07, Donald S Brant Jr via
groups.io wrote:
On Mon, Sep 23, 2024 at 12:05 AM, Paul - AI7JR wrote:
Don't know what the comparative losses will be in a
switching regulator... Close maybe, but I don't know which
would be better!
A switcher at 95% efficiency would waste 12W x 0.05=0.6W vs 1.8W
with diodes.? So 1/3 the loss.
73, Don N2VGU
--
Paul -- AI7JR
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Another option is to try your library. Most these days have one if not several 3d printers. Usually incredibly cheap too. It's been a while since I checked but last I saw, ours was a few cents a gram of plastic used. Some may charge by time.?
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Re: Removing flux. Is it necessary? Yes/No
Thanks for the toothpick suggestion to clear the lint, I used a Q-Tip with Isopropyl alcohol yesterday working on my QMX build and found a lot of that.
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Paul - do a search on Facebook Marketplace. I found someone locally to print my (tr)u-sdx boxes.
gl de va3rr
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Anyone have a recommendation for someone or a website that does 3D printing at a reasonable price. I have the digital file for the object I need printed?
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73 Paul W2ECK
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Re: Removing flux. Is it necessary? Yes/No
Two tips from my experience (YMMV):
1. Warm water with a bit of dish soap and a toothbrush, followed by an isopropyl alcohol wash and a compressed-air blowoff, works well. Removing the water promptly with alcohol prevents it from causing mischief. Using both water and alcohol gets things that dissolve in either.
2. The sooner you clean the board after soldering, the easier it is to remove the flux.
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An earlier commenter mentioned alcohol attacking the green solder mask on his PCB: I've never seen this happen over many years; I would suspect a bad batch of solder mask or an unreliable PCB supplier.?
73 de N1XNX
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Re: QMX (not-plus) power issue
It seems to be constant, regardless of band. I haven't had time to do much other investigation, but I do remember that was the case.
/m
On Sun, Sep 22, 2024, at 02:41, Roy - KI0ER wrote:
I agree with Stan's assessment. When I had a blown PA transistor in my QMX, the rig (12v) was drawing over 200mA during receive.?
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I didn't have to remove the Heat-sink washer to find the bad one. It was quite obvious which one was bad, but it likely helps to remove it to see if any are warmer than others. Start with a cold radio, and don't transmit at all.?
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Stating the obvious, you have an extra 35mA going somewhere. Is that constant, or does receive current draw change by band??
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Hopefully someone else can jump in and help you with diagnostics.?
--
73
de Roy - KI0ER
Littleton, Colorado USA
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Re: Removing flux. Is it necessary? Yes/No
Thank you community of builders!
I bought "new" soldering supplies (63/37 solder paste and No Clean flux paste both in syringes) to teach myself to solder surface mount devices-- it, and I, did well on a couple of the SMD practice boards. All the test points measured correctly and all the lights blinked as they should-- success! I did 1206, 0805, 0603, and 0402 size components all successfully. So when I started on the QMX+ I thought I'd try these "new" products-- gunky stubborn flux!?
I dug out some old rolls and found one each of; KESTER 63/37 flux 285 .020 dia. & KESTER 60/40 flux 44 .031 dia.
I think I'll proceed with the '285' and keep using cotton swabs (Q-tips!) and 91%ISA. Again I appreciate very much the community of experts and experimenters we have here together.?
'73 Robert AD6XJ
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Re: Removing flux. Is it necessary? Yes/No
BTW, I have used (and hate) no clean flux solder. ?The only thing I found that would take it off was acetone and even with that it took a while/some scrubbing.
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Re: Removing flux. Is it necessary? Yes/No
Here’s a pic of one of my boards.
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Re: Removing flux. Is it necessary? Yes/No
I’ve been using water-based flux cored solder (and same in a flux pen) for many years now. ?After assembly, I wash my boards with water, a bit of dishwashing detergent and an old toothbrush. ?Shake off vigorously and follow that up with drying using an old hair dryer. ?My boards look as good or better than machine built boards (if I do say so myself). ?I still have rosin-cored solder but doubt I’ll ever use it again.
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73,
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Robert, WA2T
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Joe AI5DD
Donald S Brant Jr
Paul - AI7JR
Barb WB2CBA
va3rr
Steve H