QMX RX dead after testing TX with dummy load - can FST3253 replace CBT3253?
Hello, same problem as some other users (DG8YBJ, DG8RCN, DD6DO).
Checked the usual R and C parts, all are correctly populated. Voltage at IC402 pin 9 (MUX common) is between 4.86 to 4.91 V, when
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ok4rm
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#115877
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Re: QMX HI Band Rev 2. Immediate current limit on startup
Thanks Jeff.? ? I'm still looking it over some each day trying to determine if I messed up somewhere, but so far, nothing.? The only voltage that has ever been applied was the first attempt to
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Ken W4KAC
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#115876
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For Sale QDXs Rev 3 and a QCX mini
I have 2 QDXs Rev 3 unassembled with enclosures.
I am asking USD 95 each with shipping to CONUS
If you buy both, I will include a QCX mini Rev 1 that is assembled but not working. The screen lights
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Chris Hoffman
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#115875
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Re: Questions re: PA socketing and Zener & L14 diodes
I soldered the diode across L14 on the top side of the board.....seemed to work for me. Hundreds of QSOs since and finals are still intact on my QDX. (Made it 440+ before blowing the original BS170s,
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Nate Reik N8BTR
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#115874
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Re: QMX HI Band Rev 2. Immediate current limit on startup
My experience with VDD shorted to GND on the main board is that it’s usually but not always in the MPU chip. ?You can determine that with a milliohm meter. ?Find where on the board the lowest
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Jeffrey W Moore
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#115873
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Mags sez HI !
72,
Bill, WB4HIO
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Bill, N4QA/QRP
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#115872
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Re: QCX CW Filter
...is it possible to set the center frequency for either of the QxXes?
Happy New Year to all of you!
73 de Razvan dl2arl
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DL2ARL
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#115871
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Re: QDX Low output power
For accurate power measurements you need a 50 ohm output impedance, a short cable to a good through line meter and a high quality 50 ohm load right on the meter output (or a terminator type meter)
if
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Bruce Akhurst
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#115870
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Re: #qmx #firmware 1_00_014 releasse
#qmx
#firmware
FB, Hans !
72,
Bill, WB4HIO
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Bill, N4QA/QRP
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#115869
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Re: #qmx #firmware 1_00_014 releasse
#qmx
#firmware
I've spent some time this afternoon identifying bugs with the 1.00.014 firmware. This is what I have found:
- calling CQ on 30m CW into a well matched antenna (SWR circa 1.2:1), towards the end of my
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Simon G0FCU
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#115868
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Re: QDX Low output power
That sounds similar to what happened when I fried my output transistors.
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pgramsey, N9LFF
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#115867
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Re: QDX-hi kit
#qdx
Hello all,
I have a Rev2 board that I wish to run on the high bands and can't identify, from the schematics, the processor pin that needs to be grounded.
Any clues please?
73 Phil G8DDN
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Phil Bennett
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#115866
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Re: QCX CW Filter
Thank you to everybody. I figured the response might be “That sounds about right”. I just wanted to double check. I have a QMX that my son finished building yesterday and I was comparing them
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Mike McCarty
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#115865
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Re: QMX SWR meter gone mad (SOLVED)
Good to hear it's working!
Having a slightly higher SWR on 20m is normal, try moving the 10 turn windings as far as possible from the 1 turn ones, it should improve it a bit. In my case, I couldn't
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Adrian YO3GFH
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#115864
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Re: QCX CW Filter
Hi Danny, Peter, all
Attached is a comparison of the QCX vs QMX CW filtering. These are actual
measured responses. Not simulation or calculation. It's quite clear how
much steeper the QMX filter
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Hans Summers
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#115863
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Re: QCX CW Filter
Agree. The first time I used a radio without really sharp filtering it was quite a shock just how much activity I could hear above and below the frequency I was tuned on.
The QMX is pretty good. I
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Danny Bower
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#115862
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Re: Happy New Year 2024
- ..-
-.. .? -.-. .... .-. .. ...
-- .-? ..- ... .-
--
Chris / W2BPL
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Chris / W2BPL
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#115861
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Re: QMX order form problem (kit/assembled)
#qmx
The QMX is much more complex than the truSDX. There are many more components and the boards are much tighter. There are more complex windings to do as well.
However, if you have done a nice neat job
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Danny Bower
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#115860
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Re: QMX output power 40 m vs 20 m (JS8Call)
SOLVED
After I fixed SWR bridge transformer, output has changed (and increased) on all bands.
With a fully charged Li-Pol battery and dummy load:
80 meters: 6 W out
60 meters: 6.5 W out
40 meters: 5 W
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ok4rm
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#115859
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Re: QMX SWR meter gone mad
I don't see how there can be any confusion.? Each end of the 10 turn winding has a wire that comes out of each end of the toroid and there is a hole for the 10 turn winding next to it. The obvious
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Chris, G5CTH
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#115858
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