Re: 50W AMP R12 and Q5 Assembly Question
Hi,
Not sure about your case but I have seen data sheets for the BS170 that erroneously reverse the source and drain pins. Try another data sheet just to be sure.
Tony
AD0Vc
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Am building this amp and the two components Q5 (a BS170) and R12 (a 2W 470 Ohm resistor) are exceedingly close to each other because of R12's size.? I have unfortunately already soldered in both legs of the resistor and pin #1 of Q5. Checking the PCB (i.e.,
closing the gate after the horse has left the corral) shows they are continuous.
Here's where my ignorance kicks in. I am unfamiliar with the BS170 and the data sheets I checked out don't seem to exactly coincide with the schematic, to wit: it looks like the source (pin3) is connected R12 rather than the drain (pin 1). Anyway, things do
not make sense and, although I have cleaned the connections and looked at them under a magnifying glass AND THERE APPEARS TO BE NO SOLDER BRIDGES BETWEEN THE PIN #1 PAD AN THE CLOSER OF THE R12 PADS, I STILL GET CONTINUITY.
So, is this correct or not. If not, what should I expect?
Thanks in advance for the help!
--
William, k6whp
--------------------
"Cheer up, things could get worse. So I cheered up and things got worse."
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Hi all,?
Kinda new to the forum and so forgive me if I am repeating something already covered.??
I have a QMX I plan to build this winter but looking on the shelving of Boat anchors I have collected for years.? I found a small brown box I had completely forgotten about.? An unbuild QCX rev 3.? Decided I would build this first and work my way up to the QMX. I'm building in order provide in the manual and during the capacitor stage I found I don't have all the correct values.?
?
I need the following:
.1 uF "104" C52
470nF "474" C11
39nF "393" C17
33nF "333" C15
For the improved Keying envelope mod:
2.2uf C31
150 ohm R41
1.2k R42
The kit came with a couple that doesn't appear to be used, marked "181" and "220".
Where would be a good place to order these parts, and what composition are they?
Thank you very much!
73,
KA0INR??
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50W AMP R12 and Q5 Assembly Question
Am building this amp and the two components Q5 (a BS170) and R12 (a 2W 470 Ohm resistor) are exceedingly close to each other because of R12's size.? I have unfortunately already soldered in both legs of the resistor and pin #1 of Q5. Checking the PCB (i.e., closing the gate after the horse has left the corral) shows they are continuous.
Here's where my ignorance kicks in. I am unfamiliar with the BS170 and the data sheets I checked out don't seem to exactly coincide with the schematic, to wit: it looks like the source (pin3) is connected R12 rather than the drain (pin 1). Anyway, things do not make sense and, although I have cleaned the connections and looked at them under a magnifying glass AND THERE APPEARS TO BE NO SOLDER BRIDGES BETWEEN THE PIN #1 PAD AN THE CLOSER OF THE R12 PADS, I STILL GET CONTINUITY.
So, is this correct or not. If not, what should I expect?
Thanks in advance for the help!
--
William, k6whp
--------------------
"Cheer up, things could get worse. So I cheered up and things got worse."
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Re: #qmx Aural warning needed for QMX SWR protection
#qmx
I agree with both Chris and Jim.
I've wasted a fair amount of time myself thinking I was transmitting while I was unknowingly in SWR protection mode.
My suggestion for a more easily noticed warning would be to flash the display on and off. Either by toggling the backlight on/off or by turning off all of the characters except the "S" SWR fault indicator once per second.
--
Randy, N4OPI
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I think I may have been fooled by my efforts at power measurements on both QDX’s, QMX and QRSS. I have been using an old cross needle Power/VSWR meter and have been seeing low power levels particularly on the Hi Band QDX. I have now purchased a scope with measurement facility. Looking at the voltage waveform into a good dummy load it is a nice clean sine wave varying between 14.7Vrms and 15.5Vrms (4.3 and 4.8W) on the Lo Band QDX and 15.1Vrms and 15.8Vrms (4.5 and 4.9W) on the Hi Band QDX. Next will be tests on the QMX.
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Re: SPAM Re: [QRPLabs] Brainstorm!
Aliexpress has one even less expensive.??Full Flange Attenuator, Low VSWR, High Power, 100W, 3dB, DC-3GHz, 50Ohms, RFR3-100, DC-3.0Ghz.? ?$4.22
Mark, K9TR.
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Re: #audio #qmx No headphone audio until I do FactoryReset?
#audio
#qmx
Interesting...
On 11/10/23 03:33, John Pagett G4YTJ
via groups.io wrote:
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Gents,
I have found that when the audio output fails, the RF filter sweep
in the diagnostics goes horrible. Here are two screenshots showing
the same sweep before and after a factory reset. Notice the y axis
values are really low when it's in the failed mode. Maybe this
will help Hans find the problem.
73
John
G4YTJ
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Issue resolved after re-inspection of the 4 pin connector joints on the main board.
Found the joint connecting to the ground pin was sporadically indicating connectivity?
to ground elsewhere on the board.? Reflowing the faulty joint corrected the problem.
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Re: Best kit building solder ?
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Re: Best kit building solder ?
Heath also supplied Multicore.
--
73, N4TVC, Randy
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Re: Best kit building solder ?
Call me old fashion, when you built the Heath Kits they provided solder, Kester's, that's all I've ever used.
73 John K2IZ
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Re: Tiny plugin paddles for QMX/QCX handheld operation
I think a paper clip will work, though I used some thin sheet metal scavenged from a broken wooden ruler. The plastic paddle is a 2-pin jumper, but anything larger would work better.
The dual (iambic) paddle in the photo is actually a shortened version from the original that I made for my QCX mini two years ago, but it is tricky to adjust the gap when the levers are too short, and it causes more errors. So for the single lever paddle in the photo, I didn't try to make it short. Also the single lever is more error-free for the tiny size, as it doesn't allow iambic action. :-)
73,
Yoon KM6KJI
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Re: #qmx Aural warning needed for QMX SWR protection
#qmx
Good idea for headphone use but not useful for DIGI modes.? I usually check the display to see I get power and low SWR.? ?
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Re: #QMX - #JTDX drops on TX, WSJT-X works fine
#JTDX
#qmx
Forgot to mention, I'm using a Windows 10 based computer.
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#QMX - #JTDX drops on TX, WSJT-X works fine
#JTDX
#qmx
I gave JTDX a try with my QMX this morning with all the same settings I use for WSJT-X. But like I've seen reported for FLDigi and the Android JT8 software, JTDX goes into transmit for a second or so, then drops out of TX mode. I do have the output audio, PWR slider all the way up to the top in JTDX (like I do in WSJT-X). I'm using Kenwood 440s for the Radio setting in both programs.
Seems like others are using JTDX with their QMX just fine based on a search for JTDX on this forum.
Any suggestions on what I should do to get JTDX working with my QMX?
73!
Roy - KI0ER
Littleton, Colorado USA
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#qmx Aural warning needed for QMX SWR protection
#qmx
The new feature in the QMX which locks out transmit when the SWR is too high is wonderful. It saves finals. But the only indication when it trips is the letter S showing just after the frequency. How about adding an aural signal via the sidetone to let us know it has tripped. A string of dots would be the obvious warning. Maybe others have a better idea. Again, thanks for a nice feature, Hans.
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Re: SPAM Re: [QRPLabs] Brainstorm!
Andy, I've made the same error. Much better to do that than to not tune the antenna! Best one I did was during a CWT. I thought I was running 100 W into my vertical. I wondered why the bands were so dead, but I did make a few contacts with the Gulf coast from Pennsylvania. Turns out I was transmitting into my dummy load! -- 73, Dan? NM3A There are moments when everything turns out right .... Don't let them alarm you; they pass.?
-Jules Renard
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Re: Standalone keyer kit with same timing as QCX+
Some radios only support iambic mode B. I find this mode unusable; i guess I'm too old to be retrained. Thank goodness Hans let's us choose mode A or B. For my Icom 7300 I had to get the tiny Mortty keyer which supports mode A. It is Arduino based so if you are familiar with that environment you can make it do whatever you like. /g/mortty
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Re: Best kit building solder ?
FWIW I have had good success with
MG Chemicals solder from the "A" place.? Available is several sizes and
quantities. and fluxes, as well as lead-free.? Prices are, as with
everything currently, ridiculous currently, but I bought several spools
before prices went ballistic.? As always YMMV!
73, John Payne
W4CWZ
Curt M. wrote on 11/10/2023 8:45 AM:
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Hi Bands on QDX Rev 3a board
Hi,
I'm *finally* assembling my QDX, which has been sitting for quite a while.
I've got a Rev 3a board, and I bought the Hi Band kit.
However, I notice that the instructions for the Rev 3a do not mention
the LPF's for high bands. Is there any reason that I can't just fit?
high band filters to a Rev 3a? Are there any other mods that need to be done
besides the different LPF's?
Thanks in advance.
Mike G8LKD
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k6whp
Mark K9TR
Paul - AI7JR
Randy, N4TVC
Jim AJ8S