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QMX Rev 4 mid-band schematic / L405a and L405b connected to GND

 

Hi all, I am building a mid-band Rev 4 QMX. After installing the L502 toroid, I checked some connections using a continuity tester and noticed that all leads connected to L405a and L405b are connected to GND. This seems suspicious to me, as the assembly manual shows on page 37 that the toroids are connected to RF IN, so I wanted to check the Rev 4 schematic. However, I could only find the Rev 3 schematic on the QRP Labs website, without a mid-band version.
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Any pointers regarding this?
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Thanks, 73
Donat HA5MZX
 

I'm building this version soon as well, I've been thoroughly going over the manuals and videos. Do you mean L405a and L405b? I've noticed the R4 manual refers these toroids as L401a and L401b in the beginning (maybe because it was a single L401) but then later calls them L405a and L405b.?
 

Joe, yes, I mean L405a and L405b, which are also referred to as L401a and L401b in the beginning, as you say.
 

On Fri, Sep 20, 2024 at 08:07 PM, HA5MZX wrote:
all leads connected to L405a and L405b are connected to GND. This seems suspicious to me, as the assembly manual shows on page 37 that the toroids are connected to RF IN,
Hello Donat,
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and RF_IN is connected via L503 to GND. For DC L503 is only a piece of wire with nearly 0 Ohm. So don't worry (see schematics for rev. 2 and higher).
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73 Ludwig
 

There is no separate rev4 schematic - the rev3 is accurate, only one minor change on the ptt out jack for rev4.? All of the terminals of L405a/b should show DC continuity to ground and the other few test points shown in the assembly instructions.


On Fri, Sep 20, 2024, 3:03 PM DH8WN via <DH8WN=[email protected]> wrote:
On Fri, Sep 20, 2024 at 08:07 PM, HA5MZX wrote:
all leads connected to L405a and L405b are connected to GND. This seems suspicious to me, as the assembly manual shows on page 37 that the toroids are connected to RF IN,
Hello Donat,
?
and RF_IN is connected via L503 to GND. For DC L503 is only a piece of wire with nearly 0 Ohm. So don't worry (see schematics for rev. 2 and higher).
?
73 Ludwig
 

Great, thank you all!
 

Hi all

L405a and L405b on QMX was an error in my documentation, it should be L401a and L401b. I have corrected it in the latest assembly manual I just uploaded now.?

73 Hans G0UPL



On Sat, Sep 21, 2024 at 12:57?PM HA5MZX via <HA5MZX=[email protected]> wrote:
Great, thank you all!

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