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Hi!

I received my QMX today, assembled it, and flashed latest firmware
(1_00_009). I didn't test it on air yet (only with a dummy load).

I have several issues with it. Two are serious, other are minor.

First serious issue. Audio filter sweeps look bad (done with a dummy
load). Yellow trace (USB) is at:

20m: -32 dB
30m: -28 dB
40m: -39 dB
60m: -43 dB
80m: -26 dB

Here are the sweeps:







RF filter sweeps peaks aren't great either, but I guess it's related (?)







What also concerns me is that the filter is set too high for 60m and way
too high on 80m. Can it be fixed easily?

For completion, here are my image sweeps. I'm not sure how to interpret
them (read: I have no idea how to interpret them), but still, the upper
(max) level seems way too low.







And here is my band configuration (default):



The second issue is the output power. I don't have an RF meter (at least
not the one I would trust), but I connected an oscilloscope to the dummy
load and measured the peak-to-peak voltage on it. I didn't calculate the
power, because at these values it would be milliwatts anyway...

Dummy load was completely cold after these tries, so I think the readings
are correct.

I also measured current consumption (at 12 V) when transmitting.

20m: Vpp = 268 mV, I = 0.90 A
20m: Vpp = 110 mV, I = 0.48 A
40m: Vpp = 114 mV, I = 1.27 A
60m: Vpp = 80 mV, I = 0.54 A
80m: Vpp = 80 mV, I = 1.17 A

These are two major issues I have and any help or hint where to look would
be appreciated...

Apart from them, I noticed a couple of other things (probably firmware
bugs):

- when using a straight key, tip and ring in configuration is swapped. My
key is connected to the tip, but it does work only when I select "Ring".
Diagnostics shows that it activates "dit" channel

- sidetone volume setting doesn't work

- sidetone frequency setting doesn't work

- battery icon behaves weirdly (it shows full battery even when I went
from 12 V down to 7 V)

Thanks!

Adam via groups.io <qrp-labs@...> wrote:

I have several issues with it. Two are serious, other are minor.

Nevermind. I had short on an RF port.

Hi Adam - I have the same symptoms as you - my rf sweeps are very similar with no receive or rf out. I've been stuck on this for hours - where was the short you fixed on yours? Did you mean the BNC socket?

I'm clutching at straws here!?

Many thanks,

Steve MW0KST

Sorry folks - found the short - yes, it was at the BNC socket.

Steve

Steve MW0KST <stevedavies77@...> wrote:

Sorry folks - found the short - yes, it was at the BNC socket.

Great to know you fixed it :)

In my case the short was exactly at the BNC socket. There's a footprint
for the SMA socket there as well, and I had a short between one of BNC
grounding pins and the unpopulated SMA center pin.

Here, in blue: