It is a great pity you have misplaced your dummy load, because your antenna appears faultless, and my next step would be to put a decent 50 Ohm load on the QMX and see what it thinks of it.
Perhaps you can fashion something out of resistors you have. 4 of 200 Ohm, or ten 1k resistors placed in parallel would do. ?Unfortunately your VNA reference load would be cooked quite quickly by the QMX’s output any longer than a few seconds. But it would only take a few seconds to see if it would show the expected 1:1.
If the QMX did think a 50 Ohm load looked like 5:1, then the bridge wiring would be suspect.
toggle quoted message
Show quoted text
On Jul 12, 2024, at 19:11, IU1SWR via groups.io <sean.nelson.riley@...> wrote:
?On Fri, Jul 12, 2024 at 06:16 PM, Dave VE3GSO wrote:
Return Loss
Thank you for your suggestion.
So I followed these 2 videos
I calibrated my VNA and set the following parameters:
Freg Range - Start: 13.8Mhz
?????????????????? - End: 14.5 Mhz?
I set 2 markers. One at 14.024 and another at 14.075 750
As you can see from the picture I have a very low SWR. I believe that I also have a Return Loss of -26.77dB at 14.024 MHz and -20.76dB at 14.074 MHz which I think is within the acceptable limits.
<20240712_195836.jpg>
I unplugged the antenna from the VNA and plugged it straight into the QMX and as you can see when I run the Hardware Test SWR Sweep I get nearly 5.0 on the 14.074 MHz frequency.
<20240712_200031.jpg>
Am I doing something wrong?
