(tr)uSDX transmit without pressing PTT

[juraj]

I just want to try wspr mode and get no receive.
So I plug a SDR on the sdr I can see, that there is a week signal comming from tru sdx, but ppt is not press.

https://drive.google.com/drive/folders/ ... sp=sharing

When ever I tune any frequency on trusdx the signal is relocating. It is a weak TX.

On the video you can see, that I am rolling the frequency left and right without transmission and there
is a peak which relocate.

Then I press the ptt button and it transmit cw.
The transmit frequency is lower then the parasitic one.

I can as well see the similar behavior on 7mhz.

I have also add a picture of top and bottom parts. Version of main board is 1. and RF section is 3,5,7...14 with bs170.

Any idea or recommendation where to look/check ?

The SDR used for visualization used passive loop antenna without amplifier.
The same occurred also when I change the main board to 1.2 release and modify to LO board.

[dl6sez]

Hello OM,

this is your personal new year challenge!
This mystique why any trx emits a signal in rx if it's a conversion trx...
You are kidding, where did you get your licence? I think you have none, this would maybe be an excuse ...

73 and hny Chris

[juraj]

Hello Chris,
I would rather thank you for technical recommendations, but there was none

Yes the the transceiver is soft transmitting in RX mode. It sounds stupid, but it is fact
That is why I create an video and you can see on the video that tiny signal peak is moving left or right.
(base on in which direction I tune freq.)

When I press ptt later on, you can see big peak and it is WAD.

But there should be not small peak in RX. And that is why I am asking!
I am sure it has no relation to main board. (Have try 1.2 with same results)

On LO board are 13 ferrites core, 3x bs170 and some relay. I have check with ohm-meter connection of each of the cores and seems OK. I have re-solder T1 and T2. But same results.

In today's world, assessing the technical competence of individuals seems futile. A significant number of people send their malfunctioning washing machines to be drop, unaware that a 20-cent resistor is the root cause it. Likewise, several thousand radio enthusiasts never get around to building their own transmitters due to constraints such as time, resources, or space.

Many opt for commercial solutions simply because they offer a quicker alternative. The complexity of modern technology and the convenience of ready-made solutions often outweigh the value of hands-on technical expertise for the majority.

If you have any technical recommendations, feel free to share them, and I'll appreciate your input. However, if you're not inclined to contribute to the discussion on technical matters, it's better to refrain from doing so.

[juraj]

Updated video
( https://drive.google.com/drive/folders/ ... 0tpe6LNn9I )

The transmission is visible on all lo bands in RX mode.
On 3mhz it was weak. But in all others it is visible.

T2: is modify to T3,T21

Any rcmd highly appreciated
thx Juraj

Receiver is HACKRf with passive loop antenna.
TruSDX is on EFHW.
Distance of antennas ~3m.

[dl6sez]

Hello OM without a license,

so you are a super tech so why are you asking here?
Startin with a greet and ending with one, you simply don't know how to be polite and bother when logical things just happen.

73 no comments any more here
Chris