with new main board high band is not working correctly

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Titanus
 

Posts: 12
Joined: 08 Jan 2023, 20:52

with new main board high band is not working correctly

Post by Titanus »

Hi!

I had a super working tru sdx transceiver, one day suddenly the main board died (Atmega was hot-no function). I ordered a new main board assembled it and the low bands working normally, the high bands only on the lower bands, at 28.500 I have only 1,2 watts and 16% effeciency, at 28060 3 watts and 45% eff. What I recognize was that the oszillator freuequency on the old working main board was near the 270000, the new is on 27001350. I have two working high bands now, because i thought something with the high band is also not working, but now i now there is something wrong with the main board, because both high band kits are working with the same problem that the 10m band is not working above about 28.250 mhz. Is there any possibiity to send it back, if really the main board has some issues? I bought a new main board a second high board, now I don´t want to order a new mainboard again, because everything is assembled perfectly, also the second harmonics on the nanovna are correct.
Any ideas??
dl6sez
 

Posts: 399
Joined: 30 Dec 2021, 22:54

Re: with new main board high band is not working correctly

Post by dl6sez »

Hello OM,

this sounds strange with the different clock, never heard about this. This would be definitely a wrong crystal for the clock of Si5351.
How have you measured it?
What does it mean "does not work above 28.250MHz" is it only in tx and rx works?

If rx works above 28.500MHz than everything should also work from tx side at these frequencies....
I think there is than maybe not everything correct adjusted at the harmonic notch of the 10m lpf filter if rx works at higher frequencies.
You know you can ask the seller how about sending it back.... nobody can tell you another way :)

73 de Chris

P.S.: Why didn't you change the Atmega328, or ask a Ham friend to do it for you?
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
Titanus
 

Posts: 12
Joined: 08 Jan 2023, 20:52

Re: with new main board high band is not working correctly

Post by Titanus »

Hi,

yes also my thought a defectiv crystal. Because the same high band RF board which worked perfectly before didn´t work with the new Main board.

You ask me, why i haven´t changed the atmega on the old board. It is really too small to solder for me.

best regards

Alex
DL2MAN
 

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Joined: 30 Dec 2021, 19:18
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Re: with new main board high band is not working correctly

Post by DL2MAN »

Titanus wrote: 26 Mar 2023, 20:07 Hi!
(..)
Any ideas??
Stupid question: Did you set it to high Bands in the Menu ?

73 Manuel; DL2MAN
Titanus
 

Posts: 12
Joined: 08 Jan 2023, 20:52

Re: with new main board high band is not working correctly

Post by Titanus »

Yes of course.
DL2MAN
 

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Joined: 30 Dec 2021, 19:18
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Re: with new main board high band is not working correctly

Post by DL2MAN »

Guido and me recently also made an experience where a certain Mainboard would not receive on 10m.
This might be related to a batch of MS5351. We´re working on it, maybe it can be fixed by software.
Please give us some time.

73 Manuel; DL2MAN
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