Tx not working anymore after 12v bad plug in

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Claire
 

Posts: 4
Joined: 31 Aug 2022, 17:36

Tx not working anymore after 12v bad plug in

Post by Claire »

On USB power, Tx & Rx were working well in all bands and all modes.
When I tried for the first time the 12v power , the connector wasn't properly connected and consequently during several seconds the radio switched rapidly on and off.
Then Rx still works well (both USB & 12v power) but Tx is not working anymore.
When PTT is keyed :
_ USB powered : Rx display doesn’t change to Tx and the S meter value is gently droping (e.g. 6 to 5)
_ 12v powered : Same as in usb power + OLED brighting is gently droping
_ Overall, no output power!

The 3 mosfets have been changed but that didn't fix the issue.

Any suggestion would be much appreciated !
Claire
dl6sez
 

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

Re: Tx not working anymore after 12v bad plug in

Post by dl6sez »

Hello Claire,

this sounds very crazy to me.....
But there could be one thing:
Have you changed in the Menue Practice to ON.... no TX than

Your new BS170 Fets can be also chinese fakes, no MosFets either or nothing in.
To resolve this test them in a simple component tester before switching the Fets the next time.

Measure the voltages 5V and 12V in circuit with measurement tips,
does the 5V Regulator work and produces 5V?

You could also have killed the RX/TX switch BS170 (SMD on the pcb).
Hopefully something helps... not sure with this strange problem.

73 de Chris DL6SEZ
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
Claire
 

Posts: 4
Joined: 31 Aug 2022, 17:36

Re: Tx not working anymore after 12v bad plug in

Post by Claire »

Chris Thank a lot to take care of my rig problem

Have you changed in the Menu Practice to ON.... no TX than: I confirm Practice OFF

Your new BS170 Fets can be also chinese fakes, no MosFets either or nothing in.
To resolve this test them in a simple component tester before switching the Fets the next time.

New BS170s have been tested before installation. Is it possible to test them once they are solded ?

Measure the voltages 5V and 12V in circuit with measurement tips,
does the 5V Regulator work and produces 5V?

On J3:
pin 11 [4.7v (USB power); 3.9v (12v power)] both PTT keyed or not
pins 7 & 8 [4.8v (USB power); 12.6v (12v power)] both PTT keyed or not

You could also have killed the RX/TX switch BS170 (SMD on the pcb).
Sorry Chris, but I cannot find any RX/TX switch on the DLSMAN schematics
This radio technology is new for me, so I can only try to understand through the DL2MAN schematics.

As RX is working well, I conclude that most of the rig elements are operational: Band slot management, Clock, Tayloe QSD, MCU, …

So working hypothesis could be any default on:
· Main Board : TX Mosfet Driver (DRIVE signal is a sinusoidal one I suppose, and could be tested with any component tester ?)
· RF Board : Mosfets (see above)
· or any RX/TX switch (do you have info to locate it and to test it)
(I assume (could you confirm?) that Power/SWR Bridge & Efficiency Measurement modules are not required to be operational in order to transmit)

I confess I am disturbed by the 3 labels “RF” on the RF Board : I assume that “Mosfet output drivers” output is connected to the “LPF Filters” input. But, is the J3 pin 4 (The RF of the Rx I presume) also connected to the output of LPF Filters? LPF Filters Input in Tx and LPF Filters Output in Rx being the same one?

In order to add more confusion, in FT8 configuration (Sorry Chrys, I promise to practice CW when my rig will be ok!), “T” appears on the rig display when necessary ( but … without any power output).

May be we are not far from the resolution , I hope so ...

Any help would be much appreciated !

Claire
relistan
 

Posts: 38
Joined: 23 Jun 2022, 12:12

Re: Tx not working anymore after 12v bad plug in

Post by relistan »

Claire wrote: 02 Sep 2022, 17:06 You could also have killed the RX/TX switch BS170 (SMD on the pcb).
Sorry Chris, but I cannot find any RX/TX switch on the DLSMAN schematics
This radio technology is new for me, so I can only try to understand through the DL2MAN schematics.
I am also debugging power issues on my rig on another thread and was reading the schematics. There are only 3 BS170 FETs on the board and they are PA FETs. They are driven from DRV, which is exposed on the headers between the boards.
Claire wrote: 02 Sep 2022, 17:06 · Main Board : TX Mosfet Driver (DRIVE signal is a sinusoidal one I suppose, and could be tested with any component tester ?)
· RF Board : Mosfets (see above)
· or any RX/TX switch (do you have info to locate it and to test it)
(I assume (could you confirm?) that Power/SWR Bridge & Efficiency Measurement modules are not required to be operational in order to transmit)
The power and efficiency measurements appear to be reading the real power output via the INA219AxD, so if they are low, or 0, then your power really is low or 0 from what I can tell. To me, in my debugging of my rig, that indicates to me that the FETs are blown.

I only have a multimeter for testing, and what I observed was that the DRV pin on the breakout header is at about 4.5v vs ground when in RX mode on USB power. When running CW and pushing PTT, this drops to about 2.5v. In SSB it appears to fluctuate with volume on the mic input. To me, that indicates that everything up to this point is OK with my rig. Using an SDR I can hear it transmitting. But power shows 0 and it doesn't appear to be putting any power out.

I am not quite sure how to test the FETs in place. But using a multimeter, on my rig, I don't see any voltage change across drain and source when transmitting. I suspect this means that my FETs are blown. You might measure yours and see what it looks like. Or maybe someone who is actually an expert will be able to educate us both.

Hope it helps
Karl
EI9ITB / KB8SWH
dl6sez
 

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

Re: Tx not working anymore after 12v bad plug in

Post by dl6sez »

Hello Claire,

There must be a switch to TX otherwise nothing will happen, only one possibility to check without is:
Have you tried Vox in SSB mode?
Maybe your PTT button switch is simply not working.
Use the inbuild microphone to be safe without a maybe wrong connected 3.5mm connector at an extern micro.

Regarding RX/TX switch, sorry i thought about RXmute transistor Q1 2N2007, in uSDX this was a BS170 :),
but it can do nothing wrong to TX function, this would be RX missing only, so no point to check.

Maybe you should check TX driver IC U1 74AC00. There is no sinusoidal waveform our (tr)uSDX uses rectangular signals :b
The clock output of Si5351 is rectangular and should be kept rectangular in order to drive the Class-E amplifier at best efficiency (our three BS170s)....

There should be no brightness change in OLED on TX.... don't understand what happens there :(

In RF path nobody should measure with DMM, could kill the circuit from my point of view.

And yes RF gets back to RX Tayloe Mixer and is muted on TX mode by RXmute Q1,
otherwise you could not receive anything!

73 de Chris DL6SEZ
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
Claire
 

Posts: 4
Joined: 31 Aug 2022, 17:36

Re: Tx not working anymore after 12v bad plug in

Post by Claire »

Thanks a lot Chris for your suggestions

Reminder & Current situation:
· Rig was working well on USB Power : i.e. RX, TX and all displays
· After a try with 12v Power, PTT button is not running ==> Display stays in Rx mode + (in USB powered : the S meter value is gently droping and in 12v powered : OLED brighting is gently droping)
· Of course the PTT button component has been changed ==> no improvement!
· Moreover, RX is running (USB & 12v Power). TX is always possible (I have tried only with USB power), but only in FT8 ==> QCO have been performed yesterday (so 74AC00 is running well, Chris).
Note that in FT8, the display shows “T” but the Rx S-meter stays present (this appears as a normal FT8 behaviour, isn’t it?)
· Firmware displayed 2.00i: firmware reinstalled after the 12w power issue


VOX : this mode activation appears on my rig as a mess (in the continuity of the PTT button issue I presume):
· Either VOX activation is achieved (“Enter” button is keyed, and V is displayed) but Tx is never activated.
· Or T appears as soon as the VOX mode is activated with the RotaryEncoder, and the Rig appears stuck , then an On/off is mandatory.



I note for the PTT/Key(a) circuit:
· An electrical circuit continuity when the rig is off
· A EPD value ~1.45v when the rig is on, while the others circuits (e.g. key(b)) are ~4.6v.
==> A MCU behaviour I presume, but is the ~1.4v ok? On the other hand, I presume that when the PTT button is keyed, EPD is 0v and this value should be relevant to trig the MCU.

Main questions:
· In order to switch in TX mode , to key the PTT button is enough or other conditions are needed by the MCU? (e.g. Power/SWR/Efficiency values provided by the RF board, ...)
· On the other hand, a PTT button keyed with a standalone Main Board (i.e. without the RX board) is enough to switch in Tx mode (with a complete TX display too)?
· Is the TR(u) SDX software source available ? (in order to answer my previous questions)

I keep hope alive ...!
Claire
dl6sez
 

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

Re: Tx not working anymore after 12v bad plug in

Post by dl6sez »

Hello Claire,

i think in your Atmega328 something died, PTT input should measure Vdd when open so your 4,6V...
Think about that there is no ESD protection, as normally is none in every arduino shields or circuits.
But one could also kill the Mic input of a Yaesu trx with simple ES Discharge :) there is also no real ESD proof circuit but a little bit more than in the truSDX.
This could have happen when you have connected it to the 12V supply.
Software is not open source for truSDX but you can simply programm Bootloader to a new Atmega328 and will get the serial number or take the latest beta which is always available at the bottom of DL2MANs download site.

You can try to switch to TX without PA-LPF board. RX TX components are all on Upper board only PA-LPF and SWR-Power measurements are on the second board.

73 de Chris DL6SEZ
Chris DL6SEZ, JN48XL near Ulm, Southern Germany
Murphyv310
 

Posts: 52
Joined: 18 Apr 2022, 19:33

Re: Tx not working anymore after 12v bad plug in

Post by Murphyv310 »

I'd have done a reset first.
Hold down the rotary control then apply power. It will then reset.
Also double check that practice mode is OFF.
I had the same issue with the DC Socket being intermittent, a simple reset cured all the issues, also I hard wired a cable and used power pole connectors.
The radio could do with a larger input cap, 1000uf 16v IMHO, Fuse & diode, the diode in parallel with supply and fused before the diode. This way there is no losses and if the supply is the wrong way just the fuse will blow.
The reason I advise a 1000 uf cap on the supply (inside the radio) is to reduce the effects of a poor connection to radio resulting in spikes.
Regards, Trevor. MM0KJJ
Ohwenzelph
 

Posts: 207
Joined: 01 Jan 2022, 03:47

Re: Tx not working anymore after 12v bad plug in

Post by Ohwenzelph »

I don't think there is room for a 16v 1000uF, using aluminium electrolytic I think the biggest I can find that I am sure will fit is a 150uF. At least between the top board and the case. Could be wrong...
If you manage to do it please post a picture and share the details.
Tnx
73
Jer aa1of
Murphyv310
 

Posts: 52
Joined: 18 Apr 2022, 19:33

Re: Tx not working anymore after 12v bad plug in

Post by Murphyv310 »

A small form factor radial non SMD 1000uf 16v electrolytic will fit on its side, it just needs to be at the power input, I've also fitted a parallel diode and my input lead is fused with a 1.25a inline fuse.
Regards, Trevor. MM0KJJ
Ohwenzelph
 

Posts: 207
Joined: 01 Jan 2022, 03:47

Re: Tx not working anymore after 12v bad plug in

Post by Ohwenzelph »

My error, I was thinking on top of control board (about5mm) and it would be below, between the control and RF boards. How many mm is that? Looks like one would need at least 8mm.
Claire
 

Posts: 4
Joined: 31 Aug 2022, 17:36

Re: Tx not working anymore after 12v bad plug in

Post by Claire »

Chris:
please find below my answers to your proposals

1/ "I think in your Atmega328 something died, PTT input should measure Vdd when open so your 4,6V"... ==> values ~1.45v on the PTT/Key(a) circuit & 4.6v (for exemple) on the KEY(b) circuit [PTT/KEY(a) circuit , KEY(b) circuit as they appeared on 1.0(m) Main Board Schematic] ==> which values should be on PTT/Key(a) & KEY(b) circuits?

"Software is not open source for truSDX :" too bad !

"You can simply programm Bootloader to a new Atmega328 and will get the serial number or take the latest beta: version 2.00m installed" ==> same issue

"You can try to switch to TX without PA-LPF board :" ==> same issue



Murphyv310:
please find below my answers to your proposals

"Hold down the rotary control then apply power. It will then reset.
Also double check that practice mode is OFF."

Don’t worry: Reset (a lot of …), Firmware (+beta one) reinstalled, Practice mode (OFF) … checking have been my initial operation

"A small form factor radial non SMD 1000uf 16v electrolytic will fit on its side ":
As your proposal appears as one of the best improvement for the safety of the (tr)u SDX, I will appreciate you “post a picture and share the details” as Jer (aa1of) suggested you. It will be useful for the (tr)u SDX community.

Any way thank you both for your time.
Claire
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