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First HF radio..incensed a week ago...I think I blew up my uBitXv4.


Jonas Sanamon
 

Hi Randy,

I have used my uBitx's a lot for portable use (Flora Fauna) the last year, with over 3000 QSOs logged in 2020 mostly on 80m, but also 160m, 60m and 40m. Mostly SSB, but also CW. I use Li-ion battery packs 16-20v and feed the PA with this voltage directly to get a few more W output power. I've used lots of different antennas with unique mounting styles for every "field day", sometimes SWR is as bad as 2:1. (it depends a lot on how high up in a tree I can get the line) that holds the antenna centre point up. I usually use a resonant antenna without any tuner.
I've never blown an IRF510, so I'm not sure that an increase in reliability really is needed :-)

73 de SM4VEY - Jonas


On Mon, Oct 5, 2020 at 6:50 AM Randy.AB9GO <randy.ab9go@...> wrote:
Ashhar I should have been more specific in my question. Is there an increase in reliability using the Mitsubishi part or is it about the same?  The only reason I would switch is if the output devices would be less likely to fail.  The irf 510s are so cheap unless there would be an advantage I wouldn't move to the Mitsubishi part.

Thanks,
randy.ab9go@...

_


Ashhar Farhan
 

Randy,
I haven't blown up an IRF510 yet due to a bad antenna. So, I can't hazard a guess. Perhaps someone else could do that? At 12v and with a proper heatsink, the IRF510s are virtually indestructible. You would worry about that at 25 volts drain voltage.
It is, btw, good fun and even greater education to blow up an IRF510 on the bench. Pipe down the RF output of the ubitx to about 2 watts, and build an external linear amplifier with two IRF510s (like the WA2EBY design). 24V power supply for LEDs are quite cheap. Building a linear is an inexpensive, very straightforward project. It dramatically impacts your signal reports.
73, f 

On Mon, Oct 5, 2020 at 6:50 AM Randy.AB9GO <randy.ab9go@...> wrote:
Ashhar I should have been more specific in my question. Is there an increase in reliability using the Mitsubishi part or is it about the same?  The only reason I would switch is if the output devices would be less likely to fail.  The irf 510s are so cheap unless there would be an advantage I wouldn't move to the Mitsubishi part.

Thanks,
randy.ab9go@...


Randy.AB9GO
 

Ashhar I should have been more specific in my question. Is there an increase in reliability using the Mitsubishi part or is it about the same?  The only reason I would switch is if the output devices would be less likely to fail.  The irf 510s are so cheap unless there would be an advantage I wouldn't move to the Mitsubishi part.

Thanks,
randy.ab9go@...


Ashhar Farhan
 

The increase of power is very nominal. It would be best if yoy added an external linear like the HF packer that will take you to beyond 50 watts range.


On Sat 3 Oct, 2020, 2:03 AM Randy.AB9GO, <randy.ab9go@...> wrote:
What is your feedback on changing to the Mitsubishi part? Did it make a difference worth the cost of the new device? Have you seen any downsides?

randy.ab9go@...

This message sent to you from my mobile device via speech-to-text technology.


Randy.AB9GO
 

What is your feedback on changing to the Mitsubishi part? Did it make a difference worth the cost of the new device? Have you seen any downsides?

randy.ab9go@...

This message sent to you from my mobile device via speech-to-text technology.


Rubens Kamimura
 

Hi,

Yes, but I didn't install an aluminum heatsink, installed a fan and changed the MOSFET transistors to the MITSUBISHI RD16FFH1.


Em sex., 2 de out. de 2020 às 11:21, Evan Hand <elhandjr@...> escreveu:

On Fri, Oct 2, 2020 at 06:41 AM, Rubens Kamimura wrote:
I think about putting the PA 10W (qrp-labs - Hans Summers) in place of the power stage of uBITX v4 (QRP 10W), I thought about this modification to suit jobs in digital modes. Taking advantage of that I'm putting the uBITX card in a new box.
I thought about this modification because the PA 10W of qrp-labs has a bigger heatsink already incorporated.
I await suggestions and comments.
Hello Rubens,

Have you thought about just adding a large heatsink to the two output MOSFETs that are already in the uBITX?  Many have done that or mounted to an aluminum box,  or just added a fan to cool the devices.  The one thing to be sure to do is to insulate the MOSFETS from the heatsink with thermal insulators for TO-220 case transistors.

73
Evan
AC9TU


Evan Hand
 

On Fri, Oct 2, 2020 at 06:41 AM, Rubens Kamimura wrote:
I think about putting the PA 10W (qrp-labs - Hans Summers) in place of the power stage of uBITX v4 (QRP 10W), I thought about this modification to suit jobs in digital modes. Taking advantage of that I'm putting the uBITX card in a new box.
I thought about this modification because the PA 10W of qrp-labs has a bigger heatsink already incorporated.
I await suggestions and comments.
Hello Rubens,

Have you thought about just adding a large heatsink to the two output MOSFETs that are already in the uBITX?  Many have done that or mounted to an aluminum box,  or just added a fan to cool the devices.  The one thing to be sure to do is to insulate the MOSFETS from the heatsink with thermal insulators for TO-220 case transistors.

73
Evan
AC9TU


Rubens Kamimura
 


Em sex., 2 de out. de 2020 às 08:41, Rubens Kamimura <rubens.kamimura@...> escreveu:

All, hi.

I think about putting the PA 10W (qrp-labs - Hans Summers) in place of the power stage of uBITX v4 (QRP 10W), I thought about this modification to suit jobs in digital modes. Taking advantage of that I'm putting the uBITX card in a new box.
I thought about this modification because the PA 10W of qrp-labs has a bigger heatsink already incorporated.
I await suggestions and comments.

73's
Rubens
py2pvb (GG49in07)


Em sex., 25 de set. de 2020 às 17:41, Allen Hundley <allenphundley@...> escreveu:
I was only interested in this hobby as a way to communicate with Baofengs during hunting, etc. Well I had a few spare dollars and ordered a uBitX v4 off eBay.

Last night I wired it all up and listened...didn't have an antenna just a piece of wire. It worked all right. I tried to turn up the volume to listen to a feint signal, turned it back down...all was well.

Then I went to go use it this morning and it instantaneously started transmitting. The MOSFETS in the back got hot rapidly and I turned them off.

Well, I noticed that if I removed the harness on the display/arduino that it would work again. I then isolated that behavior to a 4.7k resistor that is explicitly required in the instructions to prevent this exact phenomenon from happening. I tested continuity and resistance...it was fine. I unsoldered it and the radio appeared to work. I replaced the resistor. Same problem.

I left it unsoldered and attempted to listen. It was then that I noticed the rotary encoder was behaving strangely. The arduino clearly was recognizing something, but something was messing with the signal.

Before I break out the oscilloscope, I was wondering if someone could point me in the right direction. Thanks!


Rubens Kamimura
 

All, hi.

I think about putting the PA 10W (qrp-labs - Hans Summers) in place of the power stage of uBITX v4 (QRP 10W), I thought about this modification to suit jobs in digital modes. Taking advantage of that I'm putting the uBITX card in a new box.
I thought about this modification because the PA 10W of qrp-labs has a bigger heatsink already incorporated.
I await suggestions and comments.

73's
Rubens
py2pvb (GG49in07)


Em sex., 25 de set. de 2020 às 17:41, Allen Hundley <allenphundley@...> escreveu:

I was only interested in this hobby as a way to communicate with Baofengs during hunting, etc. Well I had a few spare dollars and ordered a uBitX v4 off eBay.

Last night I wired it all up and listened...didn't have an antenna just a piece of wire. It worked all right. I tried to turn up the volume to listen to a feint signal, turned it back down...all was well.

Then I went to go use it this morning and it instantaneously started transmitting. The MOSFETS in the back got hot rapidly and I turned them off.

Well, I noticed that if I removed the harness on the display/arduino that it would work again. I then isolated that behavior to a 4.7k resistor that is explicitly required in the instructions to prevent this exact phenomenon from happening. I tested continuity and resistance...it was fine. I unsoldered it and the radio appeared to work. I replaced the resistor. Same problem.

I left it unsoldered and attempted to listen. It was then that I noticed the rotary encoder was behaving strangely. The arduino clearly was recognizing something, but something was messing with the signal.

Before I break out the oscilloscope, I was wondering if someone could point me in the right direction. Thanks!


Allen Hundley
 

Kind of. I replaced the encoder first, tried and it didn't work. Then I put the the new arduino on...worked but the new encoder must be slightly different or less encourage because it was skipping steps.

Soldered old encoder on and everything's good.

On Sep 28, 2020, at 1:19 AM, Evan Hand <elhandjr@...> wrote:
Allen,
Glad that you found the issue.  By chance did you do any troubleshooting other than replacing the Arduino Nano and Encoder one at a time?  The reason for the question is to understand how to isolate the issue without going to a "replace one part at a time process" (what some call the Military Methode)?

73
Evan
AC9TU


Evan Hand
 

Allen,
Glad that you found the issue.  By chance did you do any troubleshooting other than replacing the Arduino Nano and Encoder one at a time?  The reason for the question is to understand how to isolate the issue without going to a "replace one part at a time process" (what some call the Military Methode)?

73
Evan
AC9TU


Allen Hundley
 

I just got some encoders and arduinks today. I replaced the encoder first...no cigar. I replaced the arduino and everything works.

Anyone know exactly what happened there?

On Sep 26, 2020, at 3:43 AM, Evan Hand <elhandjr@...> wrote:
Allen,
The encoder output is a switch that connects the Black or Brown wire (Encoder input A or B) to the Yellow wire (ground).  So most of the time the value will be high, and only briefly go low when the switch pulses it low.  You can test the Nano I/O with your sketch.  On the encoder short each of the leads to digital ground (the Yellow wire).  The value should change from a high value to a low value when you short it to the Yellow wire.  If you do get the high and low values, then you might have a bad encoder.  The previous does assume that your change to the sketch is directly reading the A0 and A1 analog inputs.

I would suggest that you go back and very carefully verify that you have wired the rig correctly.  You can also compare with this original wire-up from HFSignals:
https://www.hfsignals.com/index.php/ubitx-wire-up/

I still believe that you have a wiring issue.  It is too easy to cross wire the audio and digital connectors, as they both use the same wire colors.  You could also have a bad/loose connector wire.  The pins can get pushed out such that they do not connect to the header properly.

The less likely fault is a bad encoder.  The encoder uses switches, not electronic devices, so not very likely to fail unless there was a high current across them.
73
Evan
AC9TU


Evan Hand
 

Allen,
The encoder output is a switch that connects the Black or Brown wire (Encoder input A or B) to the Yellow wire (ground).  So most of the time the value will be high, and only briefly go low when the switch pulses it low.  You can test the Nano I/O with your sketch.  On the encoder short each of the leads to digital ground (the Yellow wire).  The value should change from a high value to a low value when you short it to the Yellow wire.  If you do get the high and low values, then you might have a bad encoder.  The previous does assume that your change to the sketch is directly reading the A0 and A1 analog inputs.

I would suggest that you go back and very carefully verify that you have wired the rig correctly.  You can also compare with this original wire-up from HFSignals:
https://www.hfsignals.com/index.php/ubitx-wire-up/

I still believe that you have a wiring issue.  It is too easy to cross wire the audio and digital connectors, as they both use the same wire colors.  You could also have a bad/loose connector wire.  The pins can get pushed out such that they do not connect to the header properly.

The less likely fault is a bad encoder.  The encoder uses switches, not electronic devices, so not very likely to fail unless there was a high current across them.
73
Evan
AC9TU


Allen Hundley
 

Well I definitely did have the wrong purple wire soldered to the mic jack. I just switched that out so the digital harness doesn't use the purple wire. I have the green wire as you said and the blue going to PTT, tip of the key jack, and the sleeve of the mic jack. I fixed that and the rotary encoder still didn't work.

I removed the whole arduino assembly and removed the harness. I modified the firmware code to output the numbers on the pins for the rotary encoder.

Got 1021 for A and 1024 for B over and over. Then I hooked up the harness. when I would spin it nothing would happen. Randomly with the harness attached pin B would say that it was 14. Not sure what to make of that.

On 9/25/20 6:33 PM, Evan Hand wrote:
Alan,
From the pictures, you are direct wiring the kit.  With that information, I would suggest checking the Purple, Green, and Blue wire wiring from the Digital connector (the one on the Raduino/Display/Nano board).
- Purple should not be connected to anything.
- The Blue wire goes to the tip connection of the 3.5mm Jack
- The Green wire is soldered to the 4.7 k resistor and the other end of the resistor to the same tip connection as the Blue wire.

I cannot see if the connections are correct.  I lose the Purple wire in the area around the jacks.  I would look there for an intermittent short.  Those are the wires that get disconnected from the Raduino when you pull the header off.

I am really thinking it is a wiring issue.
73
Evan
AC9TU


Evan Hand
 

Alan,
From the pictures, you are direct wiring the kit.  With that information, I would suggest checking the Purple, Green, and Blue wire wiring from the Digital connector (the one on the Raduino/Display/Nano board).
- Purple should not be connected to anything.
- The Blue wire goes to the tip connection of the 3.5mm Jack
- The Green wire is soldered to the 4.7 k resistor and the other end of the resistor to the same tip connection as the Blue wire.

I cannot see if the connections are correct.  I lose the Purple wire in the area around the jacks.  I would look there for an intermittent short.  Those are the wires that get disconnected from the Raduino when you pull the header off.

I am really thinking it is a wiring issue.
73
Evan
AC9TU


Allen Hundley
 

I used this set of instructions. I used the key option 1 and the fused main power option.

My 3d printer is broke so I literally just used the shipping box as the chasis for now.

Its not the best...for sure. Let me know if I can explain the wiring. I checked for continuity in leads that shouldn't be touching that were near each other.

Everything is correct per those instructions as far as I can tell...

On Sep 25, 2020, at 4:57 PM, Evan Hand <elhandjr@...> wrote:
Allen,
Does your uBITX use a case kit to wire your uBITX, or is it wired direct per the wire-up directions from HFSignals?
https://www.hfsignals.com/index.php/ubitx-wire-up/

I would be really surprised if it was the Nano that failed again.  If so then there is a wiring issue that is causing the problem.  You need to resolve the wiring issue(s).

Can you post a picture of the inside of your v4 uBITX?  I think that you have a v4 mounted in an AmatureRadioKit enclosure, that or a custom-built enclosure that you will need to know how it was wired.

Trying to understand what you have and how to answer your questions.
73
Evan
AC9TU


Curt
 

Allen

as Evan has suggested, possibly it is some phantom connections and non-connections.  since things have worked sometimes - it is pointing to construction issues - yes I had a few on my own v4 - and yes I have that case type. 

I am thinking place it aside until you are patient - then some patient disassembly and inspection with a magnifier and DVM (power off on the rig!).  do careful mark which cable goes where AND orientation of each cable. 

there is a cool rig there - and I am thinking it may still be undamaged.  the finals are cheap - but let's not smoke them unnecessarily.  a dummy load that can handle about 10 watts is very useful.  without one of those - be very careful to insure rig isn't going into transmit. 

with everything on receive seeming to work now except the encoder - it may be an intermittent connection issue there - and that board that Evan mentioned is quite subject to poor solder connects the way it is constructed.  proceed patiently and try to learn at the same time. 

73 Curt wb8yyy


Evan Hand
 

Allen,
Does your uBITX use a case kit to wire your uBITX, or is it wired direct per the wire-up directions from HFSignals?
https://www.hfsignals.com/index.php/ubitx-wire-up/

I would be really surprised if it was the Nano that failed again.  If so then there is a wiring issue that is causing the problem.  You need to resolve the wiring issue(s).

Can you post a picture of the inside of your v4 uBITX?  I think that you have a v4 mounted in an AmatureRadioKit enclosure, that or a custom-built enclosure that you will need to know how it was wired.

Trying to understand what you have and how to answer your questions.
73
Evan
AC9TU


Allen Hundley
 

I think I must have busted the arduino? I went through it a few more times with a muktimeter. Every thing seems in order.

I thought it might be the Arduino. So I updated the firmware on it expectj g that to fail. It worked and even fixed my problem with the key.

Now I only have one problem. Now the rotary encoder doesnt work! The push button does, but not the rotation. Super weird. I ordered 3 more arduino nanos.

Any thing else jump out at you?

On Sep 25, 2020, at 3:30 PM, Evan Hand <elhandjr@...> wrote:
My first thought is to check the mic and key connections.  I have had similar issues with 3.5mm plugs that being pushed in all the way.  One of my key paddles has that issue, and I must constantly check that it is pushed in all the way.

I would verify the operation of the key input.  That is the line that needs the 4.7kohm resistor.  Check with a voltmeter after connecting a dummy load, or disconnecting the power to the power amp finals (the middle connector, brown wire, on the 3 pin header on the main board).

Did you by chance get one of the AmatuerRadioKits cases?  If so, I would verify the soldering on the front PCB, making sure that all of the 3.5mm jacks are soldered correctly, and no shorts.  You will also need another 3 pin header plug to separate the PA power, as the instructions for that case has you connect them together at the back PCB.

In any case, I think that you have a wiring issue that you need to resolve.  With the situation that you describe, even a short blip on the transmit key can cause the Nano to lock up due to RF feedback when you do not have a matched load.  Before breaking out the scope, I would attach a dummy load and verify that it operates properly. 

A good 20 watt low-cost dummy load can be ordered from QRP-Labs for $8.50 plus shippling.  Alternates can be had from Amazon, though without the power breakout circuit.
https://smile.amazon.com/Mcbazel-Surecom-0014-0153-PL259-1-0GHz/dp/B07MH6WPZL/ref=sr_1_12_sspa?dchild=1&keywords=qp+50+ohm+dummy+load&qid=1601068560&sr=8-12-spons&psc=1&smid=A263LSCPZJCHO0&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFNVFBaN1dGWk1aNzEmZW5jcnlwdGVkSWQ9QTA0NTU4MjgzVVFLVFNaQjZNWExSJmVuY3J5cHRlZEFkSWQ9QTAzMjY5MjkzSlFaSlpRQUdGU0xNJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Hope this helps.
73
Evan
AC9TU


Evan Hand
 

My first thought is to check the mic and key connections.  I have had similar issues with 3.5mm plugs that being pushed in all the way.  One of my key paddles has that issue, and I must constantly check that it is pushed in all the way.

I would verify the operation of the key input.  That is the line that needs the 4.7kohm resistor.  Check with a voltmeter after connecting a dummy load, or disconnecting the power to the power amp finals (the middle connector, brown wire, on the 3 pin header on the main board).

Did you by chance get one of the AmatuerRadioKits cases?  If so, I would verify the soldering on the front PCB, making sure that all of the 3.5mm jacks are soldered correctly, and no shorts.  You will also need another 3 pin header plug to separate the PA power, as the instructions for that case has you connect them together at the back PCB.

In any case, I think that you have a wiring issue that you need to resolve.  With the situation that you describe, even a short blip on the transmit key can cause the Nano to lock up due to RF feedback when you do not have a matched load.  Before breaking out the scope, I would attach a dummy load and verify that it operates properly. 

A good 20 watt low-cost dummy load can be ordered from QRP-Labs for $8.50 plus shippling.  Alternates can be had from Amazon, though without the power breakout circuit.
https://smile.amazon.com/Mcbazel-Surecom-0014-0153-PL259-1-0GHz/dp/B07MH6WPZL/ref=sr_1_12_sspa?dchild=1&keywords=qp+50+ohm+dummy+load&qid=1601068560&sr=8-12-spons&psc=1&smid=A263LSCPZJCHO0&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFNVFBaN1dGWk1aNzEmZW5jcnlwdGVkSWQ9QTA0NTU4MjgzVVFLVFNaQjZNWExSJmVuY3J5cHRlZEFkSWQ9QTAzMjY5MjkzSlFaSlpRQUdGU0xNJndpZGdldE5hbWU9c3BfbXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Hope this helps.
73
Evan
AC9TU