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uBITX will not turn on

giant
 

Hi everyone,

I just built my uBITX kit, but it won't turn on. So far I have been able to check voltage at the power jack and the volume pot. Is there a guide for checking the radrino or other parts? Any other ideas?

Bob Recny <n8sqt@...>
 

Ensure you have your antenna jack grounded. At least that's what the Ham Radio Crash Course podcast found - he did a live build during the podcast:  https://www.youtube.com/watch?v=ZJRak2571Sk


On Tue, May 28, 2019 at 4:17 PM giant_g2 via Groups.Io <giant_g2=yahoo.com@groups.io> wrote:
Hi everyone,

I just built my uBITX kit, but it won't turn on. So far I have been able to check voltage at the power jack and the volume pot. Is there a guide for checking the radrino or other parts? Any other ideas?

giant
 

I couldn't see exactly what he did in the video. Is there somewhere else that I have to run a ground wire other than the black and brown wires on the 2 pin connector? I'm using a plastic case if that makes any difference.

Bob Recny <n8sqt@...>
 

I'm not sure. I don't have my kit yet (due in Thu) to do a closer inspection.


On Tue, May 28, 2019 at 4:34 PM giant_g2 via Groups.Io <giant_g2=yahoo.com@groups.io> wrote:
I couldn't see exactly what he did in the video. Is there somewhere else that I have to run a ground wire other than the black and brown wires on the 2 pin connector? I'm using a plastic case if that makes any difference.

Sam Tedesco
 

Pic of your wire up? If u have a cable, plug the raduino to 5v and make sure it fires up on its own. 

Curt
 

Use your dvm to verify continuity fron dc input to the board, power off just use ohms setting.

Its easy to misinstall raduino one pin off in the connector.

Patiently look for a simple cause.

Curt

giant
 

How do I hook up the 5v directly to it? Is it the miniUSB?

I verified that all the pins are lined up for all connectors. With the power on, I verified that I have power to main board using the black wire at the power port as my ground. I'm not sure if this is the correct way to measure it.

Sam Tedesco
 

Yes...mini usb. Just to confirm the raduino is ok. Then, we can go after the wiring and main board

giant
 

The raduino turns on when powered directly. My version is 5.1. I found this interesting as all the troubleshooting guides I've found were for versions 3 and 4. Is v5.1 very new? Could I be experiencing an issue with this version not documented in the previous versions?

I still need to figure out if I need another ground wire on the antenna in addition to the black and brown wires and where that would attach to (as seen in the video). 

Sam Tedesco
 

That's good news about the raduino. Is it possible to get a pic or two of the build so we can get a better idea of the wiring?

giant
 

I have continuity between the ground and conductor on the antenna port. That doesn't seem right. Is this ok?

giant
 

It seems like I can't upload pictures.

Clark Martin
 

Quite normal.  The receiver input is to a mixer through a transformer.  At DC the transformer shows approximately 0 ohms.

And in general many RF devices will show approx. 0 ohms DC resistance for one reason or another.  At RF frequencies it’s a wholly different matter.

Clark Martin
KK6ISP

On May 30, 2019, at 9:00 AM, giant_g2 via Groups.Io <giant_g2@...> wrote:

I have continuity between the ground and conductor on the antenna port. That doesn't seem right. Is this ok?
_._,_._,_

giant
 

Sam Tedesco
 

It's hard to tell from the pics, but your power wiring might be suspect. Can you confirm that you have a single hot line from dc in to one switch post on the volume pot and the return switch post has the brown/red wires?

Or, if possible...bypass the switch for now and just have red/brown to dc in and black to dc ground.

Martin Potter
 

KK6ISP wrote :
"And in general many RF devices will show approx. 0 ohms DC resistance for one reason or another."

Clark,
The reason is reactance, which is frequency dependent. See the relevant section of any edition of the Radio Amateurs' Handbook.
73,
... Martin VE3OAT

Clark Martin
 

I’m quite familiar with reactance from years of working with it.

Clark Martin
KK6ISP

On May 30, 2019, at 12:11 PM, Martin Potter <ve3oat@...> wrote:

KK6ISP wrote :
"And in general many RF devices will show approx. 0 ohms DC resistance for one reason or another."

Clark,
The reason is reactance, which is frequency dependent. See the relevant section of any edition of the Radio Amateurs' Handbook.
73,

giant
 

Oh, the way you describe the power wiring makes more sense. The directions I saw said to wire the red to the pot switch and did not mention to run the brown with it. My brown is still going to the 3 pin connector directly. I will change this since that configuration would make more sense, but I don't see how that would cause my issue.

giant
 

I rewired the power and it's still the same.

giant
 

After watching the video several times, it looks like he just missed the ground on the antenna, nothing else. I do have the ground on the antenna, so that isn't it.