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question about current after building the DC connector

nomadg360@...
 

All the documentation I have seen says you should bet around 100 MA of current when you first connect the power connector to the board.  I am seeming about .50 MA   Is this a problem?

_Dave_ K0MBT
 

.5ma?

 

You need to be more specific.

Have you switched it ON ? Looks like it not!

Are you measuring on the center pin (Should be Brown) of power supply connector which goes to TX finals or the wire that goes to the
rest of the circuit (Should be Red) ?

The center pin on the board will show no current while in RX mode.

Raj

At 11/07/2019, you wrote:
All the documentation I have seen says you should bet around 100 MA of current when you first connect the power connector to the board. I am seeming about .50 MA Is this a problem?

nomadg360@...
 

Not sure my earlier reply got logged.

1. Not sure what you mean by switched on.  I had my power supply hooked up to the board, 13.5 volts, and could see that voltage at the DC connector pins.

2. I tried to measure the current by putting the meter on the incoming positive lead, i.e., connected in series on the positive lead from the power supply.  Seems that should have given me total current going to the board.

3. When you say "Are you measuring on center pin . . .," not sure what you mean.  Since both the brown and red are soldered to the center pin how would I connect the meter to read just what goes to the brown wire and where would I be connecting the other lead to get a current read?

4.  I am doing just the initial "out-of-the-box," install, so just the first step, soldering up the DC connector and connecting to power supply.

KD2QMZ
 

On your statement number 2, it will not show the total current coming to the board, but the current the board is drawing. For example, I got a 30 amps power supply, but the radio when not transmitting and on, it will measure at input the total voltage, but only the current is drawing.

On transmitting, then it will put few more amps, until mike is release or stop transmitting.



On Thu, Jul 11, 2019 at 1:44 PM <nomadg360@...> wrote:
Not sure my earlier reply got logged.

1. Not sure what you mean by switched on.  I had my power supply hooked up to the board, 13.5 volts, and could see that voltage at the DC connector pins.

2. I tried to measure the current by putting the meter on the incoming positive lead, i.e., connected in series on the positive lead from the power supply.  Seems that should have given me total current going to the board.

3. When you say "Are you measuring on center pin . . .," not sure what you mean.  Since both the brown and red are soldered to the center pin how would I connect the meter to read just what goes to the brown wire and where would I be connecting the other lead to get a current read?

4.  I am doing just the initial "out-of-the-box," install, so just the first step, soldering up the DC connector and connecting to power supply.

nomadg360@...
 

Thanks for the reply.  Yes, little sloppy with my language there -- I should have said, "current being drawn", not "going to."   It is still the case, that the reading I got there was about .5 ma, actually more like .47ma.

I suspect that I am missing something assumed in the instructions.  I have connected power to the board before I have done any of the other build steps.  That seem to be what the "Wire-up" doc says.  But likely it assumes that I have done something more than just soldered the DC connector.  Anyway onward and see what happens when I do some of the other steps.

Gary Anderson
 

On Thu, Jul 11, 2019 at 11:31 AM, KD2QMZ wrote:
On your statement number 2, it will not show the total current coming to the board, but the current the board is drawing
Same difference: "current being drawn" or "going to."  Kirchoff's 1st law.

 

Firstly I assume it is a V5 board.

0.5 mA means the power is not going to the board. Check if you are getting 12V at least at the board ground and any RX power points.
Start at the 3 pin power connector top. Then check on the board contacts below. Sometimes the connector wires which are crimped
may give some issues.

Raj

At 12/07/2019, you wrote:
Thanks for the reply. Yes, little sloppy with my language there -- I should have said, "current being drawn", not "going to." It is still the case, that the reading I got there was about .5 ma, actually more like .47ma.

I suspect that I am missing something assumed in the instructions. I have connected power to the board before I have done any of the other build steps. That seem to be what the "Wire-up" doc says. But likely it assumes that I have done something more than just soldered the DC connector. Anyway onward and see what happens when I do some of the other steps.

Evan Hand
 

It might help us better understand your situation if you describe how the rig is built, especially how the power is wired.  Are you building from scratch, or using additional purchased components like a case with supplied power wiring boards (there are a number of them available)?  A picture of the power section of the build would also help.

73
Evan
AC9TU

nomadg360@...
 

Building from scratch. (I do have a case kit, but for now I just want to get it hooked up as per "out-of-the-box." That is, using the parts that come with the board and following the instructions in the "HF Signals, MBITX -- WIRE UP" document.)

For power, I am connecting to my Alinco power supply set for 13.5 volts. (Using alligator clips for now to connect to the plug that came with the board.)

I am seeing 13.5 volts at the DC connector, i.e., between the positive pin (red-brown wires) and ground pin (black wire.) Not sure if there are other test points that I could hit that will tell me what the voltage is at other points on the board. (Also, unplugged the power cable and tested the voltage at the connector that plugs into the board -- also showing 13.5 volts between red and black, or brown and black.)

I am pretty confident that I have 13.5 volts up to the board.

nomadg360@...
 

I think it is V5. (I've had it about 4-5 months,just getting around to working on it.) On the board, (in the right rear corner), there is an embossing that says UBITX V5.)

All the connections I did are soldered. As noted in reply to Evan -- I see 13.5 up to the connector that mates to the board. (For now, I am using just the parts that come with the board and trying to follow the "Wire-UP" document.)

I see test points on the board, but haven't found any documentation as to what I might expect to see at those points if I used a meter on them?

 

I just did another voltage test. Between the red/brown pin on the power connector and the chassis mounting points (where you install the stand-offs, which I take to be board ground), I also see 13.5 volts.

 

Finally, on the main connector for the Arduino I see 13.5 volts on the socket flagged as +12 on the wiring diagram.

Evan Hand
 

Is the Raduino installed, and does it power up? By that I mean does the display light up?  If you are testing prior to installing the Raduino (I believe that the current test is suggested prior to inserting the Raduino) then do not install it down.  Instead test on pin one of the connector (the end closest to the power connector) for 12 volts there (should be the same as the supply voltage to the rig).

I really believe that there is a wiring error, or a bad trace/solder joint on the board.  This would be possible, however all boards are tested an "calibrated" prior to shipping, so not likely.

I will try to make time to run some measurements on my v5 board.  Please verify that it is a v5.  I also have a v4 board, so can test it as well.

73
Evan
AC9TU

Evan Hand
 

sorry, did not read your reply before answering with the prior response.  The schematic provided as a pdf on the HFSignals web site is the best tool to figure out where to test.

After I checked the schematic, I noted I was one pin off on the 12v supply to the Raduino.  mIt is actually pin 2 of that connector.

Here is a link to the pdf schematic:
http://www.hfsignals.com/wp-content/uploads/2019/02/ubitx_v5.png


There have been threads on Group.io that have documented the values that can be found on the test points. though some are for RF testing with either a scope, frequency counter,  or spectrum analyzer.

So do you have all of the wiring complete including the Raduino installed?

73
Evan
AC9TU

nomadg360@...
 

Thanks everyone for your responses. I went ahead and put together the various parts and connected them up. When I did that and turned on the power, it looked like everything was working. That is, the display lights up and there are values in the display fields. I played with the turner and the frequency displayed changed.

 

I am not sure what I did wrong, but in the process of doing the other steps, I "fixed" something :) I suspect I had a wire wrong I had to make a couple of changes when I went back and reviewed each. step and did continuity checks on the wiring that I did.

Thanks again. Now I need to figure out how to do the initial testing and how to change the color on the display so I can see the writing, that yellow is hard on the eyes .....

Edward Reynolds
 

On the back of display there is a contrast adjustment it might need a tweak.
Ed


On Jul 13, 2019, at 5:28 PM, nomadg360@... wrote:

Thanks everyone for your responses. I went ahead and put together the various parts and connected them up. When I did that and turned on the power, it looked like everything was working. That is, the display lights up and there are values in the display fields. I played with the turner and the frequency displayed changed.

 

I am not sure what I did wrong, but in the process of doing the other steps, I "fixed" something :) I suspect I had a wire wrong I had to make a couple of changes when I went back and reviewed each. step and did continuity checks on the wiring that I did.

Thanks again. Now I need to figure out how to do the initial testing and how to change the color on the display so I can see the writing, that yellow is hard on the eyes .....

nomadg360@...
 

Thanks Ed, I assume that is the small pot (blue in my case) on the back of the board.

Edward Reynolds
 

👍


On Jul 14, 2019, at 12:03 PM, nomadg360@... wrote:

Thanks Ed, I assume that is the small pot (blue in my case) on the back of the board.