Topics

Calibration success #ubitx #calibration

Dean Souleles
 

Hi all -

Thank you for all the suggestions and advice. 

Here is my uBITX 5 post calibration video

The solution to my garbled audio turned out to be adjusting the BFO - 

Factory was 11.054.220
My setting: 11.056.220

Master calibration is unchanged from factory: 131250

I upgraded to the CEC firmware and  used ubitx memory manager.

Next step - transmitting - my radio doesn't appear to transmit.   I'm using a uniden/cobra mic connected through the 4 pin connector that came with the amateurradiokits.in case.  Mic is wired pin 1 shield, pin 2 mic audio, pin 3 tx control/ptt, pin 4 not wired.  The PTT kicks in but as far as I can tell, there is no RF out.  Need to recheck the wiring - but after that I don't quite know where to start.  

Dean
KK4DAS

Dan Schaefer
 

Dean

If you haven’t tried it you might go into cw mode and see if you get RF power out in that mode. You can just use a piece of wire for the key if needed. 
If you get CW power and the mike ppt works it is likely the Mike or audio amp isn’t driving the modulator. Does your mike need a dc bias voltage to generate audio?   
Sounds like you are on the right track. 

Dan W3BU 




On Aug 11, 2019, at 10:12 AM, Dean Souleles <dsouleles@...> wrote:

Hi all -

Thank you for all the suggestions and advice. 

Here is my uBITX 5 post calibration video

The solution to my garbled audio turned out to be adjusting the BFO - 

Factory was 11.054.220
My setting: 11.056.220

Master calibration is unchanged from factory: 131250

I upgraded to the CEC firmware and  used ubitx memory manager.

Next step - transmitting - my radio doesn't appear to transmit.   I'm using a uniden/cobra mic connected through the 4 pin connector that came with the amateurradiokits.in case.  Mic is wired pin 1 shield, pin 2 mic audio, pin 3 tx control/ptt, pin 4 not wired.  The PTT kicks in but as far as I can tell, there is no RF out.  Need to recheck the wiring - but after that I don't quite know where to start.  

Dean
KK4DAS

Dean Souleles
 

Thanks Dan -

I will give CW try. I have a watt meter on the antenna output so that is how I know there is no RF out.

The mic is a cobra/uniden electret CB mic.  I believe the element is essentially identical to the element that came with the kit.  

Dean

Evan Hand
 

Dean,

I assume that you were whistling or saying "Helloooooo" into the mic when measuring.  My v4 and v5 uBitx both do not register power out until audio is applied.

If you were able to calibrate with the stock firmware, it went into transmit mode for the calibration.  Did that register on the watt meter?

Dan's suggestion on CW as a test is the correct course.  It will verify if you have an RF or Audio issue.

If the CW checks out, then you wight want to wire up the supplied mic and button to the supplied 3.5 mm plug and try it.  I am pretty sure that the case kit that you got has both the 4 pin and 3.5 mm connections for the mic/PTT.

73
Evan
AC9TU

Dan Schaefer
 

If your mike is similar to the kit supplied one  you will likely need a dc voltage to the mike for it to work.  That should already be in the current design.  Check the mike connectors for a dc voltage on the radio mike connector and make sure it matches with the equivalent mike cable pin. Otherwise you might not have audio from the mike. 

Next if you have a way to do it check for audio at the mike amplifier output on the radio board.    
Just trace through the circuit schematic.  

Dan W3BU 



On Aug 11, 2019, at 11:25 AM, Dean Souleles <dsouleles@...> wrote:

Thanks Dan -

I will give CW try. I have a watt meter on the antenna output so that is how I know there is no RF out.

The mic is a cobra/uniden electret CB mic.  I believe the element is essentially identical to the element that came with the kit.  

Dean

Dean Souleles
 

Thanks guys!

1. CW test produces power out! So far so good.
2. The mic I am using is a UNIDEN/COBRA replacement electret mic:
3. I have it wired to the 4 Pin connector that came with the case, per the attached diagram
    Pin 1 - GND
    Pin 2 - MIC
    Pin 3 - PTT

Question - should there/will there be voltage from MIC to GND any time the radio is on?

I can wire up the mic that came with the rig to the 3.5 mm plug and give it a try also.

Thank you again,

Dean
KK4DAs

Dean Souleles
 

Step by step....

I have +5 volts on 4 pin connector pin 3 when the radio has power - it measures +5 against either Pin 1 or Pin 2 or the case.

Again - from the Uniden/Cobra wiring that I have found on the net it should be 
1. Gnd
2. Mic
3. PTT

Is there supposed to be voltage on the PTT line or am I possibly cross wired?

(as an aside - I really dislike mic wiring!)

And there was no 3.5mm pig-tail or connector in my kit - I presume I need a stereo plug - I can harvest an old PC speaker wire.    Just need to get that wiring right!

Dean
KK4DAS

Dean 
KK4DAS

Dan Schaefer
 

Wire the mike that came with the rig and use the plug to the phono mike input.  Haven’t looked at the audio diagrams recently but think the dc voltage should show up on the mike line when it is keyed by the ppt.  
Not sure about your wiring instructions that came with the chassis box.  
You should be able to measure a dc voltage on the mike line.   
Also get on the internet and look up the connect wiring for your specific Mike.  

Dan W3BU 


On Aug 11, 2019, at 5:55 PM, Dean Souleles <dsouleles@...> wrote:

Thanks guys!

1. CW test produces power out! So far so good.
2. The mic I am using is a UNIDEN/COBRA replacement electret mic:
3. I have it wired to the 4 Pin connector that came with the case, per the attached diagram
    Pin 1 - GND
    Pin 2 - MIC
    Pin 3 - PTT

Question - should there/will there be voltage from MIC to GND any time the radio is on?

I can wire up the mic that came with the rig to the 3.5 mm plug and give it a try also.

Thank you again,

Dean
KK4DAs
<38462384_10156437004964280_6827556150053961728_n.jpg>

Dan Schaefer
 

Sorry.  Think there is voltage only when the ppt is keyed for the uBitx 
Dan


On Aug 11, 2019, at 5:55 PM, Dean Souleles <dsouleles@...> wrote:

Thanks guys!

1. CW test produces power out! So far so good.
2. The mic I am using is a UNIDEN/COBRA replacement electret mic:
3. I have it wired to the 4 Pin connector that came with the case, per the attached diagram
    Pin 1 - GND
    Pin 2 - MIC
    Pin 3 - PTT

Question - should there/will there be voltage from MIC to GND any time the radio is on?

I can wire up the mic that came with the rig to the 3.5 mm plug and give it a try also.

Thank you again,

Dean
KK4DAs
<38462384_10156437004964280_6827556150053961728_n.jpg>

Dean Souleles
 

Thanks Dan!

I appreciate the response.

I did lookup the mic wiring - that is where I started.   Uniden BC-645 is a Cobra compatible electret 4 pin mic wiring 1-GND, 2-MIC, 3-PTT, 4-RX - I have 1, 2 and 3 wired correctly, I believe, per my enclosure instructions.  

Sadly - no 3.5mm plug at hand at the moment - but I will wire up the mic and PTT button that came with the kit and test.

Curious if anyone has experience with this mic.

Dean
KK4DAS

Jerry Gaffke
 

For transmitting CW, clk2 drives mixer d1/d2 at the transmit frequency.  The modulator, 2 crystal filters, and 2 IF amps are not used. 

When transmitting SSB, all of that stuff must work.

Jerry, KE7ER


On Sun, Aug 11, 2019 at 08:56 AM, Evan Hand wrote:

Dan's suggestion on CW as a test is the correct course.  It will verify if you have an RF or Audio issue.

Dean Souleles
 

Success.  The problem turned out to be a short between the mic audio line and ground.  Sunil from amateurradiokits.in had sent me a second front panel PCB after I reported my initial problem to him. (His customer services has been awesome and very responsive.)

I could not figure out where the short was - so I wired up a the new PCB - using a smaller iron tip and smaller gauge solder.  No short this time.  I can report that the Uniden/Cobra mic with the 4 pin connector works fine - completely unmodified.   

Here is a video of the completed rig receiving (sans the send/receive LED which I still have to wire up)

https://photos.app.goo.gl/78sKsTqsvm63NzE7A

Thanks everyone for the help and advice.  

Dean
KK4DAS

kc0wox Leeper
 

I'm glad you found the answer. I looked at the schematic trying to make a suggestion on what to check but I have no experience with the ubitx. There has been quite a few Cobra mikes used over the last 10 years or so. http://golddredgervideo.com/kc0wox/cobramike.htm The main thing to watch is not to overdrive the bitx mike input.
Leonard

Dean Souleles
 

Thank you Leonard. This particular mic doesn’t have a preamp....so no chance of over driving.

Dean