Hello Raj
After some more time checking the board, I have found a little copper scratch to earth, which seems to short circuit the 12v rail on the PCB in question.
To be honest, Im not really practical minded when it comes to the Structure of PCBs. This morning, I have asked for another board to be sent, Im buy another type of PCB too so perhaps, I will just have to desolder all the components!
Thanks for your help.
Regards & 73
m0wsa
Stacy Williams
On 29 January 2012 03:03, Raj <vu2zap@gmail.com> wrote:
Stacy,
Post a schematic for us.
Reading negative voltages in circuits can be due to wrong ground -ve reference. The meter -ve probe is not at 0V wrt the battery/PS.
Check the voltage between the battery or ps -ve and your board ground. Should be Zero.
Check between various ground points, somewhere you should spot a large difference! That area check for cut ground tracks on the PCB.
73 Raj vu2zap
>Does anyone have experience with this kit, G6LBQ multi-band bitx? Iv finished the build but, had some really strange reading with my DMM, all the way, through the build.
>
>Firstly, I thought it was the battery, which seemed very low so it was changed. Secondly, I started using analogue current and volt meters, which helped me diagnose the problem. Thirdly, I realised that the voltage had become negative on the board, I have checked all the components and this was the same, right the way across the build. Lastly, I have checked the bench power supply that was used and, the polarity is good. Basically, if I reverse the +ive and -ive from the supply to PCB then, I can normally measure the voltage. This was so weird...
>
>Its so strange how the voltage has been completely inverted when routed through the populated PCB. Has anyone come across this before, maybe with a bitx? Any ideas on this problem would be greatly appreciated.
>
>Regards & 73
>m0wsa
>Stacy Williams
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