Re: Low power output on ubitx

MVS Sarma

Are you using electret mic as the mic pin is having dc bias voltage?
Generally we provide a 1nF  cap across the electret. That filters rf induced on the mic cable.

Reg ver 3 drawing 650mA on Rx with volume control at minimum, please check whether the audio amp is landing into oscillation. You could place a 1nF at  Vol mid pin close to the tda2822 and gnd. If the chip is too hot oscillation could be suspected. 
Once the Rx  current comes down to expected standard, you can adjust the mos fet currents one  by one after making the gate bias as zero at first stage.

Perhaps you might have already exercised all above steps.

  He k once whether the bias regulator output is dropping down not allowing needed Id  for the IRF510s.

Hope to see you solving out the issues.
sarma   u3zmv

On Tue, 7 May 2019, 9:38 pm sdr freak <sdrfreak55@... wrote:
I have V3 and i have an idea to rise up the output with an mic amplifier but i want look for an simple homebrew mic amp, but i think the problem is the voltage on mic cable for the amp, i read here in the forum of an simple 2N3906 amp directly after the mic capsuale and without any voltage from battery, only the voltage on the mic line should work, but i have built this and my first usage of it have no output, anything wrong in the circuit i solder or it is the voltage on the mic line that is not enoug.. but i think an mic amp is the first what i need..

My power output with cw is more than ssb on 80m i habe test, on other band i dont have testing cw against ssb power output. But it look like anything is wrong..

How can this less power output have any reason, which reasons there to look when receive is 160mA and ptt only 450mA and with adjust the rv2 and rv3 to each 100mA to the 450mA so i have made, the ubitx have 650mA pttonly by 12V and with say Haaaallloooo it have 1A but only 4-5W on Dummy on 80m and on Dipole 80m it have onmy 4W too.. 

There is the mic amp i look for the next step to rise up power in ssb mode.. but the mic amp should be self made because i have not much money for buy an mic amp module in online shop, and i have many items at home like Transistor,R,C,L,ICs and many messuaring Tools so it should be an ubitx mic amp for homebrew and the circuit i only found of this kind doesnt work..

If any Ideas for an mic amp shematic for the ubitx 3 or any help to me to become more power i would be proud!

Join to automatically receive all group messages.