Re: LOW tx output

Soundararajan Ra.
 

Dear Farthan
my RF out is 2 watt the following are voltage Pk to Pk with CRO
1. RF peak to peak at hot end of the R136, (the shiny preset near the driver transistor) 450 mv
2. RF peak to peak at the R150, the 47 ohms resistor at the gate of IRF510 is 85 mv
3. RF peak to peak at the drain of IRF510 is 1.5 volt
4.Driver Q14 base 250 mv collector 500 mv
5.pre driver transister  q13 base 20 mv collector 1100mv

transformert5 & t6 checked for short circuit of winging and cleared with tooth pick.
Till no improvement
idle irf current increased to 200 ma
Adjusted 100 R R136 pot to maximum at that time power output 2 watt .
Soundar
vu2rjw


On Tue, Nov 22, 2016 at 9:12 AM, Ashhar Farhan farhanbox@... [BITX20] <BITX20@...> wrote:
 

By now a number of builders have reported low output. This seems to be a distinct trouble as opposed to being a one-off report. Let's analyze and fix this.

I would start my asking if anyone who has seen just  2 watts output and has an oscilloscope to report the following while transmitting a loud 'HAAAAALOOOWW!'
1. RF peak to peak at hot end of the R136, (the shiny preset near the driver transistor)
2. RF peak to peak at the R150, the 47 ohms resistor at the gate of IRF510
3. RF peak to peak at the drain of IRF510

let's go from there

- f


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