hello if anyone could help this is my first attempt at building a rf amp i seem to be getting a voltage drop when i plug the amp into a vswr power metre ..when the amp is just plugged in to a 50 ohm dummy load it reads just 12 volts..i will upload a few pics in a min its not the best construction its just a quick put togeather but i will rebuild once i find out the problem any help would be great..the amp is 1 watt...i will update another comment in a min..

emitter voltage is 1.33 volts .. base is 906 milli volts ... collector voltage is 11.50

1 watt rf

1 watt

1 watt

1watt

put a capacitor in series with the output 1nf or try from 20pf to 1nf remmber in serie.That is the problem for shorting down,and hope that the transistor is not burn due to short circuit ,what type is it 2n ?

the transistor is 2n4427 ive tested it and it still working as for the board i did remove some trimmers 65pf thats why it lloks like that . lol ...i will give that a go tommorow with the capacitors thanks for the reply ..

it olny shorts out when i plug the vswr meter in ...when ive only got the dummy load pluged in with out the vswr meter there no short .i will try that tommorow with the caps thanks

at the so239 sockit it reads 12 volts .thanks for your help this is my first attempt at makeing an amp .....lol..

my vswr meter is working fine ive tested the meter. i have 2 vswr meters . the amp all so shorts out on the other meter .

Because you have no dc block cap after the output. Your feeding you swr meter with DC voltage. You want to pass the signal only. Put like a 102 in. Remove those output coils, they’re doing nothing.

i will try that some time later today in the afternoon thanks .

yes ugly and bad cold joints,go and practise away with a proper soldering iron and put flux etc....good luck .search online from a proper 1w .btw where is the transmitter to feed that baby ?

i have a vfo to drive it i will up date later to night on the amp

thank u everyone for the info its all working the dc blocker did the job...

This 4427 looks like cheap (not working) chinese fake

It’s also best to keep the leads as short as possible

I've got another problem lol.. Seems like the amp has become a transmitter I unplugged the vfo driver and the amp is transmitting on its own.. Any advice would be great...

Personally I think it would be better to just start over.The bad construction is probably what’s causing the amp to oscillate and why you need to keep leads short.