i am driving crazy

[radium98]

Hi please help me i tried 2 make an fm amplifier for 15w listed on the net with the mosfet RD15HFV1 and i failed i get only 2-3 watts .so i am aware from this desighn can u help me post a wideband /easytune pcb layout if anyone have of such an amplifier or have the pcb layout of the well known rdvv no tune i will cut the amplifier stage
pictures of my amp .Thanks for helping me.or a easy tune design pcb i have one npn bipolar 2sc1946a thanks not the one listed on the net .

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[sinus trouble]

Hello Mr Radium
Im not familiar with the design you have there?
A few suggestions!
I would consider checking the RD15HVF1 datasheet. designs are shown for 175Mhz but should give a good basis to work with!
You will need around 1watt drive to the device and also set the gate threshold voltage correctly!

A good power supply is critical to obtain the output power you are looking for!
The heatsink you are using is FAR too small aswell

Good luck!

[sinus trouble]

Sorry, My apologies!
I did not see the BFR91 and 96s! Is it this you have built?

bfrk41.gif

I am sure these amplifiers were discussed in previous topics? From experience? the BFRs are very sensitive to damage! Also be careful of fake RD15s

If you have limited test equipment? it will be very hard to diagnose?
Firstly! Visually check for any bad joints or shorts and 15v to RD15!
Secondly! The BD139 should apply a voltage to the collectors (And base) of the BFR96s and a small voltage to the gate of the RD15 when you trim the PWR Adjust?

[sinus trouble]

Oh and not forgetting 9v to the collector of the BFR91

[radium98]

sinus trouble hello thanks for replying yes this is the same board i have and all mentions abose do the trick and this time the rd15 is not fake
would anyone have the rdvv transmitter layout that have at his outpout this kind of transistor so i cut this part and use it with the 1w veronica .

[radium98]

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