schematics for fm amplifiers

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easyadam
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schematics for fm amplifiers

Post by easyadam »

hi

i am looking for schematics, and have scoured the net looking for them. Most of them that i come across are so old that the Rf transistors are out of date, dead links, or there like 10000000watts which is not what im after.

veronica appear to make nice power amps, but they are sold as a working product and not as a kit. I enjoy building the kits so didnt really want to buy an assembled product.

I do however want to follow a schematic, that has nice features like gain attenuation, SWR protection etc. if possible!

I should also mention the power im after is around 10 to 20 watts, with the amplifier being able to accept 1watt power input.

I would appreciate any suggestions for schematics, or to point me in the direction of some. I have looked at the schematics on this site, but they are not quite what im after. i guess they could be modified though ?!?

cheers for your help.

Adam
easyadam
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help with schematic please.

Post by easyadam »

Hi,
I have searched some more and come across this schematic, it is taken from the data sheet of the philips BLY89C. although I cant source this transistor i can source its replacement which is PT31963. The schematic is shown as a test circuit for 175MHz. I want to use it around the FM band of 88 - 108MHz. Can anyone tell me if this schematic is suitable, and do i need to change any component values. The circuits in the philips data sheets are useful as most have pcb layouts as well.

here is a link to the schematic

http://easyadam.idohost.com/bly/bl89c.jpg

really hope someone can help

Adam.
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pcs
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Post by pcs »

You have to change coils and capacitors.

Increase turns and add more capacity.
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Marko - PCS Electronics
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