alex-gr wrote:

Good morning from Greece,
please exist anyone who have a credible circuit for fm
amplifier(87,5-108mhz) that uses tube 3cx1500 to send it to me?

If it's for FM, it's not a linear.

Try the Broadcast Electronics FM-1B, which used one of those 8877s as the
final. They were solid and reliable and turn up surplus at reasonable
prices. You should be able to find schematics online.

If you attach photos would be a great help...

Surplus FM transmitters are far cheaper than attempting to build your own.
Try Mooretronix or Armstrong Transmitters, both of which should drop-ship
to Greece.

The 8877 will need about 100 watts input power for FM broadcast use, so
it's not like some of the tetrodes which can just be driven right off a
10W exciter. Remember, it's not a linear... you _have_ to provide enough
input drive or it won't turn on at all. No, a 6146 won't provide enough power.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."