RF Circuits

This RF Amplifier designed for FM broadcast using a single 2SC1946 VHF Power Transistor. This 10-30W RF amplifier circuit provides an appropriate power boost with an input of 1-3 watt. Tower are 30 meters high will send signal surrounding air should be around 15 km.

RF Amplifier Artwork
The layout of the 2SC1946 28 Watts FM broadcast RF amplifier has been created with sPRINT Layout v3.0. You can get a Shareware copy at: http://www.abacom.de. The pcb outline is 100 x 50 mm (width x height), all bitmaps have a resolution of 600dpi.Use FR-4 single sided photoresist epoxy pcb material for best results.



RF Amplifier Parts List
All component values are drawn on the .comp and .silklayer bitmaps, with the following exception(s);
all four (4) coils (in the lowpass filter section) are: 3.5 turns, 8 mm DIA., 1.2 mm CuL closewound i.e. no wirespacing.


Note:
CuL = magnetwire, enameled copper wire, insulated (rigid) copper wire e.t.c..
2 mm equals approx. to #12 A.W.G
1 mm equals approx. to #18 A.W.G
1.2 mm equals approx. to #17 A.W.G
0.8 mm equals approx. to #20 A.W.G
0.3 mm equals approx. to #28 A.W.G.)

• all diameters are measured from the inside of the coils, i.e. 'internal' diameter.
• make sure to mount the rf-transistor on a appropriate heatsink and use some thermal heatsink compound between the flange of the transistor and heatsink! (Thermal resistance heatsink at least 6°C/W.)

Source: http://www.3-mtr.info/shareware/Amplifier%2028Watt%20MicroStripline%20(2SC1946A)/