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Circuits > RF circuit > Linear FM 30Watt
Linear FM 30Watt
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Manufacture: Soulis Papanastasiou |
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Copyright:
Technical Election |
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Cost of manufacture: 52,80 ? |

Note: The text is AUTO translated from
Greek
version
A amplifier of medium force RF for the FM, is always
essential for the amateur that wants it strengthens some small transmitter, that
likely it has already it manufactured! The present circuit can give force
25-30W, with control no bigger than 4-5 W.
As it appears in the analytic drawing, the amplifier is
manufactured with the transistor TR1 of type ΒLY89 of
Phillips. The transistor this is specifically drawn for operation in frequencies
up to 175Μhz, with very good
results. His special characteristics appear below:
| · Tendency of operation: 18V |
| · Current of Collector: max 3 5th |
| · Gain: max 10dB |
| · Force of Expense: 25-30 W |
| · Output (order C): > 60% |
Variable capacitors C1, C2, with inductor L1, constitute
the coordinated circuit that adapts the exit of our transmitter in this
amplifier RF. the circuit has been calculated suitably, so that it covers all
band the FM with the biggest
possible output. Inductor RFC1 polarize the transistor, so as to it works in
order C that is to say with the biggest output. Inductor L2 in the collector of
TR1, constitutes the charge of amplifier, while RFC2 prevents the RF signals
escape in the line of catering. Capacitor C2 and resistance R1, protect the
circuit from auto polarize.

The coordinated circuit of expense that is constituted by
inductor L2 and variable capacitors C3, C4, adapts the exit of amplifier RF with
the next stage that can be some amplifier RF of high force (> 100W) or a aerial.
MANUFACTURE
The manufacture of amplifier is very simple and easy.
Puncture the point PCB that will pass the nutshell of TR1. Stick the capacitors,
variable, the resistance, the RF tsok and the inductors. Finally you stick the
TR1, being careful not overheats at the welding and blend pin his. Clean finally
PCB from the residues of soldering. Make a very careful control for by any
chance errors, omissions, short-circuits, chills you stick also anything other
that could you make wonder why does not work the amplifier.
PARTS
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C1, C2, C3, C4 = 10 – 80pF |
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C 5 = 10nF |
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C6 = 1000pF |
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C7 = 100nF |
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C8 = 2200mF/35V |
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L1 = 1 coil with diameter of 10 mms, 1 mm |
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L2 = 7 coils with diameter of 10 mms, 0,8 mm |
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L3 = 3 coils with diameter of 10 mms, 1 mm |
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TR1 = BLY89 |
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RFC = RF tsok |
If all they are it includes, you connect the exit of your
transmitter (3-4W) in the entry of amplifier. The exit of amplifier him you will
connect in some charge (dummy load) or in the aerial, through a bridge stagnant.
Be supplied with tendency 11-15V
your amplifier. (Power supply it should it provides current
45th). Regulate the 4 variable (C1-C4, until you take
the biggest force of expense. The amplifier is ready.

Note: The TK1 needs a wiper of dimensions 5x10cm for
trouble free operation. This wiper screw in the TR1 without isolators, after his
central screw has electric isolation from remainder pins.

E-mail:
steve_filianos@hotmail.com for questions - info.
Title: Linear FM 30Watt
Source: www.electronics-lab.com
Published on: 2005-02-03
Reads: 1267
Print version:  Circuits > RF circuit > Linear FM 30Watt |
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