sâmbătă, 2 iunie 2012

Compact microwave amplifier module arrays





The modules are based on microwave-integrated-circuit (MIC) thin-film circuitry.




The modules are surrounded by AC-to-DC power circuitry, heat sinks, and a variety of protection circuitry and components.  The compact microwave amplifier modules  are suited to narrowband as wideband applications, this model is designed for use from 13 to 15 GHz.





















vineri, 18 mai 2012

Klystrons, Traveling Wave Tubes



Traveling-wave tube (TWT) is a specialized vacuum tube used in satellite systems  to amplify or generate microwave signals. Here you find some pictures of a CPI VTU-6397C3 type.












In the Klystron, a negatively charged cathode emits a beam of high-speed, high-energy electrons that travel through the cylindrical tube in straight lines to a positively charged anode. The surrounding magnet provides a magnetic field along the axis of the tube to focus the electrons into a tight beam. A coil is wound around the tube.



 That’s the helix, that provides a low-impedance transmission line for the RF energy within the tube. When the coil is energized with a radio-frequency ( RF ) signal, then accelerates an electron beam along the axis of the tube and some of the energy from the electrons is imparted to the signal in the coil. The result is amplification of the signal.




miercuri, 21 septembrie 2011

Some experiments for a Time Delay circuit using triacs.



PCB for the above circuit







Components used for:


Triac = TIC206M/TIC216M -sensitive gate triacs


Thyristor = C106M


datasheets:




DIAC = DB3


duminică, 18 septembrie 2011

Mini FM Transmitter.


The complete adjusting process requires lot of patience because the presence of your hand and the tool will slightly change the capacitance of the trimmer.
First have a FM radio near the circuit, set your FM receiver for a clear, blank space (no reception). Apply power to the circuit, then, with a non-conductive tool, start adjusting the trimmer capacitor until you find the right point, the clearest reception.
Second time try to place radio far away from the circuit and re-adjust trimmer capacitor.
L1 is 6 turns of 0.5 -1mm solid wire (air-wound) 8 mm diameter coil. You may use wire reclaimed from an old transformer. If you can't find wire to recycle need to buy enamel covered wire as in the specialized shops selling "magnet wire" (also search for shops which specialize in rewinding electric motors). The coil are wound in a single layer using a drill bit as a winding form. Use a 8 mm diameter bolt and wrap the wire in the threads.



Parts list:
C1 = 22nF up to 100nF
C2 = 100nF up to 470nF
C3 = 1nF up to 3.3nF
C7 = 22nF up to 470nF
C4 = 8.2pF up to 12pF ceramic type
C5= 27 up to 39 pF ceramic type
C6 = 3-30pF trimmer capacitor (any value minimum 1-5pF, maximum 25-50pF)
R1 = 4.7k -- 6.8k
R2 = 820k- 1.5M
R3 = 10k-15k
R4 = 39k-56K
R5= 390- 680ohms
T1 -- general purpose silicon NPN bipolar transistor
BC109, BC173, BC238
T2- general purpose silicon NPN bipolar transistor
BC107, BC238, 2N2222, 2N2306A general purpose silicon NPN bipolar transistor
BC238 used for amplifier applications was used.
However, you may substitute the BC238 with a 2N2222 or a 2N3906, these are also general purpose transistors




Testing the FM transmitter:

http://www.youtube.com/user/LEDchaser#p/u/10/pQepqtqJBJg