July 2nd, 2009
Comments Off

No items matching your keywords were found.


No items matching your keywords were found.

Simple Diode Mixer

Help! I need a schematic diagram of a simple radio frequency(rf) mixer?


A simple RF mixer will do just fine. I just need a complete schematic or circuit with specified components (like what specific diode to use, what specific resistance...)

I just need a simple RF mixer, nothing too complicated yet

Thank you!

See sources



No items matching your keywords were found.


No items matching your keywords were found.


No items matching your keywords were found.


No items matching your keywords were found.


Mixer


Mixer


$12.99


Mixer

Pacer 12 Diode LED Light


Pacer 12 Diode LED Light


$12.95


LED (Light Emitting Diode) lighting gives extra brightness and longer life than conventional bulbs. Pacer's LED Light Kit works well as a third brake or turn signal indicator. It is actually 12 LED lights within 1 larger light. The compact, slimline design allows a great variety of mounting location options. Includes one light. Mounts with two-sided tape Simple two wire installation Long life Low power draw Each light is 4 5/8'' L x 7/16'' W x 3/4'' H. Available in Red, Amber, White and Blue* *White and blue lights are an additional $2.00

Pacer 20 Diode LED Light


Pacer 20 Diode LED Light


$15.95


LED (Light Emitting Diode) lighting gives extra brightness and longer life than conventional bulbs. Pacer's LED Light Kit works well when a light with extra length is needed. It is actually 12 LED lights within 1 larger light. The compact, slimline design allows a great variety of mounting location options. Includes one light. Mounts with two-sided tape Simple two wire installation Long life Low power draw Each light is 8'' L x 5/8'' W x 3/4'' H. Available in Red, Amber, White and Blue* *White and blue lights are an additional $6.00

Basin Mixer Classic Chrome


Basin Mixer Classic Chrome


$158.94


Basin Mixer Classic Chrome Simple, single lever basin mixers. Heavy duty cast manufacturing. Thread type: 1/2 Male NPT

Vortex Mixer


Vortex Mixer


$68.51


High Quality Content by WIKIPEDIA articles A vortex mixer is a simple device used commonly in laboratories to mix small vials of liquid. It consists of an electric motor with the drive shaft oriented vertically and attached to a cupped rubber piece mounted slightly offcenter. As the motor runs the rubber piece oscillates rapidly in a circular motion. When a test tube or other appropriate container is pressed into the rubber cup (or touched to its edge) the motion is transmitted to the liquid inside and a vortex is created. Most vortex mixers have variable speed settings and can be set to run continuously, or to run only when downward pressure is applied to the rubber piece. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 88 Publication Date: 2010/08/21 Language: English Dimensions: 6.00 x 9.02 x 0.21 inches

DIODE


DIODE


$12


When these electrical items fail there is little choice but to renew - With this genuine Suzuki par..

Soundcraft 6-Channel Mixer - Black


Soundcraft 6-Channel Mixer - Black


$249.99


This 6-channel mixer features 2 configurable auxiliary buses, XLR and 1/4" metal jack connector sockets and an easy-to-understand control surface for simple connectivity and reliable performance.

Nailtini Mixer Nail Base Color - Simple Syrup


Nailtini Mixer Nail Base Color - Simple Syrup


$13


Use these shade-altering base coats to transform any shade. Espresso - to deepen and intensify any shade Shade-altering base coat in black coffee to deepen and intensify any shade Cream - to lighten and brighten any shade Shade-altering base coat in french white to lighten and brighten any shade Directions: Use these shade-altering base coats to transform any shade. Net Weight: 0.5 oz. / 15 ml Ingredients: Butyl Acetate, Ethyl Acetate, Nitrocellulose, Acetyl Tributyl Citrate, Phthalic Anhydride/Trimellitic, Anhydride/Glycols Copolymer, Isopropyl Alcohol, Stearalkonium Hectorite, Adipic Acid/Fumaric Acid/Phithalic Acid/Tricyclodecane Dimethinol Copolymer, Camphor, Citric Acid. May Contain: Titanium Dioxide, D&C Red #6 Barium Lake, D&C Red #7 Calcium Lake, D&C Red #34 Calcium Lake, FD&C Yellow #5 Aluminum Lake, FD&C Yellow #10 Aluminum Lake, FD&C Blue #1 Aluminum Lake, Ferric Ammonium Ferrocyanide, Red Iron Oxide, Black Iron Oxide, Guanine, Bismuth Oxychloride, Mica, D&C Violet #2, D&C Red #17, D&C Red #33, D&C Yellow #11, FD&C Blue #1, FD&C Green #3, D&C Green #6, D&C Yellow #10, Polyethylene Terephalate, Calcium Sodium Borosilicate (and) Titanium Dioxide, Silica (and) Aluminum Powder (and) Iron Oxides, Aluminum Powder

Triton Sema Bar Mixer


Triton Sema Bar Mixer


$165


The wall mounted Triton Sema Thermostatic Mixer Shower is simple in design and suitable for most bathrooms.Features: Surface mounted bar mixer, adjustable maximum temperature safety shutdown, and a single pattern scale resistant showerhead.Type of shower: Mixer.Usage: Suitable for both high and low pressure systems.Effects and finish: Chrome.Guarantee: 5 year manufacturer's guarantee included.

Smooth Blend Mixer: K


Smooth Blend Mixer: K


$22.49


Fit & Fresh Smooth-Blend Mixer is the perfect way to mix and carry a healthy drink with you wherever you go. The removable mixer allows you to leave the blades at home, instead of at the bottom of your cup! First, add the healthy ingredients to the cup, then screw on the mixer. Simply turn the cup and mixer over and attach it to the base. Once the smoothie is mixed, remove the mixer and screw on the drink spout lid. The convenient on-the-go cup is top rack dishwasher safe for easy cleaning. Durable stainless steel blades chop ice and frozen fruits while blending yogurt, protein powders and your favorite ingredients into a smooth, healthy drink. The Fit & Fresh Smooth-Blend Mixer's stylish, compact base plugs into all standard outlets so it's ideal for home, work or travel. 1.Great for making smoothies, protein shakes, and more chops ice, blends frozen fruit and powders 2.16 oz. on-the-go cup has drink spout lid and fits in car cup holders 3.Ideal for home, work, or travel makes it easy to drink healthy on the go 4.Compact and elegant style easy to clean, simple to use

Numark 3-Channel Rack Mixer


Numark 3-Channel Rack Mixer


$99.99


This rack mixer features 1 mic, 2 switchable phono/line and 4 dedicated line inputs for simple connectivity. A stereo/mono switch allows you to send your mixes out over most PA systems, amplifiers, headphones and recording systems.

Numark 3-Channel Scratch Mixer


Numark 3-Channel Scratch Mixer


$109.99


This mixer features switchable phono/line inputs to easily connect audio equipment and 3-band EQ/rotary kills on each channel for easy control over your audio. The replaceable crossfader with reverse and slope controls provides simple operation.

Numark 2-Channel All-Purpose DJ Mixer


Numark 2-Channel All-Purpose DJ Mixer


$79.99


This Numark M101X110 2-channel all-purpose DJ mixer features a built-in 2-band EQ for quick, simple sound adjustments and a stereo RCA output for connecting to a speaker, amplifier or mixer.

Bristan Java Bath and Shower Mixer


Bristan Java Bath and Shower Mixer


$205


Made from durable brass with a handsome chrome finish the Bristan Java Bath and Shower Mixer includes a hot and cold bath and shower mixer tap stainless steel shower hose sturdy plastic handset and wall bracket. Modern looking and attractive they'll fit in with most bathroom suites. Suitable for high or low pressure systems the mixer has a minimum dynamic pressure of 0.2 bars and maximum operating pressure of 10 bars. The drip-free valve requires only a simple lift to operate. The Bristan Jav

Bristan Sonique Bath and Shower Mixer


Bristan Sonique Bath and Shower Mixer


$140


Made from durable brass with a handsome chrome finish, the Bristan Sonique Bath and Shower Mixer includes a hot and cold bath and shower mixer tap, stainless steel shower hose, sturdy plastic handset and wall bracket. Modern looking and attractive, they'll fit in with most bathroom suites.Suitable for high or low pressure systems, the mixer has a minimum dynamic pressure of 0.4 bars to bath fill and maximum operating pressure of 10 bars. The drip-free ceramic valve requires only a simple quarter turn to operate.

Numark Professional 2-Channel Scratch Mixer


Numark Professional 2-Channel Scratch Mixer


$89.99


This mixer features switchable phono/line inputs to easily connect CD players, turntables and other audio equipment. The replaceable crossfader with reverse and slope controls provides simple operation.

Stanton 3-Channel Mixer - Black/Gray


Stanton 3-Channel Mixer - Black/Gray


$129.99


Bring out your inner DJ with this 3-channel mixer that features a sturdy aluminum design for durability and a versatile cueing section with cue/master control for simple operation as you create your own customized sounds.

Stanton 4-Channel 19 Mixer - Black


Stanton 4-Channel 19 Mixer - Black


$299.99


This mixer features 4 channels, 3 microphone inputs, a subwoofer output with gain and crossover control and 3-band EQ per channel for creating customized sound. USB connectivity provides a simple connection to a computer for recording or playback.


We did not find any matches for your request.




Abstract - Drum And Bass Mix 12/08

Radio Astronomy Centre

 

 

 

 

 

 

Radio Astronomy Centre

 

Tata Institute of Fundamental Research

 

Ooty

 

 

 

 

 

 

 

 

CONTENTS

 

 

 

  • Introduction
  • Construction
  • Electronic systems
  • Electrical systems
  • Protection systems
  • Data acquisition system

 

 

INTRODUCTION

 

The Radio Astronomy

 

Radio astronomy is the study of universe with the help of radio waves emitted by celestial objects. Radio waves are mostly coming from highly energetic charged particles moving with velocities close to that of light in presence of magnetic fields with the help of directional antenna or telescope the strength of radio waves received from different directions from sky can be determined and a map of the radio signals from the sky can be made.

 

Radio Astronomy Centre at Ooty

 

The radio astronomy is one of the research institutes under Tata Institute of Fundamental Research(TIFR) proposed the hail tool of radio astronomy. A large structure radio telescope was designed in July 1963. A suitable site was

Selected in Nilgiri hills. The work that started in 1965 was completed by 1969. the co-ordinate latitude:11 22' and co-ordinate longitude:-76 40'.

 

Ooty Radio Telescope (ORT)

 

ORT is located on the hill slopes close to muthorai village in Ooty. The unique feature of telescope is that it is stepped in the north to south direction down a natural hill slope of about 11 equal to the ideal latitude of the observatory. This arrangement  ensures the axis of the telescope is parallel to the earth axis. This enables the ORT to track celestial objects for about 9.5hours by simply rotating the telescope mechanically in east to west direction.

 

CONSTRUCTION

 

The following are the building blocks of ORT:

 

  • Reflector
  • Dipole feed
  • Receiver

 

 

 

 

 

Reflector

 

The antenna reflector of ORT is the parabolic cylinder with its surface formed by 1100 stainless steel wires. Each fine stainless steel wire is of .38mm in diameter. These stainless steel wires are stretched along the length of cylinder.

 

Dipole Feed

 

The dipole feed consists of 1056 half wave dipoles hacked by a corner reflector and placed along the focal line on feed tracks. The physical aperture of antenna is 530 m long and 30 m wide.

 

Receiver

 

The local oscillator signal at 296.5 Mhz is generated in the receiver room that is located near adjacent to the telescopic antenna. The signal is carried in the transmission line to a central part where it branches into two parts. One branch is for the northern element modules and the other for the southern element modules. The RF amplifier is followed by a mixer which down converts the RF band to an intermediate frequency(IF) band centred at 30 Mhz. the IF signal from each module is transmitted to the receiver room through a separate coaxial cable.

 

ELECTRONIC  SYSTEMS

 

Low Noise Amplifier(LNA)

 

The LNA, which comes immediately after the dipole, plays major role in determining the system temperature, and thus the overall sensitivity of the telescope. It should have a lowest noise figure at the frequency of operation with a noise figure of .06 db at 2 Ghz was chosen for LNA.

 

GaAs FET devices are generally used at microwave frequencies for optimum gain and low noise performance using high gain, high frequency gas FET at VHF and UHF frequencies however possess special problems.

 

A simple technique broadband loading of FET drain, was used to ensure stability over the wideband.

 

Phase shifters

 

Scanning the beam of a radio telescope consists of an array of antennas electronically switchable phase shifters employing PIN diodes are commonly used.

 

Types of phase shifters:

  • Phase lead-lag type
  • Micro strip line type

 

 

 

The second type is used in ORT. The characteristic impedance is 50 ohm. Here extra loss of .1 db and .05 db are provided in the direct path.

 

Image rejection filters

 

It is basically a band reject filter. The o/p of 326.5 Mhz from RF amplifier is fed to this filter. The o/p is obtained is in the band region of 15 Mhz.

 

Mixer

 

The mixer is generally an adder or subtractor circuit. The o/p's from IRF and local oscillator phase shifter to produce the sum and difference o/p of the two frequencies.

 

Intermediate Frequency amplifier

 

It is a tuned amplifier tuned to 30 Mhz and bandwidth is limited to 4 Mhz to avoid unwanted signals. The receiver gain around 100 db. The receiver system is known as Super-heterodyne receiver.

 

ELECTRICAL SYSTEMS

The main functional units are as follows:

 

  1. Power Supply
  2. Rotation
  3. Protection

 

 

Power supply

 

the incoming supply for RAC is 22 KVA from the sandynalla substation. There are two lines which are provided in case of failure from any one of the lines. One supply is given to current transformer and to the protection circuit. From this, it is stepped down to measuring device. Since the three phase power lines have to travel a large distance before reaching the centre. From 220 KV supply –stepped down to 440V. The transformer contains oil cooling and silica gel to observe moisture. The 440V is taken to distribution board and is given to various loads. If there is no need of heavy loads, a small generator of 40 KVA is used.

 

 

 

 

 

 

 

 

 

 

ROTATION

The telescope can rotate in East-west direction.

 

Before rotation

 

 

 

 

 

 

 

After rotation

 

 

 

 

 

 

 

 

 

There are two modes of rotation

  1. Slew circuit
  2. Track circuit

 

Slew circuit

  • It employs 12.5 hp induction motor at 1440 rpm located at 4 trusses (N4,S4,N10,S10)
  • Induction motor's speed torque is converted to 75 rpm using gear trails.

Track circuit

  • Used to track the object continuously.
  • It employs 3-phase 5 hp motors that rotates the shaft at 3 rpm with the help of gear trails.

 

 

 

 

Usually the motors brought to a stop, the telescope strips further away from the required position due to momentum. This is a positional error.

 

PROTECTION SYSTEMS

Overspeed tacho circuit(need)

 

The telescope (ORT) is rotated at a speed of 75 rpm. Due to any fault conditions such as shaft breakage or motor failure, the telescope is subjected to overspeed. If the telescope is subjected to overspeed then the entire system would fail and telescope will be damaged, so to prevent the damage, overspeed tacho circuit is used. When the overspeed occurs, it is identified by the overspeed Tacho circuit that activates a relay.

 

 

Misalignment loop:

 

If any trusses are not rotated or twisted misalignment may takes place. To avoid this circuit rings are at the alternate trusses and a wire is connected in between them with a 30-v dc supply. When any misalignment occur to wires will touch the ring, which will then ac the relay to switch off supply.

 

Differential Synchro

 

The system is used to detect the misalignment in the main shaft of the ORT.

The synchro motor is fixed at both the ends of the shaft and the differential error W is fed to an electronic circuit, which operates a relay. The relay is set to trip the main supply when the misalignment goes beyond 150 in either direction.

 

Braking

After a track or slew operation, brakes are used to place the antenna at desired position without failing. The braking is in nature and when given a DC supply pushes the brake shoes and stops the rotation of the shaft.

 

Data Acquisition System For Eas At Grapes-III

 

Introduction

 

The Cosmic Ray Laboratory(CRL) is situated jus few meters above the RAC. The CRL constructed with more than 700 detectors arranged in hexagonal manner, to detect the cosmic showers from the sky by giving very high voltage to plastic scintillation squares.

Description

 

The very high voltages in range of 2450-volts are given to detectors,

then the output signal will given to controller section.

In this section the total signal is processed in the form of ,

  • TDC
  • ADC

 

 

Possible Radio Interferences

  • Spurious effects as a result of the sun appearing through distant side lobes of the telescope.
  • The radio interference is generated when faulty television booster amplifiers are in function.
  • Also potato insecticides sprayers used by farmers , will produce radio interference.
  • Hence to avoid it the observations in these are temporarily suspended.

 

CONCLUSION

 

The IPT which we underwent gave us a new great experience at RAC, Ooty. This training program will surely help us in our future. We would like to thank everyone at RAC, Ooty for their support and encouragement through out the training period.

 

 

 

 

 

 

About the Author

here i jus gave my experience which i got through an inplant training at RAC,ooty. i got permission through Mr.K.KALYANASUNDARAM, who is working there. It is useful for those who are interested in space science and astronomy science.

Sorry, comments for this entry are closed at this time.

Subscription

Subscribe to posts feed or to comments feed
Subscribe by email address (Powered by FeedBurner)