Quantcast Delayed Automatic Gain Control

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
2-22 forward bias. Any increase in signal level causes an increase in agc voltage. An increase in agc voltage increases conduction, which in turn drives the transistor to or near saturation. As the transistor approaches saturation, its gain is correspondingly reduced. On the other hand, if the input signal level decreases, the negative agc voltage decreases. The forward bias is then reduced, and the transistor operates on a lower portion of its characteristic curve where gain is higher. Forward agc provides you with better signal-handling capabilities; however, reverse agc is simpler to use, causes less loading of the tuned circuits, and produces smaller variations in input and output capacitance. Q17.   What does manual gain control do to strong and weak signals, respectively? Q18.   What is the purpose of agc/avc in a receiver? Delayed Automatic Gain Control The disadvantage of automatic gain control, attenuating even the weak signal, is overcome by the use of delayed automatic gain control (dagc). Let’s take a look at the typical dagc circuitry in figure 2-19. This type of system develops no agc feedback until an established received signal strength is attained. For signals weaker than this value, no agc is developed. For sufficiently strong signals, the delayed agc circuit operates essentially the same as ordinary agc. Figure 2-19.—Delayed agc action. Our circuit uses two separate diodes; one is the detector diode and the other the agc diode. The agc diode is connected to the primary of the last IF transformer and the detector diode to its secondary. A positive bias is applied to the cathode of the agc diode. This keeps it from conducting until a prearranged signal level has been reached. The adjust delay control allows manual control of the agc diode bias. Manual control allows you to select the signal level at which agc is applied. If mostly weak stations are to


Electrical News
Engineers Solve Analog/Digital Problem, Invent Creative Expletives
An analog engineer and a digital engineer join forces, use...
eetimes.com
Friday Quiz: EMC & ESD
Get your EMC/ESD head in gear for the 2014 EMC...
eetimes.com
Is Tesla's Gigafactory a Gigablunder for Panasonic?
Panasonic signed a deal with Tesla on a large-scale battery...
eetimes.com
Android, China Rise in Smartphones
Nearly 300 million smartphones shipped worldwide during the second quarter...
eetimes.com
Movidius Vision Processing Unit Enters 2nd Generation
Movidius announces a new chip and lays claim to the...
eetimes.com
Q'comm Shares a Wearable Strategy
The future of ubiquitous wearables will require more innovation than...
eetimes.com
3D Printing in Space
Among the technological advances that will make our dreams of...
eetimes.com
Sony, Panasonic, Japan Display Plan OLED Joint Venture
Sony Corp., Panasonic Corp., and Japan Display Inc. are working...
eetimes.com
Sony, TSMC Win Award for Silicon-Plastic Process Development
Sony and TSMC's paper describing a process to integrate a...
eetimes.com
What's the Best Traveling Toolkit?
When one is travelling, it can be really handy to...
eetimes.com
Power Week: Google's $1M Power Inverter Challenge - How Small Is Possible?
This week, Google, along with the IEEE, is offering a...
eetimes.com
Teardown: Oculus Rift Dev Kit 2 by iFixit
Using a Samsung Galaxy Note 3 display, Oculus Rift DK2...
eetimes.com
6 Things to Expect at Flash Summit
A coming out party for NVMe PCIe SSDs, more flash...
eetimes.com
Metaio Brings Augmented Reality to the Smartwatch
Leading augmented reality software developer, Metaio, is bringing its visual...
eetimes.com
Google Glass Goes to the Opera
Italy's Teatro Lirico di Cagliar will become the first in...
eetimes.com
EEVblog #646 – Gravity Detection Using A Frequency Counter!
Did you know you can use your frequency counter to...
eevblog.com
Creating an 8x8x8 3D LED Cube: Testing the RGB LEDs
Creating an 8x8x8 3D tri-color LED cube from the ground...
eetimes.com
Massive Job Cuts: Dark Clouds Over Lighting Business
Amid the decline of conventional illuminants like incandescent bulbs and...
eetimes.com
Next-Gen HiFi Competition Takes Place in the Car
Car radio? Old school. Infotainment? Better. Now the next generation...
eetimes.com
No More Dialup: Grandpa Gets DSL
We all talk about needing multi-megabit-per-second home Internet, but not...
eetimes.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +