antentopSince2 July

** PLEASE DESCRIBE THIS IMAGE **
** PLEASE DESCRIBE THIS IMAGE **
** PLEASE DESCRIBE THIS IMAGE **

 

 

 

 

 

Antentop is FREE e-magazine devoted to Antennas and Amateur Radio an

Special page devoted to

Some Thoughts on Regenerative Receivers

Custom Search

 

ANTENTOP- 01- 2010, # 012

Some Thoughts on Regenerative Receivers

 

 

One of Armstrong Regenerative Receiver

Credit Line: Thermionic Tubes in Radio Telegraphy and Telephony, by: John Scott- Taggart, The Wireless Press LTD, 1921

 

·        Effectively increases the "Q" of the tuned circuit by  the concept of "negative resistance." Any circuit that accomplishes this will do the trick. Typically, an oscillator circuit, such as a Hartley, Colpitts, or the like is chosen. One then sets the loop gain of the oscillator circuit by some means to be just below the point of oscillation. Later, it will be seen that there are some clear design advantages to some circuits over the others.

 

·        Runs in "oscillation" mode, if desired, to act as a direct conversion or autodyne detector for CW or Single Sideband signals. The oscillation mode provides the BFO, or course.

 

The workings are not dependent on vacuum tubes versus transistors. The real problems in any design at least, are:

 

1. Interaction with the antenna, and QRM generated by the receiver itself. "Grounded Grid" or equivalent isolation amplifier does the trick here. An un-tuned grounded gate FET amplifier seems to be the modern choice.

 

 

 

 

2. There is massive interaction with tuning as a function of regeneration setting. If there is a way to separate detection from regeneration, this problem can be addressed. One typical vacuum tube design uses a Colpitts oscillator in parallel with a plate or grid leak detector (my favorite for vacuum tube designs). Another alternative (my Senior EE project in 1960!) was to insert a cathode follower between the tuned circuit and the detector/feedback vacuum tube).

 

Edwin H. Colpitts, “Oscillation Generator,”

U.S. patent 1,624,537 (filed: 1 February 1918: issued: 12 April 1927)

Figure Credit Line: Wiki

 

http://www.antentop.org/

Page 65

 

63 64 65 66 67 68 69 70 101 102

 

 

 


 

 

Just for Fun:

Map IP Address
Powered byIP2Location.com

Thanks for your time!

Last Updated:

August 2, 2016 18:16

** PLEASE DESCRIBE THIS IMAGE **

** PLEASE DESCRIBE THIS IMAGE **

2003entop