Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: PROJECT: next generation SWR/wattmeter  (Read 745 times)
AG4DG
Member

Posts: 537


WWW

Ignore
« on: September 23, 2003, 12:06:35 PM »

Last semester, I designed and built the QROP Meter for my graduate school independent study project. Go to my web page at http://www.jasonhsu.com/ee.html
to learn how to build the instrument.

What makes my SWR/wattmeter different from the numerous versions available from MFJ and the numerous homebrew designs out there?

1. Works from 200mW to 100W! You get the best of both worlds! MFJ SWR/wattmeters don't work at QRP, and QRP SWR/wattmeters can't handle 100W. Tuning up at 1W instead of 100W reduces the QRM you cause by
20dB, or over 3 S units! You can also safely change the tuner's inductance taps WHILE transmitting at 1W.
2. GOOD resolution at SWR values above 3 and even above 5! This can be very handy at 160m and 80/75m.
3. 10-LED display for the SWR meter and another 10-LED display for the wattmeter: No more squinting at cross-needle meters!
4. More accuracy at low power levels: Most SWR meters understate SWR at low power levels due to the infamous diode drop loss. My design compensates for this and allows accurate SWR measurements at QRP power levels.
5. Needs NO calibration!

Let me know what you think, and feel free to contact me if you have any questions or suggestions. I intend to have this article published in QRP and homebrewing publications. If you decide to build the QROP Meter, let me know how it goes.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!