Windfreak Technologies Frequency Synthesizers - RF Cafe
LadyBug Technologies LB480A RF Power Sensor Connectors - RF Cafe

About RF Cafe

Kirt Blattenberger - RF Cafe Webmaster

Copyright: 1996 - 2024
    Kirt Blattenberger,


RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.

My Hobby Website:

Electronics World articles Popular Electronics articles QST articles Radio & TV News articles Radio-Craft articles Radio-Electronics articles Short Wave Craft articles Wireless World articles Google Search of RF Cafe website Sitemap Electronics Equations Mathematics Equations Equations physics Manufacturers & distributors Engineer Jobs LinkedIn Crosswords Engineering Humor Kirt's Cogitations RF Engineering Quizzes Notable Quotes App Notes Calculators Education Engineering magazine articles Engineering software Engineering smorgasbord RF Cafe Archives RF Cascade Workbook 2018 RF Symbols for Visio - Word Advertising RF Cafe Homepage Thank you for visiting RF Cafe!
Innovative Power Products Combiners / Dividers

Signal Strength Comparison Circuit - RF Cafe Forums

RF Cafe Forums closed its virtual doors in 2012 mainly due to other social media platforms dominating public commenting venues. RF Cafe Forums began sometime around August of 2003 and was quite well-attended for many years. By 2010, Facebook and Twitter were overwhelmingly dominating online personal interaction, and RF Cafe Forums activity dropped off precipitously. If the folks at phpBB would release a version with integrated sign-in from the major social media platforms, I would resurrect the RF Cafe Forums, but until then it is probably not worth the effort. Regardless, there are still lots of great posts in the archive that ware worth looking at.

Below are the old forum threads, including responses to the original posts.

-- Amateur Radio
-- Anecdotes, Gripes & Humor
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews
-- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

Post subject: Signal Strength Comparison Circuit Posted: Fri Oct 28, 2005 6:06 am
Just wondering if anyone could help me with a problem:
Basically I am using two separate AM receiver modules and I want to display the strength of the received signals (using RSSI pin) however I only want the strongest signal of the two to be displayed. I intend to have a stepped L.E.D series for each of the modules to indicate signal strength, however i only want the LED series displaying the strongest signal to be active at any one time.
Does anyone have any ideas for creating this kind of signal strength comparison circuit?
Does anyone know of any similar circuits that I could modify or use as reference?
Many Thanks


Post subject: Posted: Mon Oct 31, 2005 5:15 pm
Assuming your RSSI out of each module is a analog voltage, then all you need is a simple comparator IC (LM339, LM311, and many others). Run the two RSSI signals to the comparator inputs. The output of the comparator will be high is one is greator and low if the other is. You might use the output to blank one display or the other through whatever means you have available. You might need to add a little more analog logic for cases where neither one has a signal (i.e. blank both).

Posted  11/12/2012
Copper Mountain Technologies - RF Cafe
EMC Directory
Axiom Test Equipment - RF Cafe

Please Support RF Cafe by purchasing my  ridiculously low−priced products, all of which I created.

These Are Available for Free