Search RFC: |                                     
Please support my efforts by advertising!
Serving a Pleasant Blend of Yesterday, Today, and Tomorrow™
Vintage Magazines
Electronics World
Popular Electronics
Radio & TV News
QST | Pop Science
Popular Mechanics
Radio-Craft
Radio-Electronics
Short Wave Craft
Electronics | OFA
Saturday Eve Post
Please Support My Advertisers!

Aegis Power | Centric RF | RFCT
Alliance Test | Empower RF
Isotec | Reactel | SF Circuits

Formulas & Data

Electronics | RF
Mathematics
Mechanics | Physics


About | Sitemap
Homepage Archive

Resources

Articles, Forums, Radar
Magazines, Museum
Radio Service Data
Software, Videos


Artificial Intelligence

Entertainment

Crosswords, Humor Cogitations, Podcast
Quotes, Quizzes

Parts & Services

1000s of Listings

Please support RF  Cafe's GoFundMe campaign! Software: RF Cascade Workbook | Espresso Engineering Workbook
RF Stencils for Visio | RF Symbols for Visio | RF Symbols for Office | Cafe Press


Temwell Filters

Noisecom

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

RF Cascade Workbook for Excel

RF & Electronics Symbols for Visio

RF & Electronics Symbols for Office

RF & Electronics Stencils for Visio

RF Workbench

T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads

These Are Available for Free

Espresso Engineering Workbook™

Smith Chart™ for Excel

Crane Aerospace Electronics Microwave Solutions

More Sensitivity from Your Transistor Radio
January 1969 Electronics World

January 1969 Electronics World

January 1969 Electronics World Cover - RF Cafe  Table of Contents 

Wax nostalgic about and learn from the history of early electronics. See articles from Electronics World, published May 1959 - December 1971. All copyrights hereby acknowledged.

Magnavox Model 789 AM / FM / Shortwave Radio - RF CafeWhere else on the Internet other than RF Cafe can you go for a daily helping of electronics-related material that ranges from the very beginnings of our chosen vocation through to the latest leading edge developments? That Q is rhetorical of course - and self-serving to boot ;-)  This handy-dandy trick for enhancing the signal on your AM radio appeared in a 1969 issue of Electronics World magazine. I remember doing this magnet "tuning" technique on my small, el cheapo pocket transistor radio that I carried with me when wiring houses and buildings while working as an electrician many moons ago after high school. It often made the difference between being able to listen to my preferred Top 40 AM station (combo top and music at the time) in Annapolis, Maryland - WNAV - and having to settle for Public Radio concerts. The "NAV" part of WNAV probably derives from "naval" both due to the U.S. Naval Academy being there and the fact that the entire Annapolis area is very water-centric, being located on the Chesapeake Bay and multiple surrounding tributaries. I do not miss the long, hot, extremely humid summers of boyhood. BTW, since I still listen to AM radio part of the day, I grabbed a magnet and ran it along the area where the internal AM ferrite rod antenna is located in my 1970s vintage Magnavox Model 789 AM / FM / Shortwave radio (it was Melanie's when she was a teenager) and sure enough, I was able to locate a peak in reception. Incredibly, I am able to use it daily to listen to WJR out of Detroit, which is 150 miles away in a straight line across Lake Erie. Here's an article showing how to repair a broken ferrite rod.

More Sensitivity From Your Transistor Radio

Ferrite rod AM radio antenna inside my vintage Readers' Digest Model 800-XR stereo receiver - RF Cafe

Ferrite rod AM radio antenna inside my vintage Readers' Digest Model 800-XR stereo receiver.

By John E. Campbell

Have you ever wished that you could squeeze just a little bit more sensitivity from your transistorized AM broadcast receiver, especially on a single station? If so, a gentle wave of a magic wand may make your wish come true.

All you will need is a permanent magnet and your receiver. If the magnet has a fairly strong field you won't even need to open the case of your set. Just tune in the station you wish to "perk up" and make a slow pass with the magnet down the length of the built-in ferrite antenna rod. If you detect a rather sharp increase in volume anywhere along the line, slow down and find the peak. That's all there is to it. You can now either balance the magnet where it is, tape it in place, or obtain some small ceramic magnets and tie or glue them in position directly on the ferrite rod.

Suitable magnets are available from Radio Shack, Edmund Scientific Co., and many others, A more universal supplier may be your local hardware dealer who handles magnetic cabinet latches. Just about any magnet will do as long as the field is strong enough to saturate a small portion of the ferrite rod.

 

 

Posted August 30, 2023
(updated from original post on 6/23/2017)

Crane Aerospace Electronics Microwave Solutions