RAN Technology

why 50 ohms?


Technical 0 Comments 09/06/2020 

The Forgotten Impedance

Posted By: Robert Nickels (ranickels)

 

Why do we use 50 ohm cables?    If you're like most hams the answer is:  "I dunno!"

In fact, it's a compromise (like most things in life) - between lowest loss when handling power and voltage breakdown, as Belden engineer Steve Lampen explains here

A pdf copy can be found below as well.   And now you know!


Description Comment  
50 ohms - the forgotten impedance

  

The WRL Duo-Bander 84

An "only 50 cents per watt" transceiver
Category: Vintage Ham Radio
  Go Mobile!  That was an attractive marketing message to 1960s era hams who were enjoying the fun of operating SSB mobile, and WRL knew a low-cost rig that didn't have to be hauled back and forth to the car would be a winner.   Heathkit and Swan had already proven that with their single (mono) bander transceivers, but what if you're heading out in the middle of th...  READ MORE
- Robert Nickels (ranickels),  03/27/2021 
    After the conclusion of World War II, there were only about 300 radio amateurs in Japan.   In the  year 1952, the JARL reported that only 30 provisional licenses were granted.    Realizing the value of ham radio in developing a technological workforce, Japan introduced its entry level Class 4 licence in 1959 -  it would prove to be the world's most succ...  READ MORE
- Robert Nickels (ranickels),  03/24/2021 
   Every radio aficionado can recognize at least three notes of music:   G-E-C - the famous NBC chimes!In fact there is so much history about the chimes it deserves it's own website, and someone has put a great deal of effort into creating one: The NBC Chimes Museum A Celebration Of Old–Time Radio’s Most Famous SignatureCLICK HERE TO VISIT THE NBC CHIMES MUSEUMIt is wel...  READ MORE
- Robert Nickels (ranickels),  03/20/2021 
  

The Codar AT-5

A long-sought addition, enabling my mid-60s UK ham station
Category: Vintage Ham Radio
  For many years I have wanted to add this cute little AM transmitter to my collection, but since it was never sold in the US,  the number that came up for sale were few and far between.   And there was usually a buddy waiting in line, or a reluctance for UK sellers to bother with the hassle of shipping to their former colony when local buyers were close to hand.However I&...  READ MORE
- Robert Nickels (ranickels),  03/20/2021 
  

Christmas Wishbooks

Great fun from https://christmas.musetechnical.com/
Category: Historic
How many got their start in radio with a Christmas gift?    And how many times did it come from the Sears or Mongomery Ward "Christmas Wishbook"?Mine did...the little crystal radio in the upper right?   Didn't work very well but was really cool!    The Remco Crystal radio was memorialized in this photo from about 1958 - age 7:  T...  READ MORE
- Robert Nickels (ranickels),  03/06/2021 
   The B&W 850 is a kilowatt-rated tank assembly that was used in the company's linear amplifiers and sold as a component for many years.  Unfortunately most of the plastics available were not capable of surviving for 50-70 years and thus have deteriorated to the point they no longer support the coil turns properly and must be repaired.    Here's a typical example from...  READ MORE
- Robert Nickels (ranickels),  02/28/2021 
   Lakeshore Industries of Manitowoc WI was an early follower of Wes Schum and Central Electronics to supply single sideband transmitters to early adopters of the new mode in the mid-1950s.   Both companies used the phasing method developed by Don Norgaard at General Electric and made popular through articles in QST, CQ, and GE Ham News.  Like most companies, Lakeshore sought to c...  READ MORE
- Robert Nickels (ranickels),  02/26/2021 
  

International Crystal and the crystal synthesizer

How a crystal company reduced the number of crystals needed
Category: Vintage Radio
I have always been intrigued by the International Crystal CB radios which had a unique appearance with a channel selector that resembled a telephone dial.    The high end "Executive" models were big and expensive and sported an aluminum trim ring that no other radio had.    So I had to buy one to play with.     It was cheap, like $25 and ...  READ MORE
- Robert Nickels (ranickels),  02/19/2021 
  

KBCX - US Forest Service Regional Radio

from Missoula Montana to the northwest
Category: Historic
Hams, especially those who enjoy operating AM and QRP should be aware of the pioneering efforts of the US Forest Service to adopt and advance the radio art in the early decades of the 20th century.The history of radio in the USFS literally takes a book to cover, but an interesting example can be found in station KBCX, the Region 1 Radio Operations Center in Missoula Montana.    It w...  READ MORE
- Robert Nickels (ranickels),  02/11/2021 
   Working on various vintages of equipment gives one a better appreciation for what we have today.    Example - this is a frequency counter from the "HF Manual Receiver" which was part of a wideband surveillance receiving system that extended from VLF to microwave frequencies using a bank of front-ends to cover the range.    It was designed as "ESM":...  READ MORE
- Robert Nickels (ranickels),  02/09/2021 

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