Homepage Archive - April 2026 (page 2)

Thursday the 30th

Hide and Seek - Peenemünde to Canaveral

As the Soviet army closed in on the Peenemünde rocket base in March 1945, German engineers led by Wernher von Braun initiated a desperate evacuation of their revolutionary research. Tasked by von Braun, engineer Dieter Huzel organized the transport of tons of top-secret blueprints and records to avoid capture by the advancing Red Army. Amidst the chaos of collapsing lines and aerial warfare, Huzel successfully secured the documents in an abandoned, ironclad mine near Goslar, shielding them from Soviet hands. After dynamiting the entrance to seal the cache, Huzel and fellow scientists fled westward to surrender to American forces. Following their successful arrival in U.S. lines, the location was revealed...

Lost Your Money? Wire KUBIT

Sending telegraph messages, whether by wire or wireless means, has always been expensive, particularly considering charges are determined by the character (letter, number, symbol). Accordingly, the Shakespearean line from Hamlet declaring that "brevity is the soul of wit" can be reworked to "brevity is the soul of economy." A telegraph wire, unlike a telephone call, is a legally binding communiqué, as is of course a written letter, but a telegram is immediate transmission of information for time-critical messaging. A series of "commercial codes" were developed enabling senders to save often significant money by sending multi-character codes that represented entire phrases and/or sentences. What struck me about this article that appeared in a 1948 issue of The Saturday Evening Post magazine...

Just Starting in EMC?

"With all the many pressures you have as a product designer, does electromagnetic compliance (EMC) always seem like a stumbling block to delaying product sales? Is your product exhibiting one of the top three failures: radiated emissions, electrostatic discharge, or radiated immunity? Are you continually cycling between design/fixing - running to the compliance test lab - failing again - and back to shot-gunning more fixes? Wondering how to attack these issues earlier in the design cycle? Would you like to learn how to characterize and troubleshoot simple design issues right on your workbench? Then, this monthly column is for you..."

Radio Service Data Sheets for Vintage Radios

In 1938, the designers at Sears, Roebuck & Company's, Silvertone radio division were truly thinking "outside the box" when they came up with this "Rocket" model Models 6110. It is an ultra compact tabletop design with a unique rounded top and a huge tuning dial that comprised one entire end of the Bakelite cabinet, along with a set of six pushbuttons for station recall.  Also published were datasheets on the Allied Radio Knight Model E10913, the General Electric Model GD-52,, and the Zenith Models 6D302, 6D311, 6D326, 6D336, 6D360. An ever-growing list of models is at the bottom of every page...

Mallory Clutch-Type Potentiometers

What drew my attention with this P.R. Mallory & Company advertisement was not an actual electronic component that they are most noted for - potentiometers, capacitors, switches, metal alloys, and of course batteries (later renamed Duracell). Philip Rogers Mallory began his company manufacturing tungsten wire for lamps. Rather what interested me was the huge variety of standard potentiometer and rotary switch extension shafts. Unlike modern electronics where pots and switches are typically mounted to the enclosure with wires running to the circuit assembly, many...

Wednesday the 29th

Nathan B. Stubblefield - America's Marconi

The failure to recognize Nathan B. Stubblefield as the primary inventor of radio is a classic example of how institutional power, financial interests, and the legal machinery of the telecommunications industry tend to favor those with corporate backing over solitary, unconventional inventors. Stubblefield's technology, which he demonstrated as early as 1892, utilized induction and conduction through the earth and water rather than the electromagnetic wave propagation (Hertzian waves) that ultimately became the standard for modern radio. Because his method was effective only over relatively short distances and functioned on different physical principles, it was eclipsed by the work of Guglielmo Marconi. Marconi was the superior marketing force. He was backed by a massive corporate infrastructure and was savvy in securing international patents...

Standing Waves on Transmission Lines

Author T.A. Gadwa employs a standing wave mechanism analogy that I don't recall having read before - that of a dam on a river. The river is the transmission line with a lake as the source and then he imagines a dam load. The dam standing waves, per his description, have phase and amplitude characteristics that depend on how tall the dam wall is relative to the surface height of the dammed river. An extensive array of graphs is provided showing how the current of the dam standing waves react to the dam transmission line termination impedance...

Electronic-Themed Comics from 1951

Here are a couple more electronics-themed comics, this time ones that appeared in the October 1951 edition of Radio & Television News magazine. When is the last time you saw a comic in a technical magazine? Note the AC power cord attached to the "portable" television. Television was a big deal in the day (I assume the "His" on the guy's towel implies that "Hers" is at the other end of the power cord). Color TV was not commercially available until a few years later. Nowadays, a person would have a smartphone, tablet, or notebook computer while on the can. There is a huge list of other comics at the bottom of the page...

Reviving Teletext for Ham Radio

"Once upon a time in Europe, television remote controls had a magic teletext button. Years before the internet stole into homes, pressing that button brought up teletext digital information services with hundreds of constantly updated pages. Living in Ireland in the 1980s and '90s, my family accessed the national teletext service - Aertel - multiple times a day for weather and news bulletins, as well as things like TV program guides and updates on airport flight arrivals. It was an elegant system: fast, low bandwidth, unaffected by user load, and delivering readable text even on analog television screens. So when I recently saw it was the 40th anniversary of Aertel's test transmissions, it reactivated a thought that had been rolling around in my head for years..."

Wireless Engineering Crossword Puzzle

I have a confession to make regarding the puzzle titles. While all RF Cafe crosswords do in fact use only my hand-entered dictionary of terms and clues (literally thousands accumulated over the years) that pertain exclusively to science, engineering, chemistry, physics, mathematics, astronomy, etc., the choice for a particular title is to help attract search engines to the page. There is nothing deceptive going on, just an attempt to exploit the nature of search engine algorithms that rank pages based on meta tags coinciding with relevant...

Anatech Electronics April 2026 Newsletter

Sam Benzacar, of Anatech Electronics, an RF and microwave filter company, has published his April 2026 Newsletter that, along with timely news items, features his short op-ed titled "Bell Labs in Murray Hill Celebrates." Sam, whose company is located not far from Murray Hill, extolls the many discoveries and inventions that took place there since its founding in 1925 as Bell Telephone Laboratories. It was originally a subsidiary of AT&T and Western Electric, later becoming part of Lucent Technologies and Alcatel-Lucent before Nokia's acquisition in 2016. Sam reports on the facilities' recent 100th anniversary celebration. The list of accomplishments would will volumes...

Tuesday the 28th

Ferrites - The Mighty Midgets of Electronics

The transformative role of ferrites - crystalline structures composed of iron oxide and metallic additives - in advancing modern electronics, is reported in this 1961 Electronics Illustrated magazine article. Ferrites uniquely combine magnetic properties with electrical insulation, enabling high efficiency at frequencies where standard iron cores fail due to eddy current losses. This "electronic wonder material" proved critical for television development, allowing for larger picture tubes through efficient flyback transformers and deflection yokes. Furthermore, ferrites revolutionized computing by providing reliable, compact memory cells, replacing failure-prone vacuum tubes in machines like the Whirlwind I. Beyond these core applications, the material facilitates innovations such as ultrasonic ...

Engineers Kick-Started the Scientific Method

"In 1627, a year after the death of the philosopher and statesman Francis Bacon, a short, evocative tale of his was published. The New Atlantis describes how a ship blown off course arrives at an unknown island called Bensalem. At its heart stands Salomon's House, an institution devoted to 'the knowledge of causes, and secret motions of things' and to 'the effecting of all things possible.' The novel captured Bacon's vision of a science built on skepticism and empiricism and his belief that understanding and creating were one and the same pursuit. No mere scholar's study filled with curiosities, Salomon's House had deep-sunk caves for refrigeration, towering structures for astronomy, sound-houses for acoustics, engine-houses..."

Werbel 2-Way Power Divider for 1.5-20.5 GHz

Werbel's new WM2PD-1.5-20.5-S-ECO, 2-way power divider covers 1.5 to 20.5 GHz and is designed for engineers who need wideband performance in a compact, cost-efficient package. Optimized for size, bandwidth, and manufacturability, it is well suited for high-volume applications, lab use, and general-purpose signal distribution where extreme port match is not required. Designed, assembled, and tested in the USA. "No Worries with Werbel!"

The Electronic Mind - How it Remembers

The radar system I worked on in the USAF used two early memory types described in this 1956 Popular Electronics magazine article. In fact, the radar was designed during that era, so it is no surprise. Our IFF secondary radar had a whopping 1 kilobyte of magnetic core memory in its processor circuitry. It consisted of 1024 tiny toroids mounted in a square matrix with four hair-width enamel coated wires running through them as x and y magnetization current lines, sense, and inhibit functions. If my memory serves me (pun intended) after three decades away from it, the TTL circuitry (no microprocessor) stored range values to calculate speed and direction from sample to sample. The other memory type was a mercury acoustic delay line contraption having a piezoelectric transducer at one end to launch an electrical pulse along its length and another transducer at the other end to convert back to an electrical pulse...

Schematics and Parts Lists for Vintage Vacuum Tube Radio Models

These are the schematics and parts list for vintage vacuum tube radios Westinghouse Model H-133; Arvin Models 150TC, 151TC; and Admiral Model 7C63, Chassis 7C1 as they appeared in the December 1947 issue of Radio News magazine. I scan and post these for the benefit of hobbyists and historians seeking such information. As time goes by, there is less and less likelihood that records of these relics from yesteryear's archives will be made available. As with all historical information, it takes someone with a personal interest in preserving the memories in order to fulfill the mission...

Many Thanks to KR Electronics for Long-Time Support!

KR Electronics has been designing and manufacturing custom filters for military and commercial radio, radar, medical, and communications since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for special applications - both commercial and military. State-of-the-art computer synthesis, analysis, and test methods are used to meet the most challenging specifications. All common connector types and package form factors are available. Designed and manufactured in the USA. Please visit NIC today to see how we might be of assistance.

Monday the 27th

Lamp Brightness Quiz

Here is another electronics quiz for you to try. Intuition from experience goes a long way here, but if all else fails you can work out the details of the rectifier circuits to determine which lamp received the most current. Keep in mind that the diode symbols are not LEDs; it is the "A," "B," and "C" symbols inside circles that are the lamps whose brightnesses are being considered. LEDs did exist at the time this quiz was created in 1969, but the circuits would perform differently if in fact LEDs were used for double duty of rectification and illumination...

Good Operating Pays Off

The more things change, the more they stay the same. That saying applies to many recreational activities. Pick up a copy of QST magazine that was published in the last year and look at reader comments and you will find laments about the dwindling participation of youngsters, an increased degree of incivility and rule breaking during engagement, the high cost of getting into the hobby, yadda yadda yadda. I witness it regularly in the model aircraft world, too. That is not to say the issues are not true or irrelevant, just that they are persistent. Each generation, it has been said, tends to think...

ButtonWorx Pressure-Sensitive Switch Replacements

I have long-maintained that the vast majority of electrical problems on consumer products can be attributed to bad connector or switch contacts. Just yesterday, I restored a 1970's-era TI talking kids' toy to working order just by cleaning the plug-in program module and mating motherboard contacts. RF Cafe website visitor / contributor Bob Davis sent this suggestion for curing intermittent or non-responsive front panel buttons on test equipment and other electronic gear like radios, remote keypads, games, tools, vehicles, keyboards, locks, etc. His problem was with a R&S spectrum analyzer. He found a solution from ButtonWorx, who manufactures replacement pressure contacts for a large range of products. Some are entire arrays to replace original parts, and others are individual switches for custom requirements.

Coronet Model C-2 Schematic & Parts List

You wouldn't know it from the schematic, but this Coronet Model C-2 tabletop radio has a very unique feature: The tuning scale/pointer, and volume and tuning knobs are on the top of the case, that is, the face of the radio points upward when properly displayed. When searching for photos of the Coronet C2, I found a few examples where the radio was sitting on a surface with the face situated vertically like a standard model, but the feet are clearly on the side opposite the face. The schematic and parts list for the Coronet C2 radio appeared in the February 1947 issue of Radio News magazine. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. I keep a running list of all data sheets to facilitate a search...

WH Correspondents Dinner Shooter Video

Have you noticed that every time a shooting or other attack event occurs - especially pertaining to "R" targets - the quality of the video looks like something from the 1970s, or of a UFO sighting? Most private surveillance cameras in homes, cars, and businesses - even traffic cams - have resolution and full color so good you can distinguish faces and even identify brands of clothing, weapons, etc. This is a frame from the attempted assassination attempt this weekend at the White House Correspondents Dinner. The perp, a celebrated "Teacher of the Month" from California, rushed the security point with multiple weapons. Conceal carry, do training, and watch your six.

Friday the 24th

World's Most Powerful Radio Transmitter

In the early 1950s, the U.S. Navy built what was at the time the world's largest and most powerful radio broadcast transmitter station at the Jim Creek Naval Station on Wheeler Mountain in Washington state. Its 1.2 MW, 24.8-to-35 kHz VLF transmitter (call sign NLK) can reach anywhere in the world, even to submarines. A half wavelength at 24.8 kHz is 19,830 feet. Photos indicate that the transmitter is located in the middle of a dipole arrangement. "Catenary cables," if you are unfamiliar with the term, refers to the sagging shape assumed by both the antenna cables and the tower support cables. "Catenary" stems from the word "chain" since it is in the form...

Mac's Radio Service Shop: Carbon-Tet Can Kill

Carbon tetrachloride (CCl₄) was a common cleaning agent used commercially through about the early 1950s when it began receiving a lot of bad press due to a linkage to severe kidney damage from exposure even in vapor form. I notice that Mac mentions having read an article about the potential danger of "carbon-tet" in an edition of Radio & Television News magazine, not coincidentally the publication where the "Mac's Radio Service Shop" series appears. He also mentions a publication called International Projectionist, which included instructions for cleaning movie film with carbon tetrachloride, and had...

Transmission Line Systems for FM & Television Home Receivers

It is amazing to me how many times I read an article, whether in a vintage magazine like this 1947 issue of Radio News, or a current edition of QST, how when discussing maximum power transfer from a source to a load, the author states merely that the load impedance must equal the source impedance. The fact of the matter is that the source and load impedances must be the complex conjugates of each other in order for maximum power transfer to occur. That is to say that if the source has a complex impedance of R + jX, then the load must have a complex impedance of R - jX (and vice versa)...

War Assets Administration Advertisement

Unlike today when resources of all types seem to be endlessly available, during World War II countries needed to collect and recycle much in the way of metal, rubber, cloth, and other basic materials for re-purposing into products used in fighting the enemy. Media coverage of bottle, metal, and tire drives showed children pulling Radio Flyer wagons loaded to overflowing with such items gathered from trash piles and soliciting neighborhood residents for anything that could be spared. Raw materials were not the only type of items needed, however. "Use it up, Wear it out, Make it do, or Do without" was the slogan. Finished goods like electronic components - vacuum tubes, transmissions cable, transmitters and receivers, tuning capacitors, d'Arsonval meter movements, and other parts - were sorely needed by manufacturers both for building new equipment and for servicing damaged gear. After the war was won, the War Assets Administration...

Thursday the 23rd

The Great QSL Quarrel

Around the time when this "The Great QSL Quarrel" appeared in a 1960 issue of Electronics Illustrated magazine, there was a long-standing friction between amateur radio operators and shortwave listeners regarding the exchange of QSL confirmation cards. Far from mere paper, many hams view their custom-designed cards as valuable reflections of their personal rigs and efforts. Consequently, they often discard subpar listener cards that are illegible, aesthetically dull, or lacking meaningful data. To ensure their reports are actually welcomed, shortwave listeners are urged to adopt higher standards: utilizing professional printing or clear handwriting...

"Frequency" vs. "Amplitude" Modulation

A momentous development that changed the field of radio communications warranted merely a half-page announcement in 1935 when frequency modulation inventor Edwin Armstrong had his article published in Radio-Craft magazine. It indisputably changed the world while causing poor Mr. Armstrong much grief while defending his right to the invention. Spread spectrum modulation / demodulation would be the next big communications advance that began with the frequency hopping (FHSS) scheme dreamed up by Hollywood actress Hedy Lamarr and pianist Antheil George during World War II. Direct sequence spread spectrum (DSSS) followed in the digital age, and since then I do not know of any fundamentally new communications technology in that time...

Flying Probe PCB Testing

Since 2005, San Francisco Circuits has been a trusted U.S. provider of advanced PCB manufacturing and assembly solutions for R&D innovators, prime contractors, and integration experts. Flying Probe Testing (FPT) has long been a reliable method for validating PCB designs, particularly for prototypes and low volume production. Unlike traditional in circuit testing (ICT), which relies on custom built fixtures, flying probe systems use movable probes to test electrical connections directly, eliminating the need for dedicated hardware. Flying probe testing uses multiple programmable probes to contact pads...

Electronics-Themed Comics

The February 1947 issue of Radio News only had two electronics-themed comics. Many months have up to half a dozen comics. Maybe the winter blues had set in with the magazine's illustrators. The first comic is a tad bit prescient in that it depicts a robber running past a television store and seeing a TV in the front display window showing a real-time video of the cop chasing him. That was way before there was a video surveillance camera on every street corner. I haven't discovered a vintage magazine yet with someone taking a "selfie." There is a growing list...

Schematics and Parts Lists for Vintage Vacuum Tube Radio Models

These are the schematics and parts list for vintage Emerson vacuum tube radio models 501, 502, and 504; Crosley model 56TD-W; and Arvin model 140P as they appeared in the November 1947 issue of Radio News magazine. I scan and post these for the benefit of hobbyists and historians seeking such information. As time goes by, there is less and less likelihood that records of these relics from yesteryear's archives will be made available. As with all historical information, it takes someone with a personal interest in preserving the memories in order to fulfill the mission...

Wednesday the 22nd

Test Equipment Teaser Crossword Puzzle

John Comstock created many crossword puzzles for Radio & TV News magazine, and a couple others, in the 1950s and 1960s. This one titled "Test Equipment Teaser," appeared in the March 1959 issue. It is not a densely populated grid with complex intersections of crossing words (unlike the RF Cafe crossword puzzles, which do have them), but at least with this kind, all of the words and clues are directly related to electronics and technology (like RF Cafe crosswords). Anyway, it shouldn't take you too long to zip through this one. The only clue/word that might give you trouble is 32 Across. Enjoy...

Exodus Mission-Ready SSPAs for UAV Counter-UAS Systems

Exodus Advanced Communications' representatives, in discussions during last month's EMV (Elektromagnetische Verträglichkeit) show in Cologne, had many attendees express interest in receiving an Exodus brochure covering our RF amplifier solutions for drone (UAS) applications. Exodus supports defense contractors with a family of RF amplifier modules optimized for UAV, drone, mobile, and fixed Counter-UAS platforms. At the center of this portfolio is the AMP10008, an ultra-lightweight solid-state RF amplifier module that demonstrates what is possible when SWaP is treated as a primary design driver rather than a compromise...

Resistor Trial by Test

The cover of this month's Radio & Television News magazine is part of the issue's story on performance testing of resistors. The author was an engineer for International Resistance Company (IRC), which is still in business as part of TT Electronics. The massive ovens were used for load-life testing to certify resistor products for both military and commercial uses. When required, humidity enclosures subjected resistors to increased levels to test for insulation breakdown at high voltage. As the article observes, since a 10-cent resistor can take down a multi-thousand system, it is important to guarantee every component's integrity...

Please Thank Werbel Microwave for Continued Support!

Werbel Microwave is a manufacturer of RF directional and bidirectional couplers (6 dB to 50 dB) and RF power dividers / combiners (2- to 16-way) with select models operating up to 26.5 GHz and 100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are designed and manufactured in our Whippany, NJ, location. Custom products and private label service available. Please take a couple minutes to visit their website and see how Werbel Microwave can help you today.

Tuesday the 21st

Espresso Engineering Workbook - Free!

RF Cafe's spreadsheet-based engineering and science calculator, Espresso Engineering Workbook™, is a collection of electrical engineering and physics calculators for commonly needed design and problem solving work. The filter calculators do not just amplitude, but also phase and group delay (hard to get outside of a big $$$ simulator). It is an excellent tool for engineers, technicians, hobbyists, and students. Equally excellent is that Espresso Engineering Workbook™ is provided at no cost, compliments of my generous sponsors. 49 worksheets to date...

U.S.A. Calling - Your Meters Go to War!

Although the Japanese attack on Pearl Harbor on December 7, 1941, was a complete surprise and shock to the nation, that fact that the United States would eventually be drawn officially into World War II was well known. The amateur radio community had begun talking about the potential impact on radio communications hobbyists earlier in the year, as evidenced by articles printed in QST and other magazines. Within a couple weeks of Congress declaring war, all unauthorized transmissions from Ham stations were terminated in order to prevent both intentionally and unintentionally conveyance of information that could proves useful by the enemy. Along with being a patriotic bunch that were eager to help defeat Axis powers, they also...

Electronics-Themed Comics

Here, for your work-week enjoyment, are a half dozen electronics-themed comics that appeared in the January 1950 edition of Radio & Television News magazine. When is the last time you saw a comic in a technical magazine? I particularly like the one with the "green worm" displaying on the television. There is a list of other comics at the bottom of the page...

New 8-Prong "Glass-Metal" Tube

If this Radio-Craft magazine article is accurate, it was sometime around 1935 that the 8-pin glass-encased vacuum tube base came into existence. The glass-metal designation refers to these being glass enclosed equivalents to otherwise metal encased vacuum tubes. Evidently, the relatively new (and expensive) line of metal tubes sported 8-pin bases so these glass tube designs had to conform in order to be suitable substitutes...

Monday the 20th

Don't Fry That Ham!

If some of the images in this issue of Electronics Illustrated magazine were made within the last couple years, I would swear they were AI-generated. Surely, there are not really people as stupid as those shown here... but, alas, there apparently are. These photos were published in 1960. The ARRL has always published recommended safety practices - particularly regarding high voltages from overhead power lines and lightning strikes. How anyone, like the guy in the first photo, could ever even considering standing on a ladder and sticking his arm between even the 240-volt house supply line from the utility pole - without even a current-limiting device like a fuse or circuit breaker inline - is beyond comprehension. Clearly, the antenna already installed...

Mac's Radio Service Shop: The Worm Turns - and Squirms

This episode of "Mac's Radio Service Shop" goes down a drastically different path than most, at least until the very end where a completely unrelated anecdote about interference with a remote garage door opener is told by Mac. Although the exact issues chanted by electronics technician cum repairman Barney Gallagher regarding many manufacturers' penchant for designing and selling unserviceable equipment is dated, the principle remains the same. We have all wished a designer had to service the product he/she has designed and sold to us...

Scientists Can't Seem to Stop Going Missing Under Mysterious Circumstances

"Ten U.S. researchers and scientists have reportedly died or disappeared over the past 33 months amid increasing speculation about the cause of some of the disappearances, according to news coverage. Steven Garcia, a 48-year-old government contractor who allegedly had top-level clearance at a key nuclear facility disappeared in August 2025 after reportedly leaving behind his phone, wallet and keys, taking a gun and leaving his home in New Mexico on foot, NewsNation reported Thursday. Moreover, retired Air Force Maj. Gen. William Neil McCasland similarly went missing on Feb. 27 after leaving his home in Albuquerque on foot, the outlet reported. Eight other well-known scientists and researchers..."

Radio & Radar Crossword Puzzle

For the sake of avid cruciverbalists amongst us, each week I create a new crossword puzzle. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger, and have only words and clues related to RF, microwave, and mm-wave engineering, optics, mathematics, chemistry, physics, and other technical subjects. As always, this crossword contains no names of politicians, mountain ranges, exotic foods or plants, movie stars, or anything of the sort unless it/he/she is related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia). The technically inclined cruciverbalists amongst us will appreciate the effort. Enjoy!

Bendix Models 636A, C, D Schematic & Parts List

Here is Bendix Models 636A, C, D schematic and parts list as featured in a 1947 edition of Radio News magazine. No operational or alignment information was provided. The 636A is a tabletop radio using five vacuum tubes in the detector and amplifier stages, and a single vacuum tube rectifier in the power supply. Its shiny Bakelite cabinet sported an Art Deco style, which was popular back in the day. The images to the left are from a recent eBay listing, for $60, where the seller says it is in working condition. As mentioned many times in the past, I post these online for the benefit of hobbyists looking for information to assist in repairing or restoring vintage communication equipment...

Please Thank to Johanson Dielectrics for Support

Johanson Dielectrics has been a worldwide producer of high quality ceramic chip capacitors for over 60 years. We design and manufacture capacitors in a state-of-the-art facility in Camarillo, CA. Standard and high voltage SMT ceramic chip capacitors, as well as a variety of standard and custom high voltage & high capacitance value ceramic capacitors.

Friday the 17th

IGY - An 18 Month Report

The 1958-59 International Geophysical Year was an unprecedented eighteen-month global scientific initiative involving 30,000 participants from 66 nations who invested up to 1.5 billion dollars to study Earth's interior, oceans, and atmosphere. Utilizing military rockets and emerging satellite technology, researchers achieved major breakthroughs, most notably Dr. James Van Allen's discovery of the radiation belts surrounding Earth and enhanced understanding of ionospheric radio propagation, solar flares, and geomagnetism. While the project aimed to improve communications...

Erie Resistor Corporation Advertisement

When I first saw an Erie Resistor Corporation advertisement in the December 1958 issue of Popular Electronics, I decided to research its history here in Erie, Pennsylvania, where I live. Click on that hyperlink if you are interested in what I discovered. This advertisement appeared in the January 1952 issue of Radio & Television News magazine, so I figured I'd post it as well...

Windfreak 5 MHz-8 GHz, 15-Band RF Filter

Windfreak Technologies is proud to announces the availability of our FT108, an innovative programmable bidirectional filter bank spanning a frequency range of 5 MHz to 8 GHz in 15 bands. Band selection can be controlled through USB, UART or at high speeds through powerful triggering modes. Each unit is factory tested via network analyzer with unique data stored in the device to help with its use. Crossover frequencies are stored so the user can send a frequency command and the FT108 will utilizes Intelligent Band Selection logic to automatically toggle the optimal filter path based on minimum insertion loss. Readback of FT108 insertion loss at any frequency between crossover points allows for easy amplitude leveling...

Radar on the Great Lakes

An article title with both "radar" and "Great Lakes" in the title is sure to catch my attention, as did this. Author Norman Schorr reports on the state of the art of radar equipment and usage for the purpose of maritime navigation. Research and development, along with an ample surplus of components left over from World War II facilitated a rapid adaptation of radar to many venues. Included among its applications were airway and waterway navigation, rocket trajectory tracking, security systems, speed measurement, weather observation, and aerial mapping...

Many Thanks to Johanson Technology for Support!

Johanson Technology (originally part of Johanson Dielectrics), located in Camarillo, CA, has for over 25 years designed and manufactured high quality RF & microwave ceramic chip capacitors, inductors and integrated passives. These includes chip-format antennas, capacitors, lowpass, highpass, and bandpass filters, couplers, inductors, baluns, power dividers, substrates, chipsets.

Thursday the 16th

Infrared - A New Field of Electronics and Optics

Details the evolution of infrared technology, tracing its origins from William Herschel's 1800 discovery to its deployment in military and industrial sectors, are presented in this 1959 Radio & TV News magazine article. It emphasizes the shift from active, illuminating systems to passive, sensitive detectors capable of identifying thermal signatures in total darkness. The piece highlights infrared's superior resolution compared to radar, noting its utility in applications ranging from missile guidance and ballistic tracking to industrial quality control and chemical analysis. Since the publication of this article, infrared technology has achieved remarkable sophistication, evolving from bulky lab instruments into the invisible, ubiquitous...

Coupling to 300-Ω Flat Lines

An ample supply of surplus coaxial cable after the end of World War II provided an inexpensive and easy to use form of transmission line. Not having to worry about cable routing and unintentional radiation makes transitions through walls, running along metal surfaces, and routing high power transmission lines near habitable areas a no-brainer. Issues like power handling, bend radius, and higher attenuation need more attention during the installation design phase, but that pales in comparison to coaxial cable's advantages. Author Byron Goodman addresses some of the issues Hams accustomed to using flat transmission lines...

A New Pocket Radio

Not surprisingly, there is a website dedicated to only the Regency TR-1 transistor radio and its history from development through retail sales. As reported in this January 1955 issue of Radio and Television News, The TR-1 was the world's first commercially available, fully transistorized portable radio. A complete schematic and functional description is provided. It used four germanium transistors and operated on a 22-1/2 volt battery, which provided about twenty hours of listening pleasure. The unit weighed eleven ounces and cost $49.95...

Marconi - Father of Radio?

This is a must-read article for all persons interested in the history of wireless communications. Seriously. Stop what you are doing and read it. I guarantee the vast majority have never heard of this challenge to the veracity of Mr. Guglielmo Marconi's bestowed title of "father of wireless telegraphy." Most of us are at least passingly familiar with challenges to Samuel Morse's, Thomas Edison's, and a few other notables' claims to being the first at a particular technical breakthrough, but herein, as penned by of Lieutenant-Commander Edward H. Loftin, is a first-hand account of multiple successful challenges by the U.S. Patent Office against...

Please Thank ConductRF for Their Long-Time Support

ConductRF is continually innovating and developing new and improved solutions for RF Interconnect needs. See the latest TESTeCON RF Test Cables for labs. ConductRF makes production and test coax cable assemblies for amplitude and phased matched VNA applications as well as standard & precision RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the iBwave component library. They also provide custom coax solutions for applications where some standard just won't do. A partnership with Newark assures fast, reliable access. Please visit ConductRF today to see how they can help your project! 

These archive pages are provided in order to make it easier for you to find items that you remember seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is to use the "Search RF Cafe" box at the top of every page. Some quoted items have been shortened to save space. About RF Cafe.

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