Tag Archives: Bob Colegrove

Bob’s Radio Corner: Focusing on Hardware

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Figure contributed by Copilot

By Bob Colegrove

I have a friend who has collected antique cars for many years. So far, his collection is no immediate challenge to that of Jay Leno. However, it is his collection, and he is very proud of it. The cars festoon the inside of a large barn on his rural property. You will rarely see one of his vehicles out on the interstate. He has gone beyond the primary function of using these cars to get from Point A to Point B. Instead, he has chosen to focus on the means of transport – the cars themselves – the hardware.

By way of that analogy my point is that whatever your interest, the primary objective of the endeavor may become incidental, and the focus transforms to hardware. Take radio for example. I have spoken a couple of times about the many facets of radio. The primary interest is simply listening to program content, with perhaps a concentration in DXing. Others among us have gone beyond this function and attend seriously to the container the sound comes from – the radio – the hardware. This interest might be subdivided into collecting, restoring or modifying radios.

As proof, I have observed that the most interest in this blog is generated by radio reviews. There is a noticeable increase in the pulse rate whenever a new model comes to market. We seem easily infected with curiosity, and comments soon append the original posting. What are the possibilities? Does it have SSB? What are the bandwidths, etc.? Appearance is important; features are important; ergonomics is important. How well does it perform?

What Attracts Us to Hardware

Appearances

Our reaction is sometimes irrational. Techno-appeal might very well be the first grabber. Certain radios are captivating, irresistible. Examples are the Transoceanic, the old German manufacturers like Grundig, Blaupunkt, Telefunken, and then that RCA dial that shows up here on SWLing Post occasionally. You get the idea. In each of these examples, the beauty of the beast draws us into a closer look. There is a feeling that this radio will carry us off on an exciting adventure.

An attractive setup conjured by Copilot

Appearance gets serious attention from the manufacturers. Raymond Lowey, a noted industrial designer of the last century, was hired by Hallicrafters to bring some of its products out of the pre-WWII functional motif into a more appealing modern appearance. Examples included the SX-42 (1946), S-40A (1947), and S-38/S-38A (1946–47). These models helped shift Hallicrafters from purely technical ham gear to stylish consumer electronics, blending streamlined industrial design with functional engineering.

Raymond Lowey

Features

Of course, features are an important checkbox. We all have our lists. Although there is an ordered list of popular items, features come down to personal preferences. You know what you want. Sometimes it is a compromise based on what is available. Sometimes it is a compromise based on economics.

Ergonomics

The relative ease of operation generally occupies a portion of receiver reviews – the ergonomics. In general, entry and recall of memory locations has become a feature of diminishing returns (see https://swling.com/blog/2023/11/if-memory-serves-me-right/).

  • Excessive direct entry key presses can be annoying.
  • Locating controls along the sides.
  • Poor display arrangements.
  • Overly complex clock/alarm setup.

I could go on and present some examples, but you get the idea.

Control Curiosity

We have an insatiable curiosity about how things work. Despite the foregoing pitfalls of ergonomics, many of us are fascinated with the operational intricacies of radios – pressing buttons, twirling knobs, throwing switches. I am easily entertained. To amuse myself, I once did a full-page cause-effect flowchart of button presses for the Tecsun PL-660. It was interesting and kept me out of mischief for a while.

Performance

Performance is a gray area – sensitivity, selectivity, tone quality, etc. Lacking laboratory test results or side-by-side comparisons, the review of a new radio may fall short. Additionally, accepting the manufacturer’s specifications can be misleading or confusing. Ideally, variables must be isolated and controlled. We should not rush to judgment. Still, the typical consumer can render an honest appraisal if it is properly qualified.

Accessories

The radio stands as the centerpiece. For today’s all-in-one portables, an external antenna and a pair of earphones may be the only other hardware needed. In earlier times, the radio was likely a fixed unit requiring AC power. Many models were not as capable as even a moderately priced portable today. As a result, accessories such as external speakers, q-multipliers, and crystal calibrators complemented the capabilities of the radio. Knowledgeable operators who knew how to fix things might have servicing gear like signal generators, vacuum-tube voltmeters, and oscilloscopes positioned on nearby shelves. All this hardware was a source of pride and gave one the assurance that the listening experience was the best possible.

Thinking inside the Box

Beware of SWLs with soldering irons. There is a quantum leap in going from a listener to a certified tinker. It’s not for everybody. It’s the result of long mystic contemplation and self-surrender to obtain unity with the radio – Zen and the art of radio maintenance. Ultimately, you gather the tools. You open the case. You’re on the way to either Valhalla or complete annihilation. As you open the cover, you are transported down a long, dark cavern and suddenly arrive at an alien Tron-like world of strangely shaped parts.

An inside view by Copilot

Some folks are prepared for the adventure. They have read a book, taken a course, or earned their ham ticket. Others, like me, have thrown caution to the wind with no assurance of success, just a curiosity impervious to reason and a glimmer of hope that we can touch something and make it better. For us, it’s an embarkation on a long encounter with trial and error. Only by persistence and occasional reference to the previously neglected training materials will we finally earn our stripes.

Before I took up the soldering iron, I tackled alignment. I have heard beginners mistakenly thinking that every one of those slotted screws needed to be completely torqued down. Somehow, I had been cautioned that each one had a sweet spot at which the receiver displayed optimum performance. Each one of these adjustments operated in series with all the others, and near total synchronization was necessary to produce even a whisper of signal. It is a sort of electronic Rubik’s Cube; there are many combinations but only one solution.

To be sure, I made my share of mistakes. Initially I did all this by ear without the benefit of an RF generator, voltmeter, or even an insulated tool. I do remember one occasion getting an intermediate frequency adjusted up into the broadcast band. What a squeal that made. Over a period of a few years, I made progress and gradually came to tackle the dual-conversion Hammarlund SP-600 with great aplomb.

Source: Better Shortwave Reception, William I. Orr, W6SAI,
Radio Publications, Inc., Wilton, CT, 1957.

The purported goal in all of this is to squeeze every microvolt of signal out of the ether and hear more stations. In truth, that is only a cover so we can play with the hardware.

Today’s radios don’t have nearly as many adjustments. Through digital processing and phase-locked loops, most of the resonant circuits of old radios have been eliminated. It might be an improvement in performance and reliability, but it’s not the same.

Even the tinker’s quintessential soldering iron has mostly gone cold. The large-scale integration and surface-mounted, robotically-installed components have rendered radio repair and modification intimidating if not impossible. Only a few isolated Merlins of wizardry can deal with this.

For that reason, tinkers have largely retreated to experimentation with antennas. It does not require post-doctoral work in electronic engineering to produce tangible results. While there is a valid wealth of professional theory and practice which has gone into antenna design, the rest of us can still amuse ourselves by hanging wire, winding coils, and empirically evaluating the results.

Collecting

It only takes one radio to get things started. Where it goes from there depends on your interest. About 10 years ago I bought a Hallicrafters S-38E in virtually unused condition. The Hallicrafters lettering was printed on each of the original tubes. There wasn’t a mark on it. Obviously, someone bought this radio new, circa 1959, decided they weren’t interested in shortwave radio, and stored it in an environmentally ideal closet for more than half a century. (No, I have not felt the slightest need to recap it.)

I also bought my first S-38E in 1959. Unlike the first owner of my current S-38E, I have had a persistent affair with radios over the years. It started with just one radio, but I didn’t start collecting them for many years. Instead, I traded up, first an S-40B, then an SX-43, and ultimately the Hammarlund SP-600. It was at that point I was well into tinkering and wound up with three -600s plus one hulk for parts. The Sony ICF-2010 came along in the ‘80s, and I have just kept collecting from time to time with no thought to downsizing.

Let’s look at the economics of the thing. The S-38E cost $55 in 1959. Adjusted for inflation, this would be roughly $600 today. How many folks would be induced to spend that kind of money today to try out shortwave radio? If you bought a $600 radio today, it would be far superior in quality and features to the humble S-38E. Even an entry-level $55 radio today is better. We just can’t make comparisons other than to say radio has become a cheap hobby, unless, of course, you are a collector.

Hardware Groups

There are at least two healthy user groups in groups.io which deal with radio hardware: https://groups.io/g/HallicraftersRadios/topics and https://groups.io/g/SonyICF20102001Dusergroup/topics. There are others, but I am most familiar with these.

For these folks, listening and reporting station reception is incidental to the acquisition, care, and feeding of the radio – the hardware. What are you hearing on the radio? More specifically, are you hearing anything you hadn’t heard before? These questions often go unasked in these groups.

It amazes me that both groups remain very active long after the hardware production ended. Hallicrafters ceased operation in 1980. The Sony ICF-2010 and 2001D radios were manufactured from 1984/1985 to 2002/2003, depending on your reference. Yet each interest group has a core membership steeped in the history and technology of these radios and is quick to address the inquiries of others.

The Hallicrafters Group

The Hallicrafters Group focuses on both receivers and transmitters from the 1930s through the 1960s – the vacuum tube or “hollow state” era. For most purposes, a soldering tool is essential, schematics are necessary documentation, and diagnostics is a required skill.

It was a hands-on era; repair was down to the component level. Today, parts are becoming an issue. While tubes, capacitors, and resistors are still reasonably common, unique items such as transformers, variable capacitors, and various mechanical items (knobs and dials in particular) are more of a problem. This has resulted in cannibalization or “parting out” units in more extreme states of deterioration for their valued parts. This isn’t always a helpful solution, as a defective part may be a common occurrence among other units. A few enterprising vendors have taken up the challenge and come up with innovative solutions, including the use of 3-D printing to replicate parts such as knobs. Bottom line: Restoration of antique hardware appears to be a primary focus of this group.

The Sony ICF-2010/2001D Group

The Sony ICF-2010/2001D Group represents another generation of radios, which were produced in the closing decades of the 20th century. Even more amazing, their interest focuses essentially on a single model receiver. There were at least 6 different versions tailored to local regulations. The -2010 was the North American version.

The complexity of these radios was orders of magnitude greater than those of the vacuum tube era. Being solid-state, they were relatively compact and reasonably portable. They achieved the pinnacle of excellence in portable shortwave reception. Among aficionados, they are still regarded as such today.

Memory capacity of a digital radio can quickly become a point of diminishing returns. While not the first portable to have digital memory, these radios sported an 8 x 4 matrix of memory buttons. Recall is instantaneous, not only frequency but other tuning parameters.

Today’s group remains quite active. Due to the complexity of these radios, troubleshooting and repair are much less common compared with the Hallicrafters Group. However, from time to time capable repair sources have shown up to provide this service as well as several useful modifications. The ICF-2010 and -2001D occupy a unique spot in the hardware collection arena, commanding high prices on the used market. They are regarded as truly classic radios worthy of preservation. They also remain high-performance shortwave receivers today.

Conclusion

Cars and radios are similar. They do not necessarily have to be driven or tuned to be enjoyed. The proof is in the barns and shacks of true hardware lovers. On the other hand, you may have just one radio, but it’s still a special piece of hardware and a captive testimony of your love of technology.

Good DXing.

Bob’s Radio Corner: Where it Began – The AM Medium Wave Broadcast Band

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Copilot Radio, Model Unknown
The dial certainly has some problems, but the rich, Bakelite, art deco cabinet is superb.

By Bob Colegrove

One of the great attractions of the radio hobby is that it has so many different areas on which to specialize.  As examples, one can focus on a particular band, collect or restore radios, DX or just listen.  With so much to choose from, one can impulsively skip from one area to another.  I have tuned the shortwave bands for many years, but I also like the AM medium wave band.  If there is a purpose to this post, it is simply to bring some occasional attention to AM listening and DXing.  There is nothing new in what follows.

What’s in a Name?

To start with, this subject is somewhat confusing by calling it what we do.  There are at least three common terms for the electromagnetic spectrum between 530 kHz and 1700 kHz: 1) AM, 2) broadcast band, and 3) medium wave.  This poses an identity dilemma; that is, none of these names are exclusive.  AM defines a form of modulation, amplitude modulation, which is used in other portions of the spectrum.  The same may be said of broadcast band.  There are several international broadcast bands within the shortwave spectrum.  That leaves us with medium wave.  But that term lacks precision.  What exactly are the boundaries of medium wave?  Shortwave bands have relatively precise names related to their wavelength, 80 meters, 31 meters, etc.  Should we call medium wave the 176-thru-943-meter band, instead?  Let’s just stick with any of the old familiar terms.

In the Beginning

I’m sure many readers share the experience related here.  Even before shortwave there was medium wave.  Our initial encounter may have been with the monolithic, multi-band console radio in the parlor.  However, the house was likely home to one or more less pretentious table radios, which were limited to the medium wave broadcast band.  It all began with curiosity about what lurked in the relative space between the few local stations that played so clearly along the dial.  We likely found less listenable stations poking through in the inter-station space.  These were stations like our own in neighboring communities.  Then, at night, a strange thing happened.  Like stars in the sky, more stations appeared, some hundreds of miles away.  At the same time, some of the stations we heard during the day disappeared, maybe even a local station or two.

Well, one thing led to another, and soon we were keeping track of stations that we heard.  We took note of where they were located and their position on the dial using a new term called kilocycles.  The fastidious among us kept daily logs with dates, times, and reception conditions.  So, our DXing career began.

I came along a full generation after the advent of AM radio broadcasting.  In my early years, it was still the mainstay of public information and entertainment.  Television stations were beginning to pop up across the country one by one, and FM radio’s popularity was still a decade away.  Like any imposing distraction, there was curiosity in what was being heard and, in the case of radio, where it was coming from.

Our house was home to perhaps three or four AM radios.  At the age of seven, I was gifted of a 4-tube Sears Silvertone – mine to keep in my own room.  But the radio that really got me going came along several years later and belonged to my father.  This was a General Electric Model P755A, five-transistor portable.  Shaped somewhat like a lunchbox, including the handle, it was the quintessential portable radio that the world had been waiting for.  It ran for many hours off a single, but pricey 9-volt carbon-zinc battery.  There was purposely no provision to run it from AC power.  Also, it used an internal ferrite core antenna.  There was no jack or terminal for an external antenna.  Besides the tuning knob and volume control, it had a jack for a single earplug.  It was truly portable in all respects.  For all its simplicity, it did its job very well, and I borrowed it whenever the occasion presented itself.

Left: Silvertone Model 132.818-1, Sears, Roebuck & Co (1949, $11.95)
Right: General Electric Model P755A Transistor Portable (1957, $19.95)

As an only child, I was the sole recipient of any goodies that came along, and it wasn’t too long before I had my own comparable Westinghouse portable.  But the GE was really the one that got things started.

A Plethora of Stations

I have recently wondered whether shortwave use has contracted about as far as it can go.  This is not the case with AM, at least not yet.  The graph below shows the total number of AM radio stations in the US throughout history, 100 years.  The total has remained relatively stable since 1960, albeit with a slight downward trend from the peak around 1990.  Stations occasionally come and go.  Some rebrand with a different format or fresh call letters.  Note that the steepest rate of decline, 217 stations, occurred over the past five years, amounting to 4.7%.  Whether this rate of attrition will continue is a matter of speculation.

Medium wave DXing is a lot different than shortwave.  The density of stations will vary depending on what part of the world you live in.  Here on the East Coast of North America, the AM band is saturated with signals.  That is, with a suitable antenna, one can at least detect a station on each of the 118 available channels – certainly at night and possibly even during the day.  On the other hand, some years ago, I had an opportunity to visit Honolulu, Hawaii.  With little time to listen, I only heard a few of the islands’ stations but imagined what possibilities nighttime Dxing held.

Despite the density of stations on the East Coast, there will still be limits on the number of stations logged.  My experience is that initially the log grows quickly, then tapers off steadily as you go along.  Your time is eventually spent locked in on a local or regional frequency, waiting for something you’ve heard to fade out and something you haven’t heard to fade in.  In a previous posting, I worked the lower end of the band rigorously for some time, coming up with a fair number of catches.

Ten-kHz channel separation is the convention in Region 2, the Americas.  There have been some occasional anomalies.  Several years ago, there was a handful of so-called “split-channel” nonconformists, who placed their carriers midway between channels and presented an opportunity to log some hard-to-hear countries.  It was also possible to pull in a few very high-power European and North African stations.  This took advantage of the 9 kHz vs. 10 kHz channel spacings between Region 1 (east) and Region 2 (west).

Seasonal changes are also important.  Winter is the best.  Propagation is generally better and more consistent.  Atmospheric noise is minimal.  Local stations limited to daylight operation have shorter hours.  The gray hours around sunup and sundown can produce unusual DX conditions.

Programming

Programming has changed since the 1950s.  As the go-to medium for public information and entertainment, content was original and competitive.  Mornings were often filled with local DJs playing occasional songs and generally keeping listeners apprised of news and weather.  Traffic helicopters were still in the future.  The genre of soap operas was born and consisted of 15-minute, serialized dramas one after the other during the middle of the day.  Faithful audiences followed these melodramas for many years.  DJs took over the airwaves again in mid-afternoon and continued through dinner time.  Prime time lasted throughout the evening hours with regular drama, comedy and variety shows which were networked throughout the country. Continue reading →

Bob’s Radio Corner: Industrial, Scientific, and Medical (ISM) Bands

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Industrial, Scientific, and Medical (ISM) Bands

Noted by Bob Colegrove

This is not the sort of thing you might consider typical DX.  One reporter traced a signal like the one I describe here to the innocuous utility box at the corner of his lot.  No, it is not noise.  It is an RF signal, essentially a shortwave station.

With the dearth of stations on the international shortwave bands, my attention often turns to the vast swaths of frequencies in between.  These are still commonly referred to as “utility” bands, and were once themselves filled with industrial, marine, aviation, and military signals using all manner of transmission modes.  Like the international shortwave bands, they are now mostly intergalactic space open to an occasional user.

Among these are the Industrial, Scientific, and Medical (ISM) Bands.  The ISM bands are defined by the ITU Radio Regulations.  Individual countries use the bands in different ways.   The table below shows the ISM bands within the shortwave spectrum.  Besides these, there are ISM bands extending up through the gigahertz range.

Frequency Band
Width
Low High Center
6.765 MHz 6.795 MHz 6.78 MHz 30 kHz
13.553 MHz 13.567 MHz 13.56 MHz 14 kHz
26.957 MHz 27.283 MHz 27.12 MHz 326 kHz

Unlicensed operations are typically permitted in these bands; therefore, communication devices using the ISM bands must tolerate interference from ISM equipment.  Examples of devices that may use ISM frequencies include common household appliances such as microwave ovens, cordless phones, Bluetooth devices, garage door openers, and wireless computer networks.

But more prevalent signals reaching the radio are identified as coming from locally positioned telecom company equipment such as those of Fios or Xfinity.  Several years ago, both providers in my area switched to fiber optic distribution, which does not radiate RF.  Thus, the source of my signals remains a mystery.

My attention was drawn recently to a very strong continuous wave (CW) signal operating on 6780 kHz.  Further tuning turned up progressively weaker signals on 13560 kHz (2nd harmonic) and 27120 kHz (4th harmonic).  Note that these frequencies are squarely in the center of each ISM Band.  A signal was also heard on 20340 kHz (3rd harmonic), which was not in any ISM band.

Poking around the Internet, I found that others had similar experiences in recent years.  As expected, the signal I received did not provide any identification during my monitoring.  As stated, transmissions were continuous wave and pulsed at 1-second intervals much like a time signal.  At irregular intervals, there would be a skip beat followed by a longer beep.  After long intervals, the 1-second pulses would be replaced by a steady continuous wave lasting a couple of minutes, then return to the 1-second time-pip pattern.  The signal remains on throughout the day and night.

The signal was tuned as any other CW station by setting the radio to either USB or LSB and tuning slightly down or up from the carrier.  Note in the recording that there are not always the same number of time-pips in each set, and that the longer beep between sets can differ in length.  Perhaps this is some sort of data encoding.

Besides my own reception in Central Maryland, a weak “time signal” could be heard at the WEBSDR site in Central Pennsylvania (http://k3fef.com:8901).  There was a steady CW signal at 6780 kHz from the U. Twente WEBSDR site in the Netherlands, possibly indicating another type of ISM application.

What’s in your ISM Band?  You may or may not hear a similar signal at your location.  Let us know.

Bob’s Radio Corner: It’s DX Season

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Noted by Bob Colegrove

In the Northern Hemisphere the nights continue to get longer as we approach the winter solstice; we gain an hour of early evening darkness on Sunday, November 2nd; the summer atmospheric disturbances are nearly gone; propagation is better.  It’s time to set aside the activities of summer and once more dive underneath the headsets.

DXing is not the same thing as listening.  For listening you position yourself in a nice recliner with the radio on a table beside you.  You set the radio to ATS and scan the available fare.  You select one of the more interesting results and, together with your favorite beverage, listen to the programming.  DXing, on the other hand, requires well planned work and lots of patience.  Critics might say it also requires some imagination; however, I have always tried to be honest with myself and ask if what I am hearing is truly QSLable.

Sir Oswald Davenport, intrepid DXer and Chairman,
National Association of Armchair Adventurers

Don’t get me wrong, I listen a lot, but I also DX.  Living on the East Coast of NA, I often direct my antenna toward Asia and the Pacific hoping to hear Japan and New Zealand.  However, more often than not, these have proven to be illusive.  DXing is like fishing.  Often, you pull up an old boot or find the bait is gone.  Further, the sound quality of a true DX signal will have no appeal to an audiophile.  It is intentionally weak and subject to fading.

So, you get your wins when you can.  Last February I scanned the 49-meter band stopping at 6130 kHz to identify some faint pop/rock music.  There were two possibilities, a Chinese station and Radio Europe.  If you have never heard of Radio Europe, it is in Alphen aan den Rijn, The Netherlands, and has a rather imposing name for a modest 1 kW station.  It is targeted to Western Europe, and is listed in HFCC, B25.  The station is identified periodically in English by a dramatic baritone male announcer.  The recording was made at 0211 UTC on February 6, 2025.  The announcement begins 9 seconds into the clip; Radio Europe is mentioned at 23 seconds.

The curious thing is Radio Europe is not necessarily well received at the U. of Twente SDR site just 100 miles away.  Science notwithstanding, there is simply no accounting for propagation.

Well, Radio Europe is back this season as strong as I have heard it, and if you’re a NA East Coaster, you might give it a try from 2300 UTC on.  I see it was reported in Florida in 2023.  Using exalted carrier single sideband (ECSS) (SSB in simpler terms) seems to produce the best results.  Despite low power and long distance, it’s occasional stations like Radio Europe that keep this DXer fishin’.  For a clear sample, it streams here http://p.liveonlineradio.net/?p=radio-europe.

Good DXing ’25-’26.

Dexter D. Xer

Bob’s Radio Corner: Shortwave Multiplex?

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Reported by Bob Colegrove

Incurable DXers are always looking for new challenges.  So it was, I recently did some scanning between 42 and 45 meters (~6600 to 7000 kHz).  Trenton Military on 6754 kHz and the MARS net on 6913 kHz are regulars here, as are a selection of pirates above 6900 kHz.  However, I have never experienced anything like this.  It took me a while to sort things out.  A pirate on 6930 kHz was quickly detected on the upper sideband, but there was some garble slightly lower.  It turned out to be a few folks having a QSO in Spanish on the lower sideband of 6930 kHz.

Two transmissions both squatting on the same frequency.  The irony was, sans carriers, there was absolutely no mutual interference.  Each signal was clearly received by alternately pressing the USB and LSB buttons.  Likely the QSO folks were somewhat out of band for 40 meters, and it goes without saying that the pirate shouldn’t have been there.  Nevertheless, I would call that efficient use of the spectrum.

Date:  October 11, 2025

Time:  0030 until 0100 UTC

Receiver:  Tecsun PL-880

Antenna:  Bob’s Updated Passive, Resonant, Transformer-Coupled Loop Antenna for Shortwave

Bob’s Radio Corner: Uncle Clayton and His National NC-188

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National NC-188

As recalled by Bob Colegrove

Uncle Clayton was my very first SWLing buddy.  In the late ‘50s there was no Internet – very few ways for SWLs to interact with one another.  There were clubs that published mimeograph bulletins every month or so.  These were mailed to SWLs across the country and around the world.  To come across a fellow SWL in your own town was rare.  As chance would have it, Uncle Clayton and I quite independently discovered our interest in SWLing about the same time, and then only after knowing one another for several years.

Uncle Clayton was not my real uncle.  He and his wife, Evelyn, were dear friends of my mother and father.  You see, there was a social decorum at that time which frowned upon members of the younger generation from referring to members of an older generation by their first name.  At the same time, “Mr. Smith” and “Mrs. Smith” (not their real surname) were regarded as unnecessarily formal; so, for this situation “Uncle Clayton” and “Aunt Evelyn” became the accepted form of address.

My story begins with television, not radio.  By mid-1950 both the Smiths and the Colegroves had acquired their first black and white TV “sets,” theirs a 12-inch RCA and ours a 12-inch Arvin.  Each of these occupied 8 to 12 cubic feet of space and required two well-fit individuals to move them.  Ironically, they were termed “portable” in that they required a low table or stand for proper positioning.  This contrasted with “console” models which incorporated the stand and the TV in a single cabinet.

One must understand that television at that time was what computers would become a generation later.  The nation was on the cusp of a TV frenzy.  My dad and Uncle Clayton jumped into it with both feet.  They couldn’t let the darn things alone.  Antennas were the most obvious source of tinkering.  “Rabbit ears” were the customary solution but adjusting them was a skill rivaling that of playing a cello.  Later, attic designs were fabricated for the new channel in Bloomington, Indiana.

Vaccum tubes, both necessarily and unnecessarily, became questionable components, and Uncle Clayton and my dad developed well-stocked arsenals of spares.  In retrospect the pair were, well…a couple of hacks, and I say that lovingly.  Picture two large, middle-aged men behind the RCA with the back cover off alternately trying to get a 9-pin peanut tube aligned and reinserted into its socket in the very front of the chassis – all this while trying to avoid the high-voltage discharge from the picture tube.  I still recall the looks of frustration and muffled puffs of blue air.  After some time, Aunt Evelyn appeared, looked over the dilemma, grabbed the tube, and jabbed it into the socket on the first try.

SWLing came along several years later.  I discovered it in the fall of 1958 while idly tinkering with the Howard Radio Co. Model 308 radio-phonograph console, which by that time had been relegated to the basement.  After moving it to my room and stringing up a long wire I was forever captivated.  The single SW band covered 5.5 MHz through 18 MHz across a dial a mere four inches long.  I milked that old radio relentlessly finally coming up with about 20 or 30 SW broadcast stations, all in English.

I have no recollection of how Uncle Clayton and I discovered we were going down the same path.  He had already purchased his National NC-188 with a matching speaker and set up his shack in an unused upstairs bedroom.  How I envied him.  His NC-188 was everything I envisioned in a SW radio. I was still earning my way towards purchasing a Hallicrafters S-38E.

National NTS-1 Speaker for the NC-188 and NC-109.
Better radios had separate external speakers, the claim being that there was insufficient space in such feature-packed units

Uncle Clayton’s NC-188 was my first encounter with a bandspread – a term which has virtually gone out of existence.  I immediately knew what it did, but it would take me a while to understand just how it worked.  On my old Howard console, the dial pointer travelling less than a 16th inch could cover 100 kHz or more, conceivably containing 10 or 20 stations.  Furthermore, this range was traversed by a nearly imperceptible rotation of a small knob.  Conversely, the NC-188 might cover the same tuning range over a space two inches long and require four full rotations of a 2-in diameter knob.  That was an incredible mechanical advantage.

For SWLs, there was a restriction on the use of the bandspread.  Most receivers had scales neatly calibrated for the 10-, 15-,20-, 40-, and 80-meter ham bands.  This provided reasonable frequency readout – not the precision we have with today’s digital radios, but close enough.  For international broadcast bands, the listener had to rely on a 0 to 100 linear logging scale which bore no relation to frequency.  This required the listener to generate several lists or graphs translating log readings to frequency.

The NC-188 and -109 had 4.5” bandspreads, not as long as some, but the 2” knob required 9 full rotations to traverse end-to-end.

Everything I have described so far depended on the position of the main tuning dial.  The bandspread operated electronically in parallel with the main tuning.  In short, the main tuning dial had to be positioned precisely at the high end of the tuned band for the bandspread to produce the same results.  Within these restrictions, a bandspread was still a marvelous device.

Uncle Clayton and I were still in our formative SWLing period when our family would visit him and Aunt Evelyn.  I remember him patiently tuning across portions of the SW spectrum oblivious of the international band boundaries slowly rotating the main tuning dial and stopping at points that interested him.  When my turn at the helm came, I would often seek out the General Overseas Service of the BBC and listen to the football scores or Victor Sylvester and his Ballroom Orchestra.

Victor Silvester conducting his Ballroom Orchestra in 1938. His orchestra was still a fixture on the BBC in the ‘50s and ‘60s. Source:  Victor Silvester and His Orchestra – You’re Dancing on My Heart

Neither Uncle Clayton nor I set the bar very high in terms of DXing prowess.  We had fun and made a lot of interesting discoveries.  Isn’t that what it’s all about?

Some years ago, I had the opportunity to buy a fairly clean National NC-109.  The -109 is an upscale version of the -188.  It has a crystal filter, an early SSB product detector and a voltage regulator.  Otherwise, the two radios are virtually identical.  I did all the usual things, cleaned it up, performed an alignment, and restrung the main tuning and bandspread dial cords.  Later I found a matching speaker.  When I was finished, I had what I regard as a museum-quality radio.  It occupies a prominent corner of the shack, but I don’t operate it that much.  Sometimes I just sit in front of it, spin the dials and remember Uncle Clayton and how it all started.

National NC-109

Bob’s Radio Corner: Illuminating Radios

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An operating 50C5 pentode is a thing of beauty.

The Book Lamp; or Shedding Some Light on a Radio

Illuminated by Bob Colegrove

There was a time in this writer’s memory when radios were well lit – well, at least the ones with glass tubes.  Tubes emitted a warm glow which made the radio come alive, generated some heat on a cold winter night, and created an aura of mystery revealing signals from faraway places.  Besides glass tubes, a #44 or #47 incandescent bulb was likely inserted just out of sight beside the dial.  This illuminated the dial information, which, however, required some mathematical interpretation.

Today’s radios are dark.  Inside them, circuit boards and ICs look like an unanimated scene from Tron.  Most often, the only illumination is from the LED or LCD display, and that is often weak, or lasts just a few seconds.  Unlike the old dials, displays do convey some useful information; but they have shortcomings which can be summarized into three general categories:

  1. Some displays are very dimly lit.
  2. Some displays don’t have continuous illumination.
  3. Some displays have continuous illumination, but their use consumes power.

I have radios in each of these categories.  A desk lamp, if available, can’t always be placed in the right position relative to the radio.

Having a natural bent to fabricate things, I began to conjure a solution.  This would require three components:

  1. An independent source of light,
  2. a bracket to hold the light in place, and
  3. a stand to counterweight the light and bracket.

I quickly began to see mechanical problems attendant to fabrication, plus the realization that construction would demand some effort on my part.  My project quickly transformed into a search for a product on the Internet which would satisfy the requirements without me expending any work.

I found a book lamp has the advantage of illuminating the entire radio keyboard, not just the display.

There is a wide selection of book lamps.  My search focused on LEDs with rechargeable lithium batteries.  That didn’t narrow things down very much.  There are a lot of them.  My choice without a whole lot of research was a Vekkia 3000-K Warm LED Rechargeable Book Light [SWLing Post affiliate link].  It has not disappointed.

  • It’s the right size for most portable radios, ~7-in long flexible gooseneck, 2.01-oz weight.  The clamp opens about 1.8 inches.  It folds up into a compact bundle and it would be no problem to pack for a trip.
  • There are six 3000-K LEDs having three brightness levels.  Some of the other models have multiple color temperature settings.  3000 K is relatively warm, easy on the eyes during long use.
  • The vendor claims up to 80 hours of operation at the lowest light level.  I have been operating mine at the middle level.  Full charge is claimed to take 1.5 hours.  A short USB-C cord is supplied.
  • The clamp and battery assembly are heavy enough to serve as a stand and can support the lamp without clamping.
  • The clamp will fit on the end of the radio kick stand.  This might be the preferred way to operate the radio if it is being handheld.
  • Most importantly, the lamp was operated separately near the radio and the antenna and did not produce any noise.  This would not be the case during charging with a USB wall wart.

The photo below shows how the problems listed above have been resolved with a book lamp.  The arrangement is complemented with a 7-inch Kindle Fire tablet displaying a current shortwave broadcast listing – a nice package at home or away.

Tecsun PL-990 with its switch-settable continuous light turned off

There is a certain charm operating the radio with only a book lamp for illumination – certainly not like vacuum tubes, but charm, nonetheless.  Improving the radio listening experience is an on-going process.