Tag Archives: Bob Colegrove

Bob’s Radio Corner: It’s DX Season

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?

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

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

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.

Bob’s Radio Corner: The Last Radio I Really Needed

My original PL-660 has high mileage but still
has its original kick stand and whip antenna.

The Last Radio I Really Needed

By Bob Colegrove

Like most folks, I have a favorite radio.  My favorite radio is the one I happen to be listening to at the time.  Each radio has its own attractions.  The fact that one particular radio is turned on indicates that, at least for the moment, it is my favorite.

I also have a special radio.  It is special because, ever since I bought it, there has never been a compelling reason to buy another radio.  That said, there is no accounting for irrational behavior which has subsequently caused me to buy several more radios, always with the hope that the next radio would somehow provide better performance than my special radio.

My longstanding experience has been with vacuum tube radios.  I have used multiband radio consoles.  I have used everything from a Hallicrafters S-38 to a Collins R-390A and most everything in between.  I tried a couple of analog, multiband, solid-state portables in the 1960s and ‘70s.  I bought a Sony ICF-2010 early on and still have two of them fully functional.  For many years, the -2010s were my go-to radios.

Then, I happened to read the review of the Tecsun PL-660 in the 2012 WRTH.  The price seemed reasonable, and I decided to buy one.  From the very beginning, I was not disappointed.  Selectable sidebands and synchronous detection – not a Sony, but very good.  Further, the -660 was notably smaller and packed quite easily.  I could include a pair of earphones, a length of wire and this radio, set up away from the shack, and operate.

So why is this radio special?  It is not perfect.  But for LW, MW, SW, and FM, there is nothing I can hear on any of my radios that I can’t hear on the Tecsun PL-660.  Reception seems to be especially sensitive and clear.

I must qualify the claim above.  Normally I use external antennas.  External antennas are the great equalizers.  Properly matched they make a radio perform at its best.  Radio reviews and comparisons will often include judgements about sensitivity.  Unfortunately, many reviewers do not specify the conditions under which they tested the radio.  The reader must assume that these judgements are based on the use of stock internal antennas — most often the LW and MW ferrite loop and the SW and FM whip.  For portable radios this makes sense, as internal antennas are paramount to the radio’s transportable versatility.

Not Perfect

I will spare everyone yet another review of a radio now in its adolescent years.  I merely focus on a couple of picks I have with the PL-660.  There are others which are well documented.

Birdies

Probably the worst fault with the -660 is birdies.  There are a few along the LW spectrum but the worst by far is one which generally appears between 950 kHz and 1000 kHz in the MW band.  I have read where this is traceable to the DC-DC converter but have never found a remedy.  This nasty signal is very rich in harmonics and will replicate through the entire SW spectrum.  Further, the fundamental birdie and its harmonics tend to slowly drift upward for about an hour after the radio is turned on.  The drift accelerates with multiples of harmonics.  For example, while the fundamental birdie is creeping up 1 kHz, the second harmonic will travel 2 kHz, the third 3 kHz, and so forth.  There are many harmonics where no harm is done; however, the 4th harmonic will blaze a trail squarely through the 80-meter ham band.  Wait a while and it will drift onward but ultimately stop at some equally inconvenient location.

Poor Encoder

The PL-660 tuning encoder, as with its cousins in the -600 and the -680, is … well, very poor.  From the get-go it will jump erratically forward or backward.  This becomes worse over time, particularly with any prolonged periods of disuse.  I have not determined whether this is dirt, poor contact, or just poor design.  I have found that vigorous exercise forward and backward with the tuning knob is the best temporary remedy.  This will generally bring the encoder back to tolerable performance.

Replacement encoders are available at modest cost.  I went this route as a last resort but managed to lay up my -660 for several months having failed to make the replacement work at all on the first attempt.  A few months later with renewed determination, followed by a series of deep cleansing breaths, I reopened the radio and discovered that my mistake was just a solder bridge between two of the encoder pins.  Note to self: For the future, this surgery should only be performed by people with good vision and steady hands.  After several months of storage there was unbounded joy when the 12-year-old -660 came alive and began to tune perfectly – well as perfectly as it could.

My Mods

One of the reasons why the Tecsun PL-660 is special to me is that it is a tangible link to my tinkering past.  In former times, much satisfaction was obtained by aligning RF and IF stages, restringing dial cords, and replacing leaky capacitors.  For most tinkers, the advent of large-scale, solid-state integration and surface-mounted components has made tinkering virtually impossible.  Detailed data are scarce, parts much more specialized, and soldering skills more demanding.

The PL-660 came along at a point where vacuum tube tinkering was still within recent memory and the skills for maintaining and modifying high-tech radios had not become so intimidating.  To summarize, with just a few exceptions, today’s radios are for all practical purposes unrepairable, unmodifiable, and therefore more readily disposable.  What a pity.  The term “parted out” has entered our vocabulary, whereby a defective radio is cannibalized to provide its serviceable vital organs to its remaining siblings.

Dynamic Squelch

Briefly, the Tecsun PL-660 dynamic squelch function automatically adjusts the signal threshold based on its strength.  Ostensibly, this helps prevent the radio from being overwhelmed by noise when no signal is present while still allowing strong signals to be heard.  The “dynamic” part of the term refers to the feature turning itself on or off as the situation demands.  The downside is twofold:  a) weak signals may be totally blocked with squelch engaged; and b) the feature may oscillate on an off as a signal fades and then gets stronger.  There are several demonstrations of this on YouTube.

In 2012, a Russian radiofile managed to identify the transistor that switched the feature on and off.  By the simple expedient of grounding one of its leads, it could be permanently turned off, eliminating its drawbacks.  An optional further modification provided for the tone control switch to be repurposed to manually enable or disable the basic modification.

The relatively simple concept turned out to be rather involved surgery requiring a large metal circuit shield to be unsoldered and removed to access the transistor.  The old Yahoo PL-660 Group was abuzz with interest at the time.  Many folks were doing the modification.  Had it not been discussed so widely, I would likely have ignored it.  But being a wild, impulsive 70-year-old at the time, I had to give it a go and fortunately was successful.

Disablement of the dynamic squelch required removal of a shield on PCB

External LW and MW antennas

I do not like to be limited by the lack of an external LW/MW antenna connection.  The PL-660 has no means to switch one on.  You can easily inductively couple an AN-100/200 or Terk Advantage loop and get good results, but I wanted more.  I took the classic approach of winding a 5-turn transfer coil around the ferrite bar.  Initially I simply connected this to a twisted pair which ran out the unused hole for the wrist strap.  The twisted pair was connected to a phone jack and dangled out of the radio like a pig tail.

Pigtail used the hole in the case vacated by the wrist strap.

Sometime after my mod, Geir Laastad, LA6LU, published a paper with a much more elegant solution.  He discovered that the PL-880 used a stereo external antenna jack, the center (ring) terminal was not used, and the cumbersome pigtail could be eliminated by connecting the added transfer coil between this center terminal on the jack and the radio ground.  This necessitated use of a stereo plug to mate with the jack for connection of a LW/MW external antenna, but the jack could otherwise be used normally for SW.  I found that Tecsun used the same stereo jack approach on the -600, -660, and -680, and was able to connect the transfer coil to each radio the same way.  Geir’s paper is at https://groups.io/g/Tecsun-PL-880/files/_Tecsun_PL-880_LW_&_MW_Antenna_Mod.pdf, but you may have to request membership in the group to download it.

Enlarged fine tuning knob

One of the weak features of the -600, -660 and -680 is the fine-tuning pot.  Zero-beating a signal is a bit touchy.  The problem is exacerbated by a mechanical detent in the control’s center of rotation, that is, the point where zero beat is likely to be encountered.  I found a foam, doughnut-shaped packing spacer from a spindle of CDs had just the right internal and external diameters to slip over the fine-tuning knob and provide some added gear reduction.  By pressing the foam against the case, the effects of the detent could be mitigated.

Well, unfortunately, CDs are going the way of cassette tapes these days, so the availability of the packing spacers may not be so good.  It may be within the realm of possibility to fabricate one.

Wrist Strap

My final alteration is not so much a modification as it is a simple omission.  On the first disassembly of the -660 I omitted reinstalling the wrist strap.  IMHO, this piece of ribbon is no more useful than fender skirts on a ’57 Chevy.  Besides, it’s usually in the way.  Sometime in the murky past, this appendage made its appearance on a small portable radio.  Since then, nearly every manufacturer has felt compelled to include one.  I envision someone grabbing the radio by the strap and sashaying down the street with it dangling precariously by one’s side.  I have tried to imagine how its purpose might be inverted into a safety feature – perhaps first looping the strap around the wrist and then grabbing the radio with the hand.  But somehow, I can’t imagine anyone going to that trouble.  Maybe I’m missing something.

The wrist strap on this Realistic 12-714 AM/FM pocket radio from 1984 is hard to ignore.

The reader may be aware of other modifications to the PL-660, but mine are limited to those described above.

Epilogue

The old -660 has never been coddled.  Neither has it been subjected to the same vicissitudes as a soccer ball.  It remains a relatively handsome, finely crafted instrument still capable of soldiering on in the frontlines of the DX battle.

Is my old PL-660 a better-than-average “creampuff” off the Tecsun production line?  Does that make it special?  During the three or four months it was laid up with the encoder problem, I took the precaution of buying one of the last production units – this on the chance it might be my only opportunity of having an operational PL-660.  The newer one looks like its predecessor; it operates like its predecessor, even to the extent that it has the same birdies and the erratic encoder.  It does have the added feature of dial recalibration – a feature totally unnecessary on the original PL-660.  Somehow, it’s just not the old PL-660.  That one is special.

Maybe you have a special radio.

Bob’s Radio Corner: Tuning Single-Letter Cluster Beacons

Source: Better Shortwave Reception, William I. Orr, W6SAI, Radio Publications Inc., Wilton, CT, 1st Edition, p. 25, 1957.

Tuning Single-Letter Cluster Beacons

by Bob Colegrove

Part of the allure of shortwave listening for me has always been vicarious visits to “those faraway places with the strange-soundin’ names.”  After one has logged several big-time broadcasters, one begins to look for new challenges.  Most of the so-called “utility” content which once occupied the space between the broadcasters and hams is now a vast open desert interrupted only with an occasional digital buzzsaw, a wide-band CODAR experiment, or some RTTY.  But now and then you come across a signal that grabs your interest.  In this case it happens to be a group of signals referred to as the Russian single-letter beacons.  A good introduction to these beacons is here

https://en.wikipedia.org/wiki/Letter_beacon

and here

https://www.hfunderground.com/wiki/Letter_beacon.

After many years, there is still some speculation as to the history, purpose and power of the single-letter beacons.  Rather than repeat what has already been said, this posting focuses on my technique for monitoring a subset of these beacons called “cluster beacons.”  They are called that because they are grouped close together, just 100 Hz apart, at ten different locations across the shortwave spectrum.  A good tabular summary is at https://priyom.org/military-stations/russia/single-letter-beacons.  Some stations may not currently be broadcasting or may be on at selected times.

These stations will neither captivate you with content or readily QSL.  They are all continuous wave (CW) and are thus heard by turning on your radio’s beat frequency oscillator (BFO) or selectable sideband (SSB) detector.  I am Morse-code-challenged – always have been.  Fortunately, these stations all broadcast their single letter dits and dahs repeatedly and slowly.  Having relatively low power, the challenge here on the East Coast of North America is just to pick them up through the band noise.  Some nights are better, some not so good.

For purposes of this posting, I have focused on the stations around 7508 kHz.  This seems to be the best cluster, at least at the current time and location.  “D” is invariably the strongest and most consistent, with “P,” “S,” “C,” and “A” fading in and out at different times depending on the propagation.

To tune through the cluster, first tighten up your selectivity as narrow as possible – 500 Hz if you have it.  Use the fine-tuning control – 10 Hz if you have it.  The best way to catch these beacons is to sneak up on them.

  • Approach upward from the low side of the cluster using USB, start tuning around 7508.3; or
  • Approach downward from the high side of the cluster using LSB, start tuning around 7509.5.
  • Try tuning in both USB and LSB to determine the better reception of the signal you are trying to hear.

Depending on which signals are audible, you may hear two or three making it through the 500 Hz filter at the same time, each with a different pitch.  The beacons will change pitch as you approach, going from a high pitch heterodyne to a lower pitch.  When you reach zero beat with a station you will be directly on its frequency.  Zero-beating a strong signal may help you hear a weaker one.  Tables 1 and 2 show how this works for USB and LSB respectively.  They indicate the heterodyne tone you will hear as you tune towards or away from each signal.

The negative value tones in the tables may not be heard if you are using a radio with selectable sideband (SSB).  If your radio has a traditional BFO, you will hear a tone at either side of zero beat.  In the tables, interpret the negative numbers for their absolute value, for example, |-100 Hz| = 100 Hz.

As part of the challenge for the 7508 kHz cluster, you may have to contend with interference from WRNO, 7505 kHz.  When you finish this challenge, try it again on the 10781 kHz cluster.

Good DXing.

Bob’s Radio Corner: Do You Need a Break from Radio?

A new resource such as Passport was always an incentive to turn on a radio.

Do You Need a Break from Radio?

by Bob Colegrove

A couple months ago I became one of the last 10 people east of the Mississippi River to acquire a smart phone.  It was a great improvement for someone who had been trying to navigate through modern life for several years using a flip phone.  The transition came at a cost, however.  It required an investment of time learning the basic features and functionality.  Having a long-standing familiarity with computers and tablets, there was a degree of experience I could draw from.  Still, it was different, plus it included new features I found to be amazing and demanding of my attention.

Not long after this I was informed by Microsoft that I would soon be needing a new computer to remain safe and functional.  Having logged on to a mainframe for the first time in September 1976, I had been around the block too many times to be greatly alarmed by such warnings.  Nevertheless, having not purchased a new computer since 2014, I decided to use this information as leverage to do just that and treat myself to a new laptop.  The basic features and functionality remained similar; however, the transition still required time to find where they had been relocated.  An operating system upgrade is kind of like buying a new car and finding the steering wheel in the trunk and the spare tire in the front seat.

These new technological acquisitions demanded my undivided attention for a period of several weeks – time which had to be carved out of life’s normal activities.  Admittedly, being retired helped.  Still activity tends to progressively slow with age.  The transitions were completed relatively painlessly; I would even say with a good level of discovery and enjoyment.

I told you all of that in order to tell you this:   While all this transpired, not a radio functioned for several weeks.  Neither a knob was turned nor a button pressed.  Notwithstanding the newly enhanced forces of 5G and Wi-Fi, the world could have stood still.  Not once, but many times during this period I would look over at the radio table and see them all silently looking back like so many forelorn puppies in want of a scratch behind their ears.  Coldly and cruelly, I would turn my back and set up another email account.

I was on what is simply called a “break.”  Not my first.  I am hard-pressed to say how many breaks I’ve been on over the years; nor can I tell you how long each one lasted.  I am reassured by my fellow radiofiles that I am not alone.  I occasionally read comments or blogs from folks who have returned after a break, sometimes after several years.

In the old days tinkering could reignite flagging interest.

Breaks may be caused by many things, the increased burdens of life being the most obvious.  Maybe there is illness.  Seasonal changes can initiate a break; it’s just good to be outside when the air is fresh and warm.  It might be an increased level of boredom where one simply neglects to turn the radio on.  In my case, it was an irresistible distraction like a new gadget.  I have never consciously told myself I needed a break and turned the radio off for a planned length of time.  It has never ever become a matter of work to operate a radio.  Perhaps that’s how you know you’ve been irrevocably hooked.

We all come back – eventually.  It’s in our DNA.  Are breaks bad?  No.  Every human endeavor requires a break now and then.  Sportspersons hang up their spikes or sneakers for six months at a time every year.  The idea is they come back refreshed and renewed ready again to conquer the mountain.  While success may be illusive, it is the break that provides the incentive to go on.  So it is with radio.

I could spend hours to the point of ignoring meals attentively getting a dial cord to run smoothly.
Source : The National NC109 Communications Receiver.

Eventually you turn the radio on with renewed enthusiasm.  Perhaps you recall a previous discovery, an untried band, a different time of day, a new tuning technique, a suggestion of something you read or heard.  Maybe it’s a new radio, or one you haven’t used for a long time.  Maybe it’s just the attraction of the dial and buttons that draws you back.  These are some of the sparks that reignite your interest.

Eventually, the initial flash of enthusiasm for the new phone and computer subsided.  Sound again emanates from the headsets.  What was old is new again.  Regardless of why you went away or how long you’ve been gone; you’ve got that old feeling and you’re back.

Do radio designers try to attract us with appearance?