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Finding Your Best Crystal Radio ‘DX Diode’

July 20th, 2024 |

Over the past few weeks I’ve had time to examine many dozens of diodes, mostly germanium, in my crystal radio diode collection. Many of them were removed from equipment built in the '50s and '60s (old diode matrix boards), some are vintage NIB 1N34As while others are modern SMD Schottky style diodes.

There are numerous excellent websites such as this one by Dick Kleijer or SV3ORA's site ... all describing elaborate ways to determine which diode is ‘the best one’ (the holy grail diode!) for crystal radio work. Most methods use a vigorous, somewhat complex test procedure plus a lot of math, most of which is well beyond my old brain, in attempts to flesh out each diode’s inherent characteristics ... as the sites referenced above illustrate, the simple appearance of a crystal diode belies its complexity and determining diode behaviours can be more challenging than one might suspect.

My testing procedures were much more basic, and in the end, may hopefully reveal the best diode in my collection. I think one needs to undertake this with the understanding that there really is no overall ‘best' crystal radio diode but rather, only a diode that is best for your particular system and what works best in my system may not necessarily be the best one in yours.

My plan was to measure a few diode behaviors, shrink the list of candidates and then compare them against each other in my system's high-Q tank circuit.

My first step was to measure Vf or the forward voltage needed to ‘turn the diode on’. This can usually be determined to reasonable accuracy by using the diode test function on most digital multimeters. I’ve always supposed that the diode with the lowest Vf turn-on threshold would probably be the most sensitive, but is it the only factor? Hopefully my tests would indicate if anything else is in play.

The next task was to determine the minimum signal level of a 1000 Hz modulated carrier on 1400 kHz that could be detected by each candidate diode. An RF probe was used to measure the level of signal capacitively coupled into my crystal radio’s antenna tuning stage which was then lightly coupled into the detector stage, using the diode under test. No importance was given to the actual base level of this signal other than to note the level at which it could first be detected by ear (using sound powered phones) and making sure the coupling distance between stages remained the same for all diodes under test. This allowed me to compare weak-signal diode ‘sensitivity’ to the diode’s previously measured turn-on point or Vf value. Would the diode with the lowest Vf also be the most sensitive when used in a detector circuit composed of complex impedance, resistance, reactance and capacitance values that the test diode would be looking into?

The RF signal coupling was adjusted so the injected carrier could be varied between 0 and 10mV as measured on the RF probe. For each diode, the signal level was slowly increased from ‘0’ until the 1400kHz tone-modulated AM signal could first be detected.

The lowest 'first detected' signal level was .6mV while the highest level required 3.4mV, representing a pretty good range of diode behaviours. There were 49 different diodes in the test pool.

Four of the 49 diodes detected the .6mV signal, six detected the signal at .7mV, and nine first detected the signal at .8mV. The remainder required a still higher level of injected signal. The average level of first detection was 1.2 mV.

Of the four .6mV ‘best detectors’, their turn-on Vf values ranged from .15V to .38V while the .7mV and .8mV detectors had a Vf between .181V and .40V!

It seemed, not surprisingly, that generally the higher the Vf turn-on threshold, the greater was the level of signal injection needed for first detection … but evidently using the Vf value alone to determine the ‘best diode’ was not the hard axiom I had always assumed it to be!

Since a low Vf was not necessarily needed for good sensitivity, would there by any other tests that might indicate best performance?

The next trial was to measure actual diode currents in my hi-Q detector while receiving a lightly-coupled constant level input signal (1400kHz) to see how this value related to Vf. Measured diode currents (Id) varied from 9uA to 14uA for the same level of input signal, with the diode having the lowest Vf also producing the lowest current level ... hhhm! There was more to this than I expected, but generally, the lower valued Vf diodes tended to produce the most current and consequently the louder headphone signal … but not always! Some diodes with a Vf as high as .46V yielded high currents!

This now begged the question, “Does the higher current diode with a higher turn on (Vf) prove to be a better overall performer than the diode that turns-on early but produces a weaker signal?” What is the relationship between diode current and weak signal detection?

The next step was to express the relationship mathematically by calculating the ratio between the diode’s Vf and the level of diode current (Id) measured in the previous test (Id / Vf). Each diode could then be assigned a number (Vdx) that might possibly indicate it’s true performance potential in my own system.

The diodes with the highest Vdx values would then be A-B tested under real receive conditions to see if any (or just one!) particular winner(s) might emerge … and if Vf was as critical as initially believed.

The Vdx values proved most interesting and seemed to account for some of the anomalies noted in earlier measurements with some of the higher Vdx values coming from diodes not necessarily with a low Vf. I’m hoping that this sorting concept properly takes into account both turn-on level (Vf) and current level (Id), since a higher level in either number will compensate for a lower level in the other. Vdx values ranged from 23 to 66, with seven diodes in the higher 53-66 range.

Click Image For Larger View

All of the 49 diode's test parameters were put onto a spreadsheet and listed in order of their Vdx value.

Click Image For Diode Spreadsheet Data

The highest Vdx assignment of 66 went to my 40-year junkbox resident, a JHS Sylvania 1N3655A microwave mixer diode. It will be interesting to see if it really is the best of the lot! Although it did not produce the loudest signal (Id) compared with others, its Vf turn-on was an impressive .181V and its weak-signal detection level was good although not the lowest. A couple of the UHF diodes exhibited the interesting behaviour of picking up the UHF data stream 'clicks' from my nearby wifi booster. The 1N3655A was one of them.

1N3655A Vf = .181V Id = 12uA Vdx = 66

Diode #2, with a Vdx of 62, is a mystery diode with a very low Vf of .197V. It was slightly louder and oddly enough, dug down slightly further than the 1N3655A, which had a slightly lower Vf. Although I don’t recall specifically, I suspect the diode may have been removed from a VCR front end many years ago.

Mystery diode Vf =.197V Id = 12.2uA Vdx = 62

Diode #3 with a Vdx of 61 is a modern SMS7630 Schottky microwave detector diode in an SMD package. Although it did not produce a competitive level of loudness (Id) in the diode current test, its shockingly low Vf turn-on of .147V and weak-signal detection threshold were the best of all diodes tested. Before testing, all SMD diodes were mounted on small PC boards in order to attach leads.

SMS7630 Schottky Vf = .147V Id = 9uA Vdx = 61

Diode #4 (Vdx of 60) is an ISS98, another modern Schottky microwave detector. I recall seeing this diode recommended for good performance in an FM crystal radio detector. Its sensitivity level was excellent.

ISS98 Schottky Vf = .211V Id = 12.5uA Vdx = 60

Diode #5 (also with a Vdx of 60) appears to be a normal germanium of unknown type. I suspect it was used as an RF mixer since it was found on a small printed circuit board with three others, connected in a diode ring configuration typically seen in balanced RF mixers. It produced high current as well as good weak signal capability.

Mystery diode Vf = .22 Id = 13.2uA Vdx = 60

Diode #6 (Vdx of 55) also looks like a germanium of unknown type with a body striping of gray-white-green-gray. If the last band is ignored, this could be a 1N895, a UHF germanium diode. It shows the typical internal cat-whisker type of junction often seen on the 1N34 germaniums.

Mystery diode Vf = .238V Id = 13uA Vdx = 55

Diode #7 with a Vdx of 53 is marked as a ‘95481’ on a green body. It had excellent sensitivity and produced a strong signal (Id), elevating it to the top tier to be looked at more closely.

'95481' Vf = .246V Id = 13uA Vdx = 53

Diode #8, another germanium mystery, earned a Vdx of 49 due to its fairly high Id level.

Black 'T'. Vf = .258V Id = 12.5uA Vdx = 49

The rather beat-up looking Diode #9 is marked with what appear to be house numbers, '1846' and '6628'. I believe this was pulled from an old portable radio's FM section many years ago. Interestingly, like some of the UHF mixer diodes, '1846 / 6628' detects my high speed modem data stream clicks. Additionally, this tortured specimen produced the highest level of signal among all 49 diodes, with an Id of 14uA.

Vf = .294V Vdx = 48 Vdx = 14 (Schottky?)

Diode #10 appears to be the brother of Diode #8 with a Vdx of 48. Although it has a lower turn-on point and was a better weak signal detector, it did not produce as much Id as its sibling, dropping it one notch lower on the list. Like its brother, it also has the mystery 'T' marking. Both are most likely unmarked 1N34As.

Vf = .252V Id = 12 Vdx = 48

As well, three other diodes garnered my interest. Although they ranked lower than I expected, all had previously been found to be good detectors in my system. Their lower ranking may be a hint that my system of grading is not a valid method of determining best performance. All three will be given a harder look in the upcoming elimination tests.

The first is the germanium FO-215. Often touted as 'the holy grail' crystal radio diode but I have never found it to be particularly outstanding. Maybe my system has a lower Q than it really needs in order to show its stuff. This diode is shown on the bar graph above as #11. During testing, it appeared much less capable of weak signal detection than most others but its low Vf and high Id elevated its overall ranking.

Vf = .272V Id = 13uA Vdx = 48

The second diode is the Soviet-era D18, a military-grade germanium in a glass '50s-style package. I have previously found it to be a very good detector but its high turn-on level lowered its ranking. The D18 appears on the bar graph as #12.

Vf = .366V Id = 12.2uA Vdx = 33

The third diode is a vintage Sylvania 1N34 from the 50s and likely one of the first 1N34s to be manufactured. Although it produces a loud signal, its Vf was higher than expected. As I recall, it was salvaged from an old parted-out Heathkit. It appears on the bar graph as #13.

Vf = .335V Id = 13uA Vdx = 39

As mentioned earlier, one can measure and calculate a large amount of data for crystal diodes while they sit passively on the bench but they really need to be mounted, tested and compared in the actual system in which they will be used. Comparing diodes 'A-B' style in real time with weak signals may be better than any measurements made on a diode being bench-tested.

Will a new ‘holy-grail’ emerge from the pile? This type of testing requires a lot of careful listening so time will tell.

Testing will be ongoing over the summer / fall months ... stay tuned for the final results, hopefully in time for the fall DX season!

Building Alfred P. Morgan’s “A More Selective Crystal Receiver”

February 15th, 2024 |

Author: Steve VE7SL

As I’ve been seeing a lot of new membership requests on my Facebook Crystal Radio DX group indicating that they wish to build a crystal receiver, I’ve been examining some simple inexpensive circuits that should work well for local reception and possibly even to hear some skywave DX signals.

Since I’ve always wanted to build Alfred P. Morgan’s ‘A More Selective Crystal Receiver’ from his second ‘Boy’s Book of Radio’ ever since first seeing it at around age 10, I chose this as a start.

How did it Morgan’s design work? Could it hear all of my 15 locals and separate them? Was it a DX machine?

I invite you to read about the whole process on my web page, just published today:

https://qsl.net/ve7sl/morgan.html

New Page On VE7SL Radio Notebook!

February 11th, 2024 |

Author: Steve VE7SL

Thanks to May (VA7MAY) and Mark (VA7MM) spending the time to scan my 630m QSL card collection, I have now been able to complete their work by posting a dedicated page for the cards.

If you've ever wondered what can be worked on this 'below the broadcast band' MF amateur band, then viewing the cards and reading their comments may give you some insight into its character.

The new page can be found here.

Hunting For NDBs In CLE279

October 25th, 2023 |

Author: Steve VE7SL

Another month has zoomed by and it's CLE time once again. This is a challenge for all newcomers to NDB listening and the ultimate test of your medium frequency receiving capabilities. Can you meet the challenge?

'CLE's are 'Co-ordinated Listening Events, and NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

With the number of targets slowly being decommissioned, the hunting grounds have been slightly widened ... this month the frequency range is for the NDBs whose published frequencies are between 335.0 - 349.9 kHz.

For example, 'AA' near Fargo, ND, transmitted on 365 kHz and its upper sideband CW identifier was tuned at 366.025 kHz while its lower sideband CW ident could be tuned at 363.946 kHz. Its USB tone was actually 1025 Hz while its LSB tone was 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.

From CLE organizers comes the following info:

Hello all

Here are the full details for this weekend's co-ordinated listening event.
It is open to everyone including CLE new-comers:

Days: Friday 27 Oct. - Monday 30 Oct.

Times: Start and end at midday, LOCAL time at the receiver.

NB: Most of us are changing our clocks by one hour this weekend.

However UTC time (as shown in our logs) continues unaffected.

Range: 335.0 - 349.9 kHz

Wherever you are, please join us and log the NDBs that you can positively
identify that are listed in this busy frequency range (it includes 335.0 kHz
but not 350 kHz), plus any UNIDs that you come across there.

Short and long logs are welcome (in-between ones are good too!)

    Send your CLE log to the List, preferably as a plain text email
    (not in an attachment) with ‘CLE297 FINAL’ in its subject line.

    Please show on EVERY LINE of your log:
       # The date (e.g. '2023-10-27' or just the day no. '27') and UTC
           (the day changes at 00:00 UTC).
       # kHz (The beacon's nominal published frequency)

If you don’t know it, please visit https://rxx.classaxe.com

where you will find all the details.
# The Call Ident.

Show those main items FIRST on each line, before other optional details such as Location, Distance, etc. If you send any interim logs during the event, please also send your 'FINAL', complete, log.

Always make your log interesting to everyone by giving details of your listening location (the 6-character Locator) and brief details of the receiver, aerial(s), etc., that you were using.

We will send the usual 'Any More Logs?' email at about 19:00 UTC
on Tuesday so that you can check that your log has been found OK.
Do make sure that your log has arrived on the List at the very latest
by 08:00 UTC on Wednesday 1 November. We will then hope to complete making the combined results within a day or two.

You can find full information about current and past CLEs from the

CLE page https://www.ndblist.info/cle.htm.

You can also find your relevant seeklists made from REU/RNA/RWW by visiting https://rxx.classaxe.com/cle.

Good listening

Brian and Joachim

(CLE Coordinators)

(Reminder: You could use any ONE remote receiver for your loggings, stating its location and owner - with their permission if required. A remote listener may NOT also use another receiver, whether local or remote, to obtain further loggings for the same CLE)

_._,_._,_

CLE's provide several purposes. They:

• determine, worldwide, which beacons are actually in service and on-the-air so the newly-re-vamped Rxx online database can be kept up-to-date

• determine, worldwide, which beacons are out-of-service or have gone silent since the last CLE covering this range

• will indicate the state of propagation conditions at the various participant locations

• will give you an indication of how well your LF/MF receiving system is working

• give participants a fun yet challenging activity to keep their listening skills honed

Final details can be found at the NDB List website, and worldwide results, for every participant, will be posted there a few days after the event.

The NDB List Group is a great place to learn more about the 'Art of NDB DXing' or to meet other DXers in your region. There is a lot of good information available there and new members are always very welcome. As well, you can follow the results of other CLE participants from night to night as propagation is always an active topic of discussion.

You need not be an NDB List member to participate in the CLEs and all reports, no matter how small, are of much value to the organizers.

Remember - 'First-time' logs are always VERY welcome!

Reports may be sent to the NDB List Group or e-mailed to CLE co-ordinator, Brian Keyte (G3SIA), whose address appears above. If you are a member of the group, all final results will also be e-mailed and posted there.

Please ... give the CLE a try ... then let us know what NDB's can be heard from your location! Your report can then be added to the worldwide database to help keep it up-to-date.

Have fun and good hunting!

Magic Band Summer Season

August 17th, 2023 |

Author: Steve VE7SL

This summer’s Sporadic-E season has pretty much wound-down once again. As E seasons go, this one ranked right up there with the worst of them but this comes with some provisos.

Over the past several years, my only interest has focused on Europe and Asia, looking for any DXCC entities that I have not yet worked and I tend to ignore most domestic openings unless the MUF appears to be climbing into the range of 2m.

There were several openings from here in British Columbia to most regions of the US and Canada, so many would likely disagree that it was a poorer season than normal!

Unlike last year when we had several good days to Europe over a two-week period, this year’s fireworks were pretty much confined to June 12, when the somewhat unstable polar-path to Europe jumped from country to country for several hours. In spite of making 62 contacts to Europe, only one new country was worked when 9H1TX in Malta replied to one of my CQs! Other than him, there were no other signals being heard at the time but after our QSO, his fellow countryman, 9H1TX, also appeared ... so it was exciting to find two rare 9H1s in the 6m log! For about 4 minutes, the only two signals in my FT8 waterfall were both CQers from Malta! Note the power and antenna being used by 9H1LO ... it doesn't take much when the magic appears, albeit momentarily.

Last summer’s E season was not as heavily influenced by the active Sun, unlike this summer’s constant stream of solar flares keeping the polar regions anything but calm and quiet … a seeming requirement for good transpolar Es on 50MHz from the west coast.

Last year produced 8 new DXCC entities and in most cases, like this year, signals were strong enough for CW but almost all DX prefers the few db advantage offered by the FT8 mode. Exchanges can be made MUCH more quickly on CW than the snail-pace of FT8. The addition of 9H1 brings my 6m DXCC confirmed total to 109.

If Cycle 25 continues to grow as it has been (in small spurts), it’s difficult to predict if there will be any long haul F2 propagation in the late fall or not. In previous cycles we’ve needed to see some steady flux values in the 200 or higher range for several days in a row … at least for us here in VE7 land.

If the F2 MUF does indeed manage to manifest itself, we should expect to see early morning openings to the New England / NY regions with blowtorch signal levels before seeing the path crawl down the eastern seaboard then possibly into the Caribbean and South America. Later in the afternoon, expect signals from Japan and the far East for several hours up until sunset, once again at bone-crushing signal levels. There are few things in ham radio more exciting than experiencing 6m F2 and hearing the level of signal strengths that can be reached when operating near the edge of the MUF.

If not this fall then hopefully in 2024 for sure … but as of now, it’s anyone’s guess as to if or when the rare winter magic will appear once again!

Hunting For NDBs in CLE294

July 26th, 2023 |

Author: Steve VE7SL

YZS-362 Coral Harbor, NU (ve3gop.com)

'CLE's are 'Co-ordinated Listening Events, and NDB DXers around the world focus their listening time on one small slice of the NDB spectrum.

A good target for all NA listeners is powerhouse YZS on 362 kHz, located at Coral Harbor, Nunavut. Listen for its upper sideband CW identifier on 362.402 kHz.

When tuning for NDBs, put your receiver in the CW mode and listen for the NDB's CW identifier, repeated every few seconds. Listen for U.S. NDB identifiers approximately 1 kHz higher or lower than the published transmitted frequency since these beacons are modulated with a 1020 Hz tone approximately.

For example, 'AA' near Fargo, ND, transmitted on 365 kHz and its upper sideband CW identifier was tuned at 366.025 kHz while its lower sideband CW ident could be tuned at 363.946 kHz. Its USB tone was actually 1025 Hz while its LSB tone was 1054 Hz.

Often, one sideband will be much stronger than the other so if you don't hear the first one, try listening on the other sideband.

Canadian NDBs normally have an USB tone only, usually very close to 400 Hz. They also have a long dash (keydown) following the CW identifier.

All NDBs heard in North America will be listed in the RNA database (updated daily) while those heard in Europe may be found in the REU database. Beacons heard outside of these regions will be found in the RWW database.

From CLE organizers comes the following info:

Hello all,

Our 294th Co-ordinated Listening Event is almost here.

First time CLE logs too? Yes, please!

Short logs are always as welcome as long ones.

Days: Friday 28 July - Monday 31 July

Times: Start and End at midday, your LOCAL time

Range: 350.0 - 369.9 kHz

Please log all the NDBs you can identify that are listed in this range (it includes 350 kHz but not 370) plus any UNIDs that you come across there.

Send your final CLE log to [email protected], preferably as a plain text email, not in an attachment and - important - with 'CLE294' and 'FINAL' in its title.

Please show the following main items FIRST on EVERY line of your log:

# The Date (e.g. 2023-07-28) or just the day (e.g. 28)

# The Time in UTC (the day changes at 00:00 UTC).

# kHz - the beacon's nominal published frequency, if you know it.

# The Call Ident.

Optional details, such as Location and Distance, go LATER in the same line.

Please make your log useful to everyone by including your listening location, its 6-character Maidenhead Locator if you know it, and brief details of the receiver and aerial(s).

We will send the usual 'Any More Logs?' email at about 19:00 UTC on Tuesday so you can check that your log has been found OK.

To be included in the combined results, do make sure that your log has arrived on the List by 08:00 UTC on Wednesday 2 August at the very latest.

We hope to make all the combined results within a day or so.

You can find full information about current and past CLEs from the CLE page https://www.ndblist.info/cle.htm.

You can also find your relevant seeklists made from REU/RNA/RWW by visiting https://rxx.classaxe.com/cle.

Good listening

Brian & Joachim

(CLE coordinators)

(Reminder: If you wish you can use a remote receiver for your loggings, stating its location and owner - with their permission if required.

A remote listener may NOT also use another receiver, whether local or remote, to obtain further loggings for the same CLE)

CLE's provide several purposes. They:

Conjectural Chats

July 7th, 2023 |

Author: Steve VE7SL

A recent e-mail in the AWA Group from Eddy, VE3CUI, elicited some intriguing comments which you may find of interest. Highlights from the exchanges have been selected for brevity:

Eddy VE3CUI – VE3XZ/3:

I’m here at the summer cottage, gamely calling “CQ” with my trusty old Vibroplex Vibrokeyer on what sound like dead bands on 15- and 20-meters…yet, when I check the on-line DX Beacon, my quota of entries at 100 is exhausted from across the continent, and beyond, from monitoring stations that have clearly copied me.

All of a sudden, 15-meters just explodes with CW contestors in the middle of Wednesday afternoon with morse machines all honking out endless “CQ CWT” at some 30+ WPM. I snag some very easy quickie exchanges from “VE7” and “W6” from the west coast — and then just as suddenly, the contest is over and I’m right back to “CQ…CQ…CQ” in silence again, all in vain.

How very ironic that self-professed “…devotees” of the CW art and craft — “CW Tops-Ops” — can all devote attention to the object of their affection for but one single hour, and in the middle of the week…! Shouldn’t they otherwise be gainfully fully employed earning a living, like all of the other non-retirees…?! Otherwise, why “…kiss and run” so, if they really and truly love the mode…?!

I just do not get it, I’m afraid…

**************Robert KG4KGL:

Well, as for the middle of the week timing, more people work from home now. I guess they stepped away from their work computer and spent an hours snagging some QSOs.

I work 12 hours, two days for one week and five days the following week, then rinse, lather, and repeat. So on my off days, I am on all the bands looking for QSOs and I hear the silence you speak of, all while registering on various beacons.

**************

Eddy VE3CUI – VE3XZ/3:

I guess that I especially noted the AWOL ops on the CW sub-bands about 3 years ago, or so…about the time that FT8 became all the rage, I s’pose.

But there’s a decided absence on the phone bands, too.

I can appreciate demographics having a hand in our diminished numbers, but this is all akin to outright extinction…! So many times I feel just like “…the last man standing”…

**************

Steve VE7SL:

I think most of these CW guys you hear during sprints and weekend contests are guys that love contesting more than love CW….making CW music with their laptops, copying and entering the exchange info and then on to the next guy … kind of like a long action-filled video game. In fact I suspect that many of these modern CW sprinters and weekend CW flash-crowd participants were probably weened on video games as there’s a lot in common with those things and watching a scrolling vibrant waterfall of signals, especially if the rest of their week is spent on FT8. I agree with Eddy that the emergence of FT8 coincided perfectly with the sudden demise of CW (and phone) activity that now seems the new normal. It’s boring as hell but seems to mesh nicely with the present generation of no-code hams and those living in condos and apartments with no room for antennas and a ton of noise to contend with.

**************

Eddy VE3CUI – VE3XZ/3:

Can you recall — nostalgically, of course — reading those QST features on the crucial need of Q-multipliers & crystal lattice filters in our receivers to “…help combat the crowded congestion on our Ham bands”…?!

I sure do. It all seems so very quaint & innocent from the standpoint of to-day, doesn’t it…? “The Lost World”.

**************

Steve VE7SL:

Indeed things have changed Eddy and seemingly very quickly. When I was first licenced and up until just a few years ago, a CQ on 7030 at ANY time of the day or night would guarantee an immediate response. Now you can CQ until the cows come home with nary a peep.

Something has also changed with the ionosphere as well over the past decade and I’m not sure why. Are we just seeing the long term effects of a terribly poor solar cycle (24) in spite of the newest one struggling to gain serious momentum? We’ve maybe just been spoiled by a series of above average strength cycles our whole lives up until Cycle 24 but something has changed. Both 40 and 80 go completely silent now on most winter nights, shortly after sunset. What happened to the awakening of the band at sunset? I’ve seen only enough of those the past two winters to count on one hand. It’s all very odd. Thankfully we experienced those bands at their very best, years ago. Hopefully the new cycle will pump them back up again, if that’s the problem. I dare not mention global-warming but it seems to have widespread consequences in the upper atmosphere so one has to wonder … the ionosphere as well?

**************

Eddy VE3CUI – VE3XZ/3:

Wow, that’s how long I’ve been AWOL myself from 40- & 80-meters at home — I had absolutely no idea that both bands were now dead at & after sunset like that…not so much as even a clue. And I’m old enough here to recall getting peeved-off about all of the foreign BC stations that routinely crowded-out SSB QSO’s on 40 as it grew dark here.

Like you & so very many others, I too expected the bands in general to “…shape-up back to normal” with the new sunspot cycle — & I’ve been waiting now for so very many years that even I’ve actually forgotten their number…! It just never seems to happen. Is it that oft-cited “Maunder Effect” that we all heard so much about a coupla years ago that’s responsible…? And as for global warming’s influence, who knows…? We’re all still wrapping our heads around how it might affect the climate on the planet, never-mind what might be happening hundreds of miles above its surface. All bets are off in that regard, I think…! But again, who knows, right…?

Anyway, I have the ICOM 751A & groundplane verticals at the ready here at the cottage, & we spend a lotta time here in the summer, too — so do listen for me in the CW sub-bands, on 40- straight to 10-meters, & all of the WARC bands in between. You can’t miss me — I’ll be the guy calling “CQ”, with zero takers in response…!

**************

Jim AJ8S:

Here’s an article about changes to the upper atmosphere which might or might not have an impact on ionospheric propagation:

https://www.wired.com/story/the-upper-atmosphere-is-cooling-prompting-new-climate-concerns/

I too have noticed a distinct decline in CQ ops except for the contests.

**************

Steve VE7SL:

That’s a great and somewhat troubling read Jim. Thanks for the link. Although the ionosphere was not singled out, the regions containing it all seem to be getting thinner which might certainly affect propagation behaviours as we’ve come to expect over the past few decades … which seems to be exactly what is happening, at least on the lower bands. In actuality, the amateur radio community might be one of the first to notice any long term changes not particularly explainable by solar activity.

**************

Eddy VE3CUI – VE3XZ/3:

A most interesting read, indeed. Does it partially explain, somehow, the state of Ham radio conditions to-day…? Could be…I just dunno. But does anyone else “…get it”, for that matter…?

I liken the situation of to-day to that proverbial Monarch butterfly that just alighted onto the bough of that maple tree in your yard: to the insect, that tree has always been there, unquestionably, throughout its lifespan. Which is true — for its lifespan.

But the reality of it is, that convenient resting spot is in reality a dynamic one, & not a static one. It wasn’t there maybe 15 years ago, & it might not be there after the next 30, or so. But the butterfly cares not a whit — that tree was always, and is always, there. Its limited lifespan will not afford it any other conclusion (assuming that insects can even actually derive any…!). Ditto our human lifespans. Maybe the current environmental trends are all otherwise “…normal” somehow & fit into some sorta pattern that goes well beyond our limited number of years of observation…?

Again, I dunno — what I DO know after some 10 years of very serious CW DX pursuit on160-meters, is this: up until about the 2010 winter DX “season” on Top Band, there was always a path, more open than not, to Europe well into the month of March, & beyond. But in the 2010-2011 season, the band essentially slammed shut for regular DX contacts across the Atlantic in February…in the 2011-2012 season it closed its doors in January…& in the 2012-2013 season (when an ice storm here rendered me QRT) the band simply folded for regular trans-Atlantic DX in December…!

How it has been at any time during the past 9 years, I have no idea. But I definitely witnessed & experienced a creeping steady trend there.

And now I’m witnessing a variation of this same “AWOL”-type stuff on all of the other bands, that started some 3 years ago, & which hows no sign of abating.

What an awful uninspiring time for any newbie to take-up an interest in SWL’ing, or Hamming. There is nothing whatsoever to aspire to — literally…!

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Steve VE7SL:

You haven’t missed much Eddy and like you, the last ‘great’ topband conditions here were the winter of ‘09-‘10. This coincided with the longest and deepest quiet-period from the Sun in as long as they have been keeping records. From the west coast, EU on topband has always been a rare short-lived treat but that winter had me questioning everything I thought I knew about the band. There were several weeks of nightly openings from here to Europe that would often start before my local sunset but the strangest thing was that during this extended period of transpolar activity there were no signals from the USA at all! It was nothing but EU CW from 1840 down to 1800, wall-to-wall and night after night. Signals were of the level often heard on 20m and if I had been tuning around blindfolded I would have guessed that I was listening to 20! I recall calling one exceptionally loud UA1 while running only 10W out and he came right back.

Sadly the following winter saw none of that propagation repeated as Cycle 24 had started to come to life. Even the bottom of Cycle 24 had nothing similar although there were a few good nights where I managed Cyprus, Mauritania and South Africa all on topband. It’s been terrible ever since as have been condx for our beloved ‘29 BK for the past several years, so much to the point where I had decided last year to forgo the work involved in setting-up the ‘29 station and give it a pass. However at the last minute, Lou convinced me to give it another shot. It turned out to be my worst BK ever (!) and what really proves it is that not only did I not work Lou (a first) but I didn’t even hear him, also a first!

[Lou is VE3AWA and the ‘BK’ is the annual AWA 1929 Style QSO Party]

I don’t know what’s going on with the bands either Eddy but as you say, in our own short lifetime of observation’s perhaps what we are seeing is more like the norm and we were just lucky enough to see several decades of abnormal (great) conditions! It’s all part of the magic of radio in the long run.

BTW, our chat here inspired me to spark-up on 20 CW this afternoon and my first CQ was answered by a 5W mobile down near San Francisco. After him and just to test my theory, I went to 7030 at 2PM and called CQ on 7030 and just about fell off my chair when my first CQ got a Washington state reply! I guess everyone just needs to get on the air and make some CW music rather than sending e-mail :-))

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Don VE3LYX:

Lots of cw activity. NRR group is one very active group. Every monday night. over 2500 members. Straight Key club is another … U can talk about it or get on the air . Make a sked with a friend BUT IF YOU DO honour Your commitment. I operate cw sometime every week usually on 40m.

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I think the last comment can go a long way to making the bands busier but with so many distractions that we have in today’s world compared with a few decades ago, it’s often difficult to squeeze-in some air time … even when retired!

I found the article regarding the physical changes noted in the upper atmosphere of great interest. My speculation regarding the ionosphere and global-warming may not be so far-fetched after all.

Another propagation oddity that is new (along the lines of my “something has changed” comment) is the annual summer sporadic-e season on 6m. I have been very active every summer on this band since the early 70’s but something peculiar began happening in the summer of 2001. In the middle of the ARRL VHF Contest, the band suddenly opened to Europe! This had NEVER happened before from the west coast and a number of ‘firsts’ were made that morning.

Since then, 50MHz has opened to Europe at least once per summer with these ‘over-the-pole’ openings becoming somewhat ‘normal’. What changed? Some summers will see polar openings for several days in a row, often lasting for several hours as the propagation bounces from one European region to another every minute or (often) less.

For some years now, it has been speculated that this over-the-pole summer propagation is somehow correlated with the formation of Noctilucent Clouds. Interestingly, these clouds follow the same yearly time slot as sporadic-e, almost to the day, with their seasons beginning and ending at the same time each summer! Do the NLCs form the reflective medium needed for 6m propagation between EU and NA or does the same phenomenon that causes polar-e also cause the NLCs? The NLCs usually form in the high Arctic regions, directly associated with our over-the-pole 6m paths.

This summer however, the polar path has been largely non-existent, with just one good polar opening (June 12) so far. Interestingly, a recent newspot in the Spaceweather website pointed out the fact that, this summer, the NLCs have been largely missing in action (!) adding further evidence to their possible link with the polar-e openings. There is still much to be learned about the magic band and its special propagation!