AmateurRadio.com

In the classic educational film titled “Electronics at Work,” produced by Westinghouse in 1943, viewers are introduced to the fascinating world of vacuum tubes. This film highlights the crucial role these devices played in both military and commercial sectors, including radio telecommunications, radar, and various industrial applications. The narrative suggests that vacuum tubes provided the United States with a significant advantage during World War II, particularly in enhancing communication and technology.

The Continuing Relevance of Vacuum Tubes

Despite advances in technology, vacuum tubes remain in use today for several applications, including:

– Transmitting radios
– Medical devices
– Audio amplification systems
– High-frequency applications

Understanding Vacuum Tubes

The film outlines the six basic functions of electronic tubes and illustrates how each type is employed in different industrial and military contexts.

[embedyt] https://www.youtube.com/watch?v=ZJ6rN7WEjbc[/embedyt]

Structure of a Vacuum Tube

A vacuum tube typically consists of two or more electrodes housed within a vacuum inside an airtight enclosure. Key features include:

– Electrode Types: Most vacuum tubes have glass envelopes, although some utilize ceramic or metal casings with insulating bases.

– Leads and Sockets: The electrodes connect to leads that pass through the envelope via an airtight seal. These leads often take the form of pins, allowing for easy replacement in a tube socket, as tubes were a common point of failure in electronic devices.

– Capacitive Design: Some tubes feature a top cap on the electrode to minimize interelectrode capacitance, enhancing high-frequency performance and maintaining safety by separating high voltages.

The Evolution of Vacuum Tubes

The earliest vacuum tubes emerged from incandescent light bulbs, which contained a heated filament sealed in an evacuated glass envelope. When heated, the filament releases electrons into the vacuum through a process known as thermionic emission.

– Electrode Functionality: A second electrode, known as the anode or plate, attracts these electrons if it holds a more positive voltage. This mechanism results in a flow of electrons from the filament (cathode) to the plate, creating an electric field due to the potential difference between them.

– Diode Function: A vacuum tube with two electrodes is termed a diode, which functions as a rectifier. Diodes allow current to flow in only one direction, converting alternating current (AC) into pulsating direct current (DC). This technology is widely used in DC power supplies and in demodulating amplitude-modulated (AM) radio signals.

Film Availability and Production Details

This film is available in the public domain under Creative Commons, and it can be accessed through the Library of Congress Prelinger Archives. The film has been edited and converted to HD quality for better viewing. Introductory and closing music is provided by Nero 10, with commercial use rights granted.

This film not only serves as an educational tool but also highlights the enduring legacy of vacuum tube technology in the realm of electronics, illustrating its significant contributions to both past and present technological advancements.

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Listening to the shortwave commercial stations (along with CB radio) has been a key gateway activity for entry into amateur radio. That was back when commercial shortwave was vibrant and perhaps in its heyday. There is still a very active set of SWLs contributing to the popular SWLing.com website and the legacy work by the well-known Van Horn family to just name a couple. The Spectrum Monitor publishes information about shortwave listening, too. Of course, the Grand Daddy publication, the World Radio TV Handbook is still around. But do amateur operators still listen to the shortwave radio bands? In this article, I want to address the question I just raised with a clear answer: They still do in Canada!

The Radio Amateurs of Canada (RAC) fielded a national survey of Canadian hams in 2021. A total of 2,089 responses were received, of which 1,630 (78%) were from RAC members. Approximately one-third of all RAC members took the time to complete the survey. This is an example of “voluntary response sample” and is not a probability survey. The final report compared responses to known population characteristics which suggested that the realized sample data is generally representative of Province and license characteristics. I’ve just completed a full report from the data which is available on my FoxMikeHotel.com website. The results on shortwave listening are the focus of this article.

The results show that indeed Canadian amateurs listen to the shortwave frequencies outside of ham radio bands. Out of 38 specific operating activities, over a fourth (28.8%) of Canadian amateurs said they are involved in shortwave listening in a typical month. This was ranked 16^th out of 38, ahead of QRP operations, Elmering, weather spotting, and other activities thought to be popular in amateur radio. This result may be surprising to the reader. But my further analysis shows a clearer picture of how traditional shortwave listing activity is integrated with other ham activities.

I have included in Figure 1 a map of all license-holders in Canada from the amateur radio regulator, ISED. The provided licensee address was georeferenced to the street-level for the vast majority and city-level for the remainder. There is also a bar chart showing how SWLing varies by Province.

Amateurs in Canada are concentrated all along the Southern border and in the urban centers of the Southeastern seaboard. There is another concentration on the Western coast near Vancouver. For the survey results, the bar chart in the bottom panel of Figure 1 illustrates how shortwave listening varies. A majority of hams in Newfoundland and the Northwest Territory use shortwave radio for listening. Those in Saskatchewan and Manitoba round out those Provinces above the overall survey mark of 28.8 percent. Excluding Nunavut Province with only 2 survey respondents, the lowest engagement in SWLing is Alberta. The remaining Provinces are about equal, in the lower twenty-percent figure.

Do these results make sense? The physical isolation of the two highest Provinces makes using shortwave broadcasts very practical in many ways. But there is more to it as I investigated whether SWLing is a more obscure activity in ham radio or is it more integrated into portfolio of things that current amateur operators do today?

In Table 1, I summarize my crosstabulation of shortwave listening by other activities (some 37 tables). The three groups summarized in the table reflect whether there was a statistically significant relationship between the two activities and, if so, whether SWLing was greater or less when the ham said they participate in the comparison activity. If there is no significant relationship, then shortwave listening is about the same whether the other activity is engaged in or not. If shortwave listening is a surprising yet obscure activity, there would be few other activities associated with it. Or, perhaps there might be no relationship at all with a random assortment of hams tuning into to those bands.

What the results in Table 1 demonstrate is how significantly integrated shortwave listening is with a number of activities central to the hobby. There are only seven activities without an association and one with a negative relationship. Contesters tend to pursue SWLing significantly less. This is the opposite, however, of what DXers report. Ham operators who listen to shortwave bands also practice a variety of popular activities in their practice of the hobby. These findings tend to remove any doubt as to whether listening to shortwave radio bands is fully an integrated part of contemporary amateur radio in Canada.

Another question about these results is whether it is simply a residual activity of the large Baby Boom cohort? Should this be the case, SWLing is likely to age out of existence over the next couple of decades. If so, shortwave listening would be highest among the most senior survey respondents and lowest among the youngest.

In Figure 2, I constructed a line chart of shortwave usage by age group. There is a clear downward trend as SWLing is highest among younger hams than more senior ones. The significance test suggests that this overall age pattern is not significant. The result is that the survey result of a quarter or more of Canadian hams engaging in shortwave listening is not a holdover of amateurs from a previous era of the hobby as younger hams.

Even with there being a non-significant trend in opposition to the Baby Boomer remnant hypothesis, I examined how long these hams had been licensed (tenure) and a complementary question in the survey regarding long many years they had been active. Perhaps it is not age per se but length of experience as a licensed or active ham that might influence whether nor not shortwave listening is attractive. These results, too, showed almost no difference regarding shortwave listening and length of experience or activity in the hobby. This are positive findings for shortwave band usage outside of amateur radio.

To further assess how shortwave listening might be linked to other factors, I compared the rural-to-urban locations of amateurs in the survey. There are no significant differences even when compared within these Provinces. The rural-to-urban locale does not explain why some Provinces have higher shortwave listening levels than others.

To conclude, these are somewhat unexpected findings based upon the rhetoric that ham radio operators tell themselves in the public sphere. We frequently hear that shortwave listening is passe, that the commercial and government broadcasters are retreating, and so forth. These may be factually the case from the supply-side of non-ham shortwave transmissions. But the hams in Canada do listen to shortwave broadcasts or one type or another in addition to participating in the core set of activities that comprises amateur radio. Contesting is the sole specialty that is negatively related to such listening. By contrast, DXers are more likely to listen (30.2% vs 23.6%). There are Provincial variations in listening but no patterns within any of them that vary along the rural-to-urban continuum.

The relationship of SWLing to the rest of the amateur radio hobby’s activities appears well-integrated. While the broadcast sector of the shortwave industry is at a low ebb right now, amateur radio in Canada still embraces listening to the non-ham bands. We do not know how this national survey of Canadian amateurs may compare to those of other nations. However, it is the sole survey of which I am aware that measures the activities of amateur radio operators in such detail. Until we do have comparative surveys, the RAC Survey 2021 is our only objective insight into ham radio activities.

Some readers may view these surprising results through their own “personal windshield” of listening experiences. “Why, I don’t know any hams who listen to shortwave broadcasts,” they might say. Others could counter, “Well, we need some “good” survey data on this issue.” I’ve spent a career conducting surveys, teaching survey research methods to PhD students (and fellow faculty), and advising some of the largest survey organizations in the world, such as NORC at the University of Chicago, the SRC at the University of Michigan, and the USDA National Agricultural Statistics Service to name a few. The RAC Survey of 2021 is not a high quality statistical probability sample costing a few hundred thousand of dollars. But it is the best one I’ve seen to date on a national scale with behavioral measures of amateur radio operators. So while the reader’s experiences on SWLing might indeed be differ, it is the aggregate picture that we have never had national level results like those in the RAC Survey 2021. Do they apply to the U.S.? Well, would you rather go just with your personal windshield to generalize or take the picture these results present as our best guesstimate for similar behavior in the States?

From the RAIN HamCast episode #56, 2021-XII-11 (used with permission):

When you were knee high to a grasshopper, did you undergo a game-changing experience that shaped your future career?

Here is text from the introduction:

Tomas Hood/NW7US did. Tomas has been a shortwave enthusiast since 1973. He was first licensed as a ham in 1990 at age 25.

In the mid 1990s Tomas launched the first civilian space weather propagation website, HFRadio.org, which later spawned SunSpotWatch.com. His website, NW7US has been up and running since June, 1999. Tomas has contributed to the Space Weather Propagation column in CQ magazine for over 20 years, and for The Spectrum Monitor magazine since 2014.

A product of the Pacific northwest, Tomas resides today in Fayetteville, OH. RAIN’s Hap Holly/KC9RP spoke with Tomas recently about Solar Cycle 25 and the game-changing afternoon Tomas experienced in 1973 at age 8 ( Read more about this, at his amateur radio and space weather blog: https://blog.NW7US.us/ ).

Here is the first part of the two-part interview:

Mentioned in the interview is Skylab:

From Wikipedia’s article on Skylab: Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations included an orbital workshop, a solar observatory, Earth observation, and hundreds of experiments.

Tomas was drawn into space weather as a life-long passion, by inspiration from Skylab, and from the hourly propagation bulletin from the radio station WWV.

WATCH FOR THE NEXT EPISODE, PART TWO

This video is only part one. The RAIN HamCast will conclude Hap’s conversation with Tomas in RAIN HamCast #57, scheduled for posting Christmas Day.

Hap Holly, of the infamous RAIN Report (RAIN = Radio Amateur Information Network), is now producing The RAIN HamCast. The results are both on https://therainreport.com and on the RAIN HamCast YouTube channel, https://www.youtube.com/channel/UCUbNkaUvX_lt5IiDkS9aS4g

KEEP ON HAMMING!

The RAIN Hamcast is produced and edited by Hap Holly/KC9RP; this biweekly podcast is copyright 1985-2021 RAIN, All rights reserved. RAIN programming is formatted for Amateur Radio transmission and is made available under a Creative Commons license; downloading, sharing, posting and transmission of this ham radio program via Amateur Radio in its entirety are encouraged. Your support and feedback are welcome on https://therainreport.com. Thanks for YouTube Technical Assistance from Tom Shimizu/N9JDI.

It might not take as much antenna as you may think would be necessary to make two-way contacts on shortwave radio (as an amateur radio operator putting an HF transceiver on the air). However, often, makeshift antennae are effective enough to be viable–just look at all the contacts many amateur radio operators make with their low-power (QRP) rigs (transceivers) using short, helically-wound, mobile antenna sticks. If they can work magic with such inefficient antenna setups, surely your effort at an antenna would pay off to some degree. Right?

[embedyt] https://www.youtube.com/watch?v=-k5Su–ez2Y[/embedyt]

Of course, I want to make a proper dipole out of this example antenna. But, while I wait for the rest of the parts I need to complete this antenna project (pulleys and a ladder, and maybe a potato launcher), I’ve put this makeshift antenna on the air, with it just high enough so that I can enjoy some time on the shortwave bands.

With this antenna, I’ve made successful two-way voice and Morse code contacts (QSOs) with stations in Europe and across North America. I am able to tune it on the 60-, 40-, 30-, 20-, 15-, 17-, 12-, and 10-Meter bands. Reverse beacon detection picks up my Morse-code CW signals, especially on 40 meters (the band on which it is tuned physically).

The bottom line: just get something up in the air and start communicating. Improve things over time. You’ll have much fun that way.

73 de NW7US dit dit

Sure! You don’t need to have a software-defined radio (SDR) before you start learning how to use the technology; there are a few different paths you can take, exploring and learning about SDR.

One way to gain some experience with SDR without spending a dime is to install a free software package for the very popular, non-Linux, operating system (that starts with ‘W’), and give SDR a test drive. If you like it, you might consider getting your own hardware (like the SDRplay RSPdx, for instance), and connecting it up to your computer and running this software, too.

Why I Dived Into SDR

I have always loved radio, ever since the early 1970s, when I discovered shortwave radio. In the last couple of years, I’ve had an increasing interest in the world of SDR. When I am working, but away from home (remember those days, before Covid?), I want to sample news and programming from around the world, but through shortwave. The way to do that, I found, is by using the various SDR options which allow a person to tune a remote receiver, and listen.

I also find working with the waterfall of a typical SDR-software user interface rewarding because, instead of blindly searching for signals in a subband, I can see all of the received signals on the scrolling time representation of a slice of frequency. Simply select that signal on the waterfall, and the radio tunes right to it.

I often connect to different SDR radios around the world, to catch all manner of shortwave signals, from maritime, military air, trans-oceanic air, or coast guard radio traffic, or other interesting HF communications including amateur radio CW and SSB signals. Occasionally, I also check out VHF and UHF signals from around the world. All of that, while instead an office building that is not suited for shortwave radio reception.

I’ve now decided to give back to the community; I’ve added my SDR receiver to the collection of receivers located around the world on the SDRSpace network of SDR radios.

My new SDRplay RSPdx software-defined radio receiver is live, via http://www.sdrspace.com/Version-3, using the SDR Console software (Version 3).

The receivers are online whenever I am not transmitting and when there are no local thunderstorms.

Antenna Port A is connected to a wire antenna (a horizontal 100-foot wire that runs out from my house’s chimney to a tall tree; about 10 feet of that wire is oriented vertically, where the wire passes through a pulley and then is weighted down so it can move with wind-driven tree movement), while Antenna Port B is connected up to a VHF/UHF discone.

Both antenna systems have an AM Broadcast band notch (reject) filter reducing local AM Broadcast-Band radio station signals by about 30 to 40 dB. I need to use these because the very close KLIN transmitting tower is just miles away and those signals overwhelm the receiver. When I use the signal filters, the local AM Broadcasting signals no longer overwhelm the receiver.

In the following video, I first explain my SDR setup, and in the second half of the video, I tune around the radio spectrum, using the software to control my SDR receiver.

[embedyt]https://www.youtube.com/watch?v=DHj917E1bKA[/embedyt]

A Couple of Questions

After watching this video, WO9B wrote an email to me. Michael asked of me two questions, summed up as:

1. Your SDR window has the IF screen on top. How is that accomplished?

2. Your AM Broadcast filters; more info, please. I live in the area of mucho broadcast stations and that looks like something I could use.

In the following video, I demonstrate how I changed my layout of the SDR Console software. And, I mention the AM Broadcast Filter for SDR Receivers (the hardware filter is found here: https://g.nw7us.us/3kU5SJN).

[embedyt]https://www.youtube.com/watch?v=YLBLHi441Zg[/embedyt]

To Use My Receiver

Download the latest version of SDR-Console from https://www.sdr-radio.com/download – there is a 32-bit and a 64-bit Windows installation package.

The 64-bit installation package may be downloaded from one of these three sources:

1. Google: https://g.nw7us.us/3auBq44
2. DropBox: https://g.nw7us.us/310ooIG
3. Microsoft: https://1drv.ms/u/s!AovWaZDu7Hrd3U-yqK1bs3wuaFw2?e=o4nKeh

The 32-bit installation package can be downloaded from one of these three sources:

1. Google: https://g.nw7us.us/3iLasrZ
2. DropBox: https://g.nw7us.us/3g4VcVc
3. Microsoft: https://1drv.ms/u/s!AovWaZDu7Hrd3U4mJiiRtI9lm70s?e=HDG4ZX

Install the SDR Console package according to the directions given. Once you have the software installed, you will want to add my server. It takes some work to get familiar with the software, but there are online FAQs on how to begin.

One guide on how to add a server to the list from which you can pick may be found, here:

https://www.sdrplay.com/wp-content/uploads/2018/02/SDRConsoleV3-ServerGuide1-1.pdf

I worked on getting all of the bugs worked out of my installation before making the video. It did take some work, and reading up on things. But, the software is solid and a good contender against SDRuno, and HDSDR, and, this way I can share it online with you.

My server is known as, ‘0 NW7US‘ — it will be online when I am not using my antenna systems for transmitting. It will be offline during thunderstorms, or during times when I must use the systems for transmitting.

Software-defined radio is a great way to hear all sorts of communications, from local AM broadcast stations, FM stations, VHF Air Traffic, to shortwave radio stations including amateur radio HF communications.

Thank you for watching, commenting, and most of all, for subscribing; please subscribe to my YouTube Channel: https://YouTube.com/NW7US Also, please click on the bell, to enable alerts so that when I post a new video, you will be notified. By subscribing, you will be kept in the loop for new videos and more.

73 de NW7US

.. (yes, this is an expansion of an earlier post… forgive the redundancy… thank you) ..

My new SDRplay RSPdx software-defined radio receiver is live, via http://www.sdrspace.com/Version-3, using the SDR Console software (Version 3).

The receivers are online whenever I am not transmitting and when there are no local thunderstorms.

Antenna Port A is a wire antenna (100′), while Antenna Port B is a VHF/UHF discone. Both have an AM Broadcast band reject filter, reducing local AM Broadcast signals by about 30 to 40 dB. I need to use these because the very close KLIN transmitting tower is just miles away and those signals overwhelm the receiver. When I use the signal filters, the local AM Broadcasting signals no longer overwhelm the receiver.

Let me know what you think. Enjoy!

To use my receiver:

Install the latest version of SDR-Console which can be downloaded from https://www.sdr-radio.com/download

Install SDR Console according to the directions given. Once you have the software installed, you will want to add my server.

It takes a little to get familiar with the software, but there are online FAQs on how to begin.

My server is known as, ‘0 NW7US‘ — it will be online when I am not using my antenna systems for transmitting. It will be offline during thunderstorms, or during times when I must use the systems for transmitting.

Software-defined radio is a great way to hear all sorts of communications, from local AM broadcast stations, FM stations, VHF Air Traffic, to shortwave radio stations including amateur radio HF communications.

Thank you for watching, commenting, and most of all, for subscribing; please subscribe to my YouTube Channel: https://YouTube.com/NW7US Also, please click on the bell, to enable alerts so that when I post a new video, you will be notified. By subscribing, you will be kept in the loop for new videos and more.

Video:

[embedyt] https://www.youtube.com/watch?v=DHj917E1bKA[/embedyt]

73!