Category Archives: Ham Radio

Kostas explores an alternative to Morse Code that’s been used in prisons, with roots in ancient Greece

Many thanks to SWLing Post contributor, Kostas (SV3ORA), for sharing the following guest post which originally appeared on his radio website:

TAP: A Morse alternative mode for the HAM, with no need for training

by Kostas (SV3ORA)

Introduction

The thinking of this new mode, came to me when someone posted that he quit the HAM hobby because he did not learn Morse code and he did not want to use computers to do the job for him. Some time I faced a similar situation and I believe many do one day or the other. So I thought that I had to do something about it. It is too bad people quit the hobby or missing the fun of the KEY operation, because of the obstacle of Morse code. No matter what CW operators that already learnt Morse might say, the fact is that Morse requires patience, continuous practice and most importantly time. After all military had dedicated courses on it in the past, so it must be more than true. These are things not all people can, or are willing to do. An alternative that gives the same pleasure like Morse and operates with the same techniques, but requires no training and time must exist. Meet the TAP mode!

Mode description

This mode has its roots to ancient Greece. You may read the article in Wikipedia for more information on the Polybius square. A form of it, was used in the previous century in was times, for in-prison communication. A modified version is presented here by me, that fits perfectly the HAM radio. This modified TAP code scheme, is dedicated to HAM radio and includes the numbers and the letter “k”.

This is all you need to know in order to send and receive TAP. It is easy to follow and easy to generate on paper. This is a 6 by 6 table, with the first six alphabet letters placed in the first line, the next six in the second and so on. After the alphabet ends, the numbers are put in the same manner. Thats it!

Sending TAP

It is better to describe the sending procedure with an example.
To send the letter “i” you send two dots (“i” is on the second row), wait a bit and then send 3 more dots (“i” is on the third column). In other words, you first count the number of rows where the letter exists, then wait a bit and then you count the number of columns where this letter exists. Before sending the next letter, leave a bit of more time, so as to distinguish that this is a separate letter and not the time between rows and columns. Thats it!

Try it now without any transceiver! Write the TAP table on a piece of paper (you do not need to write the row and column numbers), or read it from the website. Tap on your desk with your finger and send some words to the colleague near you. See how easy it is?

There are actually four spacings involved. The spacing between adjacent dots, the spacing between the row and the column, and the spacing between letters and the spacing between words. Follow the PARIS spacing, like Morse code does, if you intent to write a software for it. However, in practice, manual operators would need to consider just two spacings, the spacing between rows and columns and the spacing between letters. These are the most important. Just make the one bigger than the other and communication should be achieved without problems.

Receiving TAP

It is better to describe the receiving procedure with an example.
To receive the letter “i” you listen two dots (“i” is on the second row), then a short scilence time and then listen 3 more dots (“i” is on the third column). In other words, you first listen for a number of dots (this is the row where the letter exists), then sense the scilence and then you listen for the next number of dots (this is the column where the letter exists). The scilence time between two letters is greater than the scilence between rows and columns and this can be distinguished easily. Thats it!

Try it now without any transceiver! Write the TAP table on a piece of paper (you do not need to write the row and column numbers), or read it from the website. Put your coleague to sent you some TAP words and you should be able to decode them by counting the rows and columns in the TAP table.

A programmer that may need to implement the mode in software, should follow the PARIS spacing to distinguish the different parts of the code, as described above.

TAP advantages

Here are some advantages I can think, of TAP in comparison to Morse.

No training is required, start using it imediatelly, even by non-HAM people and kids. This probably is the greatest advantage and this is why most would want to use TAP in HAM radio.
The encoding/decoding square can be drawn easily, it is very easy to remember how to draw it.
Decoding by hardware or software means, becomes very easy, as there are no dashes to account for. Dot lengths can be anything and can be even varying from dot to dot, it does not matter.
All you count, is how many ON-states (taps) there are and the rough timing between them, to decide between a row-column or a letter. Because of this intependency from dashes, the code can be used on any means, radio, light, pipes, walls, desks etc.
If dot lengths are kept very short (up to the point where channel noise allows it), RF amplifiers can be pushed beyond their limits (due to limited duty cycle), or otherwise run cooler within their limits. There are some mediums, like light communication, where bright pulses of light can be produced easily (eg. xenon tubes), but not kept for duration and TAP is ideal on them.

TAP disadvantages

Here are some disadvantages I can think, of TAP in comparison to Morse.

Speed limit issues probably. TAP beginners achieve for sure faster speeds than Morse beginners. However, a trained Morse HAM, can achieve greater speeds with Morse.
Learning the table by heart, can be tricky in comparison to Morse. However war prisoners had tricks to learn by heart the 5×5 TAP square.
Not known (yet) among the HAM community, like any new mode. Why not change that by let HAMs know about it?

TAP common points to Morse

There are some common points shared between TAP and Morse code.

Both are relatively slow modes.
Both are ON/OFF keying modes, efficient class-E amplifiers can be used.
Both share the same channel bandwidth and noise-related characteristics.
Both are human-oriented, although TAP does not require training. Both share the PARIS timing when implemented in software.
Both allow for the “joy of the KEY”. You send TAP with the same equipment as Morse.
Both are ideal for homebrew QRP, due to efficiency and transceivers simplicity.

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A little off-line, off-grid camping

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You might have noticed a lack of posts this weekend and that would be because I was completely off-grid and off-line, camping with two good friends in Pisgah National Forest.

It was brilliant, actually. I got to hang with friends I’ve known for over 30 years, test my new one person backpack tent (a.k.a. the “Bear Burrito”–the one on the right above), and of course I played a bit of radio.

Black bears are a fact of life here in the mountains of western North Carolina and we spotted three hanging out within 25 meters of our campsite.

By the way: the trick when camping with bears? Don’t put food in your tent, else that whole “bear burrito” thing becomes a reality.

I had a fabulous time putting my Elecraft KX1 “Ruby” on the air. I made perhaps 15 contacts in CW (Morse Code) with 3 watts of power.

One of the cool things about the KX1 is you can change the mode to SSB and actually tune through several shortwave broadcast bands (if you have the three or four band version of the KX1). Of course, I had to do a little SWLing.

As I mentioned in my previous post, I’m also a proper coffee snob and I firmly believe coffee tastes better when brewed outdoors. Yesterday morning, I brewed a pot of Rock Creek French Roast.

Off-grid, off-line camping recharges my internal batteries and it’s for this reason, I’ll be doing a lot more this year with my family.

It’s is also a brilliant way to experience an environment without any forms of radio interference (QRM or RFI). If you want to do some proper DXing, take your radio on some primitive camping experiences. It’ll remind you what life was like before switching power supplies ruled the world!

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A Practical Application of Ham Radio – the Commuter Assistance Network

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The big gun of the operation, the Motorola CDM 1250. While sitting on The Big 94 repeater, it also scans NY State Police frequencies.

By Jock Elliott, KB2GOM

Disclaimer: this isn’t about shortwave; it’s about 2 meter ham radio, but it’s something I thoroughly love doing in the world of radio.

About 40 years ago, a Citizens Band operator named Ed Barnat started a loose-knit group called Tri-County Assistance. Its purpose was to detect problems on the roadways and report them in real time. Ed acted as the central hub for information and in turn relayed it on to the proper authorities for action. He also used the information gathered through the Tri-County net to provide on-the-air traffic reports for local radio stations. Back then, there were no cell phones and no traffic apps on smart phones. CB and broadcast radio were the only sources of traffic info for commuters.

In time, Ed got his ham license – N2RKA – and added a 2-meter section to the Tri-County net. Somewhere along the line, I got my ham license and participated in both sides of the net. Then change of jobs forced Ed to stop running the Commuter Assistance Net as it was now known.

Thrown into Deep Water

A couple of hams tried to continue the net, but struggled and ran into trouble. One day, I had just checked in when the repeater owner came on the air, because of a problem, he forbid the two hams from using his repeater to run the net and added, “Jock, if you want to run the net, you can.”

Holy smokes! I believed firmly in the concept of the Commuter Assistance Net. I had a wife and a son, and if they were out on the roadways and had a problem, I would want them to get help (no cellphones, remember?). So I agreed, but being Net Control is very different from being a net participant, and I had to figure it out as I did it. That was over 25 years ago.

At first, I kept a strict log of the callsigns of the hams who checked into the net, and I maintained a list over 70 agencies that I might need to call with an incident. With the advent of the Traffic Management Center (see below), now I have a single point of contact, and I keep a hash mark tally of the number of hams who participate each week.

One of the things I am most proud of is the lack of bureaucracy. We’ve operated 25 years with no dues, no bylaws, no formal membership list, and only three meetings . . . all for pie and coffee.

The Dawn Patrol

Scanners are part of the commuter net. Below are some of my notes for the week and my hash tag tally of check-ins day-by-day.

Every workday morning at 6 am, I fire up a Motorola CDM 1250 transceiver on 146.94 and announce: “This KB2GOM, net control, standing by for the Commuter Assistance Network.” 146.94 is an open repeater (no tone) that is located on Bald Mountain, north of Troy, NY. Its coverage footprint is enormous, reaching far to the North, South, and West. The East is pretty well blocked by the Berkshire Mountains. Official backup is our sister repeater on 147.330 – PL 146.2, and if both repeaters are down, find the net on simplex at 146.520.

The Big 94 — 146.94 — repeater has a huge footprint.

The net serves the Capital District of New York, which nearly at the eastern edge of the state, about 145 miles north of New York City. Workday mornings, a large number of commuters drive into the three major cities: Albany, Schenectady, and Troy, which have a population of about 600,000. People commute to state government offices (Albany is the capital of the state), colleges, universities, and a variety of companies.

The net runs every morning from 6 am until 8:15 am and sometimes longer when a major event happens such as a blizzard or major accident. On an average day, there a relatively long stretches of silence, punctuated by check-ins. On a typical morning, 8-10 hams will participate, and we’ll handle 1-2 incidents a day.

Most of the time, the incidents are disabled vehicles in or out of traffic which I report by phone to the Traffic Management Center, which is run by the NY State Department of Transportation. The TMC is located in the same room as the State Police dispatchers, and when a report comes in, troopers or HELP trucks, as appropriate to the situation, are sent to handle the call. Sometimes TMC calls to let me know about incidents, so the communication is a two-way street.

A trash truck that almost went over the guardrail.

Sometimes we get accidents, accidents with injuries, chemical spills, vehicles (including a propane tanker) on fire, rollovers, and even a truck that smashed into a bridge overpass. During one morning, an ice storm swept through the area, and I handled 70 calls in two hours.

Just Two Rules

Everyone is welcome to participate in the Commuter Assistance Net. The goals are simple: to detect problems on the roadways and report them to the proper authorities and to share that information with net participants.

The net has just two rules. The PRIME DIRECTIVE is: Don’t cause anything! Rule two: when in doubt, report anyway.

With all the traffic cameras that seem to be just about everywhere, one might ask: “Why do you even need a commuter net?” Three reasons: (1) the cameras don’t see everything; (2) the folks at TMC can’t monitor all the cameras all the time; it’s impossible, and (3) there is nothing like a trained observed (which the net participants are) to let you know what is actually going on in a particular situation.

Sometimes Funny Happens

Here’s a true story from the net that was posted on Reddit:

Going back a few years, I had a job that required me to commute about 45 minutes each way. On one local repeater, on 146.94, there was a “commuter net” that ran every morning from about 6-8, net control was a fellow that worked from home named Jock Elliot, KB2GOM. The ostensible purpose of the net was to track commute traffic conditions, warn about backups, construction, obstructions, debris, and to get assistance to stranded motorists. Jock had the local traffic center (the one that provides traffic reports to all of the broadcast media in the area), DOT and several fire and police departments all on speed-dial and would bring them up to date. Sometimes, they would call him as well with info, because he could be counted on to get eyes on the situation. I was a participant every morning during this stretch of time.

It was a fairly relaxed net, the channel was quiet most of the time, owing to it being largely event-driven, so some light banter went by most mornings . . . more some days than others, depending on the overall conditions . . . you get the idea, I hope.

Anyway, it was protocol, when a car was spotted along the side of the road, we would call it in, and Jock’s first question was always, “Is it occupied?” The answer to this question would decide what order he called DOT (which had a free roadside assistance service), police, and the traffic center. If it was occupied, it was in that order; if not, it was traffic center, then police.

That leads us to one particular morning. Jock gave me a call. It went like this:

Jock: KC2***, KB2GOM. Are you on this morning?

Me: KB2GOM, KC2***. Go ahead.

Jock: Do I remember right, that you take I-90 east?

Me: QSL.

Jock: Have you passed Everett Rd. yet?

Me: Negative. Probably about ten minutes ahead.

Jock: Great. The Traffic Center is telling me that they’ve got a report of debris in the road. When you get there, would you get a closer look at it so I can tell them what it is?

Me: Roger that.

About ten minutes pass. . . .

Me: KB2GOM, KC2***. I have eyes on the debris.

Jock: KB2GOM. What is it?

Me: There is a mattress sitting in the middle lane, about a hundred feet past the offramp.

A beat.

Jock: Is it occupied?

Finally, I am deeply grateful for all the hams who have participated in the net over the years . . . over 150 by my best estimate.

One day, I was thanking one of the net participants, and I said: “Without you guys, I would be just a weird old guy with a radio.”

Fred, W2EMS, came back to me: “Ah, Jock . . .”

Me: Yeah?

Fred: “Even with those guys, you’re still a weird old guy with a radio!”

When I stopped laughing, I said, “Guilty as charged.”

So if you are in the Capital District of New York on a workday morning between 6 am and 8:15, drop a call on 146.94 . . . everyone is welcome!

End —

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W9IMS: A Radio Run at the Indy 500

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W9IMS: A Radio Run at the Indy 500

By Brian D. Smith, W9IND

You can’t win the Indianapolis 500 until they wave the checkered flag – and you can’t win a W9IMS Checkered Flag Award unless you contact the Indy 500 special event.

You’ll have that opportunity from now through 11:59 p.m. Sunday, May 29 in Indianapolis (0359 UTC Monday, May 30) as W9IMS fires up daily on 20 and 40 meters SSB. usually on or around 7.245 and 14.245 MHz.

The Indy 500 special event is the second of three W9IMS operations commemorating the major auto races at the Speedway. The first event of 2022, which ended May 14, honored the Grand Prix of Indianapolis, and the third will run from July 25-31, during the week preceding the NASCAR Brickyard 200.

Both hams and SWLs are eligible for the Checkered Flag certificate and the three individual QSL cards, all of which boast new designs for 2022. To earn the certificate, however, you must work (or tune in) W9IMS during all three of this year’s special events – and it’s too late to catch the first race. But even if you miss the trifecta, you can still claim collectible QSLs from the other races.

Tips on finding W9IMS:

Check DX Summit (www.dxsummit.fi) for spots listing the current frequency or frequencies of W9IMS, if any. By typing “W9IMS” in the search box at upper right, you can customize it to show reports for only Indianapolis Motor Speedway special events.
Go to the W9IMS web page (www.w9ims.org) and look for the heading, “2022 Operating Schedule.” Click on the Indianapolis 500 link, which opens into a weeklong schedule listing individual operators and their reserved time slots. Your odds of catching W9IMS on the air improve significantly during these hours.
Prime operating time on weeknights is 6 to 10 p.m. Indy time (2200-0200 UTC). However, W9IMS can appear anytime, even on two bands at once, between now and 0400 UTC Monday, May 30.
Remember that the published schedule can be shortened by adverse circumstances, such as noisy band conditions, local thunderstorms or a lack of calling stations. Don’t wait till the final hour to chase W9IMS!
Operators often get on the air at unscheduled times. That’s why DX Summit is your best bet for locating W9IMS’s current spot(s).

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Guest Post: You might be a radio nerd if…

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Many thanks to SWLing Post contributor, Jock Elliott, who shares the following guest post:

How can you tell if you are a radio nerd?

By Jock Elliott, KB2GOM

Jeff Foxworthy made a name for himself with his comedy routine, “You Might Be a Redneck.”

That phrase – you might be a redneck – is always followed by a qualifier, such as: “If you ever financed a tattoo.” My favorite: you might be a redneck if you ever mowed the lawn and found . . . a car.

Taking a cue from Foxworthy, I thought I might help the readers of the SWLing Post determine if they are radio nerds.

You might be a radio nerd, if . . .

You think DXing NOAA weather radio stations is kinda fun. (That would be me.)
You made special arrangements with the National Institute of Standards and Technology to visit WWV, the NIST time station in Colorado. (That would be our very own Thomas, Maximum Leader of SWLing.com. Check out this post.)
You traveled to Newfoundland, Canada, to lay out hundreds of feet of wire to listen to tiny maritime weather stations in Northern Europe. (That would be Don Moore, and if you have not read Don’s posts–this one or this one–you are in for a treat!)
You see a display of pool “floaty” noodles, and all you can think of is: “Construction materials for ferrite sleeve loop antennas.” (That would be Gary DeBock, with this post and numerous posts on SWLing.com.)
You think it is fun to get up in the middle of a 10 degree Alaskan night to DX an Australian station 8,000 miles away and then find yourself on an Australian newscast. (That would be Paul Walker.)
You are constantly thinking about how you might improve reception at your station. (That would be most of us, I think.)
You have accidentally said your Amateur Radio call sign at the end of a telephone conversation. (Me, again.)
You find yourself using ham lingo in ordinary conversation: “I’m going to QSY to the kitchen.”

So, are you a radio nerd? If so, present your evidence in the comments below.

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How Giuseppe protects his Icom IC-705 during travels

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Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who writes:

Dear Thomas and Friends,

Giuseppe Morlè (IZ0GZW) here from Formia, central Italy.

This my latest video is about everything I have done to protect and transport my Icom IC-705.

I bought an aluminum case, light and very resistant with everything one needs inside to be able to use the IC-705.

- 2 power banks, one of which is solar-charged to be able to recharge the battery while in operation
- 2 wire antennas: a dipole type with BNC / banana socket with 10 meters of cable per arm and a 20 meter row, monopole, to be used in reception as you saw during the DXpedition to the Island of Ponza
- I also bought the Mydel protective “cage” with antenna attachment on the front and PVC protection of the display

Given the high cost of this little jewel, it is advisable to take all precautions for its safety during transport and use.

Click here to view on YouTube.

I hope I made you happy …
Thank you all,
73. Giuseppe Morlè iz0gzw.

This is great, Giuseppe! Like you, I’ve taken extra measures to protect my Icom IC-705 as well. Your kit looks comprehensive–I love the fact that pretty much everything you need is inside.

Thank you again. We always enjoy your posts from beautiful Italy. Ciao!

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Kostas pairs his Collins 51S-1 with a Heathkit SB-620 bandscope

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Many thanks to SWLing Post contributor, Kostas (SV3ORA), for sharing the following guest post which originally appeared on his radio website:

Collins 51S-1 band scope using a Heathkit SB-620

by Kostas (SV3ORA)

The purpose of this project, is to connect a Collins 51S-1 receiver with a Heathkit SB-620 “scanalyzer”, so as to give the 51S-1 band scope capability. Right into the schematic presented below, a slight modification is needed to the 51S-1. I usually do not do modifications to old equipment unless absolutely needed and even when I do so, I take care for them to be easily undone and to modify them as little as possible.

The modification to the 51S-1 is simply a small coupling capacitor connected to the plate of the mixer tube V4A and a short run of thin coaxial cable, connected as shown, to one of the several SPARE RCA connectors at the back of the 51S-1. Collins engineers were smart enough to include SPARE RCA connectors at the back of the radio, which are not connected to anything inside the radio circuit, to be used for different future purposes. So we do not have to drill any holes to the chassis of the precious receiver, which would be catastrophic.

Click to enlarge.

The coupling capacitor is just 5pF, so compared to C125, this presents only a tiny fraction of the loading to V4A plate, i.e. not affecting the normal operation of the receiver. Note, you cannot take directly the 500KHz IF output that is originally provided by the 51S-1 RCA in the back of the radio. This is because this IF is AFTER the filters, so it is a narrow IF. We need WIDE IF for the scanalizer to work properly, so you have to perform this tiny modification to the 51S-1.

No need to say that the SB-620 needs to be re-tuned for 500KHz instead of 455KHz. I was unlucky and my SB-620 did not have the appropriate L3 to be tuned to the IF of 455/500KHz. Mine had the L3 used for an IF of 5.2-6MHz. I converted the SB-620 to work down to 500KHz by using this original higher-frequency L3 and adding two additional inductors to it, one at its bottom and one at its top, so as to make L3 larger. The additional bottom inductor I added (connected from the bottom of L3 to the ground) was a 15uH choke. The additional top inductor I added (connected from the top of L3 to C3 and C5), was a 455KHz IF CAN transformer (the one with the adjustable yellow-painted cap) taken out of a transistor radio. Of course I have removed the internal capacitor of the transformer before using it. My transformer had something like 200-300uH in the mid-set point. It is not too critical as this is a tunable transformer.

By making this modification to the SB-620 you can bring the 5.2-6MHz L3, down to 500KHz. Of course the slug of L3 now has limited tuning range. But we can coarse tune the hybrid L3 now, by tuning the IF transformer that has been added. This solution worked like a charm and the original L3 is still fit in place, looking original and helps in fine tuning if needed. For the optional mixer input (points A, B, C on the SB-620), I used circuit #1, but I did not notice any real difference from circuit #3. RFC1 is 304uH and I connected three 100uH chokes in series to make this RFC.
The solution described in this page, will add a huge value to your vintage receiving station. SWLing feels just different by having an all-tubes computer-free band scope. Here is a picture of the setup, nicely glowing in the night. That P7 CRT blue phosphor with its green afterglow “memory” effect looks amazing! Narrow resolution is actually only achievable, because of this afterglow of the CRT, which allows for much slower sweep rates.