By Jock Elliott, KB2GOM
You never know what you will encounter while simply “tuning around” on the HF frequencies. Just a few days ago around 2 pm local time, I happened upon the Maritime Mobile Service Network. Net control was being swapped from one ham to another, and it soon became clear that the hams running the net were smooth, articulate, and friendly to those checking into the net. The frequency was 14.300 USB.
According to the Maritime Mobile Service Network’s website:
Our primary purpose now is that of handling legal third party traffic from maritime mobiles, both pleasure, and commercial and overseas-deployed military personnel. We also help missionaries in foreign countries, and volunteer net control stations from throughout North America and the Caribbean maintain the network. Furthermore, these stations are assisted by relay stations to ensure total coverage of the Atlantic Ocean, Mediterranean & Caribbean Seas, and the eastern Pacific Ocean. The network, in particular, has been formally recognized for its work with emergency traffic by the Dept. of Homeland Security, the United States Coast Guard, and the National Weather Service, to mention a few.
The network acts as a weather beacon for ships during periods of severe weather and regularly repeats high seas and tropical weather warnings and bulletins from the National Weather Service and the National Hurricane Center.
The Maritime Mobile Service Net is operational every day from 12:00pm until 9:00pm Eastern Standard Time, and from 12:00pm until 10:00pm Eastern Daylight Time, on the 20-meter *Global Emergency Center Of Activity frequency of 14.300 MHz as outlined by the International Radio Union.
* At the International Amateur Radio Union (IARU) Region 1 meeting in 2005, it was decided that certain frequencies on certain amateur bands would be designated as “Global Emergency Center Of Activity” (GECOA) frequencies. The purpose of establishing the GECOA frequencies was to designate a place for passing emergency traffic on amateur frequencies, should the need arise. Over the next few years, Regions 2 and 3 followed suit in making the following frequencies world-wide GECOA frequencies. Those frequencies are: 21.360 MHz, 18.160 MHz, 14.300 MHz, 7.240 MHz, 7.060 MHz, 3.985 MHz, and 3.750 MHz. These and other frequencies, with their band plans, can also be viewed at www.iaru-r2.org/band-plan.
You can find out more about the MMSN here: https://mmsn.org/
Wow, I thought, this is definitely a net that I would like to listen to from time to time. Since MMSN operates from noon until 10 pm, I decided that night to see if I could hear it in bed on my CCrane Skywave SSB with its relatively small telescoping antenna. I extended the whip antenna skyward, clamped on the headphones, and listened to 14.300 USB. Nothing at first . . . but then I could hear some faint modulation in the background. Then, on a whim, I picked up the Skywave and started to wiggle it around, moving the whip in different orientations, in the hope of improving the signal.
To my surprise, it worked. I could hear the signal improve in some orientations of the whip and get worse in other directions. After a bit of experimentation, I got a positive ID on the Maritime Mobile Service Network with the whip at a 45 degree angle to vertical and pointed toward the North. Any other orientation yielded poorer results.
Now, here’s the thing: in years that I have been involved in messing about with radios – including the years I wrote for Passport To World Band Radio, QST, Popular Communications and Monitoring Times — never once did see or read anyone suggesting that picking up your portable shortwave and pointing the whip in different directions and orientations might improve the signal . . . not once.
Back in March, Thomas did a survey and found that 36.8 percent of SWLing readers used portables radios as their “daily drivers.” So, while it might look weird and might draw some stares if you are in a public place, try picking up your portable and pointing the whip at different angles and orientations to see if it improves a difficult to copy signal.
Based on my experimentation on both ham and shortwave broadcast signals, you might just be pleasantly surprised.
And if you already knew about this, or if you try it and it works, I would love to hear about it in the comments below.
I have been waving around radios with whip antennas for as long as I can remember.
Does anyone remember the gymnastics people used to do with rabbit ear TV antennas?
Peter,
Yes . . . I had forgotten. And sometimes there was a different rabbit ears configuration for each of the three stations we could receive.
Thanks for the flash-back.
Cheers, jock
I think that David’s reply is spot on , as well as some of the other replies. After building and playing with antennas in Jr High School, the Army (Airborne All the Way), a university physics lab, Government, industry, and currently as a hobbyist, I agree with what an acquaintance (PhD EE, Berkeley) told me years ago, ” antennas, scattering, propagation, etc is sometimes just ‘magic’ “. I currently play with a long (~ 50 feet DX-SWL “Sloper”) and occasionally shorter wire antennas, a home-made passive loop, and an active W6LVP loop, and I agree with Jock, “if something weird or unusual makes the reception better for you, then forget the rules and just enjoy.”
I just saw your article, and I tuned to 14,300 kHz.
The QSO is very organized. I live in Harrisburg Pennsylvania, using a Tecsun PL-330 radio with a “modified ” whip antenna. (The stock antenna is okay, the Sangeon external antenna is okay. I found a suitable antenna from the store that has everything, giving me adequate length and a better signal). I found the middle part of my 2nd story house worked well, with the whip antenna vertical and tipped some some to the north. The moderator from South Carolina came in strong. We have rain today, givng some QRN. I think the skip for 20 meters is working in our favor
Dave,
I’m glad you enjoyed it.
Cheers, Jock
When I was growing up there was a ham in the neighborhood who was active in the MARS program. I think the acronym stood for Military Affiliate Relay System. The goal of this program was to relay messages and patch phone conversations between service members (often in Viet Nam) and loved ones at home. I have fond memories of watching K8SKO
help provide the valuable service.
It has been my experience that for any given length of wire a “closed loop” gives a better signal to noise ratio signal.
I say “closed loop” because you seldom can make a square, much less a circle. The oddest triangle will still pick up better. Clipping one end of a wire with an alligator clip to the tip of the telescoping whip and the other end of the wire with the appropriate plug to the ground side of the external DC power socket of the portable radio almost always results in a better S/N reception.
Taking a tip from the Vietnam era PRC military radios, carrying a small & light “snap straight when extended tape measure” to be part of one side of your make-do Loop gives you much greater flexibility than a loose drooping wire.
Someone should reproduce in kit form the out of production Kiwa Pocket Loop.
https://web.archive.org/web/20000208022320/https://www.kiwa.com/odxarvw.html
Hank,
I agree with you about loops.
In fact: https://swling.com/blog/tag/horizontal-room-loop/
Cheers, JOCK
Factors which affect the received signal strength
The effective radiated power of the transmitter or in frequencies below 3 MHz Cyclomotive Force (CMF) which determines the field strength at 1 km from the transmitter.
The path length and for omnidirectional transmissions of ground waves it reduces as a square law.
For frequencies below 3 MHz the conductivity of the earth and under 30 MHz the reflectivity and direction in the ionosphere. Above 45 MHz tropospheric ducting
Obstructions which are conductive ie metal and water.
Directionality of the antenna. For frequencies below 3 MHz ferrite rod antennas are very directional as are antennas above 30 MHz using either Yagi-Uda or log periodic designs.
Antennas which are much shorter than a half wave length long (excluding ferrite rods) tend to have either omnidirectional characteristics or more than one peak sensitive directions.
Directional antennas can be used to either maximise the wanted signal or their minimum sensitivity direction used to reduce interference.
Lastly remember that AM receivers have automatic gain control which measures the carrier signal strength to reduce the receiver’s sensitivity to try and maintain a constant volume as the received signal strength varies. In receivers of digital and FM signals (DAB+, DRM, HD Radio) a signal strength meter is essential to get the most reliable signal. Digital receivers also measure the error rate and when it is too high the receiver cannot stop making awful loud noises so a mute circuit converts them to blocks of silence. If the error rate is low enough the receiver can correct the errors for perfect reception
mangosman,
Thanks!
Cheers, Jock
Sometimes you have to ‘wiggle’ for the signal… 🙂
Moving around and such has always been something I try when attempting to get the best signal. Have to give the antenna as much advantage as possible… a little piece of metal trying to gather as much as it can.
JD,
“Sometimes you have to ‘wiggle’ for the signal” — There’s a t-shirt right there.
I’d buy one!
Cheers, Jock
It is doubtless that subtle DX’ing “wiggle” was what initially attracted my wife all those years ago.
How quickly they forget. ?? ?
Another factor to keep in mind is the fact that our homes these days are filled with so much more RF interference from various electronic devices, switches, phone chargers, etc. than in the past. Some devices seem to cause drastic, overall interference wherever you are in the house, such as plasma or big screen TVs. Other devices seem to create only “pockets” of interference. That is, there can be many small “sweet spots” of good reception around the house…sometimes within only inches of each other…where the interference is much less or even non-existent…and sometimes these “sweet spots” are MUCH closer to the source of interference than one might ever think would be possible! Therefore, moving the radios and whip antennas around a lot as you have described finds these many and varied sweet spots. Bottom line: move around and don’t always assume that a certain spot won’t be any good for reception. Try things and don’t be afraid to be creative.
Another thing: different radios respond differently.
I have found that some interference might render a certain model practically useless, while another model in the same location doesn’t seem as affected. Also, more expensive doesn’t always mean better, especially in the realm of portables.
If it’s one thing I have learned in all my years of twirling the dials of radios, it’s this: if something weird or unusual makes the reception better for you, then forget the rules and just enjoy. That’s a lot of the fun of this hobby.
David,
Those are all good considerations . . . and I agree about the fun of the hobby.
Cheers, Jock
David,
“If it’s one thing I have learned in all my years of twirling the dials of radios, it’s this: if something weird or unusual makes the reception better for you, then forget the rules and just enjoy.”
I love that!
Cheers, Jock
Jock,
I had always thought that by holding a small radio, your body acted as ground plane to the radio and antenna, thus the improvement.
A test might be for your to get the antenna in the best position, and then set the radio down and move away from it to see if it’s just the antenna position or the combination of your body along with the antenna.
I do know that by just holding some of my portable radios, I get better signal sometimes.
73
Bill WD9EQD
Smithville, NJ
Bill,
Interesting thought. I will definitely do that experiment.
Cheers, Jock
This reminds me of the other night when my wife was chuckling at me for my peculiar gyrations with my XHDATA D-808 on long wave. Of course LW uses the small ferrite antenna built into the radio, and so there I am laying in bed, raising this thing up over my head, twisting it between N/S and E/W orientation… listening intently… on USB…
“Yes, honey… that is “how it works” and so far I have DX’ed almost 10 NDB airport beacons this way, I’ll have you know…”
I assume she was impressed by that.
Shame the CCranes dropped LW… I still think it’s a lot of fun.
John,
You made me smile!
I would refer you to this: https://swling.com/blog/2023/05/a-little-barefoot-ultralight-mw-dxing-in-which-my-mental-status-is-questioned/
Cheers, Jock
Hi Jock,
That net is really fun to listen to, and they have, on occasion, actually aided in the rescue of folks, or helped people with navigation issue.
I have been twisting and turning radios and antennas ever since my early days of AM DX listening (before I knew it was called that). I presume I lucked into it early on noticing signal improvements, but I rarely have a portable shortwave or AM) radio sitting on a table. I am usually in a chair or on the couch and moving it around as needed, even when testing new radios. This no doubt will open up a whole new level of reception for you!
Cheers! Robert
As always, thanks Robert.
I knew that ultralight MW DXers change the orientation of their radios to try to improve reception, and I had seen that where you point the antenna can be very helpful in chasing low-power FM stations, but I had never seen anyone do it . . . or mention it . . . as a technique for improving an HF signal.
It promises to be fun and useful in the future.
Cheers, Jock
Hi Jock,
Yes, I listen to 14.300 MHz USB frequently with the Skywave SSB 2 antenna fully extended and have noted the directional response. I’m wondering if it’s related to the local RF field orientation in the house or changes in the effective vertical height. The other question is does the best orientation of the antenna change with different transmission sites on the net?
It’s a bit frustrating to hear only one or two sides of the conversations. I don’t have a multi-element beam 100 feet in the air. 😉
I’ve also been listening to the Big Gun Friendship Net generally on 7.128 MHz, MWF, 2300-0200 UTC – a good opportunity to catch trans-Atlantic and Latin stations. See https://swling.com/blog/tag/big-gun-friendship-net/.
Regards,
Bob
Bob,
Thanks for the tip on the Big Gun Friendship Net . . . I will definitely check it out.
While listening to MMSN, only once did I hear one of the stations other than the Net Control, and the station that was checking in was Tennessee, I think..
No multi-element 100 ft in the air here either. Still, it’s fun.
Cheers, Jock