My HF/SSb antenna attempts

[swiftibis]

Hello all,
I'm an aspiring Ham and have a good bit of fun with it.  As I live on my boat it's one of the more interesting ways of communicating while we're out cruising.  If I get bored there's always somebody to talk to.  I have an Icom 7200 with the AH-4 tuner, as well as a IC-708 UHF/VHF radio.  I use the VHF out of my masthead antenna (I unplug from the marine VHF, switches are 100$!) all the time and get ranges up to 50nm with another Ham on a sailboat down the coast.  I also talk to some pretty far repeaters. It's really cool to set it to scan all the repeaters and working channels as well as the marine VHF and emergency channels.  I leave it on scanning all day and get to hear some interesting stuff.

But the HF is problematic on my boat.  On my previous Hunter 31 I ran a copper wire from the port aft to near the masthead on a spare halyard.  This kept the antenna away from the split backstay.  It was grounded with a few inches of thin aluminum flashing to my rudder post.  Aluminum works as well as copper, consider that the rudder is SS which is much more resistive to RF.  Aluminum has about twice the resistance of copper, so make it twice as wide, and flashing is cheap.  This setup worked very well and I always had great rx and tx away from the dock.  At the dock it's too noisy for everything except digital modes.

Now on my P367 cutter I have gone through several iterations, with the goal of not spending money as long as possible, exhausting all alternatives.  I first attempted to put the tuner attached with antenna end to the backstay, and the grounding to the ship's grounding loop.  This did not work.  I could be heard not so well but couldn't recieve anything, not even WWV.

Next I raised the same copper wire up the backstay flag halyard, and first grounded off the ship/s grounding then bought a kiss ssb.  The ship's grounding was noticably noisier unless I shut everything, including lighting, off.  The LED lights on the boat caused noise, and the fridge causes terrible noise.  Even with the KISS my recieve was terrible, which is probably because the entire antenna was only inches from the backstay which was grounded to the boat.  I moved the KISS 3 times until now it curls away from the ATU which is in the aft center lazaret off toward the port hip.  It's zip tied to the ship's grounding system.  The KISS did not seem to work well when under the fuel tanks and engine, but I may go back to that in the future.

So I looked at the GAM, and understood that by having parallel equally spaced in-phase antennas there should be a 'null' where the backstay is, so seems like a great idea.  However the system is more costly than a backstay insulator, so I decided to make my own (for 10$).  I took 2 42' runs of RG8 cheap CATV cable and zip tied them to wood spacers.  The active part of this was the grounding shield, a combo of aluminum foil and wire mesh, not the inner copper core.  This is the cheapest wire possible due to mass production.  The wood spacers were loosely u-bolted every 5' over my backstay so the net effect was an identical configuration to the GAM, perhaps with a bit more spacing of antennas from the backstay.  I was not impressed.  Rx was better, and Tx was noticably improved.  I got a 5-9-9 from somebody I could hear at a 3-5-5 level about 700 mi away on 14mHz.  I used the KISS as the ground.  I tried the ship's ground but didn't work any better.  I also could pick up WWV on multiple bands but with substantial noise.  I met a cruiser returning from the bahamas and he had the Icom 802, insulated backstay, kiss SSB ground and 140 ATU, and his system sounded great on the same day that my cheap GAM knockoff sounded awful.

So... I'm tired of messing around, but I'm satisfied that I have exhausted all the low/no cost options.  I bought a Hi-mod backstay insulator today, expensive for 3/8" wire!  I hope that makes things better, should arrive in a few weeks.  It will be a much cleaner install besides.  I'm only going with 1 insulator up top and will tell my wife and guests not to touch the backstay if I'm playing with my radio.  If anybody gets a burn then they will have learned what not to touch, when, and why.  I will comment again once I get some signal reports.

Mike
Boracay Star, 1982 Pearson 367 Hull 26

[swiftibis]

This weekend I installed a Hayn Hi-Mod backstay comp-comp insulator for my 3/8" wire.  I offset from the mast top by 6' which left me with a 41' antenna which should work well on most bands (see http://www.hamuniverse.com/randomwireantennalengths.html for more details).  I didn't account for velocity factor difference, but that should be relatively small.  I ran the antenna feed from the ATU up to the place where the SS wire starts and hose clamped it on, covered in grease.  In the past I learned that threaded rod and sharp corners can kill radio power, so I didn't want to connect to the inside of my chainplate as some people do.  The RF would have to hop through the chainplate, into turnbuckle, and through the threaded stuff over all sorts of sharp corners.  I don't have a lower insulator (nor will I at the price!!), although at some point I may cover an area of the backstay with PVC to protect passengers. 

Results?  Phenomenal! Night and day, of course things weren't working very well before.  Things are finally working at the dock, where it was always very noisy before.  I heard a contact from Finland TX at 100W on 20m, although he couldn't hear me.  I also picked up many other DX stations.  Most stations in the US came through well on all the bands I listened to from 80-12m.  I'm able to tune 80-6m.  Further, I can hear all the SWL broadcast stations that I couldn't before.  If weather cooperates this weekend then I'll see if noise gets better away from the dock, as it was a S4-5 across most bands.  However I'm fully satisfied with it's functioning despite the high price of an insulator.

I should note that my Sea Frost 12V fridge causes an awful amount of interference, so I just switch it off when using the radio.

Hope this helps somebody,
Mike
Boracay Star, 1982 Pearson 367 Hull 26

[Dale Tanski]

Mike,

I must admit that I almost (OK I do) need a reference manual for some of the stuff you are talking about.  I read your first post back on the 4th and didn't quite know what to think about it all.  I was hoping someone else would jump on in with a post.  Sorry we kinda ignored you. 

I am confidently assuming that you are really into HAM and have been into this along time.  A good friend of my fathers was a HAM and his basement was full of post cards (you HAMS call them something else) from other operators all over the world. Apparently it was like a merit badge system for how diligent one was (hours spent) and how efficient their equipment was.  Merit badge probably isn't the right term maybe more like scavenger hunt, how many people, states, countries, continents and so on. 

So here are a few question for us great unlearned.  Is HAM equipment the same as SSB?  Is the term SSB the marine aspect of HAM?  What are DX stations?  You tune from 80-12 meters, how is that possible with a 41ft antenna?  (I know the antenna length is important, and trust me the link you attached and reading the article didn't help me much) You can tune down to 6 meters, don't lower frequencies travel farther but you need more power? (something about something I heard about submarine communications or was it HARRP)  What kind of voltage/amperage are you putting out that you need to cover the backstay with PVC?  It sounds like you are running your broadcasting power through (up) the backstay.  Wouldn't the stainless wire be an awful conductor and therefore very inefficient?  Wouldn't switching to galvanized wire be better?  What does the term GAM mean?  (in the nautical world it means chew the fat) And how about WWV while you are at it or did we miss world war III & IV although some will argue we are in WWIII.

Perhaps we just need a basic HAM course complete with glossary. About the only thing I could wrap my head around was your Sea Frost compressor probably has a variable speed Danfoss compressor in it and the SCR's that control the speed are singing for you.

Good Sailing...

Dale Tanski

[swiftibis]

Hello Dale,
So sorry for the jargon!  I'm an engineer and I'm filled with jargon, but I've spent a lot of time doing research on a high frequency (HF)  radio on boats for the long distance cruising I have planned for my future.  So I've only been into ham radio for a year now, but I've studied and am almost to taking the third and most difficult exam.  You're right on the money for QSL ("conversation" in morse quick-codes) cards, they're like bragging points or merit badges.  I have qsl cards that we give out to other cruisers we meet passing through Destin, or I send to Ham people I've made contacts with.

So what's the difference between Ham and SSB.  Well first I must clarify that there are HF radios (from 3 MHz to 30 MHz) and then VHF (from 30 MHz to 300 MHz).  The hardware and antennas are different so usually they're different boxes, al though there are combo units.  HF radios tend to be much bigger. 

Most people have marine VHF radios that operate around 150 MHz on designated channels, but a similar Ham VHF operates on 2 meters which is 144 MHz so they can use the same antenna.  VHF is primarily a line of sight, so masthead-masthead can go as far as 50 nm.  Ham VHF radios transmit (TX) up to 75 Watts, whereas recreational marine VHF are limited at 25Watt max.  That translates to a clearer signal at range, but doesn't really increase range too much.  The big difference between Marine, Law enforcement, etc VHF radios is that they are channelized, meaning there are strict channels assigned to frequencies, while Ham operators can almost chose any frequency in their permitted band.  I say almost because there's a good bit of voluntary channelization to make things more orderly.  A thing about almost all VHF communications is that they are in frequency modulation (FM) which is a spectrum and power inefficient method, but it's great at reducing static and noise (consider FM radio stations vs AM).  A last thought is Ham radios by default can receive (RX) on a huge range of frequencies, so a 2M ham can listen to NOAA weather, marine VHF, law enforcement and emergency, and aviation and military.  It is strictly illegal and also a bad idea to TX anywhere you're not allowed, and most radios come so TX outside of ham bands is locked out.  This lockout is almost always very easy to defeat, which is a consideration for emergency communications.  But that's all VHF, which like I said has a very limited communication radius.

High Frequency (HF) radios are sold for Ham use or for marine use (commonly called  marine SSB).  Single sideband (SSB) is a transmission type separate from AM and FM, and it's very efficient as all power goes into the signal(not the carrier) and it only takes 3 kHz of bandwidth to carry a voice.  It's basically AM where the carrier signal has been suppressed and one of the side-lobes has been removed.   Ham radios usually allow TX of other methods than SSB to include FM, AM, and continuous wave (CW) which is just a concentrated tone for morse code type communications.  The reason HF radios are so neat is because the enable long distance (DX) communications, sometimes going 3/4 way around the globe.  Marine SSB has been channelized so there is a specific radio frequency assigned to every channel.  This makes things orderly, whereas the Ham bands are a bit complicated.  Now the radio equipment itself, while not identical, may be indistinguishable from a listener's perspective, but the Ham stuff is way les expensive than marine.  For example the Icom M802 marine SSB unit is ~2000 USD while a decent HF Ham set will be less than 1000$.  The Ham hardware as I said must be defeated to allow transmission outside of the Ham bands.  The Marine HF units usually allow transmission on Ham bands by pressing a few buttons, but they don't allow TX into aviation and other bands.  Like I said it's illegal for a Ham set to TX on marine channels, but many cruisers do it because of the expense (and nonsense) of maintaining 2 radios/antennas/tuners.

So I mentioned my Automatic Tuning Unit (ATU) which is a electromagic device which matches the antenna to what your radio expects.  It is the device that allows me to use my 41' antenna to TX on a wide range of frequencies, although it will certainly not be efficient everywhere.  It's basically a bunch of induction coils that a circuit switches relays through so that the antenna matches what the radio wants.  If you don't have one of these the radio power reflects back into the radio and can fry it, although newer radios have safeties.  Pretty much every yachtie SSB installation uses an ATU unless they intend to only ever operate on a single frequency.  These things are however expensive, from 350-500 USD.

So the M802 has 150W of TX power vs. most Ham rigs which are 100W.  It's not a huge difference in range really.  Range in HF really depends on how good an antenna is in addition to how the solar weather is treating the ionosphere, the thin electrified atmosphere way above our heads.  In some ways HF is like satellite comms.  With a satellite you shoot a signal to a thing in space, it recieves and boosts the signal and bounces it back down, or maybe to another satellite then back down.  With HF radio you're actually bouncing radio waves off the upper atmosphere.  Sometimes you can get a few bounces from ionosphere-sea/land-ionosphere-land so you can truly transmit all over the world.  A neat thing with a HF radio is you can listen to radio stations from all over the world, because the radio waves can bounce a long ways.  We were listening to a station from Albania and it was clear as an FM station.  I should note there are radios for 100$ or less that can easily receive HF transmissions, not a bad thing for most cruisers to have.  You can listen to weather reports from Herb!

BTW 6 meters is actually VHF being at 50 MHz but sometimes it can be the most magical HF band because it provides really super long distance comms.  I've actually never used it...

Like I said my radio can pump out 100 Watts, but the radio frequency (RF) signals can create very high voltages, say 10 kV particularly if your antenna is a bit mismatched.  If you touch the antenna you can get a lightning bolt with accompanying burn, but the power is low as is the amperage so it won't fry you.  But RF burns are pretty nasty burns on skin.  It happened to my dad while playing with his marine VHF radio, and that's only 25 Watts.  So it's something you want to avoid.  People usually put a backstay insulator above touching height and run an insulated feedline up to it, but insulators are 350$ each for my 3/8 backstay and I'm not about to spend that kind of money when a bit of training will do.  "Don't touch the backstay when I'm playing with my radio" ="Don't touch the stove when it's hot".  See what I mean?

You're right stainless isn't the best conductor of radio, but it seems to work fine.  Copper is the best and most people use a copper clad steel wire for antennas on the land.  I used a copper wire on my hunter but it didn't work well on the pearson.  The GAM Splitlead Backstay is a product by Gam electronics which is essentially 2 wires in a plastic extrusion that clips over a backstay thereby removing the necessity of chopping the backstay.  But it's more expensive than a backstay insulator.  Like I mentioned I wanted to try cheap and simple first before dropping 350 on an insulator, but ooh well.

WWV is a very important radio station run by the US gov't in Colorado and another one in Hawaii.  It transmits on 5, 10, 15, 20, 25 MHz AM.  It mainly transmits accurate time as well as solar weather and sometimes emergency stuff.  It pumps out kilowatts so if you can't hear WWV then you won't hear anybody else.  Listening to WWV is a good check to see how well the solar weather is for HF communications.  If there's a solar flare you may not be able to hear WWV for a day, so might as well give up on talking to everybody else.  WWV also transmits 24/7/365, and you can set your watch by it!  If you're a sextant user you probably use WWV to make sure your watch is on time.

Anyway I want to quit and go sailing in a few years, so a HF radio is a good thing to have.  It's also a neat toy to play with when we are sitting at anchor and I get bored.  Plus people always think it's cool they're talking to somebody on a boat.  I can also send emails and position reports free which is cool.  The position reports are similar to the SPOT service, just noncommercial.  I should also note that to use a marine SSB you need a FCC license (which I don't have, nor do I TX on marine SSB bands) which isn't more difficult to obtain that filling out the paperwork and paying them 170$ or so.  The ham tests are like 15$ to take.

I hope that's been informative, and please look to my next post as I've managed to break the bottom of my skeg, but the boat's not sinking yet.

Mike
Pearson 367 Cutter No 26.
Boracay Star
Niceville, FL

[Dale Tanski]

Mike,

Thanks for all of the information.  I am a mechanical engineer with a good chunk of electrical engineer self taught in me.  I learned early on that to develop good mechanical designs one had to have good controls as well, and the best way to accomplish that was to do both concurrently. 

You did a great job trying to bring a non radio guy up to speed.  I understood a fair amount of what you were talking about until you got to the carrier and signal part, and then it really got fuzzy when you threw in the side lobe thing.  Don't worry, it wasn't your explanation it was my head.  You are more than welcome to get it another try just add more pictures of something.  Remember us mechanical guys draw everything and draw it to scale.

When you said you were listening to a radio station in Albania, were they speaking in english or I would assume Albanian?  I suspect listening to stations/people all over the world is less intriguing to you than making your equipment work properly.  That I understand perfectly.

I will also assume that the WWV is what makes everybody's La Cross clock automatically correct its time every day. 

I posted a picture of a 365 skeg and your theory about a secondary outer auxiliary skeg sounds very plausible.  I was not at all aware that the 376 rudder & skeg was any different than a 365.  I was only aware that the keel was a foot deeper to accommodate the taller mast.  I doubt that there is any way for water to get into the "stock" skeg, and that skeg is capped at the hull so you have several shields against sinking going for you.

Hope you can achieve your dream to pack it in and sail away.  I would keep you stores fully stocked and fuel topped off just in case the government does more stupid stuff and you find yourself without a country.

Be safe and take care my friend... Good sailing!

Dale Tanski

[swiftibis]

Dale,
I'm glad I could be informative.  Today's lesson is on analog transmission techniques, although Wikipedia does a far better job than me.  So I'll give the cliff's notes.

Starting with continuous wave (CW), all the radio's energy is focused on a tight bandwidth of 50 Hz or less.  There's not enough bandwidth to transfer much more information than on/off binary type signals, hence morse code.  The neat thing is that your power density (power/bandwidth or 100W/50 Hz) is awesome so your signal can go really far.

Now the next step is AM.  So you take a CW signal, but leave it on all the time and make it stronger and weaker (amplitude modulation).  If you make it stronger and weaker really fast (modulate) according to sound signals then you can transmit sound info.  The "carrier" is the very narrow CW portion of the signal which occupies very little bandwidth, again like 50 Hz.  However the modulation causes some of the energy to spill out of the carrier frequency into the so-called sidebands.  Linked below is an infographic from wikipedia.



So basically in AM you are taking a signal at a very controlled frequency and you're adjusting its strength to match the audio.  The sidebands are the actual information while the carrier is just the thing that creates the sidebands.  In fact the carrier is just a waste of energy, so a 100 kW AM radio station has most of its energy into pumping out a carrier that doesn't really carry the information.  So suppose I transmit at 100W, but I occupy 10 kHz, with most of the energy in the carrier, now I'm really inefficient in my power density.  This is why most AM stations are in the high kW.  The huge advantage of AM is that the send and receive circuitry is very simple and cheap.  If you've ever built a crystal radio you understand, it's just the AM's varying strength signal, that's caught by an antenna and turned into voltage, which is fed into the earpiece.

Like I said AM is wasteful in terms of energy, so why not remove the carrier?  Now all your energy goes into the signal.  But in fact the upper and lower sidebands are mirrors of each other containing the exact same information.  If we're trying to save electricity by removing the carrier, we might as well cut out a sideband also.  And viola, you have single sideband (SSB).  Again look at the infographic, you will have your choice to preserve an upper or lower sideband.  Marine SSB and a bunch of other bands use the upper sideband for everything because who wants to work on the lower sideband (literally somebody chose this arbitrarily in the early days of radio because higher is better), but the Ham folks are a bit less judgmental and use upper sideband (USB) above 10 MHz and lower sideband (LSB) below 10 MHz.

So SSB is a compromise that gives good energy density, say 100W/3kHz, with all the energy going into the voice signal without a carrier.  It's not as good as morse code for efficiency, but it's way easier and faster to talk then to do morse, although a fast morse coder may disagree.  Last is frequency modulation (FM), take that CW signal and keep it at uniform strength, but vary(modulate) the frequency a bit.  Now we have a signal that's always pumping out at a uniform power and is bouncing across a bandwidth of frequencies of about 25 kHz for a marine VHF.  All the power is still within the same 50 Hz or so (at a given instant) as CW, and you're pumping full power constantly so technically you have great efficiency.  Note this isn't so good on batteries as it doesn't matter if you're talking or not, you're always pumping full power.  There's a circuit called a phase locked loop that is awesome at grabbing the variation in frequency (modulation) and turning it into sound.  It's for these reasons that FM is so widely used, it is power efficient and good at reducing noise.  However it's very bandwidth inefficient.  A broadcast stereo FM radio station uses 50 kHz.  That's 16 SSB channels BTW.  So there's a tradeoff.  All the HF bands use SSB or AM because bandwidth is precious limited.  Think that the ham bands each take op a few hundred kHz.  Well that's like 4 broadcast FM channels, which is why they are much higher up in VHF land.

Regarding remote transmissions, there are stations like China Radio International (Albania) and Radio of Russia that are transmitted in english as a propaganda of sorts to those who would listen.  I think the foreign news is interesting at times, and it amuses me frequently.  The US also has Voice of America which is prohibited from targeting Americans, but does a good job of booming our news and propaganda into every other corner of the world.  One of their stations is Key West and I can always hear clearly.  All this falls under the term "shortwave listening" (SWL) of which broadcast schedules are available on the net.  There are lots of stations in English.

And you're right.  I get a great deal of satisfaction from things just working.  The other cool stuff I do with the things that are working makes me happy just as proof that things are working.  I expect that is a trait shared by some engineers.

Cheers,
Mike

[Dale Tanski]

Mike,

Your link to the infographic is not there (well for me anyway), but that is OK because you are making headway on me I believe.  This is all becoming very interesting, to me at least.  This carrier wave you are referring to.  In my mind it is like the moving sidewalk at the airports (remember I am a mechanical guy).  The sidewalk is the carrier for all of the people.  What happens from point A to point B is not important it is what you see coming off of the carrier.  I guess, people are kind of like Morse code.  If you are at the receiving end, each person and how they are spaced would be the code pulses.  To take that a bit farther, the modulations or side bands are kind of like if each person had a tone coming out of their mouth.  As the conveyor sped past, one would hear a song one note at a time sort of like a player piano and the music roll.  

This phase lock loop thing is perhaps like a pipe held up to your ear?  If the pipe was held perpendicular to the conveyor (CW) you would be limited in hearing one note at a time more or less as opposed to hearing some of the note that just left, the note right in front of you and some of the note that was heading our way.  Y/N?

SSB is more like a DC wave form as opposed to AC?  Am I close on that?  

Regarding the stations.  I am surprised that so many are broadcast in English.  Your comment regarding the Voice of America broadcasting propaganda is timely.  This government of ours just passed a bill that would modify the Smith Mundt act of 1948 that forbid the United States to broadcast or dissimulate propaganda to Americans in this country as you mentioned.  A few weeks ago that disappeared and they are free to use basically any means to sway public opinion through normal broadcast channels down through social media. Up until then it was illeagle to give or use false statements and facts, but the informed citizen probably realized that went out the window with the Benghazi situation.  So it is official, you can't believe anything you hear anymore. Here is a lik to that story - http://www.buzzfeed.com/mhastings/congressmen-seek-to-lift-propaganda-ban

This I think is one reason you have sparked a growing interest for me in SSB and Ham.  "Normal" channels and outlets will continue to become more and more polluted.  History shows that HAM and shortwave as you call it was the only outlet of real information during the past world "adjustment".

Thanks so much for your time and please continue or correct my thought process as needed. Perhaps your opinion on some basic (cheap) gear for future use would be helpfull.

Dale Tanski

[swiftibis]

Hello again Dale,
I think you're spot on for your allegories, however SSB is most definitely AC.  It's just like you managed to remove the expense of the moving sidewalk and people and just retain the tone, that's why it's so efficient!

It's not surprising they repealed that law.  It's rather an inconvenience for government, and after all the other important governments (China) do it to great effect.  It just means we will more than ever need to work on our internal BS filters when we read or see anything.  Well the internet already has strengthened my defences there, but I also consider that lots of people actually believe the news.

Back to long distance comms, you can buy an inexpensive but good shortwave radio for about 100$.  Sony and grundig make models that get good reviews, but I neither own nor have ever used one.  I even see radios as cheap as 20$, but you probably get what you pay for.  If the radio only does AM/FM then you can't listen to ham stuff, you'll need a radio that supports ssb.   Just do an Amazon or other web search on "Shortwave Radio" and make sure you can add your own antenna as a really long wire will outperform whatever whip they include.  If you want a used HF ham rig it seems you can get one from 300-400 on ebay or a ham trade.  It's easy to receive but costs more to transmit!  Before I take off cruising I'll probably buy a cheap radio as a backup to my ham rig, or just to use less than the 1.2A the ham rig draws at idle.

Also do a search on 'shortwave radio stations' and you'll get an idea of what you can listen to.  The US pounds out tons of religious radio, but to me the interesting stuff is from other countries.  It's refreshing to hear a whole different set of news/lies.  I have an app on my android that instantly lists whatever is playing in english that I might have a chance of hearing.

Another radio-related bit.  I bought a Baofeng UV-3R handheld VHF/UHF ham radio for 40$ on EBAY a while ago, it's so cute like a tiny cell phone.  Well the Chinese don't bother selling us stuff that complies with our FCC rules, so it arrived capable of receiving and transmitting on almost all VHF and UHF frequencies.  Naturally I programmed in marine 9, 16, 22A, 68-72 etc in addition to the local ham repeaters.  What a cool thing!  I can have it scan through programmed freqs and it's so small it's easy to take in the dinghy when I go on shore runs.  My wife isn't a ham but she uses the marine vhf, so we can stay in comms.  Naturally this is against FCC rules and it is only permitted to be used on ham bands.

Cheers,
Mike