FWIS3

For this little trip we have planned we need to either get a SSB marine radio or a HAM radio (and licenses) or both.
I'm trying to figure out the best most economical path to do this.
The SSB Marine radios pump out 150W and are about $600 but even though most do HAM frequencies we'd need a HAM license to use those, e.g. sailmail. The sailors email via HF band.

Getting a HAM radio reduces our power output and is more difficult to operate (plus we are guaranteed to need a license) and using the marine band is then an issue unless we get a license for that too. The ease of use is more the issue here than anything else since if there is an emergency what you want is the fastest easiest to use system.

Anyway, those are the choices.
I was looking at an Icom M710 SSB marine radio that can do HAM bands if they are pre-programmed in (it has no VFO mode). Its about $600 for a refurbished unit. Pumps out 150w.
Any thoughts on that choice?
Are there better deals or choices available that I'm not aware of?
Since we're getting our HAM licenses any HF band radio that is bullet proof and cheap is what we are looking for.
Just want solid state outputs, no valves.

Oh and antenna tuners. Any good cheap solutions there would be a great benefit.

With regards to antenna choices, we have either backstay line or a whip.
Both have advantages and disadvantages.
I'm leaning towards whip as I'm not too keen on modifying the rigging to isolate it.
Looking for recommendations there too.

For the email/weather fax we've ordered a signallink USB interface: http://www.tigertronics.com/
That's the cheapest I could find as the dedicated modems run in at over $1000.

My stepdad used to run a CB/Ham Radio rig that he used to talk to people several thousand miles away when the "skip" was in. One of the things that he had was a power booster that cranked the wattage up and gave him more power. The "black box" was it's name.

Of course, IIRC the "black box" was technically illegal because the CB rig wasn't supposed to push more that 5 watts at the time.

THAT is usually called a Linear Amplifier, my old man used a 600W one when doing HAM Radio in the 70s.

I always laughed at the name, "linear amplifier".
Apart from a few special application amplifiers, most amplifiers are linear.
Audio amplifiers, the most abundant type are linear for example, but, you can't use one to boost an RF signal.
So I always called them RF amplifiers, because, that's what they are.

That's what the HAM radio buddies of my old man called it....

That's what a lot of people call them, even companies that make them call them that.
It's a pretty common name.
I still find it amusing.

Bit like calling a horse, a "four legged horse".
Hey bubba" "where you going?"
"I'm going to the farm and get me a four legged horse so I can muster some four legged cows with my four legged dog and I'm about to drive there in my four wheeled car".

See where I'm going with this?

Yeah, I'll be honest, I played with radios a fair amount in my day but was always interested in the using them to talk to people part, not the rest of the technical details. Which is how you can tell these days I prefer to be a radio astronomer who uses the telescope than the engineer who builds the array.

I will note tho getting the Ham radio license is super easy- it's a multiple choice test, no Morse code these days. I mean I did it when I was 16 so how hard can it be?

Keep in mind I pretty much don't have a clue, but what about a satellite phone instead?

FZR1KG wrote:That's what a lot of people call them, even companies that make them call them that.
It's a pretty common name.
I still find it amusing.

Bit like calling a horse, a "four legged horse".
Hey bubba" "where you going?"
"I'm going to the farm and get me a four legged horse so I can muster some four legged cows with my four legged dog and I'm about to drive there in my four wheeled car".

See where I'm going with this?

No I don't, You KNOW pretty well I don't have a sense of humor

In the days my old man did Ham radio, his Radio was a Yaesu FT901, of course that thing is too bulky and power hungry for what you want, not to mention long discontinued.

Swift wrote:Keep in mind I pretty much don't have a clue, but what about a satellite phone instead?

A few issues with satellite phones:
1) The phone cost & the usage cost are higher than getting a HF set.
2) Even though they are satellite phones, believe it or not, the coverage is marginal in some areas where we are headed.
3) They can't be relied upon in emergency situations. A marine SSB will get you 4000miles range if you need it often more. A HF HAM set gets you a little less range but not by that much.
4) You can't talk to other yachts/ships and get local weather reports from those who were just there or are there.
5) You can use a marine radio to communicate with customs when entering many countries.
6) All commercial vessels by law are required to monitor the emergency bands when underway. All nations coast guards monitor the emergency frequencies. That means we'd be able to contact the closest ship to us if we need to and get the fastest possible response as well as getting coast guard response.

In no particular order...

Go with the SSB marine radio. You'll have better odds contacting someone when you need it, concentrating on the freqs where other sailors actually are.

Use on the ham frequencies -- in case of emergency (and it better be a real one), all restrictions as to radio type/power limit/licences are off. Human life comes first. This is the gentleman's agreement worldwide (language approximating this can usually be found in any nation's license rules).

As to various brands of radios and tuners, I'd start querying those with much much more experience in this scenario than me. Something to remember -- the simpler to operate the better. When the biomass hits the revolving airfoils, you want to be able to flip a switch and scream for help. Having to tune up and forgetting where ya stashed the manual are bad at these times.

Tuners -- as I said, simple. Marine grade (aka will stand up under a salt atmosphere). Manual or auto, your choice.

Antennas -- got a sailin' buddy who plies Lake Michigan with a backstay ant. His environment is not quite as severe as yours will be. Whips are nice, in that you can lean them over from the vertical, which changes the radiation angle and therefore your coverage area. Also, if you're demasted, you can remount a whip on just about anything sticking up off the deck. In an emergency, you can run a piece of wire up a halyard, feed it against a hull plate ground, and you'll be on the air. Again, the idea is KISS...

For e-mail and WEFAX on the HF bands -- the critical element is the software in question. The USB interface is nothing more than an isolation/keying circuit to go between the computer and the radio. There are numerous schematics out there for a build-yer-own version. If all you're doing is listening (as you say you're doing at this point), you don't even need the modem -- just go straight from Radio AUDIO OUT to Computer AUDIO IN (you will have to play a bit with audio levels, but that happens modem or not).

For computer/radio interfaces, check West Mountain Radio ( http://www.westmountainradio.com ). For the interfaces, tuners, and all sortsa other stuff you can drool over, check MFJ Enterprises ( http://www.mfjenterprises.com ).

That being said...if you decide to learn Morse code, recent research on distance vs power has digital beating out voice hands down. There are digital modes out there where I have PERSONALLY worked Ohio to OZ on ONE watt out the back of the radio. Granted, that was with a ginormous antenna, but the advantages remain. Even with just a whip antenna, your odds of reaching out further on the ham bands increase dramatically with non-voice modes. Remember, we're talking casual use here -- in emergencies, load everything for maximum smoke, scream as loud as you can, and worry about legalities later.

Another item -- as I understand it, one marine license is good worldwide. Ham licenses are a different story. While many nations have reciprocity agreements, until you've done the paperwork, you may not be able to use the ham radio in country X's territory. When in doubt on ham licensing and reciprocity, check out the American Radio Relay League site ( http://www.arrl.org ).

This has the makin's of one helluva trip. Pitchers! Pitchers!

All available protuberances crossed in your general direction...

Thanks Charlie.
Seems we're both leaning towards the same thing.
I've decided to get the ICOM M710, and a tuner from the link you gave me.
I'll be making my own antenna. Too expensive and PITA to mount a whip.
I've already got the USB sound card designed for HF reception and transsmission, it works great. Fully isolated so no ground loops. It controls the transceiver too. So we can get data capability.
We're still going to get out general HAM license because with that we can have email for free.
The SSB we can use but its tied in with monthly fee's and on top of that won't allow attachments other than really small GRIB files. Between those two I don't want to pay money to get less functionality, I'm funny that way.

For general interest, I found out that we reside in the "national quiet zone".
Typical.
So I'll be doing all my testing from the boat I guess.
While there are ways around it I'm not interested in investing the time seeing as we'll be out of here within 7-10weeks.

Yeah, to be fair, I have some friends up at Green Bank Radio Observatory who will give you their thanks for not messing with it. Don't worry, it's looking like it may well be shut down by the time you ever return anyway due to budget cuts.

I didn't realize you guys were that close to Green Bank tho!

Well, seeing as you have friends there, I may do a little morse testing and have them wondering who this "rommie" is and why she's saying hi. LOL

While playing around with the Extra test for the HAM license I came across a problem with one of the questions.

E7G13 (C)
What is meant by the term op-amp input-offset voltage?
A. The output voltage of the op-amp minus its input voltage
B. The differential input voltage needed to bring the open-loop output voltage to zero
C. The input voltage needed to bring the open-loop output voltage to zero
D. The potential between the amplifier input terminals of the op-amp in an open-loop condition

The question number is E7G13 and next to it is the "correct" answer, but, it's not correct.
The correct answer is (B).

I made a correction to the database on the site I was using and let them know, but it was reverted back because it wasn't just wrong at his site, it was wrong with the test pool itself, IOW, since 2007 when the question was put up it has been taught incorrectly and tested incorrectly. Can't blame him for (1)not believing me and (2)putting it back since if people ticked the correct answer they would be marked wrong.
Funny thing is, it was reworded in the last revision yet they missed the error itself.
Go figure. Something this simple being wrong and no one notices for over 6 years.

So do I like get extra brownie points for this??? LOL

I know I got extra points from my instructor when I caught a legitimate error in my algebra online text.
Getting extra points from the online people themselves is a different kettle of fish...

Well, it's been over two weeks now and I didn't even get an email from the governing body for the tests.
I kind of figured that I wouldn't since they ask you for your Ham call sign as well as email.
Guess if you're not a ham they don't consider you to have enough knowledge to claim an answer is incorrect.

Oh well. I tried at two different points of contact and no one was interested in knowing that they are incorrectly administering a question. Even when its so damned obvious, easily verified and I supply all the references.

Out of curiosity...who were you communicating with on all this?

Remember -- you may not ever hear back from them. While the correction may take place,
it will take at least until the next set of questions for testing is issued. These "pools" have triple
boatloads of questions, and the tests are assembled 'randomly' -- one question from this group of ten,
two questions from that group of fifteen, etc etc etc.

Supposedly, at least for the online stuff, that prevents the same test from being given to the same
person more than once (true occurrence -- that's how I passed my 12 words per minute code exam -- they
gave me the exact same test again, and I knew what I'd done wrong the first time).

Not as tight into the testing scene as I used to be, but if you'd like, I can check with the test types
here in town and see what's what.

The first site was https://hamstudy.org
Really good site and like I said I did agree with his reply.
He also gave me the next link so I could address it with the appropriate body.

The second was: http://ncvec.org/

I'm lead to believe they are the body that holds the question pool.
They were the ones that didn't even reply.

Will check with the powers that be around here...

Have fun with that. I really mean good for you for trying and I hope it works out rather than a sarcastic, have fun with that.

BTW, just tell them you spotted it.
I like anonymity.
In fact if I could live my life without anyone knowing that I exist that would be awesome...other than the wife and friends of course.
I also really mean the above. While family is family, they are also family by blood not choice. I place choice far more important than blood but that is me and I understand that goes against what many believe. There are family members I'd have no problem, writing off so to speak, and strangers I have come to know that I would adopt in their place and in my heart have already done.

So there goes FZ being tipsy again...woohooo

Sigh.
Found another problem in the test.

Qestion E7D07
Link to schematic diagram: http://hamexam.org/popup_image/16982

If I had to honestly answer this question the purpose of C2 is to blow up transistor Q1 in the event of the input power supply being shorted. Yes, someone designed a self destruct circuit.

There are problems with the values and the answer supplied.
C2 doesn't bypass hum around D1, that was the "correct answer"
If the input is 25V and the output of the regulator is 12V as shown, then the zener needs to be 12.6V to take into account the Vbe of Q1.
If hum came in from the 25V source it would be a minor fluctuation and that circuit if R1 was suitably chosen should work down to about 15V. IOW, you could have 10 Volts of hum and that circuit would regulate it pretty well.

The problem is the value of C2. Its 4000uF.
No one that is sane uses a 4000uf capacitor in parallel with a zener unless its used to bleed off voltage on a slow charge circuit to prevent a cap exploding due to over voltage. Pretty rare to need that though I have used such a technique once or twice in the last 30 years. Certainly not its purpose here.

What happens is that C2 will charge to the value of D1, about 12.6 Volts.
Now, if Vin drops below about 13Volts such that Vin +Vce < VZener then C2 will start discharging through the base of Q1 and splits into two currents, one flowing from B to C, the other flowing from B to E.
The latter is usually no problem since its almost guaranteed to be relatively low for Q1.
The former however has no such guarantees. So if I disconnect the 25V rail for example and short it out, two things happen.
1) C1 discharges quickly causing a spark. This is relatively harmless unless you're in an explosive controlled environment.
2) C2 discharges through Q1 causing a massive current to flow through the base of Q1 blowing it.

To fix the issues, one can add a forward biased diode inline with the collector of Q1. This prevents back flow from C2 into the feed voltage. Then what you have done is create a circuit where you can detect that the input voltage has failed and yet provide a small time when energy is still available to the following stages. Realistically however this is a waste in this case since C2 would be better placed from C of Q1 to ground and thus have four times the energy in storage and it would maintain the correct voltage for a good portion of that time.

However, the purpose of a capacitor across a Zener diode is to reduce Zener noise. This is a high frequency and low energy noise that would be amplified by Q1. Usually about 0.1uF is more than enough to eliminate such noise. It also would have no risk of destroying Q1 since it can't store that much energy. I'm assuming that is what the original intent of the circuit was since it a pretty basic low current series regulator.
In any case, its not to reduce hum, or bypass hum or any other nonsense. The use of a 4000uF capacitor would do nothing for hum removal (unless there was a design fault elsewhere and that should be addressed first) and would also do nothing for the removal of Zener noise as Zener noise is higher frequency and electrolytic capacitors (4000uF means electro) have poor high frequency response.

Do they get electronics engineers to check this stuff?
Because I really think they should.