Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 20-05-2009, 17:00   #61
cruiser
 
Trim50's Avatar

Join Date: Nov 2006
Location: West of SE Asia & North of Indonesia
Boat: Crealock Del Rey 50 Cutter
Posts: 492
Images: 23
Quote:
Originally Posted by s/v Jedi View Post
Eric,
You're not paying me for something so normal etiquette would be much appreciated.

cheers,
Nick.

Well said Nick...I will have to remember to use this line when time is appropriate.
__________________

__________________
Trim50 is offline   Reply With Quote
Old 20-05-2009, 19:26   #62
Registered User

Join Date: Apr 2007
Posts: 718
Sorry Nick, my comment wasn't meant to be derogatory. I admit that I do tend to respond a little too quickly. Percent of modulation has little meaning for SSB. Even though the SSB signal starts out as AM in the early stage of the transmitter, an SSB output is all modulation. The carrier is suppressed at least 40db. With SSB, when you press the PTT, there is no output until you start talking. All of the power is "talk power" but the amount can vary considerably. The 802 puts out 150w PEP and draws nearly 30amps peak on voice peaks. If you monitor an average reading wattmeter while speaking into the mike, the needle will bounce around 5-7 amps (M802). It will be around 8-10 amps on the M710. The 802 with compression turned on will be around 10-12 amps.

Marine radio's sold in the U.S. must be certified by the FCC and the technical standards that must be met are in Part 80, Title 47, Code of Federal Regulations. Here is a quote from the cover letter from Icom for their certification application for the M-802;

"RE: Certification Application
FCC ID: AFJ IC-M802
To whom it may concern:
Pleased be advised that the manufacture will ensure that the above-referenced model will be manufactured in accordance with the FCC Rules and Regulations."

And a quote from the top of the test report;

"CERTIFICATE OF COMPLIANCE
FCC PART 80 CERTIFICATION & INDUSTRY CANADA CERTIFICATION"

You say you "understand that spurious emissions are different from sideband suppression" yet in your previous post you did not say anything about spurious emissions and claimed that 40db suppression was good enough while referencing sideband suppression.

-50db spurious emissions suppression is pretty good as far as ham radio's go but it still doesn't meet marine radio standards.

Yes, you are right about splatter, my bad for using that term when refering to spurious emissions.

The fact is, ham radios are not certified for use in the marine service and so it is illegal to use them on the marine bands, period. The reason people do it anyway is because there is little chance of being caught. How many of you operate on the ham bands without the required ham license? You wouldn't last long before being turned in and hearing from the FCC. If the marine community self-policed their bands like the ham community does, this wouldn't be an issue.

Eric
__________________

__________________
fairbank56 is offline   Reply With Quote
Old 20-05-2009, 21:56   #63
Registered User
 
John Drake's Avatar

Join Date: Apr 2003
Location: Stuart, FL
Boat: Wauquiez Hood 38, S/V Invictus
Posts: 341
Images: 11
While there may be expert communication engineers who have perfectly adequate equipment to transmit on, that will not harm anyone....there are many many ....many MANY more people out there who do not know very much about ham or marine radio's and are going to use the cheapest equipment they can buy, used, and modified for out of band transmission, off Ebay. Transceivers that may have poor specs and poor frequency stability. They may further exacerbate bleeding over into adjacent frequencies by imprecise use of the VFO or some settings.

Why would a considerate and responsible sailor want to advocate this and tell people that it does not harm anyone and no one will even know it, if they do?

If that is your argument, then you must advise your fellow sailors not to use holding tanks. The chances that they will release truly pathogenic bacteria into the environment is very small and the dilution factor, along with the current and tide make the possibility that they will harmfully interfere with another sailor, remote. And really...no one would know and no one really checks. So...why ?

If your argument stands for one, it stands for the other. Do you advocate not using a holding tank as well?
__________________
USCG 100T Master's License
W4JIB
John Drake is offline   Reply With Quote
Old 20-05-2009, 23:44   #64
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by fairbank56 View Post
If you monitor an average reading wattmeter while speaking into the mike, the needle will bounce around 5-7 amps (M802). It will be around 8-10 amps on the M710. The 802 with compression turned on will be around 10-12 amps.
Okay, things didn't change since I was at it. When you turn on compression in the 802, it's average power draw increases about 20%. What I did in my calculation is link that to it's increased avg (not PEP) power output, which should be the same 20%. This is a linear (as far as analog components and their curves allow) relation.

As USB mode is just the modulated upper side band of AM, the carrier and LSB are suppressed before the signal enters the power stages and thus the avg power output of the radio is directly related to the avg level of power consumption and modulation. The level of modulation is what I called modulation depth as it is just AM modulation with carrier and one sideband suppressed. Too much modulation leads to clipping so I assume that early 802's had a modulation problem.

Every modern radio has ALC, Automatic Level Control. On HAM radio's, the microphone gain can be adjusted and ALC level can be observed on the display, avoiding to go over it's limit. For marine radio's this is not the case, one has to speak louder instead. This brings me to the question: as the 710 uses more avg power, is that because it's circuitry needs more power for same output (less efficient, more heat) or is the difference caused by a higher microphone gain and more output power?

When the radio is over-modulated, splatter occurs. So, this is caused by a problem with modulation, not spurious emissions. When the unwanted sideband suppression has a problem (or isn't high enough), splatter occurs too, but that is really just the other sideband.

Quote:
You say you "understand that spurious emissions are different from sideband suppression" yet in your previous post you did not say anything about spurious emissions and claimed that 40db suppression was good enough while referencing sideband suppression.
I think we agree that spurious emissions have nothing to do with splatter, but sideband compression does. This is the reason plus the on-line spec's for the Kenwood didn't list spurious emissions.

Quote:
-50db spurious emissions suppression is pretty good as far as ham radio's go but it still doesn't meet marine radio standards.
Apparently it doesn't. I am still unsure what "spurious emisions" means in English but am pretty sure it's about the harmonics. As it is very easy to lift the suppression for those to a higher level it must be that the Kenwood is happy with the -50dB figure.

I understand that the 802 doesn't meet requirements when the compressor is enabled. I am not sure if the DSP is used for the receiver but it would be very disappointing if it isn't.

A good compressor increases the avg modulation without increasing the peak modulation. A pactor modem does the same thing in order to achieve higher transfer rates. I wonder if the 802 meets the requirements when transmitting a pactor signal.

Quote:
The fact is, ham radios are not certified for use in the marine service and so it is illegal to use them on the marine bands, period. The reason people do it anyway is because there is little chance of being caught.
I think the biggest reason is about money. For me, I have a 710 and the Kenwood and use the Kenwood on marine bands now and then when conditions are so bad that the 710 doesn't give me a clear copy. During SSB nets, it also happens many times that I am requested to take calls that can't be done with marine SSB's aboard yachts in the same anchorage as me. The reason it works with the Kenwood is the advanced DSP processing in the receiver and the 200W output coupled to a very good compressor in the transmitter.

So what is the better radio, the one with an even higher suppression of spurious emissions or the one that can make the call? Different points of view. All that doesn't change anything about it being illegal to use HAM radios on marine bands. But when you get to the tropical cruising grounds, about 90% of all marine radio traffic is illegal. In Europe, one must have an operators certicate for an SSB or even VHF; using the radio without it is illegal. The US has no such requirement which shows that legal/illegal is often more a political thing than about meeting certain technical specifications. In the tropics, even the supermarkets have marine radios and advertise their deals of the day on the marine nets. And the authorities listen carefully because they don't want to miss the rotisserie chicken special for tonight's dinner! Nobody cares about a 50 vs 63 dB suppression value inside an SSB radio there.

Quote:
If the marine community self-policed their bands like the ham community does, this wouldn't be an issue.
That, imo, is the last thing we need: more self appointed radio-police who tell others what they are allowed to do while having no clue about how foolish they are themselves. How do you tell if someone is using a HAM radio instead of a marine SSB? Does the net controller have to ask about that when someone checks in? Will you report cruisers to the FCC when you know they use HAM kit on marine bands? Pls. stay home if that's what you want because the whole cruising experience will be a disappointment with that attitude. Live and let live and accept that other nations have different cultures and adept to that. Long before we go there, we need operators that are trained in using the SSB radio and radio procedures and who have passed their exams to get their certificate. The US is the big one lacking that as most other 1st world countries have that requirement for decades already, although I can't understand how some passed the nautical English exam that is part of it ;-)

About HAM's policing their band: they think they are an elite group because they managed to memorize the multiple choice questions. But most couldn't explain the simplest technical principle about it. They are just very proud that they went beyond CB. HAM used to be for amateur radio designers and builders but I don't think 1% of the HAMs today have a clue. As anyone who passed high school can pass the HAM exam, it's just foolishness. Dropping the morse code was a bitter pill for many. I love the HAM community, don't get me wrong, but it's more because it's a group of people with the same ideas about many things than about passing an exam. Only people with those ideas decide to pass the exam so they are just protecting the consistency of the group.

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 21-05-2009, 00:07   #65
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by John Drake View Post
...Transceivers that may have poor specs and poor frequency stability. They may further exacerbate bleeding over into adjacent frequencies by imprecise use of the VFO or some settings.

Why would a considerate and responsible sailor want to advocate this and tell people that it does not harm anyone and no one will even know it, if they do?
John,

I am not advocating that at all, I'm just writing about reality. Again, I have never heard "bleeding over into adjacent frequencies by imprecise use of the VFO or some settings". The bleeding most often heard is caused by stations using frequencies between the advised channels on the marine bands. That is not illegal but it is not considerate either. But many are commercial stations and they don't care much about yachties and their channel spacing.

Quote:
If that is your argument, then you must advise your fellow sailors not to use holding tanks. The chances that they will release truly pathogenic bacteria into the environment is very small and the dilution factor, along with the current and tide make the possibility that they will harmfully interfere with another sailor, remote. And really...no one would know and no one really checks. So...why ?
If your argument stands for one, it stands for the other. Do you advocate not using a holding tank as well?
I do not see that link with holding tanks. But now you brought it up, can you honestly state that you use your holding tanks because of your care for the environment and your fellow sailor? Or do you use them because the law forces you to do so? And is all (city) waste treated before being dumped in the anchorages where you are? If so, why aren't you allowed to do the same? Does the commercial shipping use them? (I really don't know, I don't even know where you are)

Also, you must realize that "your laws" can be different from "my laws". There are many countries that do not require holding tanks so it isn't illegal to not use them. Most yachts in those countries don't even have them. So, are you deleting those countries from your list of cruising destinations because of that? Are you going to lobby among the cruisers and government there to start using holding tanks? You will not be popular if you do.

Some places we've been the people don't even have toilets, let alone pump out stations for your holding tanks. I think your comparison with SSB is crappy ;-)

ciao!
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 21-05-2009, 06:14   #66
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,334
I have to post to say that I totally concur with Jedi's post #65.
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 21-05-2009, 06:32   #67
Registered User
 
John Drake's Avatar

Join Date: Apr 2003
Location: Stuart, FL
Boat: Wauquiez Hood 38, S/V Invictus
Posts: 341
Images: 11
Ciao Nick!

Thank you for the reply. You raise many good points and I am glad you do not mind spirited debate.

I cannot comment on the technical aspects of this argument, other than to say that it does convince me that there is a technical difference between the transceivers, I can hear it on many nets.

Also, I understand that you may not have ever been harmfully interferred with, however, I have, several times. It is not uncommon. True enough...there are those Russian guys who are in between the ITU bands...they are the Absolut (pun?) worst offenders. But there have been other's who are obviously using inferior equipment and either do not care or do not realize. It is not a good thing. Marine SSB communications are sometimes used for urgent, important and serious communications.....why should those of us who are serious mariners advocate or encourage more people to interfere with this?

And on that point, I will not say that you do, however, I personally feel that to say that you can do it and no one will care or complain is tacit encouragement. Why not say that while some people do, it is not legal nor is it considerate?

Glad you liked my crappy analogy. You make my point exactly. I do not use my holding tank because I have a Ph.D. in microbiology and have exacting knowledge to understand under which circumstances my effluent may harmfully interfere with other boaters. I use it because it is illegal. And not proper sailing practise. Beacuse the govt has determined that too many people who do not use holding tanks did harm others....and when I think about the large numbers of people out there sailing now, I am glad we have this law.

It is the same for marine SSB's. While there may be a few genius operators with gold plated amateur equipment, there are many more uninformed who do not care, or simply do not know, who will use the crappiest cheap radio they can find, mod it themselves and have no clue as to whether or not they are pooping all over the airwaves.

I certainly understand the reality, but when giving advice, I think I would always advocate that which is legal and most proper.

If the issue is cost, a used ICOM M700 (non pro) can be had for $400-450 easy. A new ICOM M700PRO is $1100, while a new ICOM 706MKIIG is $900+ without a couple needed filters. For the price of an ICOM 802, you could buy a new 700PRO and a used Yaesu 857D.

Is the above not true?

Thanks and my best to you for this excellent discussion.

Respectfully,

John
__________________
USCG 100T Master's License
W4JIB
John Drake is offline   Reply With Quote
Old 21-05-2009, 08:45   #68
Registered User

Join Date: Apr 2007
Posts: 718
Quote:
Originally Posted by s/v Jedi View Post
About HAM's policing their band: they think they are an elite group because they managed to memorize the multiple choice questions. But most couldn't explain the simplest technical principle about it. They are just very proud that they went beyond CB. HAM used to be for amateur radio designers and builders but I don't think 1% of the HAMs today have a clue. As anyone who passed high school can pass the HAM exam, it's just foolishness.
Wow Nick, you can't take criticism ("I find your aggressive stance not amusing so please be nice if you want others to respect you too. You're not paying me for something so normal etiquette would be much appreciated") but you sure can dish it out. I'm an extra class ham, don't think I'm elite, didn't memorize any questions, have been an electronics technician for over 30 years, never operated CB and can operate 40wpm CW without need for the ridiculous 5wpm test.

Eric
__________________
fairbank56 is offline   Reply With Quote
Old 21-05-2009, 22:25   #69
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by John Drake View Post
Also, I understand that you may not have ever been harmfully interferred with, however, I have, several times. It is not uncommon. True enough...there are those Russian guys who are in between the ITU bands...they are the Absolut (pun?) worst offenders. But there have been other's who are obviously using inferior equipment and either do not care or do not realize.
John,

The Russians you hear are legal users of the band. The marine bands are open to operators from every nation as long as they comply with the regulations as defined in national and international agreements.
They are also allowed to use their own language. Only when the other party doesn't understand that language, the regulations require both parties to switch to English.

What you hear is not in between ITU bands. They are inside the band. The ITU published channels for use within the bands and what you hear are stations that work on a frequency that is between these channels. The channels however are "advised", not a requirement. The full band is open for use.

Also, this is not caused by inferior equipment. They have programmed their radio to use the frequency in between these channels, just like you can with every marine SSB sold today.

Quote:
And on that point, I will not say that you do, however, I personally feel that to say that you can do it and no one will care or complain is tacit encouragement. Why not say that while some people do, it is not legal nor is it considerate?
There is no safety by obscurity. That means that it does not matter if we talk about it or not, it's no use to try to make this a big secret. Everyone will know and everyone needs to make the "what radio to buy" decision themselves. They all know that it isn't legal to use a HAM radio on marine bands.

Also, there are many malfunctioning marine SSB radio's, especially the cheap 2nd hand ones, which can create just as much interference as a malfunctioning HAM radio. And don't forget: any modification of the marine SSB radio invalidates it's type approval!! So if you enable LSB on a Icom 700 or open up the HAMbands inside it, you are just as illegal as someone else using a HAM radio on marine bands. And that is something not realized by everyone!

Quote:
Glad you liked my crappy analogy.
[...]
I use it because it is illegal. And not proper sailing practise. Beacuse the govt has determined that too many people who do not use holding tanks did harm others....and when I think about the large numbers of people out there sailing now, I am glad we have this law.
Wow, you have been programmed well by your government. Aren't you curious if they respect these laws themselves before enforcing them on you? But politics aren't allowed so I'll leave it at that ;-)

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 21-05-2009, 22:38   #70
CF Adviser
Moderator Emeritus
 
TaoJones's Avatar

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Montrose, Colorado
Posts: 9,850
Quote:
Originally Posted by s/v Jedi View Post
<snip>
Wow, you have been programmed well by your government. Aren't you curious if they respect these laws themselves before enforcing them on you? But politics aren't allowed so I'll leave it at that ;-)

cheers,
Nick.
Ahh . . . self-moderation . . . the best kind! Thanks, Nick.

TaoJones
__________________
"Your vision becomes clear only when you look into your own heart. Who looks outside, dreams; who looks within, awakens."
Carl Gustav Jung (1875-1961)
TaoJones is offline   Reply With Quote
Old 21-05-2009, 23:05   #71
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by fairbank56 View Post
Wow Nick, you can't take criticism [...] but you sure can dish it out.
That was good, wasn't it? ;-) But it wasn't a "personal attack" or whatever they describe it in forum rules. It was just the truth about a group of people. Also, I can take criticism very well, I love it actually. You have that mixed up with respect I think. Forums would be boring without criticism and discussion but they would be chaos without respect for each other.

Quote:
I'm an extra class ham, don't think I'm elite, didn't memorize any questions, have been an electronics technician for over 30 years, never operated CB and can operate 40wpm CW without need for the ridiculous 5wpm test.
Great, that makes you part of that 1% of the group like I mentioned, just like me (see, I am a HAM and electronics engineer too so I was criticizing myself ;-) My wife passed the theory and morse code exams and is general class too...
All I mean is that almost no one has called a CQ with a transmitter designed and build by themselves, while it used to be the other way around.

cheers,
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 22-05-2009, 03:03   #72
Senior Cruiser
 
unbusted67's Avatar

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Islesboro, ME
Boat: Looking for a new boat
Posts: 2,198
Images: 24
geek fight
__________________
unbusted67 is offline   Reply With Quote
Old 22-05-2009, 05:38   #73
Registered User

Join Date: Apr 2007
Posts: 718
Quote:
Originally Posted by s/v Jedi View Post
And don't forget: any modification of the marine SSB radio invalidates it's type approval!! So if you enable LSB on a Icom 700 or open up the HAMbands inside it, you are just as illegal as someone else using a HAM radio on marine bands. And that is something not realized by everyone!
That is absolutely NOT TRUE. Another Internet myth, and again, you are obviously unfamiliar with FCC rules.

Eric
__________________
fairbank56 is offline   Reply With Quote
Old 22-05-2009, 06:51   #74
Registered User
 
John Drake's Avatar

Join Date: Apr 2003
Location: Stuart, FL
Boat: Wauquiez Hood 38, S/V Invictus
Posts: 341
Images: 11
Wow, Nick, you are a big fan of the ad hominem attack , good effort.

I think if you read closely, I was acknowledging that the Russians were another issue, related but not the same as someone using an inferior radio to transmit on marine bands. I am really dissapointed, however, that you missed my terrific international pun...

As for "there is no safety in obscurity" nice bit of words, but I think again, if you read closely, my point is that those who care of radio transmissions should be making the point that cleaner, type accepted transceivers. To say that "everyone knows" ignores the original posters questions....it is after all, why this thread is up.

You are a fan of trying to support general arguments with anecdotal incidents. Sorry, that simply does not work.

As for me and the govt, I am no fan of govt intervention, even though I helped to shape policy at one point. In the case of people pooping in the water and over the airwaves...yes, I do think it a good idea to have rules and regulations. There are just too many people who think they know it all and can make their own decisions when in fact they do not and cannot. I think that would be called hubris.

Besides, when you or anyone else says that their Kenwood is satisfactory for use on marine bands, that is the same thing the FCC is doing. Stating that this radio can be used but this other may not. What about the ICOM 718 or 706 (whichever ver)? Who makes that call here...you? I think that is called hubris, not to be personal about it.

Cheers

J
__________________
USCG 100T Master's License
W4JIB
John Drake is offline   Reply With Quote
Old 22-05-2009, 13:56   #75
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Quote:
Originally Posted by fairbank56 View Post
That is absolutely NOT TRUE. Another Internet myth, and again, you are obviously unfamiliar with FCC rules.
Yes, I am unfamiliar with these rules. But I also see that you aren't quoting them and I can't find them on-line, so if you have access, pls. quote the relevant part!

But I am very familiar with type approvals. When you have a marine radio that supports LSB mode out of the box, it's legal to use it. When you enable HAM bands on an 802 by holding a button while switching it on, that's changing a setting and legal to do. But when you open the radio and remove components like diodes for enabling transmit mode on bands, or solder modifications on the PCB, these are considered modifications not normally done by operators and the radio should, in that modified form, be re-submitted for type approval. I think that modifying a radio with software normally not used by operators (like available to dealers) and use that to change settings normally not available to operators, that this too invalidates the type approval. An example: enable the speech compressor in a 802. I don't think that's allowed.

The whole idea of type approval is that all these radio's are the same as the one submitted for approval.

If I'm wrong, pls point me to the rules or quote them, it's a bit frustrating when you write I'm wrong without explaining why.

cheers,
Nick.
__________________

__________________
s/v Jedi is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Psycho Crew from Hell! Ocean Girl The Sailor's Confessional 96 11-07-2009 06:51
One Hell of a Powerboat BadFish Powered Boats 11 08-07-2009 20:41
Toronto - Hell Yes, Finally KrisAubrey General Sailing Forum 0 09-06-2009 08:31
Battery Replacement from Hell.... markpj23 Electrical: Batteries, Generators & Solar 6 14-02-2009 00:47



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 20:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.