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Old 25-11-2015, 19:26   #16
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Re: SSB in steel boat

I didn't see any mention of an SWR measurement in the coax line between tuner and the transceiver. It will tell you if your tuner is presenting a good match to 50 ohms. Or maybe that rig has one built in, and if so, what was the SWR reading on the bands you can't tune, and compare that to the reading at 10MHz where all works OK.

If you have the 1/2" dielectric spacing as recommended earlier, where the tuner output wire goes through the deck, and you keep the wire nearly right angles to the deck and locate the whip right over the deck feedthrough, it should work OK with your tuner.
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Old 25-11-2015, 19:45   #17
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Re: SSB in steel boat

Quote:
Originally Posted by waterman46 View Post
I didn't see any mention of an SWR measurement in the coax line between tuner and the transceiver. It will tell you if your tuner is presenting a good match to 50 ohms. Or maybe that rig has one built in, and if so, what was the SWR reading on the bands you can't tune, and compare that to the reading at 10MHz where all works OK.
This is a good way to verify that the tuner is providing a good match to the antenna. I've got this setup on my land-based ham rig. In fact, I'm using the LDG IT-100 tuner, and it works very well.

Quote:
Originally Posted by waterman46 View Post
If you have the 1/2" dielectric spacing as recommended earlier, where the tuner output wire goes through the deck, and you keep the wire nearly right angles to the deck and locate the whip right over the deck feedthrough, it should work OK with your tuner.
However, this tuner probably won't be able to match to a short whip, except on some specific frequencies. This is, I believe, the root cause of the OP's problem.
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Old 26-11-2015, 18:08   #18
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Re: SSB in steel boat

Tim,
Did you read my post here...post #10???
If not, please read it....(in addition to mentioning the insuitability of the IT-100 for your application, the details of the problems with the IC-725, I also posted some answers for you)
SSB in steel boat
Quote:
Originally Posted by tkeithlu View Post
The 725 simply shuts down (frequency screen goes to dashes) upon pushing the PTT at frequencies away from 14 MHz.
As I wrote 2 days ago...This is a common occurrence with the IC-725!!
Quote:
Originally Posted by ka4wja View Post
2) Secondly, be aware that the IC-725 is notorious for having RFI issues!! (distorted transmit audio, RF power fold-back, and in the worst cases the transmitter shuts down completely)
The 725 is very susceptible to RFI, and while getting the GTO-15 wire away from the steel hull, might improve things....having a "line isolator" in your coax line (at the tuner end), and having a more proper tuner (such as an AH-2, AH-4, AT-130/AT-140, etc.), would be the ultimate solution!!

{also, even though the 725 checked out okay at a local ham's shack....this does not mean all is well!! it could still have significant RFI issues on-board, and check out fine on-shore, on resonant antennas, etc...}



Actually, in my opinion, the next step should be understanding the unfortunate inherent issues with the Icom IC-725, and to a lesser extent, the IC-100!!
Once you fully understand those, then and only then....can you decide whether to attempt to make this rig/tuner work for you on-board!!!
(not, my recommendation btw....but, if you cannot return the radio and tuner, or get a refund on them, and you are stuck with them....you need to grasp the problems that you will have with them FIRST, before you try to involve even an experienced shore-side ham in this process...or to invest any more money!!)
Quote:
Originally Posted by tkeithlu View Post
I think my next step is to borrow a good manual tuner and a 50 ohm dummy load from my nearby (but unfortunately not able to climb on my boat) very experienced ham, and determine that the radio is transmitting and can be tuned. Sounds like the IT-100 is just not up to the job.

What a lot of very generous help! I greatly appreciate it. Do have a wonderful break, and I'll revisit the thread with news about the middle of the week. By then I should also have passed the general test.

Best wishes, --Tim.

And, btw, as Waterman mentioned....keeping the GTO-15 wire perpendicular to the hull/deck feed-thru (pass-thru), etc. should allow for no issues at all here!!
And, while having some form of VSWR measurement is nice....if the rig is shutting down (no transmit / display showing all dashes, etc.), you either have VERY BAD VSWR, and/or significant RFI, and/or low voltage at the radio (lots of voltage drop / "battery voltages" not "13.8vdc" at the radio!!!
But, we have NO idea how your system is wired/installed, so we cannot know exactly what to recommend!!!




I do hope this helps!!

Fair winds...

John
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Old 27-11-2015, 09:28   #19
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Re: SSB in steel boat/Newbie follies

Dear friends from afar:

95% of my problems with this set-up turn out to be the result of my being an ignorant newbie. I was choosing random frequencies to test tuning, and the Icom 725 only transmits in specific HF bands. It shuts down if you try to tune outside those bands. Once I found the specs and tried again, it tunes everywhere from 7 to 28 MHz. In addition, it has not been "openned" to cover the specific marine SSB channels. Those channels lie between the transmission enabled bands of the stock 725. I am aware of the legal, technical, and ethical arguments regarding openning a ham radio for marine SSB use, but 1. it appears to be a very common practice, and 2. I have not heard of actual instances of SSB spuirious emmissions creating a problem for either the Marine SSB or the ham communities.

So, it appears that I need a way of modifying my very simple antenna system (725 - IT100 tuner - 2' HF wire - 23' whip) to allow it to tune in the 1.8-4.1 MHz range, plus the nerves to get into my 725 and clip the D5 capacitor. Any ideas, particularly on the former?

Thank you for your very generous support. Have a wonderful weekend. Next week we meet as hams. --Tim.
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Old 27-11-2015, 14:01   #20
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Re: SSB in steel boat

Special to Paul Eliott: As I understand it, you've told me that adding a step-down balun between the tuner and the antenna would give me the ability to tune in the lower frequencies (I tune OK 6.9-30 Mhz, but not 1.8-4.1). Where can I find a step down balun? a web search reveals step up, and dipole, but not end feed step down. Thanks. --Tim.
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Old 27-11-2015, 15:49   #21
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Re: SSB in steel boat

Silly thought, but if you are in the US, I would spend $39 and join the ARRL for a year. And as a member, send an email in to ARRL's technical support division (or "The Doctor" column in the magazine) detailing your setup and asking what might be wrong. There are some very highly experienced people there, who delight in tackling mysteries.

Also, contacting Icom and LDG, both of whom have been known to be very familiar with their equipment and subtle mysteries of installations and problems. If there is anything grossly wrong, they'll spot it. And of course it could be something terribly simple, like a fault in the LDG tuner.

Even in this is a brand new installation, the first step should be to literally go over every connection from the transceiver power supply to the antenna itself, to look for any poor connections, whisker shorts, corrosion, etc.

If the radio is old, it may need to be checked out as well. Temporarily moving it (find a local ham radio club) and trying it directly with someone's "known good" antenna and power supply might be the fastest way to do that.

When you've got a whole "system" that isn't working, sometimes the best way to fix it is by breaking the system down and "divide and conquer".
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Old 27-11-2015, 16:07   #22
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Re: SSB in steel boat

Quote:
Originally Posted by tkeithlu View Post
Special to Paul Eliott: As I understand it, you've told me that adding a step-down balun between the tuner and the antenna would give me the ability to tune in the lower frequencies (I tune OK 6.9-30 Mhz, but not 1.8-4.1). Where can I find a step down balun? a web search reveals step up, and dipole, but not end feed step down. Thanks. --Tim.
A step-down transformer is just a step-up transformer connected the other way around. What I was suggesting is a transformer that steps the high-impedance of your short whip to a lower impedance that your tuner might be able to handle. Looking at it from the tuner side, it's a step-up, and from the antenna side it's a step-down.

Anyway, here's one from LDG: http://www.ldgelectronics.com/assets...UnunManual.pdf

You can buy one here for $30: LDG RU-4:1 Unun | Amateur Radio Supplies

(I have no affiliation or experience, etc...)

Notice that they call this a "UNUN". This means "Unbalanced to Unbalanced". This is your situation (unbalanced vertical and unbalanced tuner). It's still a transformer.

Remember, I can't guarantee that this is going to work for you. It sounds like there may be other issues. I doubt that anything simple is going to make your short whip work very well on 1.8MHz -- a proper vertical for that frequency would be about 130 ft long!

For what it's worth, on the marine bands I find the generally useful frequencies to be between 4 and 18 MHz.
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Old 27-11-2015, 16:09   #23
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Re: SSB in steel boat

Excellent thoughts, most of which I have followed, including putting the set in an existing (and experienced!) ham's network (It was fine). I've narrowed it down to its tuning just fine 6.9-30 MHz, but refusing to tune at 1.8-4.1 Mhz. I've heard one suggestion - add a step down balun between the tuner and the 23' end-fed whip antenna, and am looking for more, particularly because I can't find a balun that meets that specification. Your thoughts are deeply appreciated by this newbie. Yes, I will join ARRL. --Tim.
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Old 28-11-2015, 06:17   #24
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Re: SSB in steel boat

Thank you so much, Paul. By the way, I'm
Timothy Keith-Lucas
M/V Santa Catalina de Guale
Based in Carrabelle, FL and
Marine WDI2238
Ham KM4ODK
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Old 28-11-2015, 11:14   #25
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Re: SSB in steel boat

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Originally Posted by tkeithlu View Post
Thank you so much, Paul. By the way, I'm
Timothy Keith-Lucas
M/V Santa Catalina de Guale
Based in Carrabelle, FL and
Marine WDI2238
Ham KM4ODK
You're welcome! To clarify, even with this UNUN transformer, your tuner still may not be able to tune your antenna so that your transceiver is happy. It will probably extend the frequency range you can operate, but it might also keep the tuner from finding a match at some higher frequencies. It's a fairly inexpensive thing to try though...

Ultimately you may still want to get a tuner with a wider range, such as the Icom AT-140, which is specified to match a 23-ft whip from 1.6 to 30 MHz.

Regards,
Paul
Marine - WDB2898
Ham - WB6CXC (currently running a 10 milliwatt ham "Raspberry Pi" WSPR transmitter on 20 meters from Friday Harbor)
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Old 29-11-2015, 16:32   #26
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Re: SSB in steel boat/Newbie follies

Tim,
No worries about being a newbie!
Remember that everyone started from somewhere!
It is the smart ones that realize they don't know it all, AND actually attempt to learn!
(the smartest people I know are the ones that ask questions and appreciate the educational answers....not the ones just looking for reaffirmation of their ignorance!)


Congrats on finding the problem of no transmit / radio cut-out!
No, it will not work out-of-band....I just assumed that when you wrote the 14mhz band, you were aware of where the 20-meter ham band (14mhz band) was....
But, with this additional piece of the puzzle (as well as some other words of your here), I'd be remiss if I didn't add to the chorus of others who suggest that you spend some learning
about radio communications, electronics, maritime comms, ham radio, etc....(and especially radiowave propagation, rules and regs, transmit spectral purity!!!!)
Please do not just read some questions, take a test, and assume you've learned a lot....'cause that is just the very first step in a dozen or more step process!!!
Quote:
Originally Posted by tkeithlu View Post
95% of my problems with this set-up turn out to be the result of my being an ignorant newbie. I was choosing random frequencies to test tuning, and the Icom 725 only transmits in specific HF bands. It shuts down if you try to tune outside those bands. Once I found the specs and tried again, it tunes everywhere from 7 to 28 MHz.





As for use myth of ham radio use on the maritime bands (in fact it is very rare, in addition to taking my word, have a look at the SSCA Equipment Survey for 1000's of active cruisers' responses)....specifics on the IC-725......"opening-up" ham rigs in general, etc. etc....
Well, there is a whole lot of misassumption / misunderstanding in your posting here....
(I do not wish this to come off as arrogance at all, and I will try to be as helpful as possible.....but, I will also be very blunt here....so, please don't take offense..)
You write that you are "aware of the legal, technical, and ethical arguments regarding openning a ham radio for marine SSB use", but unfortunately the assumptions that you write are actually incorrect and/or uninformed...
Quote:
Originally Posted by tkeithlu View Post
In addition, it has not been "openned" to cover the specific marine SSB channels. Those channels lie between the transmission enabled bands of the stock 725.
You have the 725 (and IT-100 tuner), and you will make do with them....but, some of my caution here is actually not for you Tim, but rather for others that may be reading this...
So, please know that I do NOT wish for to take this the wrong way....
But, the IC-725 is one of the worst possible choices for this application....
And, yes, in addition to the poor technical specs, it's aversion to operation on "battery voltages", etc. I have personal, first-hand experience with this rig on boats....my first experience with the IC-725 on a boat was ~ 20 years ago in St. Thomas harbor, on-board a CT-54....the rig/tuner were new, and cost the owner ~$2000, plus installation...sold by a "reputable ham radio shop" in Florida, and installed by one of their "techs", just 2 months earlier....and since then I've come across 2 other boats with 725's that asked me for my help....and to this day, I cannot think of another 12vdc rig that is less suited to this application...
PLEASE do not take offense....I'm just mentioning this so that you understand


I am aware of the legal, technical, and ethical arguments regarding openning a ham radio for marine SSB use,
Yes, it is illegal...blatantly illegal (for VERY VERY good reasons!)
Yes, it causes serious interference...SERIOUS issues...
Yes, it is unethical....cheating, causing interference, etc...
But, you left out immoral, as it can cause loss of life / loss of property...


but 1. it appears to be a very common practice,
In actual fact, this is not common practice at all!!


and 2. I have not heard of actual instances of SSB spuirious
emmissions creating a problem for either the Marine SSB or the ham communities.
Well, not only have I personally heard/experienced interference on the maritime freqs from someone using an "opened-up" ham radio....I have also heard others complain about them as well...
Also, have heard ham rigs on boats, used on the ham freqs causing interference to other hams (many times this is because of "battery level voltages", which ham rigs do not like!)
BUT..
But, one of the most egregious incidents was a couple of "sailing hams" who just decided to "use some 8mhz frequency to communicate" rather than one of the assigned maritime channels (or which there are many), or even to simply use the 7mhz/40-meter ham band, well what did they do??
They just picked a frequency with an even number (I will not write it here), and they ended up being 2khz away from the primary North Atlantic Route International Aeronautical HF Oceanic channel (used by NY, Gander, Shanwick, etc.), for one of the two primary N. Atl. Routes....thereby causing interference to airline communications with international air traffic controllers!!!
NO BS here, I heard them on the ham bands, and they gave the frequency they were switching to...at which point, I grabbed for the mic and tried to call them off....but, I was too late....I followed them to their new frequency, and after a few minutes of them "tuning", I heard them gabbing away loud 'n clear, and then I told them what freq they were interfering with, to they responded with a "oh, sorry", but instead of immediately clearing off the air, they made plans to talk tomorrow, etc. and then left the air...

In addition to these yahoos, there are plenty of other users who may be on boats or on-shore, worldwide, that assume that just because someone can "open-up" a radio, that it must be okay to do so....
Unbelievable!!!!!!

I cannot fathom how/why anyone with access to the internet these days cannot figure out why this is a VERY bad idea....
But, in case anyone cares.....the 3 most important issues are:
a) Poor transmit spectral purity...(no matter what hype some may wish to BS you all with, there are NO ham rigs that even come close to being clean enough!!)
b) Poor freq accuracy....(even if the digital display shows the right "numbers", that doesn't mean that the radio is on that freq!!!)
c) Poor frequency stability....



So, it appears that I need a way of modifying my very simple antenna system (725 - IT100 tuner - 2' HF wire - 23' whip) to allow it to tune in the 1.8-4.1 MHz range,
as for the antenna system....
Best to return or sell the LDG tuner, and buy an AH-2 or AH-4...(or AT-130/AT-140)....but, if that is not possible...well, first figure out who/where/when you wish to communicate with on these lower freqs....and then figure out what you may need to allow this to work best (tell us, and we can help)




plus the nerves to get into my 725 and clip the D5 capacitor. Any ideas, particularly on the former?

Thank you for your very generous support. Have a wonderful weekend. Next week we meet as hams. --Tim.


Tim, there's a LOT more....but, I gotta' go now....I hope this brief post will be helpful..

Fair winds...

John



There are some posts that will give you a lot of info on the IC-725 and its use on a boat....if you read them, you will learn a lot...
Re: Icom 725, switch to SSB
Icom 725, switch to SSB

Icom 725, switch to SSB

Icom 725, switch to SSB


Icom 725/Pactor II Compatibility?
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Old 29-11-2015, 17:24   #27
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Re: SSB in steel boat

" It shuts down if you try to tune outside those bands."
While many radios can be "freebanded" relatively simply, and that may be a perfectly sensible option during real emergency service, it is still illegal. Usually no one notices, but if someone does complain, the FCC tends to demand WAY more than a second properly compliant radio would have cost.


Just, fwiw.


Don't know about freebanding that particular radio, that's a whole other topic.
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Old 30-11-2015, 06:34   #28
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Re: SSB in steel boat

Thank you, John. One difficulty for this newbie has been sorting through conflicting advice along the way, and owning now two 725s, one opened and one not. I may end up being a marine mobile ham (I go for the general test tomorrow) and simply listen on the specific marine radiotelephone channels. Another heavy investment in a radio at this point is not in the works, and I have a Spot, sat phone and DSC VHF on board. I am learning, but it has been fifty years since my electrical engineering course. --Tim.
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