Icom 725, switch to SSB

[Ocean Girl]

We have a icom 725. I'm getting mixed signals on whether we can open to SSB. Can it be done? And is it legal/ in compliance?

If yes to both, any links on how to do it?

Thanks
Erika

[jcapo]

Most/all modern ham SSB transceivers can be modified to transmit on the marine SSB bands. It is not legal but many, many do it.

[skipmac]

As noted, almost all modern ham radios have the capability to be used on marine SSB frequencies.

Is it legal? Not unless that model is accepted by the FCC for use on marine frequencies. The odds of getting caught or suffering any sort of penalty are miniscule.

Is it ethical? To me this is the most important question. The potential issue is marine SSB radios must meet tighter specifications on the transmission than a ham radio. This is to avoid interference with other radios using adjacent channels on the marine bands. Some ham radios are good enough to meet these standards, some aren't. The answer to this I would have to defer to someone more expert in the various Icom models but in general I understand the Icoms ham sets are pretty good.

[John Drake]

The ICOM 725 is an older amateur (Ham) radio. The ICOM specs indicate that it is not open, able to transmit, on the Marine SSB bands, out of the box.

Whether or not the radio you have has been opened is pretty simple to check. Switch to a marine SSB frequency and key the mic. If you can transmit, you should see "TX" appearing on the display (maybe not on the 725 display) or....error of some sort.

The SSB MODE on that set is "A3J"...but there it appears as though there is an SSB button on the radio.

You will need to select upper side band (USB) MODE for all marine SSB frequencies.

That said, it is not likely that the set will transmit on Marine SSB freq's. And, as noted, it is not legal nor desirable (for the sake of those using those frequencies) for you to do so.

You can get a GREAT used Marine SSB radio and tuner for under $1000 used. The ICOM M700 Pro will beat many entry level amateur sets out there. Most of the M700Pro's sold CAN transmit on all HAM bands, out of the box. You would obviously need an amateur license, but if you have a 725, I assume you have one.

Hope this helps

best

John

[donradcliffe]

Basically, you have to clip diode D5 on the PLL board. Google 'Icom 725 Mars Mod' for detailed instructions.


The legality has been covered already. The morality is that if you are a good operator, you will interfere with other radios far less than Marine SSB's with bad operators.

[Viking Sailor]

Having the ability to operate a ham radio on marine SSB channels in an emergency is a safety issue. It allows non-marine SSB equipped vessels to obtain and/or provide assistance during an emergency at sea. It can provide a common long range communications capability to coordinate rescue operations.

When used for emergencies a modified ham radio used on marine SSB channels is considered legal.

[ka4wja]

Erika,
1) Unfortunately the Icom IC-725 was a very basic, entry-level HF ham transceiver, which was barely acceptable for use on the HF ham bands when it was introduced 25 years ago...

Secondly, I've had the unfortunate task of troubleshooting/repairing a couple 725's over the years....and if yours still works good, my best advice is to count your blessings and leave it alone...

Third, the answer is yes you may find someone who remembers how to modify that old radio ("open it up" to all-band-transmit), I believe it was just clipping one diode...
BUT...
But, not only is it illegal to do so, it is unethical and a VERY bad idea!!!
PLEASE do not do this!!

Please consider spending some of the $$$ that you may have used for a new "smart phone", etc. on a real marine HF transceiver!!!
Heck, you can buy a used M-700Pro for a few hundred dollars, or a used M-710 for around $500, or so....
Or, you could consider an Icom M-802 (new for $1800, used about $900-$1000)


And, yes, Viking Sailor is correct here...

Originally Posted by Viking Sailor

When used for emergencies a modified ham radio used on marine SSB channels is considered legal.

But, you'd be MUCH better off using a marine radio on the ham bands in order to stir up someone in an emergency (unless you're within range of the USCG on 8291.0khz or 6215.0khz)....
And, further I didn't interpret Erika as desiring to use 8291.0khz, etc....but rather wanting to save some $$$ and not buy the proper radio....maybe I'm mistaken here, if so my apologies....
So, yeah, if you do already have an HF marine radio on-board and wish to modify your IC-725 in order to access the marine freqs in an emergency, then YES you can go ahead and do so....but I'd still not think it a good idea...




Please have a look at this "sticky" here, where you'll learn a lot about HF marine communications and how easy it can be with the right radio, on the right channels, etc...
http://www.cruisersforum.com/forums/...ll-114734.html




2) I usually agree with ya' skipmac, and I do agree that it does boil down to an ethical question for some....the FACT is that there are NO ham HF transceivers, made in the past 25 - 30 years, that even come close to meeting the transmit spectral purity specifications for Part 80 maritime service...

Originally Posted by skipmac

Is it ethical? To me this is the most important question. The potential issue is marine SSB radios must meet tighter specifications on the transmission than a ham radio. This is to avoid interference with other radios using adjacent channels on the marine bands. Some ham radios are good enough to meet these standards, some aren't.]

There are NO current ham HF ham radios that can meet the Part 80 transmit specifications....NO Icom, NO Yaesu, NO Kenwood, NO Elecraft, NO TenTec, NO Flex, NO Alinco, etc. (the only exception is the small, portable 5-watt FT-817 when equipped with its optional high-stability TXCO, actually does meet these Part 80 specs...although it is not actually "type approved" for marine HF use, it could've been if it was submitted for testing/approval...)

In fact you'd have to go back 30-40 years, to find HF ham radios that could meet the Part 80 maritime standards....(30 - 40 years ago, both Drake and Collins made radios that met the old standards, and could meet the new transmit spectral purity standards but fail the new freq stability standards...)

The facts are that most (99%) of the ham radios that are raved about on the ham radio bands by 1000's of hams (even "old-timers") have very crappy transmitters!!!
And, I even hear 'em on the marine bands and wonder why!!!
{yes, on the used market there are many more "ham" radios than there are marine HF radios....and they do cost a couple hundred dollars more, comparing apples-to-apples, most marine HF radios will only be a couple hundred dollars more than their similarly-equipped HF ham radio...}


And, let's not forget that most of these HF ham radios, whose specs / tests were are looking at, are being spec'd/tested on the ham bands, where they were designed to work their best [sic]....
And, when you use them out-of-band, their specs and results are worse yet!!!
All-in-all, it is a BAD idea....especially for the IC-725....
(surprisingly the IC-735 is a much better radio...although still no where near good enough for HF maritime use, it's worlds above the 725....but let's all not forget we are talking about 25 year old ham radios!!!)


I don't have access to every radio's transmit test data here....(although I DO have quite a bit of that in my files at home, on paper!!), there are some on-line resources that have VERY good, official (US Gov't) info...
There is a website were you check out what radios are NTIA complaint (which is an identical set of specs to the Part 80 maritime specs...), that was set-up for those wishing to operate radios with the Civil Air Patrol and Military MARS services...
https://comm.capnhq.gov/comm/equipme...ent.cfm?type=a

And, if you want to see some commercial HF equipment, to see what meets the standards, have a look here...
https://comm.capnhq.gov/comm/equipme...ent.cfm?type=c
BTW, the specs of the M-700Pro are truly outstanding!!! This rig has some of the cleanest transmit specs of any HF radio ever made!!! (I can't say for sure it is THE best, but if not, it's sure enough is in the top 5!!!) Better than a Collins HF-80 ( radio costing 10+ times the M-700Pro!!!)Truly a superb transmitter!!!!

The current spec is:
43+10LOG(pX) (For 50W pX = 59.98 dB, 100W pX = 63 dB, 125W pX = 63.9 dB) For 150w = 64.7db

I think this image is the current spec....but it might be the older (less stringent) spec...but in any case, it gives you an idea of how tight the spec is!







EDIT:
3) Contrary to Don's comment/advice, using the IC-725 on the marine HF bands is bad idea!!!
I've used one of these IC-725's (on the ham bands) back almost 25 years ago, when they were new, and they are really pretty awful radios...

I'm sorry to be so blunt about....I'm not trying to be rude, just honest!!!

Using the IC-725 on the marine bands WILL in fact cause problems/issues for others!!!




Erika, I know this is not what you were hoping to hear...and you can take my words / advice as you'd like with no worries on my part, just wanted to pass on some facts and learned advice!!
Good luck and fair winds...

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110

http://www.qrz.com/db/KA4WJA

[Ocean Girl]

Thank you for the great advice!! Yes, this was about money, my hubby wants a new radio with ssb bands, I was trying to save some bucks and go with what we have. I agree with the morality of it all, ameture radio is so important and serves a vital function in a whole host of ways, we want to stick within the rules.
Looks like my hubby is getting a new SSB Radio, I think he already has it picked out

Thanks again for the fantastic feedback.

[donradcliffe]

A few years ago I would have said to upgrade to an ICOM 735, but these radios are getting long in the tooth and you would need to get one with the trimmer capacitors replaced. They are also getting expensive.

[ka4wja]

Erika,
You're very welcome!!
(and if budget is a concern, see #4, below for some thoughts on that...)


As for buying a marine HF radio (aka an "SSB")...

Originally Posted by Ocean Girl

Thank you for the great advice!! Yes, this was about money, my hubby wants a new radio with ssb bands, I was trying to save some bucks and go with what we have. I agree with the morality of it all, ameture radio is so important and serves a vital function in a whole host of ways, we want to stick within the rules.
Looks like my hubby is getting a new SSB Radio, I think he already has it picked out

1) In actuality, there is more to it than the "morality" of it...there is the performance (transmit and receive), ease-of-use, reliability, versatility, and probably most important for most sailors/cruisers/voyagers, safety / emergency / distress communications (especially with other vessels near you and/or in your region!!)



2) If you care for a suggestion / recommendation for a new radio...
The Icom M-802 is a great radio...

Icom SSB Radio Kits & Components
IC-M802 HF Marine Transceiver - Features - Icom America
ICOM IC-M802 Product Reviews

Yes, it will set up back about $1800 new, or about $1000 used...but it is head-and-shoulders better than your IC-725 (even if it was new) on both the HF Ham radio bands, and on the Marine HF bands!!!




3) If you desire a better explanation of the "whys" and "hows" of choosing/buying, and using, the M-802, HF-DSC, Distress signaling, Ham Radio use, etc. etc. etc....
Please have a look at this thread, and watch the videos!!!
BEFORE you (and/or your hubby) make a decision on what radio, I would especially like to point you to video numbers 8, 10, and 3...

http://www.cruisersforum.com/forums/...ll-114734.html

And then, numbers 6 and 4....
And, finally watch the rest before you install / use the radio....


If, like many sailors that are new to HF Maritime communications, you're not aware, there have been NO HF-Voice (aka SSB) radio watch required by vessels at sea, since Jan 1999...but they ARE required to maintain a 24/7 HF-DSC radio watch while underway...
So signaling other vessels (SOLAS vessels) and/or shore stations, for "routine" comms, "assistance", or "distress", and/or confirming an EPIRB alert, etc. requires an HF-DSC transceiver (such as the Icom M-802 Marine HF-DSC-SSB transceiver)...



4) If "budget" is a concern, and you are looking to "improve" on your IC-725 (and are not concerned with HF-DSC capabilities), then an Icom M-700Pro is a great choice!!! (M-700Pro...NOT the older M-700!!)
You can find them used for about $500!!!
They are nice radios....a bit "dated", but very nice nonetheless...(and they DO have a "VFO" mode, just like the M-802 has, and once "opened-up" for the ham bands, they work well there as well!!
(and, while it is discontinued, you may still find some new, in the distribution chain, for approx. $1500....but if you can spend that amount, I recommend the M-802, new for about $1800!!!)



I hope this helps...

Fair winds...

John, KA4WJA
s/v Annie Laurie, WDB6927
MMSI# 366933110

http://www.qrz.com/db/KA4WJA

[donradcliffe]

ka4wja--

I find it very interesting that you are complaining about the spectral purity of the ham radios not meeting the current SSB specs and interfering with others, but you recommend that ICOM 802 owners turn on their speech compression. Care to comment on the morality/legality of that??

To the OP, if you buy a used 802, read all of ka4jwa's posts on the clipping problem and make sure you get a radio that works.

[ka4wja]

Don,
Thank you for bringing up this point...

Originally Posted by donradcliffe

I find it very interesting that you are complaining about the spectral purity of the ham radios not meeting the current SSB specs and interfering with others, but you recommend that ICOM 802 owners turn on their speech compression. Care to comment on the morality/legality of that??

{And I'm sorry if it sounded like I was "complaining" about modern ham transceivers' poor IMD and spectral purity....in my mind I was "commenting" on it, not complaining about it....but if others got that impression, my apologies!!}



Onto the specific point...while I personally don't see it as a "moral" quandary, but rather just a question of math, and reading the numbers...I do understand that others may not agree...so like many things on-board, and in life, it is might turnout to be a judgment call...
At best, it is proven by the math, and at worst, this is a situation of a "matter-of-degree"...


The Icom M-802 did meet the FCC maritime radio service specs, and received Part 80 certification (as well as Part 87 and 90, for aviation and land-mobile use). See links.

According to an Icom service rep/tech I spoke with in 2008, for some time following the certification (thru 2005??), the M-802 was shipped with the internal DSP-based "speech compressor" ON.
He also related to me that while the M-802 received FCC Part 80, 87, and 90 certifications as advertised (with the speech compressor ON), it would meet the more stringent standards elsewhere that Icom was marketing the radio (or attempting to market), either at the 100 watt level or by switching the speech compressor OFF...basically, with the speech compressor on, it met the standards at the 100 watt output level, and at the 150 watt output level it missed this more stringent spec by 1.7db...but, with the speech compressor off, at 150 watt level, it met the spec...
Since the M-802's speech compressor is NOT alc-based, but rather done in the IF-DSP module, it presents only an extremely minor effect (which is typically not the case in most other SSB transceivers), so this explanation made sense to me....

And, according to this Icom service rep/tech, this is why early production model (I believe those made prior to 2005/2006), such as my first M-802, came with the speech compressor ON....but later models ship with it OFF...(and I believe models manufactured today have a hardware/firmware change which makes it unavailable / unusable)

Further, using the methodology of "human voice" baseband, to determine occupied bandwidth (as described by Leif Asbrink, SM5BSZ), and my own recently calibrated analyzer, I have been unable to notice any significant, measurable difference in occupied bandwidth between the two states (speech compressor ON, and OFF), perhaps a 1db - 2db difference is present using specific two-tone tests (as mentioned by Icom), but using the human voice this seems to be within the "natural error range", and I have made the "judgment" that if it passed FCC Part 80 and other standards (or even if it missed by 1.7db), this was "'acceptable" compared to the -15db to -25db+ difference of some of other HF transceivers (mainly modified ham radios) being used on the marine bands these days....

{Also, with the M-802, there is NO alc-overshoot, NO alc-derived IMD, nor "under-voltage" caused IMD....(which is not the case with most modern ham HF SSB transceivers, including the IC-725..)}

The FCC Part 80 standard is tough, even the freq stability standard isn't met by many modern HF ham transceivers (even with optional TCXO's)....and the occupied bandwidth standard isn't easy to do "on-the-cheap", with "unwanted TX energy" outside of the 2.8khz baseband, required to be 64.7db down, and 3rd order IMD down -36dbc...even if you test within the ham radio bands, the IC-725 (and most other HF ham transceivers) doesn't even come close to the specs...

Here are some traces of the M-802's occupied bandwidth..




But this more stringent standard is even harder to meet in an affordable / consumer-priced transmitter...
These standard occupied bandwidth tests / specs are "close-in" (within 400% of the baseband), and I do not have access to Icom's wideband (OOB) tests, but assume this is where they found an issue of compliance (missing by a couple db) to the more stringent standard....as at limit of the 400% of baseband, all transmitted energy must be 80db down, falling to 100db down once removed by 5% from the fundamental....
This is a very stringent standard to meet, and looking at the traces I do have for the M-802, shows some wideband transmitted energy at the -75db to -80db level near that 400% mark...so this is where I suspect Icom found they could not get (could not get an affordable solution) the M-802's oscillators and PA clean enough to meet this most stringent standard....





And, lest we forget that ALC Overshoot is rampant among almost all modern HF ham transceivers....and further exasperating the problem when operating the radio outside its designed bands, and then things get even worse when operating the radio on voltages lower than 13.6vdc, and at transceiver-power-terminal voltages of 12volts or lower, many HF ham transceivers look more like modulated wideband noise generators than transmitters...


Here is a trace of the Icom IC-706MKIIG...(the IC-725 is a couple db better
in the 3rd, but about the same in the others....and it is the 5th, 7th and 9th products that cause most of the splatter....)






Don, I hope this clarifies things...

And, although I do hope the info above is enough, we may need to "agree to disagree" on whether or not it is "acceptable" to use the M-802 with the internal DSP-based speech compressor ON (while commenting on the poor IMD and spectral purity of most modern ham radios), at least you see my reasoning...



Fair winds...

John, KA4WJA
s/v Annie Laurie, WBD6927
MMSI# 36699110

KA4WJA - Callsign Lookup by QRZ.COM



P.S. If someone does decide to purchase a used M-802, and find that it is an older model (s/n below 0108261) and has not had the factory "clipping mod" fix done, understand that Icom WILL still perform the "clipping mod" for free....

[ka4wja]

Here's the M-802 Part 80 Cert
https://apps.fcc.gov/oetcf/eas/repor..._id=AFJIC-M802

Sorry, couldn't get the forum to accept all the traces...
But, here are two for the M-802...(note the almost total lack of IMD products, nothing past the 3rd...)







And, for comparison, here is a trace of the Icom IC-706MKIIG...(the IC-725 is a couple db better in the 3rd, but about the same in the others....and it is the 5th, 7th and 9th products that cause most of the splatter....)





Fair winds...

John, KA4WJA
s/v Annie Laurie, WBD6927
MMSI# 36699110

KA4WJA - Callsign Lookup by QRZ.COM

http://www.c470.jerodisys.com/470pix/foto_bot.htm

[ka4wja]

Sorry about a typo...
My MMSI # is 366933110...

I cannot go back and edit the above posts with the typo...sorry..

John
s/v Annie Laurie

[ka4wja]

Reading my above posting, again, I realized that it might be a bit too much for some....so here's a very brief breakdown...

Regarding transmitters...
1) In SSB voice communications, most splatter is caused by:
a) 5th, 7th, and 9th order IMD products...and some contribution from others... (such as some 3rd order products having some effect on the immediate adjacent channel....and if the transmitter is seriously flawed, with even higher order products plateauing, these higher order products can be very troublesome...)

b) ALC-overshoot / leading edge distortions, etc.

c) Wideband reciprocal mixing / oscillator phase noise derived products, etc...

d) And, use of ALC circuitry for speech processing....


Most modern HF ham radios have some issues with all/some of the above...
Most modern HF commercial, maritime, aviation radios do NOT....



2) If you look at the M-802:
a) you'll see that the wideband noise and oscillator phase noise products are nonexistent...
b) There is no ALC overshoot, nor leading-edge distortions...
c) And with 3rd => -43db to -50db.....5th => -50db to -57db....7th => -60db to -63db....and higher orders falling off from -63 to >-75db....


3) If you look at the IC-706MKIIG / IC-725 / IC-718 / etc.:
a) You usually see much higher (20db to 30db, or more) wideband transmitter noise / osc. phase noise...
b) Most modern HF ham transceivers have significant ALC-overshoot and leading-edge distortions...
c) With 3rd = -25db to -32db.....5th = -33db to - 39db....7th = -38db to -42db....and higher orders typically not falling off much / mostly plateauing...

(the IC-718's 3rd = -25db..and 5th = -39db...and 7th = -50db....with good higher order roll-off to -60db.....
most of the 706's 3rd = -28db to -30db...and 5th = -33db to -35db....7th = -38db...with higher order products plateauing at -43db to -50db.....
the IC-725's 3rd = -35db....5th = -38db...7th = -47db with higher orders plateauing at -56 to -60db...)



4) So, in a nutshell, you can see that most modern HF ham transceivers typically have transmitter IMD products 20db - 25db WORSE than typical modern HF maritime transceivers....

But, even that isn't the worst....with ALC overshot and leading-edge distortions this can be even worse...(unfortunately ALC-overshoot spikes can produce short-lived products with levels only -15db..)

And, you also have the user-caused transmitter issues....such as using most "speech processors" (most are ALC-based, and can ruin and otherwise decent transmitter)...
And, finally the "under-voltage" use of the transmitter (mostly caused by sailors who aren't aware that the voltage at the back of the radio, when transmitting, is VERY different than what their panel-mounted volt-meter shows), which can mean severe distortion as well as a great deal of wideband IMD products....




I hope the above explains things better...

Fair winds..

John