HF-SSB cable routing

[Sailor 99]

I bought a Icom M802 with an AT140. I have installed the transceiver and the head at the nav station. This nav station is about 28 feet from the transom ( 50 foot boat).



I now need to route the AT140 control able and coaxial. I am going to use RG213.







I would like to route the control cable down the starboard side of the boat past the rather extensive breaker panels were all of the other cables are routed. There are nmea 2000 cables running down this major highway as well.


If I do this i will just make it to the back of the boat with the control cable.



I would also like to route the coaxial cable here.



If I do this both of these cables ( control and coax) are going to run right past 2 refrigeration compressors in the lazarette.



I will be installing lots of ferrites on the coax and some on the AT140control cable.


Alternately I could route the coaxial cable on to the port side of the boat and then swing back around the transom to the AT140 and miss all the wiring. This will be a major pain in the butt To do this and if I need to run the AT control cable there as well, it will involve buying 2 and splicing them together.



1) So will my first option work without issues or will I get RF issues

2) If I buy a coaxial cable with factory ends what do I with the excess cable. Can I coil it?


Thanks.


Colin

[transmitterdan]

Colin,

My SSB radio is run the same way. It works ok. I have to turn off some electronics like my VHF to use SSB but it works ok. Some LED lights cause noise during receive but I just turn them off.

It will probably work using the short run. Put the ferrites around the coax at the tuner end. Put them on the control cable at both ends.

Good luck,
Dan

[continuouswave]

If you are worried about ingress or egress of radio-frequency signals to or from the coaxial transmission line using RG-213/U, you can improved the isolation or shielding by using double-shield cable. RG-214/U would be the equivalent cable with double shielding.

Since the VSWR on the coaxial transmission line between the transmitter and the antenna tuning unit (ATU) should be low (not more than 2:1 worst case), and if the ATU is working properly there should not be antenna currents flowing on the coaxial transmission line, you should not need to suppress those currents with toroidal ferrite chokes--but they won't hurt.

[Paul L]

The control cable is fine like you describe. I would not run the coax in the same chase as other wires, or in close proximity to other electronics. If you have to cross another set of wires, do it at right angles with some spacing. You don't have a length limit on the coax.

[Sailor 99]

Originally Posted by Paul L

The control cable is fine like you describe. I would not run the coax in the same chase as other wires, or in close proximity to other electronics. If you have to cross another set of wires, do it at right angles with some spacing. You don't have a length limit on the coax.

Ok that sounds reasonable. I would really like to buy a pre-made length of coaxial cable. When I do that I am going to end up with some left over.


Can I simply coil the excess length or should I try and use it up by snaking through the ceiling



Colin

[Paul L]

Coil it, try not to have the excess excessive

[transmitterdan]

Colin,

Coil the excess up at the tuner end if possible. But it’s not a big issue if you need to coil it somewhere else like in the middle of the run.

It’s impossible to get a perfect zero ohm ground at the tuner. Ferrites on the coax and on the control cable at the tuner end help prevent those wires from radiating inside the boat. Cooling the coax actually helps as well.

[Sailor 99]

Thanks everyone. Going to order the cable tomorrow. Mast back in as soon as the ice is out here in the frozen cold of the north in Toronto and we will see if it was done right. or not . Sometimes on boat projects its difficult to determine if you are winning or losing.

[Paul L]

Originally Posted by Dark Horse

Thanks everyone. Going to order the cable tomorrow. Mast back in as soon as the ice is out here in the frozen cold of the north in Toronto and we will see if it was done right. or not . Sometimes on boat projects its difficult to determine if you are winning or losing.

You make your list and work away on it fanatically, continually add new items to it as you progress. Then you decide to take off after knocking off a couple of the early items on the list. At this point you throw the list away and start a new one from scratch, this is called cruising.

[ka4wja]

Colin,
As Dan and Paul have mentioned the issue is not too critical....tuner control wiring run is fine....and while I would not recommend bundling or cable-tieing the coax to other wiring on-board, keeping it a few inches away from other wiring is usually all that is recommended...(most installs, including mine, have the coax running nearby other wiring....and with our end-fed, random wire verticals, aka "backstay antennas", it is usually necessary to use a "line isolator" in order to be sure you've eliminated most of the transmit RFI issues....)


But...
But, fyi, there is a LOT that has gone unsaid here!!
Especially your proposed installation of your AT-140!! And, GTO-15 wire!!
This is where your transmit RF is being radiated, and where receive RFI is easily picked-up....
You should concentrate your efforts to keep your AT-140, GTO-15 wire (and the backstay antenna, itself) as far away from the refrigeration units (and other RFI generating, and RF sensitive, devices on-board) as possible!!

Originally Posted by Dark Horse

If I do this both of these cables ( control and coax) are going to run right past 2 refrigeration compressors in the lazarette.

I will be installing lots of ferrites on the coax and some on the AT140control cable.

Alternately I could route the coaxial cable on to the port side of the boat and then swing back around the transom to the AT140 and miss all the wiring. This will be a major pain in the butt To do this and if I need to run the AT control cable there as well, it will involve buying 2 and splicing them together.

Instead of me re-writing everything....
Please have a look at this recent posting in the "stickie"...

http://www.cruisersforum.com/forums/...ml#post2818683

Originally Posted by ka4wja

1) Although I thought this was covered here in this thread, it might not be specifically mentioned....so...
Running of the tuner control / power wiring and coaxial cable, to/from the HF transceiver (such as M-802, etc.) and the remote tuner, is not "critical"...(see below for details)


2) But first, some additional clarification...
Of course, using clamp-on ferrites on the tuner control/power wiring (at the tuner end, or both ends) is always recommended, and using a "line isolator" in/on the coaxial cable (again, at the tuner end of the cable) is always highly recommended (and has been highly recommended for ~ 20 years) and is specifically mentioned by me and others, a lot (and in the Sailmail Primer, too).....
It should be noted that the reason for using these is to prevent any "transmitted energy" from traveling along the outside of these cables/coax and interfering with other systems on-board (which would be known as transmit RFI), and also to a much lesser extent, keep any other systems' noise/RFI from being picked up by these cables and causing you additional receiver RFI...

{Please note that a "line isolator" can have as much as 50 to 100 times, or more, the "chocking" energy of a single clamp-on ferrite....and as such is VERY highly recommended....and fyi, if you can wind your coax thru a adequately-sized ferrite / torroid (of the proper "mix"), each winding increases the "chocking" energy (aka common-mode impedance) of the ferrite/torroid by an exponential rate....i.e. 8 turns thru would be a 64 times increase in "chocking energy")....which is basically what you have inside a "line isolator"....so, they're not "magic", just a reasonably-priced, weatherproof, and easy to install way of gaining a LOT of common-mode chocking energy....}

https://www.dxengineering.com/parts/dxe-fcc050-h05-a

https://www.balundesigns.com/model-1115i-single-core-isolation-balun-1-5-54-mhz-5kw/

https://www.balundesigns.com/model-1116di-hf-low-band-optimized-1-31-mhz-5kw/


While MFJ also makes a cheaper line isolator, and it should perform well, I have no personal experience with it...but, my experience with MFJ products is generally that they have poor QC and usually have connection/assembly reliability issues....so, I don't recommend their line isolator...nor other "off-brand" / unknown manufacturers units...(but, they may work just fine)



1) (con't)
Now, in a perfect world, you'd have a perfectly "RF-sealed" coaxial cable, and a "line isolator" would do its job and there would be no issues at all with coaxial cabling running thru the boat....
And, in most cases / situations, this is true...

But, in some cases, you have poor-quality cable, and/or poorly installed connectors, and/or have poorly designed instrument / electronics wiring already installed in the boat (and/or poor connections on those wires), and/or just bad luck to have overly-sensitive electronic devices (autopilot control / corepak, etc.), etc....and then when you transmit, you have some transmit RFI being caused by your coaxial cable...
Luckily, if the radio/tuner, and their wiring is installed properly (as described above and throughout this thread), this is very rare, as almost all transmit RFI is caused by your actual transmit signal coming from your antenna!!

But, just to be clear, it is not recommended to bundle together, nor "cable-tie" together, your HF radio coaxial cable with other cables on-board!!
It is usually just fine running near / alongside other wiring, but try to keep them a few inches apart, if possible....
(I, myself, have my RG-213 coax from the M-802 to the AT-140 tuner, running in the same wiring chase as some of my NMEA0183 wiring, my autopilot power wiring, etc....and I have NO transmit RFI at all!)



3) Further, it is primarily the close proximity of your antenna itself, to all the other devices on-board that causes RFI to be worse in some cases of marine HF installs, than on shore-based systems...

And, please note that the remote tuner IS part of your antenna!!
Your antenna starts with the remote tuner....and the GTO-15 wire is a very important part of your antenna, not just "the backstay outside"!!
And, this means that anything in close proximity to the remote tuner, GTO-15 wire, and the backstay, will have the most effect on RFI....
So...

So, that means (compared to the actual location / placement of the coaxial cable) it is MUCH more important to design your HF antenna system to keep the tuner, GTO-15 wire, and backstay/whip/etc. as far away as possible from RFI generating sources (like refrigeration compressors / compressor controllers), to reduce your receive RFI....and as far away from RF-sensitive electronics, to reduce your transmit RFI...

Please let me reiterate this, for emphasis....
This means (compared to the actual location / placement of the coaxial cable) it is MUCH more important to design your HF antenna system to keep the tuner, GTO-15 wire, and backstay/whip/etc. as far away as possible from RFI generating sources (like refrigeration compressors / compressor controllers), to reduce your receive RFI....and as far away from RF-sensitive electronics, to reduce your transmit RFI...


Now before everyone says "Huh?...I've got a 40' boat....just how far away does he think I can put my darn tuner?"
I completely understand that EVERY boat is different, and EVERY installation is a compromise!!

In my case, I have my AT-140 and GTO-15 wire, on the starboard side aft lazarette....and my Adler-Barbour Cold Machine refrigeration compressor on the far-outboard port side aft lazarette....almost 10' away....and that is the best I can do....
I'm lucky....I've got a 47' boat....with twin backstays....so, I use the starboard insulated backstay as my HF transmit antenna...(and an insulated aft-lower shroud as my HF-DSC-Receive / WeFax-Receive antenna)...
But, I still get occasional "birdies" (bleep-bleep sounds) in my HF receive, on some random freqs, caused by the DC-3-phase-AC power inverter in the refrigeration compressor....although it has never been an issue, and has never caused me interference to wefax charts, nor regular SSB voice comms, on occasion I have switched-off the frig to listen to the radio, if trying to hear a weak signal....
(have a look at my videos, where I detail all of this...)


For a better understanding of HF Maritime communications, the Icom M-802 itself, HF-DSC comms, and Offshore Weather, etc...please have a look at these playlists.....they're free of course....nobody is selling you anything at all!!
They are all made by me personally, with no script, no director, just LIVE as-it-happens, in the real-world, on-board a real offshore cruising sailboat (just like most of you will be doing all of this), no laboratory simulations, no fancy edits to cover-up "oopps" moments....it's all done LIVE as-it-happens....(so, please be kind to my less-than-professional video work....it's just my M-802, my fingers, and my voice...)

Maritime HF Comms
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nPNdApNsZDo_Jk3NB_Bt1y


Icom M-802 Instruction Videos
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2npivDjoFrC-8QKVyMb4tVr


HF-DSC Comms
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2n3z5nlv-ga2zYuPozhUXZX


Offshore Weather
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2mPZAx2vWzdjTJjHlChruyY


Offshore Sailing
https://www.youtube.com/playlist?list=PLnN6ygtZ3h2nbwAGh5DKgTCj15iyl6qoY


And, for specifics on what Receive RFI sounds like, have a look at this video here...

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

05-02-2019, 13:06	#11
transmitterdan Registered User   Join Date: Oct 2011 Boat: Valiant 42 Posts: 6,008	Re: HF-SSB cable routing In my previous post the spell checker changed the word coiling to cooling. It’s ok to coil the coax.

05-02-2019, 13:09	#12
ka4wja Registered User   Join Date: May 2007 Location: Florida Boat: Catalina 470 Posts: 2,583	Re: HF-SSB cable routing Dan, No worries here... My dyslexia sometimes causes me to write coax instead of coax... Ha Ha... Coil, cool, etc....it's all good! John __________________ John, KA4WJA s/v Annie Laurie, WDB6927 MMSI# 366933110

05-02-2019, 13:32	#13
alctel Registered User Join Date: Jan 2015 Location: Victoria BC Boat: Rafiki 37 Posts: 1,390	Re: HF-SSB cable routing Quick question I used standard AWG wire to run from the tuner to the bottom of the antenna (covered lifeline hoisted on a halyard) - I have some GTO-15 but never bothered switching over. Does it make that much of a difference? __________________ www.saildivefish.ca

05-02-2019, 13:34	#14
S/V Illusion Registered User   Join Date: Oct 2007 Location: Lakewood Ranch, FLORIDA Boat: Alden 50, Sarasota, Florida Posts: 3,472	Re: HF-SSB cable routing Originally Posted by transmitterdan . Cooling the coax actually helps as well. Are you serious?

05-02-2019, 13:49	#15
ka4wja Registered User   Join Date: May 2007 Location: Florida Boat: Catalina 470 Posts: 2,583	Re: HF-SSB cable routing The short answer is, no...not much difference... Originally Posted by alctel Quick question I used standard AWG wire to run from the tuner to the bottom of the antenna (covered lifeline hoisted on a halyard) - I have some GTO-15 but never bothered switching over. Does it make that much of a difference? The long answer is, the "standard AWG wire" is actually your antenna, just as much as the covered lifeline wire is....and actually even more so, and the high-current point of the antenna (which will be the lower end / bottom end, for the lower freqs bands) is where most of the radiation occurs... So, please remember that the remote tuner IS part of your antenna, as is the wire leaving the tuner, whether it is GTO-15, or any other wire....it IS your antenna, and should be dealt with as such.. Gotta go.. John __________________ John, KA4WJA s/v Annie Laurie, WDB6927 MMSI# 366933110

[transmitterdan]

In my previous post the spell checker changed the word coiling to cooling. It’s ok to coil the coax.

[ka4wja]

Dan,
No worries here...
My dyslexia sometimes causes me to write coax instead of coax... Ha Ha...
Coil, cool, etc....it's all good!
John

[alctel]

Quick question

I used standard AWG wire to run from the tuner to the bottom of the antenna (covered lifeline hoisted on a halyard) - I have some GTO-15 but never bothered switching over.

Does it make that much of a difference?

[S/V Illusion]

Originally Posted by transmitterdan

. Cooling the coax actually helps as well.

Are you serious?

[ka4wja]

The short answer is, no...not much difference...

Originally Posted by alctel

Quick question

I used standard AWG wire to run from the tuner to the bottom of the antenna (covered lifeline hoisted on a halyard) - I have some GTO-15 but never bothered switching over.

Does it make that much of a difference?

The long answer is, the "standard AWG wire" is actually your antenna, just as much as the covered lifeline wire is....and actually even more so, and the high-current point of the antenna (which will be the lower end / bottom end, for the lower freqs bands) is where most of the radiation occurs...

So, please remember that the remote tuner IS part of your antenna, as is the wire leaving the tuner, whether it is GTO-15, or any other wire....it IS your antenna, and should be dealt with as such..


Gotta go..

John