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Gi-Lo · 03-08-2015, 14:49

So..... Finally got my mast off, ready for re-furb and new everything..... onlt to find, it only has a 1"1/2 conduit in the mast...... no room for TV antenna Co-ax... and sadly no room for RG213 Co-ax for the new Simrad RS35 VHF/AIS/DSC...... I have two power cables and a SIMNET cable to go in there.
So the million dollar Question. Do I use a smaller Co-ax cable and still mount the Antenna Masthead?...... or do I use RG213 and mount the Antenna on a Pole
at the Transom?? What will give me the best result?

**Wotname** · 03-08-2015, 15:14

Height trumps power!

But do use a low loss small diameter coax, forget the numbers right now but others will soon post them

. Some are almost as good as 213.

Sometimes possible to use 213 for the main bulk of the run and a smaller diameter tail towards the top of the mast.

**Wotname** · 03-08-2015, 15:15

Or perhaps better, install a second conduit.

S/V Illusion · 03-08-2015, 15:31

LMR 240 or its equivalent will provide similar loss characteristics compared with RG 213 but it is roughly half the diameter.

Any of the standard small dia. coax such as RG 8x has approx. twice the loss of the aforementioned. There are a myriad of coax loss charts on the internet. Why not look?

ka4wja · 03-08-2015, 16:52

Gi-Lo,
Absolutely use the masthead!!!

{There is WAY too much argument / debate about cable loss for VHF-FM-DSC (and AIS)....nobody is suggesting that cable loss is irrelevant, but if read another recent thread here, you will learn why this is an overly emphasized criteria....
http://www.cruisersforum.com/forums/...ml#post1869342

http://www.cruisersforum.com/forums/...ml#post1876295

Yes, RG-213 (or lower-loss cables) are GOOD....and Yes, I do recommend this!!!!
But, most sailors/cruiser will find little, to no, difference between the average vessel's standard-equipped RG-8x and RG-213...but, most will find a difference between "new" cable and connectors, versus their "old" moisture-ridden and corroded cable and connectors....}

So, you basically have three options....either "a" or "b" would be my recommendation....

a) Pull everything out, and pull the new wires/cable in along with the old ones (or replace the old ones, too)....using the RG-213 cable...
If you are trying to pull an RG-213 cable thru a conduit with all these other wires still in it, even a smaller diameter cable will be a REALLY difficult task (probably impossible)....and even if possible, will require WAY TOO MUCH pulling force and will damage the coaxial cable!!!
If you have been doing this already, then you must have some seriously large "power cables" in there!! (and you may want to consider using smaller power cables....)
Or maybe you have not been using wire/cable lubricant??? (it's cheap, and available at any electrical supply house...)

b) Do as in "a", but use a low-loss type of smaller diameter coaxial cable, such as LMR-240UF....
Please take note of the "UF" suffix....this is VERY important!!!
It stands for "Ultra Flexible", and is the only low-loss cable suffix to consider!!!

c) Use any 50-ohm coax cable for your new VHF, that will fit into your 1.5" conduit...

{Please note that it's hard to see from here that your "two power cables and a SIMNET cable" take up that much room???
SIMNET is a CAT5, yes???
And, what are you powering at the masthead that would require a large power cable??? (an LED masthead Tri-Color/Anchor light combo doesn't need a big power cable...nor does a Radar Target Enhancer, etc...)
RG-6 TV-coax is typically about 0.274" in diameter....and RG-213 is 0.405" in diameter....
CAT5 cable is typically about 0.2" in diameter, although heavy-jacketed, outdoor CAT5 can be a bit larger, up to 0.225" in diameter (not sure how big the SIMNET cable is)

http://www.belden.com/techdatas/english/1694a.pdf

http://www.belden.com/techdatas/english/8267.pdf

http://www.wavenet.net/products_files/Cat5E%20Outdoor%20Gel%20Filled%20spec.pdf

But, how BIG are your power wires??? }

Quote:

Originally Posted by Gi-Lo

So..... Finally got my mast off, ready for re-furb and new everything..... onlt to find, it only has a 1"1/2 conduit in the mast...... no room for TV antenna Co-ax... and sadly no room for RG213 Co-ax for the new Simrad RS35 VHF/AIS/DSC...... I have two power cables and a SIMNET cable to go in there.
So the million dollar Question. Do I use a smaller Co-ax cable and still mount the Antenna Masthead?...... or do I use RG213 and mount the Antenna on a Pole
at the Transom?? What will give me the best result?

If you wish to see the differences between using the oft-used RG-8x and RG-213 and LMR-240UF, etc., you must let us know how long of a cable run you have???
And, then look at this thread and cable chart...
http://www.cruisersforum.com/forums/...ml#post1876295

But, 'til then, I'm going to assume on a 33' boat, you have at best a mast height of 45' feet???
That means a total length of coax of maybe 55'??
This means there is going to be approx. 1db more loss thru the RG-8x, than the RG-213 or LMR-240UF....
1db, is hardly enough to worry about...

And, again, to see how/why this 1db of difference is not too big of a deal, please read this thread as well...
http://www.cruisersforum.com/forums/...ml#post1869342

Here are some more info for you...

Coaxial Cable Attenuation Chart

http://www.belden.com/techdatas/english/1694a.pdf

http://www.belden.com/techdatas/english/8267.pdf

http://www.wavenet.net/products_file...led%20spec.pdf

I hope this helps...

Fair winds...

John

wayne.b · 04-08-2015, 11:32

Quote:

Originally Posted by Gi-Lo

So..... Finally got my mast off, ready for re-furb and new everything..... onlt to find, it only has a 1"1/2 conduit in the mast...... no room for TV antenna Co-ax... and sadly no room for RG213 Co-ax for the new Simrad RS35 VHF/AIS/DSC...... I have two power cables and a SIMNET cable to go in there.
So the million dollar Question. Do I use a smaller Co-ax cable and still mount the Antenna Masthead?...... or do I use RG213 and mount the Antenna on a Pole
at the Transom?? What will give me the best result?

You could still use RG213 or even LMR400 by running them outside the conduit but surrounded by foam pool noodles or split foam pipe insulation.

DeepFrz · 04-08-2015, 12:41

Are you trying to pull the cables with the connectors already on the cables?

Gi-Lo · 04-08-2015, 21:39

Thanks for all your comprehensive replies..... I must confess, I did not give you exactly the correct information, as I was guessing with a Metric Eye..... now I have made some conversions, I can give you some exact sizes....

the Conduit is actually only 0.925 of an inch (24mm) (sorry cant do the fraction)

The RG is 0.403 Inch (10.2mm)
the Glomex low loss antenna Cable is 0.270 Inch (6.8mm)
the Simnet is 0.24 Inch (6mm)

The Power Cables Supplied are 3 Core x 2 Cables and are 0.475 Inch(12mm), However, I think these are Overkill for my Masthead LED Anchor and Tri-Colour, So I am using a 3 Core x 3mm (0.12") cable for this, OD 0.245 Inch.(6.2mm)

The Half Mast Steaming light incorporates a Halogen Deck light...... will the 3 Core 3mm be sufficient for this?? If so, that saves me another 1/4" (6.3mm)

So all Up, I would have
RG 10.2mm 0.4"
Glomex 6.8mm 0.28"
Simnet 6mm 0.24"

2 x Power 12.6mm.... 1/2"

....... and No, I am not trying to pull wires with plugs on.... although would like not to remove Simnet Plug if poss.......

However, I was not aware that it is better to pull all the wires together and not individually?....

I was also not aware that a Lubricant is available for this purpose?....

What should I be using to pull the wires?...... I have Whipping Twine through the conduit at the moment.....

Djarraluda · 05-08-2015, 00:26

Best to use a minimum of 8mm line, as I would not use wire in the mast. Look at what Telstra etc use in the street conduits.
Stagger the ends of the cables, so you do not get 1 solid lump but the real way is to use a pulling sock. It is like the old Chinese finger lock, woven tube so as you pull, it gets smaller and grips the cables. Looooong sock needed, but then the attachment to the pulling line is not adding to the bunch that you pull. See if you can encourage a tame commercial Sparky mate to help as he will have access to the socks used commercially.

DeepFrz · 05-08-2015, 00:29

Actually I think that it would probably be easier to pull one cable at a time.

Google "wire pulling lubricant".

**Wotname** · 05-08-2015, 02:34

Each of us have their own ways

Me: after pulling kilometres of cable over the years prefer to bundle all together and pull in one go. If you don't want to chase up cable lubricant, common dishwashing detergent works reasonably well.

**Wotname** · 05-08-2015, 02:37

Fitting a second conduit is not that difficult...

DeepFrz · 05-08-2015, 07:20

Quote:

Each of us have their own ways

I was thinking with such a small conduit that the connectors might bind if trying to pull them all at once. Have never pulled mast cables but have pulled lots of computer cables.

tinkrman69 · 05-08-2015, 07:44

Quote:

Originally Posted by Wotname

Fitting a second conduit is not that difficult...

the above is so true. done it many times.

when using power cables in conduit don't use multi conductor cable use individual wires. the sheath and shape take up too much space. Just label and or color code the wires at each end.

neve pull the wires individually. your just asking for trouble. pull the whole kit and caboodle, it's way easier and they lay better in the conduit. Have someone feed and lubricate, whilst the other pulls.

ka4wja · 05-08-2015, 10:14

Gi-Lo,
1) Pull out ALL the wiring out, and pull all wiring back in at once....staggering the ends of the wires a bit...
But, only tape/bundle the wires together where you attach the "pull string", except for at this "pull string", do NOT tape/secure the separate wires/cables together...

2) Feed all in from the top of the mast, and pull from the bottom....using a light line / heavy string secured to the cable bundle by several TIGHT wraps of electrical tape (or, if you have enough room in the conduit, can also tie a few rolling hitches around the wires/cables, and then tightly tape over these)...
Keep the wires CLEAN, and do NOT let them twist or kink as you feed / pull them (usually requires two people, or a large open space if you are alone)...

3) If you feed from the top and pull from the bottom, you can leave any professionally-installed / factory-installed connectors on the top / masthead end of the cables...

And, if you get REAL lucky with wire thickness and connector diameters, you might be able to pull some of the wiring thru with connectors on them.....but, this is doubtful!!

4) See here for specifics in red...

Quote:

Originally Posted by Gi-Lo

the Conduit is actually only 0.925 of an inch (24mm) (sorry cant do the fraction)

The RG is 0.403 Inch (10.2mm)

the Glomex low loss antenna Cable is 0.270 Inch (6.8mm)
(I assume this is the TV antenna cable?? RG-6?)

the Simnet is 0.24 Inch (6mm)

The Power Cables Supplied are 3 Core x 2 Cables and are 0.475 Inch(12mm),
I assume these "3 Core" cables are 3 conductor cables???
And, if so...I wonder why you need a 3-conductor cable to provide 12vdc for some lights?
A 2 conductor wire is all that is needed...

However, I think these are Overkill for my Masthead LED Anchor and Tri-Colour, So I am using a 3 Core x 3mm (0.12") cable for this, OD 0.245 Inch.(6.2mm)
Again, I'm wondering why you need a 3-conductor cable to provide 12vdc for some lights??
And, yes....LED anchor lights and/or LED tri-color lights typically draw about 1/10 of the power of older incandescent lights, so naturally can use much smaller wires!!

{Also, if you wire things up a bit differently, or use a combo anchor/tri-color light, you can use only ONE power cable, instead or two...use a DPDT switch to reverse the polarity, and then you wouldn't need to run two separate power cables all the way to the masthead...}

The Half Mast Steaming light incorporates a Halogen Deck light...... will the 3 Core 3mm be sufficient for this?? If so, that saves me another 1/4" (6.3mm)
Not sure what the power draw is of your light, so cannot be precise....
BUT...
But, I'm also not familiar with wire sized in mm, rather in "gauge" sizes....but looking online shows a "3mm wire as between an 8ga and 10ga....and that is a HUGE wire for a deck light!!!!

If you provide some conversion info, or wire gauge sizes, and the current draw of your lights, I can be precise!!

So all Up, I would have
RG 10.2mm 0.4"
Glomex 6.8mm 0.28"
Simnet 6mm 0.24"

2 x Power 12.6mm.... 1/2"
Probably will need much smaller wires....and maybe only need one of these smaller cables...

....... and No, I am not trying to pull wires with plugs on.... although would like not to remove Simnet Plug if poss.......
Don't know what the SIMNET plugs look like, nore their size....but, if you stagger the wires / plugs correctly, and TAPE everything VERY tightly (with only two layers), you might be able to do this...

However, I was not aware that it is better to pull all the wires together and not individually?....
YES....pull 'em all at once...
But, only use minimal force....anything more than pulling with one hand is too much force....

I was also not aware that a Lubricant is available for this purpose?....
Yes, it is CHEAP....and won't stain things, etc....
If you cannot source it, you can try diluted dish detergent...

What should I be using to pull the wires?...... I have Whipping Twine through the conduit at the moment.....
Whipping twine is good, and is easy to tie a few rolling hitches with....but, many times I use something a little bit larger, in order to grip better....(but then, I'm usually using a larger conduit...)

I hope this helps...

Fair winds...

John