Antenna cable?

cavelamb himself inscribed in red ink for all to know:
> I'm adding a VHF radio to my sailboat and would like to ask for details
> about the antenna cable.
>
> RG-58 is recommended, but the losses in the cable seem staggering!
>
> Is there a better cable for antenna connections???
>
> Richard
>
> Capri 18
> Spirit

Use RG8 or RG8x

bob
s/v Eolian
Seattle
 >> Stay informed about: Antenna cable? 

If you are going to the masthead the ultimate in low loss would be LMR-400
or 400UF. Slightly lighter weight than RG-8 with about half the loss at
157mhz.

LMR type coax is real popular with the wifi folks but I don't know why it
has not been better accepted in marine VHF. It is lighter weight and
handles bends with less loss than the regularly used coax.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"cavelamb himself" <cavelamb.TakeThisOut@earthlink.net> wrote in message
news:4hXdh.7885$ql2.114@newsread3.news.pas.earthlink.net...
> I'm adding a VHF radio to my sailboat and would like to ask for details
> about the antenna cable.
>
> RG-58 is recommended, but the losses in the cable seem staggering!
>
> Is there a better cable for antenna connections???
>
> Richard
>
> Capri 18
> Spirit
 >> Stay informed about: Antenna cable? 

On Thu, 07 Dec 2006 09:02:14 -0800, RW Salnick
<salnick.RemoveThis@no.spam.salnick.com> wrote:

>cavelamb himself inscribed in red ink for all to know:
>> I'm adding a VHF radio to my sailboat and would like to ask for details
>> about the antenna cable.
>>
>> RG-58 is recommended, but the losses in the cable seem staggering!
>>
>> Is there a better cable for antenna connections???
>>
>> Richard
>>
>> Capri 18
>> Spirit
>
>Use RG8 or RG8x


How long cable? Lower loss cable such as RG8 for masthead
installations, but RG58 is quite ok for shorter cables. BTW, make
sure to use good quality connectors and be carefull that connections
are waterproof. Having boating and ham radio experience for 20 plus
years, 99% of problems have something to do with poor corroded
connections ...

Mika


--
----------------------------------------------------
Haluatko lähettää postia? Vaihda osoitteen
eka (vai oliko se toka?) numero vitonen numeroksi
kahdeksan...
----------------------------------------------------
 >> Stay informed about: Antenna cable? 

Glenn Ashmore wrote:
> If you are going to the masthead the ultimate in low loss would be LMR-400
> or 400UF. Slightly lighter weight than RG-8 with about half the loss at
> 157mhz.
>
> LMR type coax is real popular with the wifi folks but I don't know why it
> has not been better accepted in marine VHF. It is lighter weight and
> handles bends with less loss than the regularly used coax.

What glen said! LMR (Times Microwave) has the LMR series coaxial cable
in a range of sizes that will replace RG-58, RG-8, or any other commonly
used coax. And it outperforms all of the "old standards" by the specs
and in my experience.

http://www.timesmicrowave.com/wireless/index.shtml

Jack

--
Jack Erbes in Ellsworth, Maine, USA (jackerbes at adelphia dot net)
(also receiving email at jacker at midmaine dot com)
 >> Stay informed about: Antenna cable? 

Mika wrote:
> On Thu, 07 Dec 2006 09:02:14 -0800, RW Salnick
> <salnick.DeleteThis@no.spam.salnick.com> wrote:
>
>
>>cavelamb himself inscribed in red ink for all to know:
>>
>>>I'm adding a VHF radio to my sailboat and would like to ask for details
>>>about the antenna cable.
>>>
>>>RG-58 is recommended, but the losses in the cable seem staggering!
>>>
>>>Is there a better cable for antenna connections???
>>>
>>>Richard
>>>
>>>Capri 18
>>> Spirit
>>
>>Use RG8 or RG8x
>
>
>
> How long cable? Lower loss cable such as RG8 for masthead
> installations, but RG58 is quite ok for shorter cables. BTW, make
> sure to use good quality connectors and be carefull that connections
> are waterproof. Having boating and ham radio experience for 20 plus
> years, 99% of problems have something to do with poor corroded
> connections ...
>
> Mika
>
>

God is in the details, so they say.

Yes, I'm mounting the antenna on the mast head.
the mast is 24 feet long (hey, it's a Capri 18!).

Add another 10 or 12 feet for routing the cable out of the way in
the cabin...

The antenna is a 3db Shakespear that has a built in cable.
The mounting instructions say the cable can be shortened but must
be at least 3 feet long. I haven't decided whether to coil it up
at the mast head or maybe put a bracket a couple of feet lower to
attach the connectors.

Either way there is a connector at the top of the mast, one at
the bottom (it's a trailerable boat) and one at the radio.

I thought about putting a deck clam near the mast and just
running the cable from the top of the mast to the radio, but
for the fact that we drop the mast to travel several times a year.

I hear ya about connector problems.

The only local source for cable and connectors is Radio Shack(!)
(PL-259 is spec)

Where do I look (and what am I looking for) in regard to connectors?

Richard

BTY, pics of my boat at:
http://www.home.earthlink.net/~cavelamb/spirit.htm#spirit
 >> Stay informed about: Antenna cable? 

Jack Erbes wrote:
> Glenn Ashmore wrote:
>
>> If you are going to the masthead the ultimate in low loss would be
>> LMR-400 or 400UF. Slightly lighter weight than RG-8 with about half
>> the loss at 157mhz.
>>
>> LMR type coax is real popular with the wifi folks but I don't know why
>> it has not been better accepted in marine VHF. It is lighter weight
>> and handles bends with less loss than the regularly used coax.
>
>
> What glen said! LMR (Times Microwave) has the LMR series coaxial cable
> in a range of sizes that will replace RG-58, RG-8, or any other commonly
> used coax. And it outperforms all of the "old standards" by the specs
> and in my experience.
>
> http://www.timesmicrowave.com/wireless/index.shtml
>
> Jack
>
Will check it out.

The recomendation from BoatUS was PVC jacket and tinned internal
conductor (ratehr than bare copper). And to avoid foam filled cables.
http://www.boatus.com/boattech/antennas.htm

So?
PVC jacket, tinned stranded internal conductor, and..
What kind of insulation? Air?


We do occasionally swim in the salt...

Richard
 >> Stay informed about: Antenna cable? 

cavelamb himself <cavelamb.TakeThisOut@earthlink.net> wrote in news:4hXdh.7885
$ql2.114@newsread3.news.pas.earthlink.net:

> RG-58 is recommended, but the losses in the cable seem staggering!
>
> Is there a better cable for antenna connections???
>
> Richard
>
> Capri 18
>

"Staggering"? RG-6 would be much better at about the same price. It's
only a hair bigger diameter, available at any marine store selling
electronics. With a 40' run of RG-6 you still get 75% efficiency.

If you must:
http://shop.electro-comm.com/ac/Product.aspx?Id=19707&view=24
LMR-1700-DB, double-shielded, direct burial, waterPROOF will give you
97.9% at 156.8 for 40' but noone will notice it on the air, only in your
pocket book at $10/ft plus some pretty impressive connectors. Way
overkill. It's 1 1/4" diameter...not good. RG-6 is better.

The Icom M802 on Lionheart has about 70' of RG-6 to a Metz Manta 6 at
55'. Savannah is 100 miles from here. I hear them all the time and I
know they can hear me because they called me...(c;



Larry
--
If we eliminate religion, will they stop murdering each other?
 >> Stay informed about: Antenna cable? 

This table shows results for the 2Meter ham band, which is very close
to the vhf marine band.
There are many other options, but most are rare so very much more
expensive, and connectors harder to find.
This data came from
http://www.antennex.com/preview/Folder01/Dec4/newstat1.htm

Note:
3dB cuts the power [or received signal] in half.

Also: mouser.com & graybar.com are places that I frequent for this
sort of thing, competative prices and market rate shipping.
tom
=-==


Cable Insertion Loss at 150 MHz, 100-Foot (30.5 m) Length Cable Type
Cable Loss Comments

RG-58C/U 6.6 dB Very short cable runs, Test Cables
RG-58U 6.0 dB Very short cable runs, Test Cables
RG-8U 3.2 dB OK up to 30 feet (9.15 m)
RG-8U FOAM 2.2 dB OK up to 45 feet (13.7 m)
9913 (Belden) 1.7 dB Recommended for all installations
..5 Inch "Hard Line" 1.0 dB Excellent but may be cost prohibitive



cavelamb himself wrote:
> I'm adding a VHF radio to my sailboat and would like to ask for details
> about the antenna cable.
>
> RG-58 is recommended, but the losses in the cable seem staggering!
>
> Is there a better cable for antenna connections???
>
> Richard
>
> Capri 18
> Spirit
 >> Stay informed about: Antenna cable? 

RG8 [not 6] is MUCH bigger in diameter than RG58. RG58 is also much
mor flexable.
But I wouldn't recommend it for this length, unless a very sharp bend
is absolutely necessary.
tom
=-==

Larry wrote:
> cavelamb himself <cavelamb.RemoveThis@earthlink.net> wrote in news:4hXdh.7885
> $ql2.114@newsread3.news.pas.earthlink.net:
>
> > RG-58 is recommended, but the losses in the cable seem staggering!
> >
> > Is there a better cable for antenna connections???
> >
> > Richard
> >
> > Capri 18
> >
>
> "Staggering"? RG-6 would be much better at about the same price. It's
> only a hair bigger diameter, available at any marine store selling
> electronics. With a 40' run of RG-6 you still get 75% efficiency.
>
> If you must:
> http://shop.electro-comm.com/ac/Product.aspx?Id=19707&view=24
> LMR-1700-DB, double-shielded, direct burial, waterPROOF will give you
> 97.9% at 156.8 for 40' but noone will notice it on the air, only in your
> pocket book at $10/ft plus some pretty impressive connectors. Way
> overkill. It's 1 1/4" diameter...not good. RG-6 is better.
>
> The Icom M802 on Lionheart has about 70' of RG-6 to a Metz Manta 6 at
> 55'. Savannah is 100 miles from here. I hear them all the time and I
> know they can hear me because they called me...(c;
>
>
>
> Larry
> --
> If we eliminate religion, will they stop murdering each other?
 >> Stay informed about: Antenna cable? 

LMR cable has polyethylene outer jacket and foam insulator so you have to be
very careful about sealing up the connectors. The LMR-DB cable is filled
with an inert gel to prevent water migration and is guaranteed for 10,
years. I used LMR-400DB with SMA connectors which are about the same
diameter as the cable and slip a piece of adhesive lined shrink tubing over
the joint.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"cavelamb himself" <cavelamb.DeleteThis@earthlink.net> wrote in message
news:IZ0eh.8144$ql2.4908@newsread3.news.pas.earthlink.net...
> Jack Erbes wrote:
>> Glenn Ashmore wrote:
>>
>>> If you are going to the masthead the ultimate in low loss would be
>>> LMR-400 or 400UF. Slightly lighter weight than RG-8 with about half the
>>> loss at 157mhz.
>>>
>>> LMR type coax is real popular with the wifi folks but I don't know why
>>> it has not been better accepted in marine VHF. It is lighter weight and
>>> handles bends with less loss than the regularly used coax.
>>
>>
>> What glen said! LMR (Times Microwave) has the LMR series coaxial cable
>> in a range of sizes that will replace RG-58, RG-8, or any other commonly
>> used coax. And it outperforms all of the "old standards" by the specs
>> and in my experience.
>>
>> http://www.timesmicrowave.com/wireless/index.shtml
>>
>> Jack
>>
> Will check it out.
>
> The recomendation from BoatUS was PVC jacket and tinned internal
> conductor (ratehr than bare copper). And to avoid foam filled cables.
> http://www.boatus.com/boattech/antennas.htm
>
> So?
> PVC jacket, tinned stranded internal conductor, and..
> What kind of insulation? Air?
>
>
> We do occasionally swim in the salt...
>
> Richard
 >> Stay informed about: Antenna cable? 

"tlindly" <tlindly DeleteThis @gmail.com> wrote
> RG8 [not 6] is MUCH bigger in diameter than RG58. RG58 is also much
> mor flexable.
> But I wouldn't recommend it for this length, unless a very sharp bend
> is absolutely necessary.
> tom
>


Besides that, if you ran RG8 on an 18ft Capri, it would likely turn turtle!

Always minimise weight aloft on a sailing vessel!

GM
 >> Stay informed about: Antenna cable? 

Gm1234 wrote:
> "tlindly" <tlindly RemoveThis @gmail.com> wrote
>> RG8 [not 6] is MUCH bigger in diameter than RG58. RG58 is also much
>> mor flexable.
>> But I wouldn't recommend it for this length, unless a very sharp bend
>> is absolutely necessary.
>> tom
>>
>
>
> Besides that, if you ran RG8 on an 18ft Capri, it would likely turn turtle!
>
> Always minimise weight aloft on a sailing vessel!
>
> GM
>
>
There is a good calculator for coax losses at
> http://www.ocarc.ca/coax.htm
A 25W VHF at 156 mhz with 40 ft of RG-58 will have 15.819W at the
antenna. With RG-8X it will be 16.741W. With RG-8U it will be 19.859W.
Assuming a VSWR of 1.3
krj
 >> Stay informed about: Antenna cable? 

Matt Colie <Matt.RemoveThis@nospam.net> wrote in news:w4eeh.4$P02.1@newsfe06.lga:

> Well,
> It's about time. I was starting to wonder why you had the VHF
> tied into the broadband.
> Matt
>
>

RG-6 would work fine. We've run some bigtime 2 meter repeaters using 75
ohm hardline we got for free from the local cable companies. I used to
have a storage yard under a paging tower that was overrun with it. I gave
it away to anyone who asked for it. Lots of ham radio stations have it
buried in their yards, still, 10-20 years later.

RG-6 is that cable running to your TV in the living room. The direct
burial stuff the cable guys on the trucks have is great. You can lay it
anywhere in the bilge and it won't leak like 8X does....even with the fancy
white cover.

There are even PL-259 UHF crimp-on connectors with sealer built into the
crimp for it.

"Coax is a terrible thing to waste"....(c
 >> Stay informed about: Antenna cable?