[C38] mast antenna cable

[Tom T.]

The coax is the biggest transmit and receive loss culprit on sailboats with
tall masts.  The large RG8X is heavy, hard to bend, and expensive but very
low loss at VHF frequencies like we use and very efficient.

Many sailors are going to the smaller "Mini-8" which is about the same size
as RG58 or RG59 but with less loss.  Another good choice is 9913 which I
believe has less loss than Mini-X (RG8X) and also much easier to use than
the large RG8.  I have never used 9913.  I prefer a high quality RG8X but
it is heavier, more expensive and harder to install.

If you have a ham radio store in your area, ask their advice.  A really
good antenna used with a high loss coax will give poor performance.  A good
antenna with a good coax is the way to go.  For every 3db of loss, you cut
both your transmit and receive power in half.

On a sailboat with a tall mast, like a Catalina 38, I would rather have a
good coax tied to a little 1/4 wave antenna than a high loss coax tied to
the best antenna on the market. Stay away from RG58 completely unless you
are running very short lengths like to a stern mounted antenna.

By the way, the reason the 5/8 wave antenna is so popular on sailboats is
that it gives a 3db gain (100% power increase) but still works fairly well
when the boat is heeled.   A really powerful co-linear type antenna like
the powerboat boys use really works well when used in a vertical position
but as sailors, our heeling makes a really high gain antenna
unsatisfactory.  A high gain antenna has a radiation pattern like a flat
flying saucer and if the antenna heals, you will end up with less gain than
a 5/8 antenna.  Gain works equally well in both transmit and receive.

Bottom line, don't scrimp on the coax.


Tom Troncalli
Recovering amateur radio operator (AB4NI)





> [Original Message]
> From: Craig Steinkraus <Navion at Charter.net>
> To: Catalina 38 Listserve <listserve at catalina38.org>
> Date: 12/7/2010 12:57:45 PM
> Subject: Re: [C38] mast antenna cable
>
> If memory serves, I used RG-59. I bought it at Radio Shack. They should
be 
> able to confirm the correct cable.
>
> ----- Original Message ----- 
> From: "Patrick Harpole" <1derful at comcast.net>
> To: "Catalina 38 Listserve" <listserve at catalina38.org>
> Sent: Tuesday, December 07, 2010 10:05 AM
> Subject: Re: [C38] mast antenna cable
>
>
> > Thanks....do you know what kind of cable I need?
> > ----- Original Message ----- 
> > From: "Craig Steinkraus" <Navion at Charter.net>
> > To: "Catalina 38 Listserve" <listserve at catalina38.org>
> > Sent: Tuesday, December 07, 2010 6:19 AM
> > Subject: Re: [C38] mast antenna cable
> >
> >
> >> Patrick, I have done it on several boats. Simply cut off the connector 
> >> and tape it to the old cable, and pull it through. You obviously need
to 
> >> replace the connector , but that's a simple job.
> >>
> >> Craig Steinkraus
> >> "Wings" C-38 # 280
> >>
> >>
> >> ----- Original Message ----- 
> >> From: "Patrick Harpole" <1derful at comcast.net>
> >> To: "Catalina 38 Listserve" <Listserve at catalina38.org>
> >> Sent: Tuesday, December 07, 2010 8:09 AM
> >> Subject: [C38] mast antenna cable
> >>
> >>
> >>> Has anyone ever replaced cable without taking mast down?
> >>> Patrick
> >>> Blue eyes
> >>> San Francisco Bay
> >>>
> >>> _______________________________________________
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> >>>
> >>
> >>
> >>
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> >
> >
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>
>
>
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