On Wed, 28 Nov 2018 14:22:12 -0500, "Mr. Luddite"
wrote:

On 11/28/2018 1:50 PM, wrote:
On Wed, 28 Nov 2018 17:40:39 -0000 (UTC), Bill
wrote:

wrote:
On Wed, 28 Nov 2018 03:06:28 -0000 (UTC), Bill
wrote:

Mr. Luddite wrote:
On 11/27/2018 7:36 PM, wrote:
On Tue, 27 Nov 2018 17:47:44 -0500, "Mr. Luddite"
wrote:

On 11/27/2018 5:22 PM, wrote:

I have a uniden CB radio (new) and have an existing larsen wb vhf
radio already on my truck. Will this antenna work with my new radio.
Derek


Can't determine without knowing what freq range the truck antenna is
"cut" for. There are two VHF bands, low-band VHF (49-108 MHz),
high-band VHF (169-216 MHz). Marine radios operate in the high band.

Generally it will receive ok but transmit range may be limited due to
high standing wave ratio (SWR).

Even a marine VHF antenna should be tweaked in terms of length to
minimize SWR in the middle of the radio's freq range.


He is talking about CB (27mz) so that is over twice the wavelength of
the lowest frequency VHF.
SWR is really going to be ugly but since they are capped at 5w,
(usually more like 4.5) I doubt the magic smoke comes out but he won't
be "getting out" far either.

If his "truck" is a real one (breaker good buddy size) and he has 8-9'
from mirror to mirror the best antenna is the co phasers you see on
big rigs. Otherwise it is hard to beat a bottom coil loaded ~48"
antenna right in the center of the roof. That is what I had on my van
but you had to remember to take off the vertical when you went into a
parking garage. ;-)



I completely missed that it was a CB radio he was talking about.
Thought he was talking about a new VHF Marine radio. But the antenna
issues remain the same. For max range whatever antenna he uses needs to
be of the proper length. At 27 MHz a full wavelength is about 103
inches. A half wave antenna would be about 51.5 inches long and
aquarter wave length antenna would therefore be about 25.75
inches.

If really anal about these things, an SWR meter should then used to trim
the antenna length to the lowest SWR on channel 20 (mid-range).

I have an old SWR meter from the CB craze years that I never use anymore
but for some reason it's one of those things I just can't throw away.






I have one for my marine VHF. Have not used it in years. Actually I am
looking at a new radio for the boat. One with AIS. Maybe Santa Clause.

My wife has her phone. That is all we need ;-)
Worst case I call a tow pirate but I have plenty of neighbors who owe
me a tow.
Sinking is not an issue, we will just wade ashore, I will plot a
course through the mangroves with my aerial photos and boy scout
compass and we will walk home.
I do have loppers on the boat ;-)


We get fog, and lots of ship traffic in SF Bay and slightly offshore.
Would be nice to know what is coming.



===

We use both AIS and radar in situations like that. Of course they're
very useful at night also.


Wayne, BTW, my friends on the "Ring of Kerry" made it safely to
Charleston, SC. and have set up for the winter. This is their first
voyage after all the work they did on the boat and it looks like they
are enjoying the adventure big time. They *did* stop at Coinjock to
sample the fare and only ran aground once on the ICW on the way down. :-)



===

Good for them. If you've never touched bottom on the ICW, then you
just haven't been at it long enough. There are some real problem
areas that are only negotiable at half tide or better, other places
that have missing navigation marks, and a few spots that are badly
charted. We are fortunate to have a full length keel with a metal
shoe on it so the props and shafts are well protected.

Charleston is not nearly far enough south for a comfortable winter on
a boat however. We have neighbors down the street that just brought
their 58 footer down here from the Charleston area.

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