Re: Marine antenna

[David Lesher]

B A R R Y > writes:


>Can we cut a wire VHF-Air antenna that we already own to work with a
>marine band (higher than VHF-Air) handheld?


Yes, but given its proximity to the ground, it's impossible to really
tune it correctly. (Hang the aircraft 8 ft up from a crane while
looking at the VSWR? No wait! Just flip the bird on its back and....)
You'll end up taking a best-guess & living with it...


>Can we have a local avionics tech simply add a BNC to the right side
>of the panel to use with the handheld and a BNC->BNC patch cord?

Legalities aside, this is trivial. I'll let others fight over
the paper issues.

You also will want some way to power it, and others have mentioned
the headset/noise issues.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

[Michael Ware]

"David Lesher" > wrote in message
...
> B A R R Y > writes:
>
>
> >Can we cut a wire VHF-Air antenna that we already own to work with a
> >marine band (higher than VHF-Air) handheld?
>
>
> Yes, but given its proximity to the ground, it's impossible to really
> tune it correctly. (Hang the aircraft 8 ft up from a crane while
> looking at the VSWR? No wait! Just flip the bird on its back and....)
> You'll end up taking a best-guess & living with it...
>
>
Just start out long (20"), put the Thruline in there, go up and TX. Note the
direct and reflected power. Land, take out 1/2" and repeat, noting the
reflected each time. From this data you can determine the optimal ant.
length.

--
Hello, my name is Mike, and I am an airplane addict...

[Doug]

Just look at the specs for marine antennaes and use those, or go to a
marine store and measure one. No need to reinvent the wheel....

[Michael Ware]

"Doug" > wrote in message
ups.com...
> Just look at the specs for marine antennaes and use those, or go to a
> marine store and measure one. No need to reinvent the wheel....
>
Well, that's true, but the VSWR should be checked, with a meter while
airborne. Failure to do this could result in a damaged radio.

[Doug]

Lots of seaplanes are buying handheld marine radios and just plugging
into their aviation antennaes without any problems. The marine hailing
frequency (I forget which channel that is), is monitored by allmost all
boats up and down the inland passage from Washington to Alaska and if
you have trouble this is a good frequency to be on. It is also
monitored by the coast guard. The aviation antennae gives better
results than the rubber ducky handheld in most planes, I can tell you
that. The newer audio panels have music input jacks that you can plug
the marine radio into and listen (but not talk) on your aviation
headset. Nice setup at low cost.

>From what I have heard the FCC isn't going to permit an aviation/marine
handheld to be manufactured. Just not in the cards from what I have
heard as Oshkosh.

Of course a built in marine radio into the panel of a seaplane is a
nice feature too. I don't know if there is a marine antennae that is
specifically made for installation on an airplane or not. Might be
interesteing to google around for one.

[Newps]

Doug wrote:


>
>>From what I have heard the FCC isn't going to permit an aviation/marine
> handheld to be manufactured. Just not in the cards from what I have
> heard as Oshkosh.

Can't imagine why not. I have the Vertex VXA-700 which is a regular
aviation handheld that also includes the 2 meter ham band, which is FM.
It also receives the FM broadcast band and the business radio band.

[Doug]

Well, that was what I was told at Oshkosh where EVERYONE was asking for
it. But it's really just a rumor. However, you don't see any of them.
Of course the FCC could change their mind.

[[email protected]]

Doug > wrote:
> Well, that was what I was told at Oshkosh where EVERYONE was asking for
> it. But it's really just a rumor. However, you don't see any of them.
> Of course the FCC could change their mind.

I would think it more likely the market to too limited for a company
to justify spending the money it would take to get something like
that through the FCC certification process.

A read through the FCC aviation and marine regs would confirm or deny
if there is any regulatory restriction to such a dual radio.

--
Jim Pennino

Remove .spam.sux to reply.

[RST Engineering]

Those two sections are my bible. I can guarantee you that there is no such
prohibition. HOWEVER, the misinterpretation of the part that prohibits
SIMULTANEOUS AM and FM modulation may be causing the confusion. So long as
it is AM on the aircraft band and FM on the marine band, there is no
prohibition.

Jim


>
> A read through the FCC aviation and marine regs would confirm or deny
> if there is any regulatory restriction to such a dual radio.

[Newps]

Doug wrote:
> Well, that was what I was told at Oshkosh where EVERYONE was asking for
> it. But it's really just a rumor. However, you don't see any of them.
> Of course the FCC could change their mind.

The FCC doesn't have anything to say about it.

[[email protected]]

Newps > wrote:


> Doug wrote:
> > Well, that was what I was told at Oshkosh where EVERYONE was asking for
> > it. But it's really just a rumor. However, you don't see any of them.
> > Of course the FCC could change their mind.

> The FCC doesn't have anything to say about it.

Other than to mandate the radio meet stringent technical standards and
that the manufacturer spend a bundle formally proving compliance before
the radio can be legally sold and that's not going to change...

--
Jim Pennino

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[Don Tuite]

On Fri, 19 May 2006 23:55:02 GMT, wrote:

>Newps > wrote:
>
>
>> Doug wrote:
>> > Well, that was what I was told at Oshkosh where EVERYONE was asking for
>> > it. But it's really just a rumor. However, you don't see any of them.
>> > Of course the FCC could change their mind.
>
>> The FCC doesn't have anything to say about it.
>
>Other than to mandate the radio meet stringent technical standards and
>that the manufacturer spend a bundle formally proving compliance before
>the radio can be legally sold and that's not going to change...

My impression was that the Japanese designed as few universal
platforms as possible, each with a multitude of features, qual'd the
platforms with the various PTTs, of which the FCC is just one, and
then disabled features in order to create application/country-specific
models. Hence the dozens of Web pages of simple
cut-the-jumper-and-tweak the-capacitor hacks.

Don

[[email protected]]

Don Tuite > wrote:
> On Fri, 19 May 2006 23:55:02 GMT, wrote:

> >Newps > wrote:
> >
> >
> >> Doug wrote:
> >> > Well, that was what I was told at Oshkosh where EVERYONE was asking for
> >> > it. But it's really just a rumor. However, you don't see any of them.
> >> > Of course the FCC could change their mind.
> >
> >> The FCC doesn't have anything to say about it.
> >
> >Other than to mandate the radio meet stringent technical standards and
> >that the manufacturer spend a bundle formally proving compliance before
> >the radio can be legally sold and that's not going to change...

> My impression was that the Japanese designed as few universal
> platforms as possible, each with a multitude of features, qual'd the
> platforms with the various PTTs, of which the FCC is just one, and
> then disabled features in order to create application/country-specific
> models. Hence the dozens of Web pages of simple
> cut-the-jumper-and-tweak the-capacitor hacks.

> Don

When done, it is usually to meet country specific nits.

For example, the Amateur frequency allocations are not 100% the same
throughout the world (close, but not 100%), so such things are common
there.

The FCC is getting anal about designs that allow jumper changes for
operation outside the original certification for non-Amateur equipment.

Besides, if a company went through all the hoops, why wouldn't it just
sell the equipment with the certified capability enabled?

--
Jim Pennino

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[Ron Natalie]

Michael Ware wrote:
> "Doug" > wrote in message
> ups.com...
>> Just look at the specs for marine antennaes and use those, or go to a
>> marine store and measure one. No need to reinvent the wheel....
>>
> Well, that's true, but the VSWR should be checked, with a meter while
> airborne. Failure to do this could result in a damaged radio.
>
>
Doubtful. No 12V (or 28V) transistor radio is going to burn up
it's finals driven into a mismatch. It won't produce much
power.