Well, I'm triangulating in on the problem. I made up a short jumper of 400
cable, and connected it to my kludge of a powered up setup for the nav radio
dangling at the helm (instead of the arch antenna feed, with which we've
already proven the radio good) and the antenna I took off the top of the
mast.

Loud and clear, just sitting in the cockpit holding the antenna outside the
bimini - tip of the whip not higher than the boom - from a slightly distant
point and a local as well, 5x5, even on low power.

So, given the lousy positioning of the antenna (no height, no grounding), I
conclude that the antenna is ok, of which I'm very gladdened, as dealing
with one on the plane when I come back would be a nuisance.

That leaves the cable, which I'm going to replace, rather than try to
troubleshoot the several pieces of it (mast and at least two jumpers,
perhaps as many as 4, I forget). Various discussions in various places have
alternated between "it's so short, and the power is so small, that anything
will do" to "nothing other than MilSpec, and, a bonus, it's lighter and
thinner" and places in between.

I'm all for lighter and thinner, and the best tx I can get, if the two are
compatible, and forever-grade corrosion/sal****er/whatever protection I can
get.

So, what part number cable should I be looking for for best longevity,
easiest handling and best throughput (is there a single item to do that?)?
I know I may have to pay a couple (maybe more) bux a foot for it, but it's
small potatoes in the boatbux equation, and I really don't want to do this
again...

Thanks, all.

L8R

Skip, glad I'm not having to deal with an antenna on the plane

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.yahoo.com/group/TheFlyingPigLog
and/or http://groups.google.com/group/flyingpiglog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hand
(Richard Bach)

On Mon, 23 Nov 2009 18:30:46 -0500, "Flying Pig"
wrote:

So, what part number cable should I be looking for for best longevity,
easiest handling and best throughput (is there a single item to do that?)?
I know I may have to pay a couple (maybe more) bux a foot for it, but it's
small potatoes in the boatbux equation, and I really don't want to do this
again...

What I used with great success on my old Cal-34 was RG-142/U. Looking
around on Google I just found a place that has it for $1.94/ft
(non-MIL spec):

http://www.wifi-parts.com/rg142u.html

That is a good price in my opinion since some places are charging as
much as $5/ft.

Here's another source for the MIL spec version
at $2.25/ft (over 50 ft):

http://www.rfparts.com/coax.html#teflon

Looks like they have the non-MIL spec version at $1.80, don't know
what the difference is but my experience is with the MIL spec.

It is easy to handle although no coax likes really sharp bends.

Solid dielectric, double shield, preferably not pvc sheath which gives
off acid decay products. Choose the correct characteristic impedance.
Coax is offered in 50 to 70 ohm impedance. Above all: minimize I said
MINIMIZE the number of BNC coax connections. They are lossy. You could
consider low loss type connectors but it adds to the general confusion
and cost I know. I hope you don't mean what I THINK you mean when you
talk about jumpers. NO WIRE JUMPERS!

Brian W

Flying Pig wrote:
...
That leaves the cable, which I'm going to replace, rather than try to
troubleshoot the several pieces of it (mast and at least two jumpers,
perhaps as many as 4, I forget). Various discussions in various places have
alternated between "it's so short, and the power is so small, that anything
will do" to "nothing other than MilSpec, and, a bonus, it's lighter and
thinner" and places in between.

I'm all for lighter and thinner, and the best tx I can get, if the two are
compatible, and forever-grade corrosion/sal****er/whatever protection I can
get.

So, what part number cable should I be looking for for best longevity,
easiest handling and best throughput (is there a single item to do that?)?
I know I may have to pay a couple (maybe more) bux a foot for it, but it's
small potatoes in the boatbux equation, and I really don't want to do this
again...

Thanks, all.

L8R

Skip, glad I'm not having to deal with an antenna on the plane

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.yahoo.com/group/TheFlyingPigLog
and/or http://groups.google.com/group/flyingpiglog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hand
(Richard Bach)

Wayne.B wrote:

/snip/
http://www.rfparts.com/coax.html#teflon

Looks like they have the non-MIL spec version at $1.80, don't know
what the difference is but my experience is with the MIL spec.

It is easy to handle although no coax likes really sharp bends.


At a sharp left hand corner, a right hand loop beats a tight left bend,
any day of the week.

Brian W

----- Original Message -----
From: "brian whatcott"
Newsgroups: rec.boats.cruising
Sent: Tuesday, November 24, 2009 7:24 AM
Subject: VHF antenna anomaly


Solid dielectric, double shield, preferably not pvc sheath which gives off
acid decay products. Choose the correct characteristic impedance. Coax is
offered in 50 to 70 ohm impedance. Above all: minimize I said MINIMIZE the
number of BNC coax connections. They are lossy. You could consider low
loss type connectors but it adds to the general confusion and cost I know.
I hope you don't mean what I THINK you mean when you talk about jumpers.
NO WIRE JUMPERS!

Brian W


Hi, Brian,

Yes, when I said jumper I was referring to a short length to extend, or, in
the particular post, just use as a very short feed line, to test the antenna
(having previously proven the radio good).

I have (in the end result) either 3 or 4 connectors, depending on how you
look at it. First is at the radio. Second is at the connector which had to
be bolted, so to speak, to the bracket, as the metz antenna threads don't go
all the way through it. However, having said that, in my test which proved
the antenna and the radio, I note that the metz has a very long male inside
of it, a nylon bushing keeping the antenna feed short enough, against it,
and then the connector piece which doesn't have threads all the way through
it.

If you look at my gallery, under SSI refit, then upgrades/electronics,
you'll see the bulkhead connector I had to use to get the Metz stem long
enough to connect, and the end result on the bracket at the top of the mast.

Numbers 3 and/or 4 would be the double male adapter I had to mount to the
top of that bulkhead connector to make the metz mount on it.

HOWEVER, you've stimulated a thought which I presume would work: If I take
that nylon bushing, stick it back in the Metz, and screw the body of the
coil onto my bulkhead connector, that connector should replace the Metz stem
reducing the connectors by either one or two.

Thanks for stimulation; let me know, any of you, who find fault with that
conclusion (replace the Metz stem with the bulkhead connector).

So, if you conclude that the antenna itself should not be counted in
connectors, I'd have two - one at the radio, and the other at the antenna.

Am I correct?

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.yahoo.com/group/TheFlyingPigLog
and/or http://groups.google.com/group/flyingpiglog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hand
(Richard Bach)

I followed the URL after "See our galleries..."
I looked for SSI refit, and didn't find it.
I looked for upgrades/electronics and failed.

So I admired the generally nice quality of the pix, and gave up.

I can only suppose you were extending the center coax conductor at some
connector with a wire, in order to stretch through a bulkhead.
This is not good practice.

Brian W

Flying Pig wrote:
----- Original Message -----
From: "brian whatcott"
Newsgroups: rec.boats.cruising
Sent: Tuesday, November 24, 2009 7:24 AM
Subject: VHF antenna anomaly


Solid dielectric, double shield, preferably not pvc sheath which gives off
acid decay products. Choose the correct characteristic impedance. Coax is
offered in 50 to 70 ohm impedance. Above all: minimize I said MINIMIZE the
number of BNC coax connections. They are lossy. You could consider low
loss type connectors but it adds to the general confusion and cost I know.
I hope you don't mean what I THINK you mean when you talk about jumpers.
NO WIRE JUMPERS!

Brian W


Hi, Brian,

Yes, when I said jumper I was referring to a short length to extend, or, in
the particular post, just use as a very short feed line, to test the antenna
(having previously proven the radio good).

I have (in the end result) either 3 or 4 connectors, depending on how you
look at it. First is at the radio. Second is at the connector which had to
be bolted, so to speak, to the bracket, as the metz antenna threads don't go
all the way through it. However, having said that, in my test which proved
the antenna and the radio, I note that the metz has a very long male inside
of it, a nylon bushing keeping the antenna feed short enough, against it,
and then the connector piece which doesn't have threads all the way through
it.

If you look at my gallery, under SSI refit, then upgrades/electronics,
you'll see the bulkhead connector I had to use to get the Metz stem long
enough to connect, and the end result on the bracket at the top of the mast.

Numbers 3 and/or 4 would be the double male adapter I had to mount to the
top of that bulkhead connector to make the metz mount on it.

HOWEVER, you've stimulated a thought which I presume would work: If I take
that nylon bushing, stick it back in the Metz, and screw the body of the
coil onto my bulkhead connector, that connector should replace the Metz stem
reducing the connectors by either one or two.

Thanks for stimulation; let me know, any of you, who find fault with that
conclusion (replace the Metz stem with the bulkhead connector).

So, if you conclude that the antenna itself should not be counted in
connectors, I'd have two - one at the radio, and the other at the antenna.

Am I correct?

L8R

Skip

"brian whatcott" wrote in message
...
I followed the URL after "See our galleries..."
I looked for SSI refit, and didn't find it.
I looked for upgrades/electronics and failed.

So I admired the generally nice quality of the pix, and gave up.

I can only suppose you were extending the center coax conductor at some
connector with a wire, in order to stretch through a bulkhead.
This is not good practice.

Brian W


Negative. Bulkhead mount, nuts on both sides of a longish connector.


Try this...

http://www.justpickone.org/skip/gall...es/Electronics

Sorry about the confusion - I'd spoken so volubly here about all that
happened in Saint Simons Island that I should have also specified 2009 refit
vs early refit...

L8R

Skip

--
Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.yahoo.com/group/TheFlyingPigLog
and/or http://groups.google.com/group/flyingpiglog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hand
(Richard Bach)
Flying Pig wrote: