I have to replace the wiring in my 58' mast plus 20' to my radio; my
question is this. RG 8x vs RG 8U. I know I lose more power with the 8x but
what does than translate to in watts output at the antenna. The West Marine
Advisor doesn't address this in a laymans POV. I need the reduced size.
Thanks
Bruce

--
Bruce and Elaine
www.cruisinglife.net

"Bruce" writes:
I have to replace the wiring in my 58' mast plus 20' to my radio; my
question is this. RG 8x vs RG 8U.

snip

RG8U and support it with a messenger cable.

The difference in cost gets lost in the wash.

I use 1/16" S/S cable and secure the RG8U to it with tie wraps every 2'-3'.

If you don't support it, it will stretch and the impedance will change or so
I was told by a radio guru I trust.

HTH


--
Lew

S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: http://home.earthlink.net/~lewhodgett for Pictures

I took a look at some sample specs to get a feel for the losses.

RG8X 7-9 dB/100 ft @ 400MHz
RG8U 4 dB/100 ft @ 400 MHz

You likely won't be operating at 400 MHz, but I'll use these figures
all the same. (Lower Fx is less lossy)

And I'll suppose that, what with the connectors, the loss is 8dB
versus 4 dB
That's 4 more dB

8 dB means you lose about 84% of your transmitter power.
4 dB means you lose about 60% of your power

So do you want 40 or do you want 16 ??

Brian Whatcott Altus OK

On Sat, 17 Jan 2004 00:46:44 GMT, "Lew Hodgett"
wrote:


"Bruce" writes:
I have to replace the wiring in my 58' mast plus 20' to my radio; my
question is this. RG 8x vs RG 8U.

snip

RG8U and support it with a messenger cable.

The difference in cost gets lost in the wash.

I use 1/16" S/S cable and secure the RG8U to it with tie wraps every 2'-3'.

If you don't support it, it will stretch and the impedance will change or so
I was told by a radio guru I trust.

HTH

All these numbers mean NOTHING if you pull foam cable around a CORNER.
The solid center conductor migrates through the flimsy foam that gives
it such a great set of numbers and it goes all to hell......

Solid center conductors also BREAK if you bend them back and forth as
the loose cable in the mast moves back and forth and back and forth on
every wave.

RG-58A/U has the same loss AFTER you pull it than when it was on the
reel. It's very flexible, finely stranded center conductor and very
hard polyethelene dielectric will take a helluva beating with no
migration around tight turns.

Most boats I know have no room for inch and a half hardline from the
radio to the mast......dammit. 58A/U (not 58/U which is solid
centered) works great for years and years......It's made for MOBILE
service.



On Sat, 17 Jan 2004 03:42:59 GMT, Brian Whatcott
wrote:

I took a look at some sample specs to get a feel for the losses.

RG8X 7-9 dB/100 ft @ 400MHz
RG8U 4 dB/100 ft @ 400 MHz

You likely won't be operating at 400 MHz, but I'll use these figures
all the same. (Lower Fx is less lossy)

And I'll suppose that, what with the connectors, the loss is 8dB
versus 4 dB
That's 4 more dB

8 dB means you lose about 84% of your transmitter power.
4 dB means you lose about 60% of your power

So do you want 40 or do you want 16 ??

Brian Whatcott Altus OK

On Sat, 17 Jan 2004 00:46:44 GMT, "Lew Hodgett"
wrote:


"Bruce" writes:
I have to replace the wiring in my 58' mast plus 20' to my radio; my
question is this. RG 8x vs RG 8U.

snip

RG8U and support it with a messenger cable.

The difference in cost gets lost in the wash.

I use 1/16" S/S cable and secure the RG8U to it with tie wraps every 2'-3'.

If you don't support it, it will stretch and the impedance will change or so
I was told by a radio guru I trust.

HTH



Larry W4CSC

Hi Larry W4CSC,

I think you need to take a look at the cable suppliers' specs before
telling us all about RG-58A/U 's wonderful features. Maybe take your
blood pressure medicine too?

Now about RG58A/U - this was the stuff you picked up for $10 at the
surplus store, wasn't it? :-) this spec is available new in
either foam OR solid insulation would you believe?

I checked several suppliers before writing this note: perhaps you
could check *your* facts too! You could start he

http://www.radialllarsen.com/docfiles/Cables.pdf


Brian Whatcott Altus OK

On Sat, 17 Jan 2004 06:01:33 GMT, (Larry W4CSC) wrote:

All these numbers mean NOTHING if you pull foam cable around a CORNER.
The solid center conductor migrates through the flimsy foam that gives
it such a great set of numbers and it goes all to hell......

Solid center conductors also BREAK if you bend them back and forth as
the loose cable in the mast moves back and forth and back and forth on
every wave.

RG-58A/U has the same loss AFTER you pull it than when it was on the
reel. It's very flexible, finely stranded center conductor and very
hard polyethelene dielectric will take a helluva beating with no
migration around tight turns.

Most boats I know have no room for inch and a half hardline from the
radio to the mast......dammit. 58A/U (not 58/U which is solid
centered) works great for years and years......It's made for MOBILE
service.



On Sat, 17 Jan 2004 03:42:59 GMT, Brian Whatcott
wrote:

I took a look at some sample specs to get a feel for the losses.

RG8X 7-9 dB/100 ft @ 400MHz
RG8U 4 dB/100 ft @ 400 MHz

You likely won't be operating at 400 MHz, but I'll use these figures
all the same. (Lower Fx is less lossy)

And I'll suppose that, what with the connectors, the loss is 8dB
versus 4 dB
That's 4 more dB

8 dB means you lose about 84% of your transmitter power.
4 dB means you lose about 60% of your power

So do you want 40 or do you want 16 ??

Brian Whatcott Altus OK

On Sat, 17 Jan 2004 00:46:44 GMT, "Lew Hodgett"
wrote:


"Bruce" writes:
I have to replace the wiring in my 58' mast plus 20' to my radio; my
question is this. RG 8x vs RG 8U.

snip

RG8U and support it with a messenger cable.

The difference in cost gets lost in the wash.

I use 1/16" S/S cable and secure the RG8U to it with tie wraps every 2'-3'.

If you don't support it, it will stretch and the impedance will change or so
I was told by a radio guru I trust.

HTH



Larry W4CSC

Noone is forcing anyone to use it. It works well for us in poly
dielectric and stranded centers. It bends around corners without
damage, which in our application was key.

Bend foam 8X or 8 hard around a corner every boat has will destroy it.

That makes the cable spec sheet all BS......



Larry W4CSC

Noone is forcing anyone to use it. It works well for us in poly
dielectric and stranded centers. It bends around corners without
damage, which in our application was key.

Bend foam 8X or 8 hard around a corner every boat has will destroy it.

That makes the cable spec sheet all BS......



Larry W4CSC

Hi Larry W4CSC,

I think you need to take a look at the cable suppliers' specs before
telling us all about RG-58A/U 's wonderful features. Maybe take your
blood pressure medicine too?

Now about RG58A/U - this was the stuff you picked up for $10 at the
surplus store, wasn't it? :-) this spec is available new in
either foam OR solid insulation would you believe?

I checked several suppliers before writing this note: perhaps you
could check *your* facts too! You could start he

http://www.radialllarsen.com/docfiles/Cables.pdf


Brian Whatcott Altus OK

On Sat, 17 Jan 2004 06:01:33 GMT, (Larry W4CSC) wrote:

All these numbers mean NOTHING if you pull foam cable around a CORNER.
The solid center conductor migrates through the flimsy foam that gives
it such a great set of numbers and it goes all to hell......

Solid center conductors also BREAK if you bend them back and forth as
the loose cable in the mast moves back and forth and back and forth on
every wave.

RG-58A/U has the same loss AFTER you pull it than when it was on the
reel. It's very flexible, finely stranded center conductor and very
hard polyethelene dielectric will take a helluva beating with no
migration around tight turns.

Most boats I know have no room for inch and a half hardline from the
radio to the mast......dammit. 58A/U (not 58/U which is solid
centered) works great for years and years......It's made for MOBILE
service.



On Sat, 17 Jan 2004 03:42:59 GMT, Brian Whatcott
wrote:

I took a look at some sample specs to get a feel for the losses.

RG8X 7-9 dB/100 ft @ 400MHz
RG8U 4 dB/100 ft @ 400 MHz

You likely won't be operating at 400 MHz, but I'll use these figures
all the same. (Lower Fx is less lossy)

And I'll suppose that, what with the connectors, the loss is 8dB
versus 4 dB
That's 4 more dB

8 dB means you lose about 84% of your transmitter power.
4 dB means you lose about 60% of your power

So do you want 40 or do you want 16 ??

Brian Whatcott Altus OK

On Sat, 17 Jan 2004 00:46:44 GMT, "Lew Hodgett"
wrote:


"Bruce" writes:
I have to replace the wiring in my 58' mast plus 20' to my radio; my
question is this. RG 8x vs RG 8U.

snip

RG8U and support it with a messenger cable.

The difference in cost gets lost in the wash.

I use 1/16" S/S cable and secure the RG8U to it with tie wraps every 2'-3'.

If you don't support it, it will stretch and the impedance will change or so
I was told by a radio guru I trust.

HTH



Larry W4CSC

On Sat, 17 Jan 2004 06:01:33 GMT, (Larry W4CSC) wrote:

All these numbers mean NOTHING if you pull foam cable around a CORNER.
The solid center conductor migrates through the flimsy foam that gives
it such a great set of numbers and it goes all to hell......

Solid center conductors also BREAK if you bend them back and forth as
the loose cable in the mast moves back and forth and back and forth on
every wave.

RG-58A/U has the same loss AFTER you pull it than when it was on the
reel. It's very flexible, finely stranded center conductor and very
hard polyethelene dielectric will take a helluva beating with no
migration around tight turns.

Most boats I know have no room for inch and a half hardline from the
radio to the mast......dammit. 58A/U (not 58/U which is solid
centered) works great for years and years......It's made for MOBILE
service.

Gee, thanks, Larry...here I thought I was screwing up...

My radio experience is painfully limited...as a teen in the '70s I ran
a 40 channel CB base station and used RG-8U...soldered my own
connections and all and put up a free-standing 30 foot tower and
directional antenna (squeaky pulley!). I know 58U was for cars, and
there was no way I was running expensive and heavy 8U up my mast, so I
used 58A/U for the 50 foot run from mast head to a splitter (for AM/FM
radio) under a settee and a further 10 feet to my VHF unit at the nav
station.

I tried a "real world" test with local Coast Guard (5x5 to receivers
about 1,200 higher than me 20 miles away) and with my wife talking to
me in a Zodiac from the boat at dawn some 7 miles away (reckoning by
GPS) over some intervening low land. I could hear her on my handheld
quite well, and she could hear me weakly, but clearly.

So I have no qualms about the 58A/U, the ICOM base unit and the old
whip antenna on a Metz mount...standard coaster rig and good for my
end of Lake Ontario, it seems.

Most of the time I use the handheld (a Standard Horizon 260S with
which I am quite pleased) in the cockpit anyway and save the base unit
for American WX and ship/bridge traffic and whatnot.

My .02 (1.4 U.S)

R.

On Sun, 18 Jan 2004 21:38:20 -0500, wrote:


My radio experience is painfully limited...as a teen in the '70s I ran
a 40 channel CB base station and used RG-8U...soldered my own
connections and all and put up a free-standing 30 foot tower and
directional antenna (squeaky pulley!). I know 58U was for cars, and
there was no way I was running expensive and heavy 8U up my mast, so I
used 58A/U for the 50 foot run from mast head to a splitter (for AM/FM
radio) under a settee and a further 10 feet to my VHF unit at the nav
station.

The various CB myths and cult followings wreaks havoc marine VHF is my
experience. Man, they got some strange physics education on CB....(c;

The gain in altitude (altitude is very important and the reason TV
stations have 2000' tall towers) is FAR more important than a few dB
loss in any kind of cabling. One of these days, I'm going to put up a
Metz on top of a 50' mast fed with RG-174/U, the tiny coax cable used
for connecting internal cables of equipment. Back 20 years ago, I got
a free 1000' roll of it from some ham or another. I never turn down
free stuff. The house is full of it, a regular packrat. Anyways, I
needed an extra antenna centered on 4585 Khz to use for the local CAP
squadron's HF comms I'd gotten my self mixed up in because a good
friend was the squadron commander and had no radio ops. Hell, it's
only 4.5 Mhz and only 100 watts of power, so use what's available. I
hung an inverted-V (dipole) from a pine tree by shooting an arrow over
a high limb with a borrowed bow....after many attempts, I might add.
The tiny RG-174 simple fed the center insulator. To my amazement, it
worked great on 4585 USB. Way early in the mornings, I could check
into the CAP net in Hawaii, causing quite a ruckus of Hawaiian
stations wanting to try to work SC DX. I got to using this big roll
for portable antennas at the local ARRL Field Day when hams camp out
on generators to see how many stations we can contact in 24 hours, a
contest.

The reality of it is a compromise between practicality and function.
Look at any receiver that has a calibrated S-meter. Notice the
calibrations are in 10 dB increments. 3 dB isn't much difference
indeed. Back to the chart someone quoted, the difference on 156 Mhz
between 8X and RG-58, which is so much easier to thread through a
boat, is less than 2 dB per HUNDRED ft. 1 dB for half of that. The
guys at the receiving end won't tell the difference.....er, ah, unless
you short out that big cable trying to bend it too sharp around the
corners...(c; It's fine....



Larry W4CSC