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Larry W4CSC February 16th 05 03:15 PM

"Doug" wrote in
nk.net:

Although I have seen Raymarine equipment corroded, the problem is
always poor installation. The other brands are just as likely to come
in encrusted with salt, etc. The guys who insist on mounting the all
around light in the lid of a radome are just setting themselves up
for water damage later on. A cheap test instrument for radar
transmission is one of those under $ 10 microwave oven leakage meters.
Of course, the old neon bulb on a wooden dowel still works also.
Doug K7ABX


Naw....Just sit a Raymarine out in a humid environment with its little
rubber drain tube breathing in and out as the sun rises and sets and it
soon fills with condensate water, destroying the pot metal the cheap POS is
made from.

This new unit we got has 4 white plastic "feet" to hold the radome up off
the mounting plate. There's no sealing it, now, but that didn't make any
difference anyways. The mounting bolts go through the hole in the center
of the plastic feet which space the dome about 1/2" off the mount, now. I
don't see that's going to solve the condensate problem, though. It rains
inside the dome through the drain tube, just like a half-empty gas tank
gets condensate water in it, left that way in the sun.

It's NOT a Raytheon, any more.



krj February 16th 05 04:56 PM

Larry,
Did you read the info on the link? The first radar system was the
British Chain Home (CH) that operated on 20 Mhz. My frequency chart
lists that as HF.
krj

Larry W4CSC wrote:

Bruce in Alaska wrote in news:bruceg-
:


gained an circulation. The basics of Radar Technology was worked out at
MIT in the late 30's after trading the British Magnitron Prototype
for all those Lend - Lease Destroyers.

Bruce in alaska who also has one of those things on the wall......



Huh?? The first radars were on VHF! They operated on common vacuum tubes,
not microwave magnetrons.
http://www.bbc.co.uk/dna/ww2/A591545



Bruce in Alaska February 16th 05 09:49 PM

In article et,
"Doug" wrote:

Of course, the old neon bulb on a wooden
dowel still works also.
Doug K7ABX


You actually use a wooden dowel? I just put the NE2's on a string, and
hang it in front of the Waveguide flange, about an inch or two.


Bruce in alaska How well does an NE2 work on a 2Kw Tx these days?
--
add a 2 before @

Larry W4CSC February 17th 05 08:47 PM

krj wrote in
:

Larry,
Did you read the info on the link? The first radar system was the
British Chain Home (CH) that operated on 20 Mhz. My frequency chart
lists that as HF.
krj


'Scuze me! In 1930, 20 Mhz was UHF, not VHF....(c;

Way back there, someplace, the genius engineers declared anything above 2
Mhz was useless, so they gave all freqs above 2 Mhz to us ham radio
operators. The sleazy *******s been stealin it back from us ever since!

NNNN

AR



Larry W4CSC February 17th 05 08:50 PM

Bruce in Alaska wrote in news:bruceg-
:

Bruce in alaska How well does an NE2 work on a 2Kw Tx these days?


Hmm...Might be fun to stick a few NE2s to the outside of the dome on the
new Raymarine 2KW we're about to put up. Then, you might be able to tell
it its really on the air.

Great idea, Bruce....



Bruce in Alaska February 18th 05 07:04 PM

In article ,
Larry W4CSC wrote:

Bruce in Alaska wrote in news:bruceg-
:

Bruce in alaska How well does an NE2 work on a 2Kw Tx these days?


Hmm...Might be fun to stick a few NE2s to the outside of the dome on the
new Raymarine 2KW we're about to put up. Then, you might be able to tell
it its really on the air.

Great idea, Bruce....



Hope, by the time the RF goes thru the waveguide, rotory joint, and is
dispersed across that little Panel Antenna, the Power Density of the
transmitter pulse will not be sufficent to cause an NE2 to ionize.

It was a good guess however......



Bruce in alaska
--
add a 2 before @

halibutslayer February 18th 05 08:33 PM



"M.F." wrote:

Does anyone no any good books on marine radar repair?


I guess not.


Larry W4CSC February 19th 05 03:57 AM

Bruce in Alaska wrote in news:bruceg-
:

Hope, by the time the RF goes thru the waveguide, rotory joint, and is
dispersed across that little Panel Antenna, the Power Density of the
transmitter pulse will not be sufficent to cause an NE2 to ionize.

It was a good guess however......


If we lay out the NE2s leads in 1/2 wave lengths, there should be plenty of
voltage at the end of the 1/2 wave "arms" to fire off 68V of neon.

I'll let you know how it looks....(c;




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