Another day in antenna hell. This time, I needed a 440Mhz antenna for
a temporary repeater installation. My last remaining antenna a rather
broken Diamond X50a. The previous owner leaned the antenna against a
wall, and then backed his car into it, breaking the fiberglass radome
and bending the guts. I managed to unmangle the antenna and epoxy the
radome, but somewhere in the shuffle, the ground radials disappeared.
Duz anyone have an X50a handy that can measure the length of the
ground radials (from the aluminum base casting to the end)? The
current random length welding rods (with toothpicks jammed into the
holes) are not going to last.



--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS

I have a relative in the communications business who would tell you to throw it away.
The reason is - unless you are going to hook it up to a junk radio -there is no reason to use a junk antenna unless the radio is of no value to you.

Moores law tells me that it is probably past it's prime and it probably isn't going to last very long anyways.

A friend of mine has a antenna that sounds identical to the one you are trying to repair and the lengths on his antenna looks to be 12 inches.

I have not taken it down to physically measure it, but we are about to move it in a month or two and if you still need the exact measurement - I will get it for you.

I am surprised that the manufacturer didn't offer give you the dimensions.
Diamond X50 - radial / part number 07003
http://www.rfparts.com/diamond/x50a.html

73's
Jerry

On Thu, 24 Mar 2011 23:24:31 +0000, Channel Jumper
wrote:


'Jeff Liebermann[_2_ Wrote:
;737205']Another day in antenna hell. This time, I needed a 440Mhz
antenna for
a temporary repeater installation. My last remaining antenna a rather
broken Diamond X50a. The previous owner leaned the antenna against a
wall, and then backed his car into it, breaking the fiberglass radome
and bending the guts. I managed to unmangle the antenna and epoxy the
radome, but somewhere in the shuffle, the ground radials disappeared.
Duz anyone have an X50a handy that can measure the length of the
ground radials (from the aluminum base casting to the end)? The
current random length welding rods (with toothpicks jammed into the
holes) are not going to last.

I have a relative in the communications business who would tell you to
throw it away.
The reason is - unless you are going to hook it up to a junk radio
-there is no reason to use a junk antenna unless the radio is of no
value to you.

Good advice, but doesn't apply in this case. I'm back into building
yet another repeater:
http://802.11junk.com/jeffl/K6BJ-MSF5000/
Due to a combination of club politics and my laziness, the repeater
will be tested at my house for a hopefully limited time.
Unfortunately, I couldn't find a suitable antenna and decided that the
trashed Diamond X50 was the least disgusting alternative to doing it
the right way. As long as it doesn't destroy the power amp with
excess VSWR, it should be fine for testing.

Various sympathetic friends have also offered to sell me spare
antennas. I could also build one (I'm partial to a center fed
Franklin/Amos antenna, but have only built these for 2.4Ghz, not
440Mhz).
http://802.11junk.com/jeffl/antennas/AMOS-7/index.html
But first, I need to finish some work, and complete my taxes.

Moores law tells me that it is probably past it's prime and it probably
isn't going to last very long anyways.

http://en.wikipedia.org/wiki/Moore%27s_law
Moore's law has to do with the number of xsistors on integrated
circuits, not the lifetime of my antennas and other abominations.

A friend of mine has a antenna that sounds identical to the one you are
trying to repair and the lengths on his antenna looks to be 12 inches.

I've seen several from the ground, but have been too lazy to climb the
towers or drop the poles in order to make the measurement.

I have not taken it down to physically measure it, but we are about to
move it in a month or two and if you still need the exact measurement -
I will get it for you.

Thanks for the offer. I don't think it will be necessary but it would
be nice to know the real lengths. I fabricated some radials using
brass welding rods and found that the lengths are non-critical.
Scaling the length from a photo, I guessed high at about 10" and cut
them to 11". When I find the real dimensions, I'll cut them to size.

I am surprised that the manufacturer didn't offer give you the
dimensions.
Diamond X50 - radial / part number 07003
http://www.rfparts.com/diamond/x50a.html

Y'er right. I should have called RFparts.

Thanks much.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com
# http://www.LearnByDestroying.com AE6KS