NORM KNAPP wrote:
The db/Andrew/Comscope folded dipoles do not have this problem? Why not? What
is the difference?
73 de N5NPO
Norm Knapp
----- Original Message -----
From: [email protected] <[email protected]>
To: [email protected] <[email protected]>
Sent: Wed May 20 11:11:06 2009
Subject: [Repeater-Builder] Re: Sinclair dipole array premature failure (noisy)
Should be in the group archives a few years back.
Sinclair renamed/changed the names/model numbers for
pretty much the exact same vhf antennas I have had all
the hell with... but they are pretty much the same design
as the current models with reported changes in the coax
harness/feed system to address the IMD/PIM problem.
I've spoken to former Sinclair Engineers in person more
than once... got a lot of smoke blown up my back side
but no resolution/solution to the antenna models I still
have in storage. I know of one state agency still using
the problematic VHF dipole assemblies and still experiencing
grief they don't acknowledge or seem to want to properly
deal with. Go figure...
The IMD/PIM generation happens/happened in that series 4
and 8 bay (two horizontal spaced dipoles per mast position)
folded dipole antenna models. A Sinclair Engineer
in a face to face conversation suggested I re-install my 4
bay antennas using the information from their current (same)
product (with a different model number). No cigar...
No fun... lots of money and time wasted.
s.
"Chuck Kelsey" <wb2...@...> wrote:
Boy, for some reason, there's a discussion I don't
recall. Oh well.
The only array from Sinclair I was aware of as being
trouble was their SRL222/SD222 series.
Chuck
WB2EDV
----- Original Message -----
From: "skipp025" <skipp...@...>
To: <[email protected] <mailto:Repeater-Builder%40yahoogroups.com>
>
Sent: Tuesday, May 19, 2009 7:01 PM
Subject: [Repeater-Builder] Re: Sinclair dipole array premature failure
(noisy)
There are known problems with this series of antennas... see
my previous posts bad-mouthing Sinclair regarding this same
situation.
------------------------------------
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We have had several failures with 2 Siclair 219 C4-2 antennas and 1
Sinclair 229 (which was replaced by Sinclair after warantee). Symtoms
were very bad dioding and reduced receiver sensitivity. As these
antennas are $1200 and $1800 for 1/2 wave spaced 4 pole up here. We did
not want a repeat of the problems. Our solution was to use Comprod
antennas which have performed flawlessly.
Roger
VA7RS
