At 01:25 PM 9/30/04, you wrote:
>Attention: Mike, WA6ILQ, Gary, K2UQ, and Randy, W0AVV
>
>Hello All:
>
>We finally took the 220 antenna apart, and it was an education. I would
>like to share our experiences with you.
>
>First, depending on the vintage of the antenna production, these
>antennas may be assembled and disassembled differently. I have looked
>at some other Stationmaster type antennas, and there are some
>construction variations, however my pictures and comments only concern
>this particular model.
>
>This antenna as I previously mentioned had been up on a tower for a
>considerable time, and it was broken (and repaired poorly) about a foot
>and a half from the top earlier in its' life. This repair job probably
>resulted in the eventual failure and extreme difficulty taking it apart
>for trouble shooting and repair.
>
>Mike, if I could Email the Jpeg pictures to you and make them available
>elsewhere, then others can easily see the construction and problems that
>can occur with this type antenna.
Please do - send them to wa6ilq at arrl dot net
>In the photo of the antenna tip, there is one allen screw holding the
>last antenna element in place. This allen screw goes through the brass
>tip which is epoxyed to the fiberglass tube and pinches against the top
>element. This allen screw has to come out in order for the whole
>element assembly to come out FROM THE BOTTOM of the aluminum antenna
>base. There was no heat necessary.
>
>There are three countersunk screws at the top of the aluminum tube base
>where the fiberglass tube meets the aluminum tube. They need to come
>out. These screws hold the circular brass doughnut connected to the
>internal brass tube part of the internal antenna. Please note that
>epoxy covers these screws, so you need to scrape the epoxy away very
>well to get at the allen head, and be careful not to strip the head with
>the allen wrench! Using WD-40 around each of the three screw rims
>carefully helped in removing them. Also, the fiberglass is never
>separated from the aluminum base tube.
>
>Next is a killer. This is the doughnut sandwich where the SO-239 UHF
>connector is mounted. The way this connector assembly is held in place
>is by tightening the three 1/4 inch bolts and compressing the two
>circular (inside the aluminum base tube) plates together with a rubber
>bushing or doughnut inside. This rubber bushing expends, and prevents
>the the inside guts or antenna stacking assembly from sliding out.
>
>What made it so difficult sliding this assembly out of the tube bottom
>was the two plates were rusted and corroded very badly. One of the
>three bolts broke because the inside end was frozen. We sprayed WD-40
>around the inside perimeter so it would slide out easily, but it fought
>us all the way. We had to make up a plate with holes to place at the
>antenna base tube, and use the two remaining bolts holes to mechanically
>screw out the assembly.
>
>The pictures show the center conductor break in the bottom element. The
>center conductor of this element needs to be replaced. Also, the two
>sandwich plates are extremely corroded and need to be replaced. One of
>the pictures displays the foam spacers used to hold the elements in
>place throughout the fiberglass tube. We also noted there was no bees
>wax in the tube, only the foam spacers.
>
>We have investigated the Polane T Plus epoxy for the fiberglas repair,
>and the index needs to be updated. The prices are out of sight as well
>as the minimum quantity. There are other solutions, but this is a
>separate story.
>
>I assume there are lots of these antennas out in the field, and they
>could be modified and/or repaired for amateur radio repeater use. This
>above information might help you make a decision to buy a new one or
>modify or fix a free bee.
>
>Have fun. Ciao, Tony, K3WX
>
>
>
>
>
>
>Tony Faiola wrote:
> >
> > [EMAIL PROTECTED] wrote:
> > >
> > > The epoxy sealing the three recessed screws on 120 deg centers near the
> > > aluminum mounting tube meets the fiberglass must be removed.
> >
> > I have removed these three allen head screws, however the epoxy is
> > wedged between the aluminum and the fiberglass. Will heating the
> > aluminum near the fiberglass loosen the physical connection?
> >
> > The set screw at top
> > > must be removed and the tip heated with heat gun. Cap will come off.
> Don't
> > > overheat fiberglass. The complete antenna then can be removed from
> the fiberglass
> > > tube.
> >
> > I did remove the allen head screw from the top metal tip. With a little
> > WD-40 on the tip (no heat necessary) the one foot of broken fiberglass
> > pulled out of the tip and exposed the one foot of copper element. It is
> > important to note that the metal tip separates into two pieces. After
> > the allen screw is taken out, the center of the tip separates from the
> > collar portion of the tip. This collar portion of the tip is fastened
> > by epoxy to the fiberglass tube at the antenna top.
> >
> > Suggest you place complete antenna on a flat board at least 4 inches
> > > wide prior to pulling fiberglass tube off.
> >
> > I can see where we have to lay it flat on the ground or a board. It
> > looks very fragile.
> >
> > It gets very floppy and the board
> > > will keep things straight for you. My problem was the first radiating
> section
> > > where it connected from one outside tube to the next center
> conductor. It flexes
> > > and the center conductor becomes work hardened and eventually forms a
> fine
> > > hairline crack. Could not see it with eye, touched it with a finger
> and it
> > > broke. Soldering the joint with lead/tin is a temporary fix. I used
> low temp
> > > silversolder. Made a sleeve from brass tubing purchased at hobby
> shop. The spacers
> > > for the center conductor will melt if you apply too much heat. Adjust
> nothing
> > > in bottom of antenna near the coax connector.
> >
> > We did take out the three bolts as mentioned, but I would assume this
> > whole assembly should slide out of the bottom...or the top of the
> > aluminum tube?
> >
> > Painted antenna with similar
> > > color fiberglass Sherwin-Williams Co paint from boat store. Worked
> fine. Don't
> > > use a dark color. Have more info from CellWave if you want, contact me
> > > directly.
> > > Gary K2UQ
> > > [EMAIL PROTECTED]
> >
> > One question is the antenna base. There are three brass bolts, 7/16ths,
> > in the base around the UHF connector. We took these screws out, however
> > nothing came loose.
> >
> > I realize what you are saying about the top of the aluminum base support
> > tube, and it has to be separated from the larger diameter fiberglass
> > tube...but what about the connector portion of the antenna coming out.
> > Does it slide out with the towards the antenna top or come out of the
> > bottom of the base aluminum tube.
> >
> > Incidentally, for this PD-200 antenna for 220, the top element has the
> > bandwidth inscribed on the copper with the two operating frequencies.
> >
> > Thanks for your first response. I did take digital pictures of the
> > various sections and parts, but the big picture will come after
> > separation of the base parts.
> >
> > 73, Tony, K3WX
>
>
>
>
>
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>
>
>
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