I recently acquired one of these antennas that has been in the air for
several years. I suspect that it was sold as an A3, then "upgraded" to A3S
status by using SS hardware. the antenna was disassembled when I bought it.
There are 3 trap designations according to the manual: TA, TB, TC. The TA's
and the TC's are identical in appearance and there are no stamps or markings
to distinguish one from the other. Is there an easy way to identify which
is which? Cushcraft doesn't supply any values.
Thanks, Butch K4NAU.

That's funny, I am in the process of rehabilitating a Cushcraft R-7.
The 15M trap was busted up a bit so I got out the epoxy and the torch.
The epoxy was for the fiberglass insulator and the torch was to help
straighten out the "trombone" capacitor. Later I used the grid dip
oscillator to check the resonance point of the now rebuilt trap. Just
for grins I tested the other traps too and labelled them. I'll bet
you could use a GDO to find the resonance point of your traps. Label
them when you're done.

Russ

On Sun, 15 May 2005 08:43:04 -0400, "Sandlapper"
wrote:

I recently acquired one of these antennas that has been in the air for
several years. I suspect that it was sold as an A3, then "upgraded" to A3S
status by using SS hardware. the antenna was disassembled when I bought it.
There are 3 trap designations according to the manual: TA, TB, TC. The TA's
and the TC's are identical in appearance and there are no stamps or markings
to distinguish one from the other. Is there an easy way to identify which
is which? Cushcraft doesn't supply any values.
Thanks, Butch K4NAU.

Thanks Russ.........I was hoping there was some little "trick" to the ID of
the traps.....guess I'll have to do it by the book........73, de Butch k4nau
"Russ" wrote in message
...
That's funny, I am in the process of rehabilitating a Cushcraft R-7.
The 15M trap was busted up a bit so I got out the epoxy and the torch.
The epoxy was for the fiberglass insulator and the torch was to help
straighten out the "trombone" capacitor. Later I used the grid dip
oscillator to check the resonance point of the now rebuilt trap. Just
for grins I tested the other traps too and labelled them. I'll bet
you could use a GDO to find the resonance point of your traps. Label
them when you're done.

Russ

On Sun, 15 May 2005 08:43:04 -0400, "Sandlapper"
wrote:

I recently acquired one of these antennas that has been in the air for
several years. I suspect that it was sold as an A3, then "upgraded" to A3S
status by using SS hardware. the antenna was disassembled when I bought
it.
There are 3 trap designations according to the manual: TA, TB, TC. The
TA's
and the TC's are identical in appearance and there are no stamps or
markings
to distinguish one from the other. Is there an easy way to identify which
is which? Cushcraft doesn't supply any values.
Thanks, Butch K4NAU.

On Sun, 15 May 2005 08:43:04 -0400, Sandlapper wrote:
I recently acquired one of these antennas that has been in the air for
several years. I suspect that it was sold as an A3, then "upgraded" to A3S
status by using SS hardware. the antenna was disassembled when I bought it.
There are 3 trap designations according to the manual: TA, TB, TC. The TA's
and the TC's are identical in appearance and there are no stamps or markings
to distinguish one from the other. Is there an easy way to identify which
is which? Cushcraft doesn't supply any values.
Thanks, Butch K4NAU.

You're in luck. I _just_ yesterday dropped my antennas and the tower
in preparation for a move to a new QTH. Let me run out to the patio
and check... .. . .. . . ... .. .. .. ..... . . . . . .

Assuming the left side of the display is the boom, we view one half of
each element sticking out to the right:

|======[ - TA ]===[unmarked]========= Director
|
|
|=======[ - TA ]===[ - TC ]============ Driven
|
|
|========[ - TA ]===[ - TC ]============= Reflector


On _my_ A3S the "TA" and "TC" markings are found on applied labels
that include the orientation arrows that I depicted above.
The 2 unmarked traps have _no_ detectable markings. By elimination,
these must be the "TB" traps - i suppose.
FWIW, the outside ends of the "unmarked" and "TC" traps have tubing
that 'necks down' to receive the smaller O.D. tubing out to the ends
of the element. So, the orientation of the "unmarked" trap should
be casual to the most obvious observer. :-)

HTH
Jonesy
--
| Marvin L Jones | jonz | W3DHJ | linux
| Gunnison, Colorado | @ | Jonesy | OS/2 __
| 7,703' -- 2,345m | config.com | DM68mn SK

hope this helps with the cushcraft a3s trap reading on the dip meter


Check each trap to insure that the cover is tightly secured. The
cover is the 1-5/8" tubing between the two large black end caps.
Any movement of this cover will cause an intermittent VSWR
condition on the antenna. You may easily test for a loose cover
while the antenna is still assembled. Grasp the cover in one hand
and the trap tubing in the other hand, apply a moderate amount of
pressure first in a clockwise and then a counterclockwise direction
about the axis of the element. If the cover slips even a small
amount it will require tightening. Remove the black cap from the
trap on the side towards the boom of the antenna. A hex head screw
will then be visible underneath. Tighten the screw with an
appropriate screwdriver or nut driver. Be careful not to apply so
much force as to strip out the sheetmetal screw. If the hole is
already stripped, or gets stripped accidentally, it is an easy
matter to be fixed by substituting a #10 3/8" or 1/2" self-tapping
screw into the enlarged hole.

If all your traps pass the mechanical test and seem to be
installed properly, then a frequency check is in order. (The
traps should be marked before removal so that proper reassembly
is assured.)

Place a trap on an insulated surface (such as a large cardboard
box) and couple a dip oscillator to it as shown. Make sure to
couple it to the end of the trap that was closest to the boom,
the end of the trap that was self-tapping treads visible inside
the tubing. Insert the tip of the dip oscillator coil slightly
into the tubing. When a dip is found pull the oscillator coil
out of the end of the trap slightly and re-dip the oscillator.
Continue to pull the dip oscillator coil out of the tubing and
re-dip until you have the smallest perceptible dip. It should
be noted that the dip meter frequency is lower than the
operational frequency of the trap. This is caused because the
trap will load the dip oscillator and lower its frequency.

TRAP Oper Dip Osc
Freq. Freq.

TA 28.60 27.50
TB 21.50 20.39
TC 21.30 20.20
TD 28.00 27.00
TE 28.80 27.60
TL 24.90 24.15
TM 18.11 17.29
TN 21.30 20.20
TK 14.18 12.62

You should use the listed oscillator frequencies as a guide.
Temperature and humidity can have a +/- 100KHz effect on traps.
If the readings are within 200KHz of the listed amounts, do not
worry, the effect upon the assembled antenna will be minimal.
Shorted turns or other serious defects will cause wide shifts
from the norm. One or two megahertz is a definite indication
of a defective trap.