Bird Technologies 8255 - Manual (Page 20)

Connecting to Transmitter
Models 8251
& 8255
Connect the load to the transmitting equipment under
test with 50 ohm coaxial cable (RG-8A/U, RG-9/U,
RG-213/U or equivalent) and a Male LC type plug. The
Male LC plug will mate with the RF input connector of
the load. After the transmitter has been connected to the
load, proceed according to the transmitter manufacturer’s
instructions. When reconnecting the antenna, it may be
necessary to slightly readjust the transmitter due to pos-
sible differences in VSWR between the load and the an-
tenna system.
Model 8252
The 3-1/8 inch EIA flange connector is fastened to the
transmission line by six 3/8-16 by 1-1/2 inch stainless
steel screw and nut assemblies. The center conductors
must be joined with a bullet for 50 ohm 3-1/8 inch coaxial
lines. Bird P/N 4600-020 Bullet Kit includes six screw
and nut sets, O-Ring and center conductor bullet.
+
Note: Avoid the use of adapters and elbows
whenever possible.
Follow the instructions below for line installation.
1. Seat the bullet so that half of the thickness of
the insulator is nested in the counterbore of each
connector flange.
2. Place the load resistor so that it will be aligned
with the coaxial input line.
3. Push in on the center contact.
4. Tighten the flange nuts evenly all around (finger
tight).
5. Tighten the nuts evenly with wrenches.
The swivel flange on the Model 8252 makes the load re-
sistor connector independent of the orientation of a fixed
mating flange on the input line.
Due to the difference in the VSWR between the dummy
load and the transmitter’s antenna, the transmitter may
require readjustment when reconnected to the original
antenna.
Bird Model 8251/52/55 Termaline Coaxial Load Resistor
8