Figure 3-5. Connection for loop mode.

TM 11-6625-922-15

(black) from 0 to 9.5 milliseconds. The black markings

s. Operate the RECEIVE LEVEL DBM control cw to

are used for 25 Hz and 250 Hz modulating frequencies

the position at which the dbm/% MODULATION meter

(for 250 Hz divide black markings by 10). The red

indicates between 0 DBM and -10 DBM. The receive

markings in .15-millisecond increments, from 0 to 3

signal may now be measured by adding the RECEIVE

milliseconds, are used for 83-1/3 Hz.

LEVEL DBM switch db setting to the indication on the

(3) The COARSE DELAY MS switch has four

dbm/% MODULATION meter, for example:

positions. The black markings in increments of 10

milliseconds, from 0 to 40 milliseconds, are used for 25

RECEIVE

Hz and 250 Hz modulating frequencies (for 250 Hz

LEVEL

dbm/%

Receive

divide markings by 10). The red markings in increments

DBM

MODULATION

level

of 3 milliseconds, from 0 to 12 milliseconds, are used for

switch

meter

the 83-1/3 Hz.

-20 db

-3 db

-23 dbm

(4) When the DELAY METER RANGE MS

0 db

0 dbm

switch is in the .15-.5 position, the delay reading is

+20 db

-5 db

+15 dbm

obtained by using the 0 to .5 (black) or 0 to .15 (red)

-10 db

-5 db

-15 dbm.

scale on the DELAY meter, the FINE DELAY MS switch,

and the COARSE DELAY MS switch. The readings on

t. Read the DELAY meter as follows:

the DELAY meter, the FINE DELAY MS switch setting,

and the COARSE DELAY MS switch setting are added

(1) The face of the DELAY meter has six scales,

together to give the total delay.

three of which (black) correspond to 25 Hz and 250 Hz

(5) If the DELAY METER RANGE MS switch is

modulation frequency (divide markings by 10 for 250

in the 3-10 position, the delay reading is obtained by

Hz), and three of which (red) correspond to 83-1/3 Hz.

using the 0-10 (black) or 0 to 3 (red) scale on the

The black scales are 0 to 0.5 millisecond, 0 to 10

DELAY meter, and only the COARSE DELAY MS

milliseconds, and -0.25 to +0.25 millisecond (used for

switch. The readings on the DELAY meter and the

reference only).

The red scales are 0 to 0.15

COARSE DELAY MS switch setting are added together

millisecond, 0 to 3 milliseconds, and -0.075 to +0.075

to give the total delay. Examples of delay readings are

millisecond (used for reference only).

as follows:

(2) The FINE DELAY MS switch has 20

positions with delay increments of 0.5 millisecond

Mod

Scale

DELAY METER

COARSE

FINE

DELAY

Correct

freq

color

RANGE MS

DELAY MS

meter

delay

Black

3 - 10 ms

10 - 20 ms

4.5 ms

14.5 ms

Black

.15 - .5

10 - 20

3.5

0.28

13.78

83-1/3

Red

.15 - .5

6-9

1.5

0.23

7.73

250

Black

3 - 10

20 - 30

3.5

2.35

(6) When a signal of unknown delay is connected

reading is used to provide a general profile of delay

between the TRANSMIT jack and RECEIVE jack, the

versus frequency. Operate the DELAY METER RANGE

following general procedure is employed in reading the

MS switch to the .15.5 position. Operate the FINE

delay. The desired signal frequency is set on the

DELAY MS switch until an on-scale reading is obtained

transmitter by the CARRIER FREQUENCY control. The

on the DELAY meter. The total delay may now be

RECEIVE LEVEL DBM switch is operated to obtain a

precisely read by adding the DELAY meter reading

receive level on the dbm/% MODULATION meter

(black 0 to .5 ms scale) to the FINE DELAY MS switch

between 0 DB and -10 DB. Assuming that 25 Hz

setting plus the COARSE DELAY MS switch setting. If

modulation is used, the approximate delay is read with

250 Hz modulation is used, all black DELAY meter,

the DELAY METER RANGE MS switch in the 3-10 ms

COARSE DELAY MS switch, FINE DELAY MS switch,

position by operating the COARSE DELAY MS switch

and DELAY METER RANGE MS switch markings are

until an on-scale DELAY meter reading is obtained.

divided by 10. If 83-1/3 Hz modulation is used, the red

This approximate value of delay is read on the black 0

markings are used.

The TS-2669/GCM provides

to 10 ms scale of the DELAY meter. The total delay is

unambiguous delay readings up to 40 milliseconds for

the setting of the COARSE DELAY MS switch plus the

25 Hz modulation, 12 milliseconds for 83-1/3 Hz

DELAY meter reading. In general, this 3-8 coarse delay

3-8