Service manual

ManualsBrandsE.F. Johnson Company ManualsGadgetsMULTI-NET II

INTRODUCTION

1-11

March 2000

Part No. 001-3139-502

12.Transmitter Site - At the transmit site record the

deviation of the transmitted signal (it should be

2.5 kHz for 800 MHz systems and 1.6 kHz for 900

MHz systems). If the deviation is not correct, adjust

U44 in the RVM (see Step 10) to attain 2.5 kHz

deviation for 800 MHz systems and 1.6 kHz devia-

tion for 900 MHz systems. Refer to NOTE 2 on

Page 1-9.

13.Voter Site - On the MLM drawer connect a Trans-

mitter Test Set to W6 of J701 and record this meter

reading for Voice Level from Switch alignment.

(Voice Level _____________)

NOTE: Either of the following two procedures can be

used to setup the RDM and RVM alignment. Procedure

1 may not work in some systems due to specific instal-

lation issues. Procedure 2 will provide repeatable and

consistent results when using properly calibrated test

equipment and is the preferred

procedure.

1.3.3 2000 SERIES RDM AND RVM ALIGN-

MENT

1. Refer to Section 3 of this manual for receiver align-

ment and Section 3.13.3 Voter Interface for RDM

Audio and FSK level Adjustment.

2. On the RVM connect a Transmission Test Set to

P1, pin 21 (on the back of the RVM) and adjust U44

for approximately -17 dBm. Record the settings of

S2 in the RVM. Refer to NOTE 2 on this page.

On the RVM adjust U44, by setting S2, sections

1-3 as shown in Figure 1-16. To decrease the level set

S2, section 4 to “On” and to increase the level set to

“Off”. Press S1 repeatedly until approximately

-17 dBm level is reached.

Figure 1-15 RVM S2 SWITCH

Figure 1-16 U44 LEVEL ADJUST

3. Disable or shut off the Signal Generator RF output.

Disconnect the Signal Generator from the RDM.

Connect the antenna cable coax to the Antenna 1

input on the RDM (S1 should still be set to

"ANT1").

NOTE 1: Two procedures are detailed for RDM and

RVM alignment. Procedure 1 requires a communica-

tions service monitor with signal generator and spec-

trum analyzer capabilities, a Transmission Test Set,

and a Multi-Net portable radio. Procedure 2 requires

an RF Signal Source capable of simultaneous internal

(frequency range of 10 Hz to 10 kHz) and external mod-

ulation, two personnel, a Multi-Net/LTR Signaling En-

coder-Decoder (PN 023-3039-360), i.e. MED box, two

RF Signal Analyzers capable of measuring deviation of

an RF signal, and a Transmission Test Set.

NOTE 2: This audio deviation adjustment procedure

should be done first at the Main Receiver Site

. The

main receiver site is typically the site that is collocated

at the transmitter site and would have the Revert option

installed. Once the levels are set at the Main Site,

NO further adjustment of U44 should be done. (See

Procedure 1 Step 9 or Procedure 2 Step 12.) The re-

maining RVM inputs will self-align using the 1200 Hz

pilot tone that is generated from the RDM as a refer-

ence. It is critical

that the pilot tone level leaving the

RDM is set properly since the RVM uses this level to

make up for losses through the links. If the RDM-Audio

Link-RVM path at the remaining receiver sites is func-

tioning properly, audio deviation tests done from these

sites should be within 0.2 to 0.3 kHz of the Main Re-

ceiver Site. Deviation levels outside of this range may

be caused by improper setup of the RDM or RVM or

poor audio response of the remote site links.

MSB

LSB