user manual

Cabling
Grounding
Outside lines
Some RF1 conditions cannot be addressed in this bulletin due to the many possible variables involved.
These variables are generally particular to each site and require that pertinent data be known, such as the
frequencies involved. In situations where RF1 is still present after following the instructions provided in
this bulletin, contact your local NEC America, Inc. SBS Field Support Engineer for further assistance in
resolving the RF1 condition.
If RF1 is present during CO (outside) calls, check for RF1 at the Telephone Company on site demarcation
terminal, with the Electra Mark11 system isolated from the demarcation terminal. If RF1 is present at the
demarcation terminal, contact the local Telephone Operating.Company.
If RF1 is not present at the demarcation terminal, reconnect the Electra Mark11 system and go off-hook at a
Multiline Terminal with RF1 present in the handset and stretch the handset cord. If RF1 changes (increases
or decreases in amplitude) when the handset cord is stretched, modify the Multiline Terminal as outlined in
step 4. If RF1 does not change, contact your local NEC America, Inc., SBS Field Support Engineer.
4. PROCEDURE - RF1 LOCALIZED TO THE HANDSET
4.1
4.2
Disconnect the modular cord from the handset.
Open the handset (See Figure 1).
4.2.1
Remove two screws from the inside grip of the handset.
4.2.2
Set the handset face down (transmitter and receiver facing down) over a solid, clean surface.
Place the fingers of one hand under the transmitter end and with the thumb of the same
hand apply downward pressure to the center of the handset grip. With the other hand, at the
receiver end, separate the handset halves.
4.3
Inside the handset half containing the receiver and transmitter elements, loosen the screws holding
the leads to the receiver and transmitter elements.
Obtain two .OlpF ceramic disk capacitors and cut
both capacitor leads approximately 3 inch in length as shown in Figure 1. Install one .OlpF ceramic
disk capacitor across the receiver element and another .OlpF ceramic disk capacitor across the
transmitter element. Use plastic sleevingover.the capacitor leads to prevent electrical shorts. Tighten
the screws and secure all leads. (See Figure 1).
-4.4
4.5
Join both halves of the handset and secure with two screws (Removed in 4.2.1).
Connect the modular handset cord and test the station for RF1 and normal audio levels. If
RF1 is still present, continue to step 4.6.
4.6
4.7
Open the handset (Refer to 4.2).
Solder a length of insulated, single strand wire to each lead of a .Ol ~,IF ceramic disk capacitor.
Ensure
the wire is the same gauge as the capacitor leads and long enough for one capacitor lead to reach one of
the transmitter element screws and the other capacitor lead to reach one of the receiver element screws
inside the handset (See Figure 1). Use shrink sleeving over the prepared capacitor leads to prevent
electrical shorts. Inside the handset half containing the receiver and transmitter elements, loosen one
screw from each element (transmitter and receiver) and install the .Ol pF ceramic disk capaci.tor
between the transmitter and receiver elements.
4.6
Join both halves of the handset and secure with two screws (Removed in 4.2.1)
. .
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