Agency: FBI
Originator: FBI
From: SAC, TP
To: DIRECTOR, FBI
Document date: 10/30/1961
Document type: PAPER, TEXTUAL DOCUMENT

## Page 1

Released under the John F. Kennedy Assassination Records Collection Act of 1992 (44 USC 2107 Hote).

DATE: 11-14-2017

JFK Assassination System

Date:

Identification Form

6/11/201

Agency Information

AGENCY :

FBI

RECORD NUMBER:

124-10210-10189

RECORD SERIES: HQ

AGENCY FILE NUMBER : 92-2781-1ST NR 350

Document Information

ORIGINATOR:

FROM:

FBI

SAC, TP

TO: DIRECTOR, FBI

TITLE:

DATE:

'PAGES:

SUBJECTS :

10/30/1961

3

LST, TESUR

DOCUMENT TYPE:

PAPER, TEXTUAL DOCUMENT

CLASSIFICATION :

Secret

RESTRICTIONS :

1B

CURRENT STATUS: Redact

DATE OF LAST REVIEW:

10/08/1998

OPENING CRITERIA: INDEFINITE

COMMENTS :

f.

v9.1

DocId: 32292913

Page 1

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## Page 2

Released under the John F. Kennedy Assassination Records Collection Act of 1992 (44 USC 2107 Hote).

JATE: 11-14-211

OPTIONAL FORM NO. 10

** UNITED STATES GOV:

(MENT

Memorandum

SECRET

TO

Director, 187 80-760) / IDENTALATE:

10/30/61

FROM

SAC,

Tampa (66-231) DU)

JUNE

SUBJECT:

2-7-957 JFK

SANTO TRAFFICANTE, JR., aka

Classified i SpAnACIse

Declassily g

ReBuairtel 10/11/61, requesting that Tampa

Office

obtain certain technical information prior to the altering

of type 80 telephones for possible SPirIluse (ly

It is noted that: this technique is being considered

as was suggested by previous Bureau airtel dated 9/26/61 and

captioned as above,

contained in Bufile 92-2781.

Mx. DONALD

WITHERS, General Plant Training Supervisor, General Telephone

Company of Florida, furnished information included in the

following:

30

The General Telephone Company of Florida does not

generally use the tip and ring party type of ringing on party

lines.

They use bridged ringing with harmonic ringers using

some or all of the below-listed frequencies:

ON:

DECLA

16.6-cycle harmonic

20-cycle harmonic or decimonic

25-cycle harmonic

30-cycle harmonic or decimonic

33.3-cycle harmonic

ALL IUFORIZATION CONTATHED

ALL INFORMATION CONTAINED

HEREIN, IS UNCLASSIFIED

DATE 10 - 240-976

ABY SA8 MAC

(JFK)

40-cycle decimonic

MERSIR IS LNCIASSIFIED

42-cycle harmonic

EXCEPT WHERE SHOWN

50-cycle harmonic onlftHERWISE

50-cycle decimonic

'54-cycle harmonic

60-cycle decimonic

66-cycle harmonic

14.2

2 = 118/

NOT RECORDED

102 NOV 15 1961

66-6-cycle harmonic

P/s

On party lines having more than five parties,

divided

and

tip ringing and dividedAring ringing could be used.

This,

however,

would not be the situation on the four-party

or private

line, as would be encountered in this instance.

No rege, nuncan perding

Tampa

EMP -KH

Xhsuis

6

NOV 17 1961

46

-NOV 3 1951

760

LED IN

ORIGINAL

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Released under the John F. Kennedy Assassination Records Collection Aot of 1992 (44 USC 2107 Hote)?

DATE: 11-14-2017

тР [66-231]($(4)

Li NEARS

SECRET

Of Mx. WITHERS that a 3,000-ohm resistor across the subscriber's.

line would possibly tend to change the ringer frequency causing

possible failure to ring or an alteration of the sound of the

bell due to the lack of full ringing current.

The "Line Compensating

Rheostat" in the manually

adjusted loop compensator circuit would normally be set at o

on a long cable loop such as in the telephone installation serving

the subscriber in this case.

With the "loop compensator" set

at zero, the 400-ohm resistor is in effect shorted out.

When

set in this zero position it is noted that the switch element

of the "loop compensator"

adds a capacitor and resistor to

the sidetone balancing impedence to more nearly match the

capacitive impedence of the long cable loop.

In installations

where it is desirable to set the compensating rheostat at zero

but where the sidetone balancing network is

not desired in

the circuit, it is the practice to set the "loop compensator"

just off zero where the 400-ohm resistance would be shorted

out but just short of the point where the switch connects the

sidetone balancing network. It is felt that a short could be :

placed across the

"400-ohm resistor of the loop compensator"

to prevent the rheostat from developing an open or becoming

noisy without effecting the operation of the instrument.

The sidetone balancing network could then be either, in

the

circuit if the "loop compensator" is set at zero, or out of

the circuit on any other setting.

On a party line this would

also apply as "loop compensators" are set without regard for

other telephones in the circuit. The loop compensation rheostat

should be set in such a position as to cause 60 milliamperes of

current to flow in the line.

Mr. WITHERS has advised that in his opinion a 3,000-ohm

resistance across the subscriber's line could cause an echo

effect and would make a noticeable difference in transmission

level.

It could possibly cause central office equipment to

reject the line indicating a trouble condition.

A Vincent Rare Gas Relay is sometimes used across:

a subscriber's line to eliminate

interference from nearby

power lines.

It is not believed

that

this will have any

effect upon an

SPNT installation.

SECRET

-2-

CONTNONTIAR

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Released under the John F. Kennedy Assassination Records Collection Act of 1992 (44 USC 210% Hote).

DATE: 1½-14-2017

SECRET

TP [66-231 / (4)

CONNENTIAL

Telephone service is presently being installed in

The actual 100p

resistance of this line is being measured and a simulated

circuit will be set up to test theories described above.

The Bureau will be advised of the result of these tests.

SECRET

COX DETA

DocId: 32292913

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