Marconi Pn1a Wiring diagram

l

JNSTALLING

AND

OPERATJNG INSTRUCTIONS

MARCONI

TRANSMITIER

-RECEl

VERS

TYPES

PNIA

AND.

PNlB

GENERAL DESCRIPTION

Th•

Mu

coni typ,s

PNt

A

•nd

PNI

8 Tcansmittor-R«eiv<r equipments

have

bttn

designed for low power portabl• and

fix<d

st>tion applications

rospoctively, primarily for use by the Armed Sen·ie<s.

Th•

PNlA

Transmitter-Receiver

Unit

ombodi<s a low power transmitter,

a.

suptrheterodyne

receiver.

a telescopic

rod

a.ntcnn1,

a

ca.cbon

microphone

wilh incorporated "press-to-talk" switch, a pair

of

light

w,ight

headphones,

a signalling key,

and

accommodation for a light weight combination

.A

and

8

batt<cy pack.

The

<quipm<nt ,s provided with a carrying harness, by

means

of

which it can

be

earned

comfortably

on

a man's back.

The

har~ss

consists

of

a light tubular

meul

framework to wh,ch

i,

attache<I

leather straps by

which the

w,ight

is ,vonly distributed

to

the weuec. A pock

et

cooveno<ntly

located on the harn<

ss,

is

provid,d

for the sroragc

of

the microphone.

The

cquipm<nt, complete with a battery pack capab

le

of

providing 8

to

9

hours

of

continuous operation, weighs approximately

;)

pounds. ·

The

8 foot telescopic

,od

antenna has' a col.lapied height

of

I)

inch«,

and

i,

socured to

one

side

of

th

e caso by means

of

• simp

[e

looking device.

When

not in use it

may

be

quickly dismant

le

d and ,tow<d in clamps which

are

provided inside the case.

The

PNIB

Transmitter-Receiver Unit is basiolly the ,ame as

thePN!A,

difforing

only

in those

deails

necessary to contribute most effectively

to

its

use

as

a fixed

or

semi-fixed station.

TI1c

PNlB

has no carrying

huness

or

rod

antenna,

but

has a 3 inch permanent magnet loudspeaker incocpon.tcd.

It

is

usu1lly used

with

a straight wire antenna

up

to • qu1rter w,.ve

in

length,

instead

of

the

whip

antenna.

The

PNlA

Transmitt«-Receiver

Unit

measures

app

roximately

19¼

" x

18"

x

16½"

ov~rall, including the cacry

in~

harness

a.nd

collapsed •ntenn1.

Th•

PN1'8 measures 1pproxim1t,ly 16" x HI" x

10"

overall.

A Battery Dox Assembly

1s

available

foe

uso with

tht

PNIA

or

the

PNlB

when

either

is

ustd

as

a

.semi

-fixed

station.

It

pro\•ides

accommodation

for a

heavy duty

combin>11on

A 2nd 8 battery pick, which is capable

of

o

p<

rating

the

tquipment

for

from

75

10

100 hours

The

assembly includes asix foot cable

for

interconnection

11.•ith

the

Transmitttr•R«eiver

Unit.

Accommodation

is

also

provided

in

the Battery Box Assombly for stowing a length

or

antenna

wir<

to

be

used

in

place

or

the

whip

antcnM.

.A

shoulder strap is provided

to

facilitate transportation.

The

a.sse.mbly

measures approximately

l}

" x t2" x

9,.,.

.

and

weigh,

approximately 45 pcuods,complet, with b1ttery and

an

tenna.

1

For

PNI

8 lixed station installations, ,12ndard A coils and B batteries arc

normally suppli«I. These large batteries will give in excess

of

200

hours

of

s,rvicc. A

sp«ial

battery cable

is

,vaihblc

for use with

the"'

batrcries, having

at

one

end

a connector which

fits

the power plugon the chassis and

at

the other

end spade lugs and l»ttery plugs for connection to the

"A"

and

"B"

batteries

respectively.

The

s,rvice life ratings which ha,•c been quoted above for the

thr,e

different types

of

battery available with this e<juipmcnt

uc

based

on

anassumed

continuous

discharsc

of

) minutes

transmit•}

minutes receive.

Con.sideubJy

longc, s,rvicc life will be rcali•«I

if

the discharge conditions 2re

lcs.,

stringent

than those

s1a1«1.

The

transmitter ·,,ill deliver a carrier pow

er

output

of

2 to

2.S

watts

10

a

resistive load,

on

any

one

of

three crystal<onlroll«I

fre<juencfcs

bctw«n

3.0

a.•d

.6.0

megacydts.

This

carrier can

be

keyed for C.W. Op<fltion, or

100%

soecch modulated for )bdiolclephone operation. On Radiotelephone Oi"'ralion

the carrier

is

controlled

by

the

"press-to-talk" switch incorporated

in

the

microphc,ne, the transp,itter b,,ing turned offand the rcccivcr

tum«!

on

when

the "prc.ss-to-12lk'' button is released.

The

receiver

is continu0tuly

tunable

over

the

.s.1mc

frequency

ringe

a.S

the

transmitter, the dial being

alibr,t«I

directly in megacycles. The

receiver

em•

ploy, six

vmcuum

tubes in a superheterodynecircuit, providing high sensitivity,

selectivity.

siJtnal

to noise ratio. and

im.1ge

atte

nu

.iti

on.

Automatic volume

control

is

us«! for telephone reception but IS automatically remov«I when the

receiver is switch«! over for the reception

of

C.W. signals.

TRANSMITTER-RECEIVER DESCRIP'I'ION

Rdcren

ce should

be

made

to

the

Oia,i:r,ms

of

Connections contained in

the

b'ack

of

this m1nu1I when reading the following technical description. The

o,·cra.11

cabintt

is

constructed

of

aluminum, we:athtrproof constroction being

used throu,thout. The transmitter and recdvtr

are

built on a common chassis,

which

fits

into the upper compartment of the cabinet where

it

is secured by

screws

thr0<1,1th

the top

.of

the front oanel and thcou~h the sides

of

the cabinet.

The

lower

half

of

the cabinet provides accommodation foe the portable bottery

and

the

telegraph

key,

and stowage

for

the whipantenna. earphones and micro-

phone when not in

us,.

In

the

PNIB

the loudspeaker

is

also mounted in

this compartment. .

B21terv

volt•~•

is

supplied, from one

of

the thrc, tvpes

of

battery

1lceady

described, through a four conductor cable, terminating in 1 locking type

plu,1t

connector which

fits

into a rectpt.acle mounted

in

2

ffJnge

un

der

the

front

p1ntl

at

the centre

of

the transmitter receiver chassis, This receptacle

is

bbelled

"Power". Another simil,r receptacle labelled "Audio'' and mounted

on.the

umc

Ran,lle

as the · Power'· receptacle. receives the plug from the microphone•

headset assemblv. Locat«I between these recepta<les, but towards the rear

of

the chassis.

is

a small jack which rcccivts the plug

on

the lead-in from

the rod antenna.

2

I,

8att<ry ,·oltagc is

appli,d

to the unit by the operation

of

the

OFF-ON

switch S6. In

the

l'NIA

(pomble)

version

of

the

equipment

this is a push

switch which extends

on

a hanging lead from the

right

reor

of

the chassis.

It

is secured

to

the bottom

of

the

use

n<ar

the right

edge,

so

as

to be within

easy reach

of

the operator

when

he

is carrying the unit.

In

the

PN1B

(fixed

station)

,.,rsion

S6 is a standard

toggl<

type switch,

and

is

mounted

at

the

low«

left

hand

comer

of

the front panel next

to

the

C.\'v'.-PHONE

switch.

When

the

OFF-ON

switch is placed in the

"ON"

position, connections

are

made to the transmittec,rteeiver circuit,

from

the "A" positive, and

from

the

combined

"A"

and

"B"

negative lead,

of

the batteries.

The

voltages dcliYer<d

by

the batteri:s

arc

180 volts,

with

a tap at

I})

Yolts,

foe

the

"B"

supply,

and

three volts for the

"A"

supply.

The

recei,-cc

,·alves require 1.4

lo

I.)

volts for each nl1mcnt,

and

are

connected in a series

par>llel arrangement across the ; volt source. A rheostat isemployed

to

reduce

the supply

to

between 2 0

and

2.1 volts for the

transmitter

valves.

This

rheostat is

mounted

on

the

front panel, where its control is designated "Fil.".

The

fli!lh tension required for the receiver is approximately

90

volts and is

obtained throu!(h

the

dropping

resistor

R31

suitably bypassed by the electro-

lytic condenserC26.

Mount<d in the center

of

the chassis is a telephone type relay which is

oper.1ted

from

the 3 volt supply circuit through

either

the

SEND-RECEIVE

switch

on

the panel,

or

the

"Press-to-Talk" switch

on

the microphone.

It

transfers

the

3 volt supply from the receiver valve,

to

the transmitter vahcs,

:i.nd

also

tr.insfcrs

the

ancenna

from

the

receiver

to

the

tr.1.nsmitter.

The

receiver

section occupies the

left

-

hand

portion

of

the

combined

ch

assis.

It

ublius six

vah·eJ

in

a.

superheterodync

ci

rcuit

performing:

ni

ne

functions,

as

follows.

The

r.(

amplifier

us,s

• type

IP5GT/G

pentode valve.

Th~

.J!rid

of

this

valve receives the incomin.l( si}!nal from thetuned

grid

winding

of

tht

r-f tr>ns-

former

Tl.

The

base

of

this winding is connected

through

Rt

to

the

·automatic volume control circuits, the tuned circuit

bein~

completed through

the

.Ol

uf.

condenser

Cl.

The

antenn• windin11

of

Tl

is

of

high

impedenct

and

m•tches

tither

the wire

or

the rod antenna.

The

plate

of

the

I

P,GT/G

is

connected

throug

h the primary winding

of

the detector transformec

T2

to the

m:un

90

,·olt

high

tension supply.

The

detector-oscillator

or

converter valve is a type I A

7G'f/G

which

performs

the

double function

of

o frequency-

_cha

ng

ing

rectifier

and

high

frequency oscillator.

A1:ross

its signal grid

,re

imoressed

the

incoming r-f

signals,

"hi

ch h1ve been selected and ampli~cd b)'

rhe

r-f

and

detector

tr

ans-

formers

and

the

r-f

amplifier valve.

The

triode portion

of

the

converter yalve

i,

used

for

the

high-frequency l)Scillator and is

shunt-fed;

the

•node

grid

receivin.1t

its 1•oltage from the

90

,olt

supply throuRh the

droppin~

raistor

R).

The

oscillator transformer

T3

pro,-ides pJ.te-to ~rid coupling,

•nd

grid

tuning,

and

the

grid

tank circuit is normally tuned

10

a frCQuency 455 kilocycles

hiJ?hec

than

the

r

-f

signals.

The

oscillations set

up

arc

fed

through

the

grid

coupling

3

condenser

C8

to

the oscillator grid, where

t~y

arc mixed with

the

signals

•ppearing in the valve from the s,,gnal grid. The base

of

the stcondary w,nd,ng

or the deta:lor lr&nsformer

T2

is

conna:tcd to the voltage divider in the

filament circuit

of

the

IA

7GT/G

convc,ter valve.

This

divider consilts

of

rcsistou

R2

and

R3

and supplies a slight negative bias, approximately 0.8 volts,

to

rhe

signal grid. Condenser

Cl

I serves

to

complete

the

detector tuned circuit.

. Ano

th<r

1P,GT/G

valve IS used as the intermediate frequency amplifier.

from the signals appearing at the plate

of

the converter valve, those

,t

455

kc

ate selected

by

the transtormer ·14,

and

impce$$ed

aero$$

the grid

of

the i-f

valve. Here they aie amplified and passed through the sa:ond

i-f

transformer

T6

to

the second detector circuits.

Ir

is

in the i-f amplifier that the major

per·

tion

of

the amplificatioo and selectivity

of

the complete receiver is obtained.

A

IH5GT

/G

valve

is

wed

for the detector, automatic volume control, and

1st

audio

ampli.ficr

circuits.

The

detector

circuit

consists of

the

diode

section

of

v,

and the diode load

R!2

and RI~. R12 in conjunction

v.•ith

<;:23,

acts

as

an

r-f filter and prevents r-f voltage from going into the audio system.

The audio component is passed through the audio coupling condenser C22 to

the top

of

the audio volume control RI7.

On

C-W

the

grid

of

the

1H,G'f/G

is

connected directly to C22 while on

PHONE

Rl

7 is connected into circuit

to provide control

ov<r

the audio gain

of

the aml;'lifier. The automatic volume

control circuit consists

of

RU,

RI, R6,

Cl

and

<.;39

and functions

as

follows:

.

In

the"diode detector circuit there

is

developed across the load resistor,

RI2 plus Rl4, a voltage proportional

to

the carrier strength at the diode.

The diode end

of

this load

is

negative with

res~t

to ground

and

a negative

A

VC

voltage

is

applied to the r-f and i-f amplifier grids.

The

AVC resist9rs

Rt and R6 are intended to provide decoupling between

the

r•f and i-f circuits.

Valve V4, a

!G4GT/G

triode,

is

used for

the

beat-frequency-oscillator.

Thecircuit is set into operation

by

the

PHONE

-

C.W

. switch

St

which, wl,en

set at C.W., supplies voltage lo the plate

of

V4 through

the

dropping resistor

RIO.

The tank circuit

of

transformer T5 is adjusted to appcoximately

4,6

kilocycles and oscillations

set

up in this transform«

>re

coupled through

the small capacity existing across pins

#4

:-

#,

of

v,

to the diode plate,

where they

are

mixed with

the

i-f

signals,

res

ulting in a IO00 cyde

beat

note.

In addition to applying high tension voltage

10

V4, SJ also performs three

othtr functioos whtn

turntd

from

PHONE

to C.W.

The

AVC line

to

Vl

and V3

is

shorted

10

ground and connection to the A

VC

resistor

Ill,

broken,

thus removing the automatic control

of

volume. The audio gain

is

fixed

by

transfeuing lhe audio grid

of

V5

from the slider

of

R

17

to the junction

of

C22 with Rl

7.

Al

so the

scmn

grids

of

VI

and

V3, which on

PHONE

receive a

fixed

supply from

the

junction

of

Rn

,nd

RI

I,

are connected to the

slider

of Rl1

where

.scrc:cn

voltage

is

varied

by

its

manipulation;

this

provides

an

r-f sensitivity control to replace the audio gain control now

fixed.

In

brief

the change1 ,ccomplished

by

changing from

PHONE

to

C.W.

are:-

(t)

Supplying

HT

to

BFO

circuit

(2)

Removing lhe AVC

(3)

fixing the audio

gain

(4)

Providing r-f gain control through the screen supply

to

VI and V3.

4

Tho

powor qutput valvo

is

a

LQlGT/G

bcam power :unpliJier. Hore

the audio signals rocoived by the grid through C24

arc

:unpliliod and impressed

ictoss the primary

of

the

output transformor TT.

In

the .PNJA the socondary

ol

this transformer supplies the inductd audio frequoncy sign•ls to

the

hoadphones th,ough the audio socket CCI. In the PNLB tho

mnsformor

£.eds oither the earphonos or the loudspeaket,

as

dot'ecminod by tho sott,ng

of

a

DPDT

Toggle switch,

S7,

connected to its output tecminals.

Th

is

sv.•

itch

i,

mounted

on

tho front panel,

above

the filament rheostat,

and

is

marked

..SPEAKER-PHONES'-.

The ovec•II arnplilication

of

the roceiver

is

controlled by

the

panel

control design1red VOLUME, This

i,

a dual control consisting

of

RI I

and

Rl7.

The functions have already

bttn

described.

The

seloctic,n

of

any

desired fr«jueocy within

the

range

of

the receiver

is

made by a

three

gang

tuning condens<r which tune> the

r-f

and

detector

transfo

,me,

ciccuits to the desired f1«ju<ncy, and as previously stated,

the

oscillator socondary

10

a fre

quoncy

455

kc

higher.

Tho

gang

condoruor

is

adjusted by the tuning dial mountod on

tho

front panel,

the

scale

of

which

is calibrated

in

megacycles. The only othec controfs neces5.try

foe

operation

of

lhc receiver arc the control$ maiked VOLUME

and

the PHONll-C.\X/,

switch.

The

r-f

detector and oscillator transformcis arc wound

on

high grade,

low loss bakclitc formers, the sccondarios being space-wound, The trans•

formers arc impregnated with a non•hygroscopic bakclite varnish, baked

and

waxed. These precaution, servo to prevont losses

due

to

excess humidity, and

provide

goo<!

stability under

111

climatic conditions.

Tho

j.[

transfonncts arc

likewi,c impregnated but use litz .,•iro coils

on

fish

p•p~r

formers. TI,e BFO

u2nsformer uses duo-latcul

wound

coils on a

ba.kclitc

former, all being

similarly treatod as tho r-f and i,f

coils.

For adjustment all r•f and

i-f

tran>•

former, use high grade powdered iron core,, which

ue

sealed

in

place bcforo

the «juipmont IS shippe<I.

The

following is a tabulation

of

tho

Technictl Specifications and Ratings

of

the

receiver

s«tion

of

the

Trinsmitter•Rcceiver.

VALVES:

1-RVC

IPlGT/G

-R-F Amplifier.

1-RVC

JA7GT/G

-Conv,rtor

.

1-RVC

LP5GT/G

-'

J.f

Amplifier.

1 - RVC

LH)GT

/G

-Dcteclor, AVC and Audio.

1-

RVC

1G4GT/G

-llfO.

I -

RVC

1Q5GT/G

-Powe,

Output.

FREQUENCY RANGE: 3 mog,cydes to 6 megacycles.

INTERMEDIATE FREQUENCY: 455 kilocyclts,

ANTENNA

INPUT:

High

impedane<

.matched to rod

anttnna up t• ¼ wavc•ltngth long . antcnn:i or wire

OUTPUT

IMPEDANCE:

For

high impc<lance phones, or loudspeaker

voice

coil. ·

POWER

OUTPUT:

350 milliwatts maximum, 225 milliwatts undistort,d.

SENSITIVI

TY

FOR

10 MILLI\VATTS

OUTPUT:

5 microvolts average.

SELECTIVITY

JN

KC

OFF

RESONANCE: Avmges 19

kc

at 60 db down.

IMAGE

ATTENUATION:

Averages 65 db.

SIGNAL-

TO-NOISE

AT

MAXIMUM

SENSITIVITY: Averages 8 db.

1-F

INTERFERENCE RA

TIO:

Averages

-85db.

A.V.C.: Holds the output level within

;t;

!}db

when the input varies 80 db.

AUDIO CIIARACTERJSTICS: Within 2

db

from 250 to 1500

cycles

Down

10

db

at

100

and

2500 cyclos.

MODULATION

CAPABILITY:

85~

. .

The transmitter section

of

the

un

it

is

loa.ted

on

the right hand end

of

,he chassis. Its cirruit emplo)'S four valves which perform functions

as

follows:

The

crystal

O$Cillator

stage employs a

type

IH

◄

G

valve. One

of

the

three crystals

is

selecte<I

by

the rotary •"·itch, whose pine! control is

deSJgnated

CHANNEL.

The

cryml

s,lected connects to the

IH4G

in a

standard grid-to-ground

O$Cillator

circuit.

The

plate circuit

of

this valve

is

tune<!

by a

tank

circuit consisting

of

an ind

uct

ance and one of three variable

,ir

condtnstrs which

art

also switched by the CHANNEL switch. Three

tank circuits

art

thus ,ffectively ffllploycd so that each tan~ can

be

pre-tune<!

to 1h,

frtqu,ncy

of

th,

associated cryst•I. These oscillator lank condenscu,

CH,

C35 and C36, are located in a row in the right hand end

of

the

chassis under their respcctivt crystal socktts.

The

inductance

in

the oscillator tank circuit

is

tappc<I

for connection

·o the I

80

volt supply

so

that

double-ended tank opccat1on

i,

rrovidcd. One

-nd

of

this•

tank

JS

connected to the p>rallel control grids o a type 1)6G

?"wer amplifier valve through • coupling condens<r, CJ2, while the other

~nd

1s

connected through the ad1ustable air condens<r,

CH,

to apply out-of-

•~ast

neutralizing voltage

to't~e

paralleled plates

of

the

p·•

inductance. •

The

plates

of

the

1)6G

p-a valve aresupplied with 180 volts

d-c

through

he secondary

winding

of

the

modulator transformer and throu8h an

,.f

hoke, while the

,.f

voltage generated by the' valve is fed through a d-c

,locking condenser, C29,

to

an output tuning circuit consisting

of

a tapped

:o

il

,nJ

\'atiable condense,.

The

taps

on

the

coil arc connected to a 17 point

,ot«y

tap

switch mounted

on

the

fro

nt

p•nel and dcsignattd COUPLING

The

variable

condenser

is

fitted

with

a

vernier

drive

and

locatts

beside

the

oil. These two compancnts arc connected

to

form what

is

commonly kno•:n

u

a.n

"L" nctwotk in which the antenna is connected

as

a series element

2thcr than a

shunt

element

of

the output tank. The main advantage

of

this

1pe

of

circuit is its simplicity, since both the

p•a

pl•te and antenna circwts

re tuned simultaneously.

The

con

st,nts

of

this circuit arcchosen to allow the

ransmitter 10 feed antenn•e

of

ltngth between that

of

the rod and a wire

ntennae one quarter wavelength long. as may

be

used

in

scmi-6xcd station

en·icc. ·

6

The

modulator valve is another

tj6G

having its two triode .sections

connected in push'•pull, and which operates cJ,.,s

"B".

It

is

transformer•.

coupled to

the

output

of

a type I

F)G

driver valve whose grid

is

in

tum

connected to the microphone tr1nsformer.

Bias

for both these audio valves

is

obtained fcom the

4,

volt

cap

on the

"C'

battery, which

is

mounted

on

the

chasm

base

bthind

the

relay

. Microphone current is obt•ined from the

Hansmitter filament circuit and

is

applied to the microphone through the

primary

of

the

microphone transformer.

Keying

of

the c.rrier for c-w operation

is

accomplished by opening

the

grid circuit

of

the

p-a

valve. This takes place when the key cable is pushed

into the jack designated KEY

on

the front panel. The break

is

transferred

to

the

key

contacts, and so

is

closed when the key

is

pressed.

This

method

of

keying is

not

perfect, since a small amount

of

power will

f_eed

through due

10

impcrfC<"t

ncutraliution.

HowC\'Cr.

a difference

in

signal level. between

key

up

and key down

of

approximately

2'

db

will be obtained ·with

an

average adjustment.

It

._,,JI

be

noted that when the

key

plug

is

pushed in,

back contacts·

on

the jack operate to open the fibmfflt circuit to

the

·modu•

la.toe

valves to

conserve

b.ittcry

current.

and

also

insert

a

rC$istaoce

in

series with

the

filaments

of

the r-f vdves to

m•int,in

approximately constant

filament voltage

on

these latter v,Jves

in

spite

of

the ,educed volrase drop in

the filament rheostat. .

The

meter

mounted

on

the

Cront

pa.nel

is

arranged

to

measu

re the

transmitter plate and filament supnlv voftages

as

well

,s

the

plate current

to

the

p·•

stage. This

is

accomplished

by

using a low current meter

in

conjunction

with

volage multipliers and a current shunt, these being

switched by

the

meter switch 54 which

is

located below the meter..

The

inain

sale

of

the meter is alibra.ttd

0-,0

ma

for p-a plate current measure-

ments. this

sale

being

read

when

the

meter ,.,.·itch is in the position marked

TRANS

TIJNE. When the switch

is

moved to B

VOL

TS, the full scale

range

is

200 volts, although a complete calibration docs not appear

on

the

meter scale,

but

merely spot calibr1tions at.180, 144

and

120 volts.

The

0-)

scale obtainable with the switch in the TRA"!S FIL

l'°'ition

is only marked

2.1)

volts at • red line

on

the

m1in

s«le,

is

this ,s the only reading·

of

interest

on

this range.

..

'

··

~

The

main tuning dials

of

both the t<1nsmitte, and

the

receiver sections

mre

fitted with clamps that act

on

the periphery

of

the dial scales,

and

so'lock

the condensers

in

any

desired position. These

locks

locate at

the

extreme ends

of

the

front

~nel.

PRELTMINARY

ADJUSTMENT

On

receipt

of

the equipment

it

should

be

carefully examined

for

possible

damage in

mnsit.

Before lea,ing.the Faclory, each set

is

thoroughly insyected

and tested, using the customers

C')'$tals

if

these arc available. Othcrw,sc the

transmitter

section

is

tested

using

st:mdard

test

crystals

at either end

of

its

frequency range, and ,ince the ,djustments are not numerous, no difficulty

shou

ld

be <Xf"'rienccd in tuning it to the desired freq

ue

ncy

in

the

/idd.

7

To

put

the unit

inlo

open

lion proceed as follows:

First

undo

the canvas cover

and

open

the

meld

doors

to

expose the

chassis panel

and

the b>ttery compartment.

Then

cemove

the

transmitter-

receiver chassis by extracting the four screws through the top

of

the p•nel

and

the

two

$Crews

into the sides

of

the

chassis.

If

the

customers

crystals

were

avaifable before shipment, these will be

in

place

in

the

sockets along

the

ri

ght

hand

side

of

the

chmis

.

If

the crystals arc separate, they ~hould be

placed

in

these sockets, care being taken to orient

them

so

that

the pin

connecting

to

the exposed metal plate

of

the holder is located in the right

hand,

or

outside hole

of

each socket, this

being

the

ground

side. Make

cc-rtain

also that all valves arc in

their

proper sockets as indicated

by

the

markings

on

the base beside each socket.

. Power should no.,. be applied

to

the chassis

before

ccplacing it

in

the

cast. Either light duty

or

hc»'Y batteries may

be

used

for

this purpose, the

connection

to

the POWER receptacle being

made

by

mans

of

the

appropriite

b>ttery coble. .

The

microphooe-beadset assembly should

be

plugged into the

receptacle designated

AUDIO

and the unit turned

on

by me•ns

of

the

OFF.ON

switch.

The

receiver should now become operative

and

if

the

volume control is advanced, a signal

or

background noise will

be

audible in

the headphones. Battery voltage will

be

indicated on

the

meter

if

it,

switch

is moved

to

the B-VOLTS position. Normally

no

further receiver adjwt-

ments

will

be

n«cssa.ry,

Now

with the meter switch

on

TRANS

FIL, pccss the bulton

on

the

m,crophone. This should operate the

reby

and

a.use

a reading

to

appear on

the meter.

The

Fil

control should be adjusted to make the meter

pointer

fall

on

the

red

line al

2.t5

volts.

If

the meter switch is

now

moved

to

TRANS

"I1JNB,

a reading of approximately U

ma

will

be

observed

if

the crystal

is

not

oscillating,

or

a

Ycry

high reading

if

it is oscillating.

The

crystal stage

is tuned by the three small screwdriver-adjusted condensers thar•Jocate

in

a

row in

the

right

hand side

of

the chassis.

Thc,e

condensers

must

be

adjusted

with

tn

insulated

screwdriver

or

socket wrench. since

the

shafts carry an r•f

patential as well

as

the 180 volt

d<

_supply.

Each

of

the

thr«

condc_nscrs is

associated

with

the

cryst1r

socket

immediately

above

it,

which

in

turii

is

in

circuit wh(fl the

CHANNEL

switch u set

to

the

channel

number

that

is

.Jso stamped beside the cry,til socket

The

condensers should

be

adjusted

to

a

point

just before the crystal stops oscillating, as

indioted

by

a falling

oi

the

meter

reading

to

about

I)

ma.

Th

e

adjustment

should not

be

so

clOS<

to

thu

point that oscillations

ace

not

established

•t

once every time the

microp

hone

button is pressed.

The

value

of

the

p-a

grid

current

(or

in

oth,r

words the m,gnitudc

of

the oscilfator

output)

may

be

measur~d,

if

desired, by plugging a d-c milli

amm,t,r

connected to a

two

-ci

rcu

it

pl

ug

in

to

the

KEY

jack, and for normal operation should

be

approximately 3 ma.

Ndutraliution

of

the

p·•

stage is catried

out

accurately

•t

the Factory

before shipment, so

ore

should

be

taken that

the

setting

of

the neutralizing

conderlscr

C}I

is not disturbed.

The

correct position

of

this condenser usually

will

be

with

its plates slight!)' less than

half

meshed,

and

such a >citing may

8

·be

tried

if

its position

is

accidently changed.

The

neutralizing adjustment

is

quite critical

if

optimum ol?eration

on

c-w

telegraphy

is

to

be

obtained and

the adjustment procedure " somewhat involved

and

requires the use

of

special instruments.

The

proper procedure will be described under

the

heading ..SERVICING INSTRUCTIONS... .

Having

adjusted the oscillstor stage

as

outlined

~ve

on

all

active

channels, the chassis now can be r,,turned to the case and

the

antenna

conn'ected. Eithec the rod ontonna

or•

wire antenna

up

to

¼ wave in Jongth

may

be

used.

(The

length in ftet

of

a ¼ wave antenna

is

equal

to

246

d,v,ded by the frequency in mogacydes.) Simultaneous loading

of

th•

p-a

stage,

.and

tuning

of

the p·t. stage and the antenna,

an

now be

ca.cried

out

The

method

of

adjustmont

is

the same rrrespective

of

which anteona is uied,

except that

if

the equipment

is

to be used for porttble operation the final

trimming

of

the

p·•

tuning 2nd loading adjustments should be made with the

transmitter-receiver raised a

few

ftet

off the ground, otherwise these adjust-

ments will be ufected when the equipment

is

transferred

to

the operator's

bade. Also,

for

6xed, or semi-fixed operation, using either the rod

or

the

wire antenn•, a ground conoection should

be

made to

oo•

of

the bolts

provided

in

the bars under the osc,

to

increase the efficiency

of

the

antenna,

and so radiUe a

muimum

of d power.

The

tronsmiller tuning condenser should be

set

al O and the

COUP

UNG

control set

at

position

I.

Select one

of

the

active channels and press the

microphone button. Quickly route the tuning condenser

in

a clockwise

directron until the

p-•

plate current rClches a minimum value (rCld with

the

meter switch

on

TRANS

1lJNE.)

Now

further advance the

COUPLING

control a step at a time, manipulating the tuning condenser after each step

to

obtain resonanct -i.

e.

minimum plate current. Jt will

be

found that

as

this

process

is

continued

the

plate

current

at

resonance

increases,

indicating

that the p•a valve

is

being loaded.

The

tronsmitter will deliver rated po•-'«

to

the

output

circuits when

the

p-a plate current lies in the range 25

to

35

ma.

The

unit

should not

be

operattd

for

long periods either with the

output

circuit

out

of

resonance

or

with

the

p•a.

plate

current

in

excess

of

40

ma,

u

this

may

sc,iously

shotten

the

life

of

the valve. Therefore, continue

to

advance the COUPLING control

until

a p-a plate current

of

between

25 and

35

ma is obtained after having obnil\ed resonance with the nu.in

tuning

condenser. When this condition has been reached

tbt

tcan,mittec

is

ready

for

oper1ti

on

on this frequtncy,

and

the

ad

justments will not

change appreciably unless the length

of

the antenn•

is

changed.

11,e proctdure outlined above should now

be

repeated

for

the other

two channels if these are

to

be

used.

The

main points to be borne in mind when tuning and operating the

transmitter

ace:-

.,

(1)

The

6Jamcnt voltage should be maintained at 2.15 volu.

(2)

Tuning

always should be commenced with the

COUPLING

ond

tuning controls

11

the low

end

·

of

their stales,

9

0)

Ad

justmtnt

of

the

COUPLING

control should

be

such that the

tune point

can

be

found within the

ranse

of

the tuning condenser

and

that

this

tune point dots not

occur

exactly

a.t

either

ma.ximwn

or

minimum

capacity.

(4)

Normal plate current with the output circu

it

in

tune should not

exceed

40

ma -normally b<lwccn

2)

and

35

ma.

(5)

Rttuning must

be

carried out

eve<y

time the

fre<juency

and/or

the

antenna length

is

changed.

In

order_

to facilitate

the

rapid selling

up

of

any

frequency with • given

antenna, it is ,uggested

that

• small chart

be

m1de and filled in, at this time,

listing the settings

of

the two controls

on

each frequency, and recording the

length

of

antenna

in

wr:. ·

ROUTINE

OPERATION

Once the transmitter section

of

the

equipment

hu

been properly tuned

with a

.given

antlnna

length

and

Olll

given frequencies

in

accordance

with

the

de-script1on

in

the pr«eding

s~ion.

the

routine

opcr1tion

of

the·

unit

is

.

ve<y

simple.

When

fixed

or serni-6xcd station operation

is

desired.

set

the

transmittcr-

receiv_cr

and

the

batteries

in

the

de,ired operating

location

,

open

the

doors

of

the transmitter-receiver case and bring the appropriate

batte<y

cable into

it

through the opening.

in

the bottom

of

the

case.

Connect it and the

M,crophone,Headsct Assembly

to

the,c respective sockets.

Erect

the

rod

antenna

or the single wire antenna.

as

required,

and

connect on a g,ound

wi,re.

Move the power switch to

ON

and manipulate the

rcceivez

tunin3

1nd

volume

controls

to

receive

the

de.sired

signal.

To transmit on Phone, press the microphone button and check that

the

meter reads

2.0

volts

in

the TRANS FIL p9$ilion

of

the meter switch and

between

2)

and

3}

R)• in the

,TRANS

TUNE

position_

(The

transmitter

tuning controls

ha•ing

Jim

been set for the required fr«juency). Talk into

the microphone at an average room level, holding

it

at

nght

angles to, but

dose lo,

the_

lip!- Relea~_the button again t? receive. .

To

transmit on ·,

:;._;

, plug the.cabJe •from the

key

into the KEY jack·,

move lhc

SEND,R.E<::EJVE

_switch' to

SEND

/ind

proceed with the trans,

missioo. Return

to

:•

RE;C~IVE

wb;n

ihe

•t

rinsni

issio

n

is

completed.

(Note

that

th;

key cable

li)u.st

be

'removtd'from

'.

it.s

jack for Phone transmissions,

O'.htrwise the modu,

lator•v_alves

will be inoper•tive.) ·

For portablc-;;pe;a·iioo

of

;he..cqui;,ment, the light duty battery

is

plugged-in, and the, Microphone-Headset cable taken out through the

•p«ture

in

the bottom

of

the

rue.

Before setting

Out

, the rod antenna

should

be

extended

to

.the required height and the tuning adjustments

of

both the transmitter

and

receiver section, made for the desired fre<jutncies

JS

for fixed sl•tion

opeution

above. As

pm

·i0usly si.ted, for portable

>peration the final adjustments should

not

be made with the unit resting

l11ect

ly

on

the ground.

The

tuning dials

then

may

be

Jocked

in

position,

he

doors

of

the

ca~

closed,

a.nd

the

'c

anvas covering

secured

in

pl11cc.

10

When

the

site

of

desired operation is reached,

pull

out

the

lcnob

of

the

ON-OFF

switch

in the bottom

of

the

cue

to apply

battery

volbgc

to

the

unit.

The

cccieiver

now

will

be

operative

. To

transmit,

press

the

button

on

lhe microphone.

releasing

it

again to

receive.

If

the

unit

is

10

be

operated conrinuousl)·

for

a

long

period, occasional

checks

on

the

transmitter filament voltage should

be

made, as

the

transmitter

output

power

falls off rapidly with small decreases

,n

filament voltage.

These

checks can

be

made

most

conveniently by an assistant

A

change

of

frequency

to

either

the

transmitter

oc

the

receive, will

also have

to

be nude

by

an

ilSsistant

unless the optrafor removes the unit

from

his

b«k.

·

When

the

equipment is

no

longer needed,

the

battery

should

be

con-

set'ed

by

pushing

in

the

operating knob

of

the

ON-OFF

switch,

and

so

opening

the

battery

circuit

.

SERVICING INSTRUCTIONS

BATTERY

REPLACEMENT

The

combin>.tion

"A"'

and

··n·

·battery packs should

be

replaced

when

the

··a--

voltage

falls

to

120 volts

or

when the

"'

A"

' voltage

fall,

to

about

2

volts, whichever

occurs

first.

The

··c-·

bo.ttery

mounted

on

top

of

the tr&nsmittcr-receivec chassis

should

be

checked periodically with a high resistance voltmeter,

and

replaced

when

the

voltage

at

its 4.) volt

tap

drops below 3 volts. Such replacement

should

not

be

necessary more

than

once every

three

months

or

so,

~roviding

,t

is

fresh

when

installed,

and

depending considerably

on

the

service

hours

and

climatic conditions

to

which the

unit

is subjected.

TRANSMITTER

SECTION

The

valves in

the

transmitter section should be chcc:kcd peciodically

using

a reliable

tube

checker

or

by

replacing them,

one

at

a time,

by

ones

known

to

be

good,

and

·noting

the

resulting operation for possible i

mprove-

ment.

Apart

from

valves, little trouble is J,kcly

to

be

experienced

with

the

,

transmitter

section

since

all

tuned

circuits

c.tn

be

kept

adjusted

quite readily

in

the

manner

outlined

under

"Preliminary

Adj...:stmcnts··.

The

contacts

or

the

telephone-type relay should be

deaned

periodically

using

• ··contact

burnis

her

" as

emplored

in

the cclephone

industry

.

Should

accurate neutralizing

of

the

p·•

st,ge

ever

be

considered neces-

sary,

the

following procedure should

be

employed:

Connect

a resistance

of

from

30

to 40

ohm,

between

the

antenna

ter-

minal

and

ground

and

tune

the

transm,tier

in

the usual way into this

dummy

load

on

the

highest frequency.

Now

plug

the

kq

cable

into

the

key j>ek,

leaving

the

key contact,

op,11

and connect • 0-

120

ma,

r-f

metec in series

..

-,th tne

dummy

load

resistance.

rr

the 1ransmirier is pcoperly neutralized,

the

II

current indicated

by

the meter will not

be

more than 10 milliamperes.

If

it

is

higher than this value,

u,c

• long bakclite scre,.·dri,·er or socket wrench to

adjust

the

ncutrahting condenser,

c;1,

until. the load current reaches a

minimum.

The

transmitter tunin~ dial should

be

tocked back and forth

through the tune point during this adjustment to ensu

re

1hal

lhe

p-•

stsgc

is

kept

in lune.

RECEIVER

SECTION

A good check on the operation

of

th•

rec•"·er section

JS

provided by

colt•~• measurements at various points in the circuit. All ,·oltages should

:,e

taken lo

_eround,

unless otherwise sp«ified, with a 1000 ohms-per-volt

·:

oltmet<r and should

be

within plus or minus 10%

of

th<

voltages ~iven

;clow. New batteries should be used

for

this check. When checkina, volt•~••

11

other points than those given. allowances should

be

made for voltage

drop

.

hrough

resistances

and

transforrper

coils.

Pin .:t;

of

Power plug ... . . .. .... . .. .. .. .. 180 volts

.:!l:4

of

Power

plug...

.........

..

.. .

..

. ........

.......

....

..

......

I;,

.:t

2

of

Power plug ..

..

..................

..

.................

..

.............. ;

Across P,n

.:!l:2

and Pin :fr7

of

Vt

10

V6 inclusive ... I 5

Junction

of

R3

I and C26 .... . .. ..

..

. .. . .. .. .... .. ... 100

Pin ::t4

of

Vt

and V3.......

..

...............................................

88

Pin ;#B

of

T2

....... ... .. ... .......

...

..... .. ...... .. ........... .. ..

08

Pin ·

::t6

of

V2

(oscillator working) . .. 60

Pin :i±6

of

V2 (oscillalor not working)............

..

.............

62

:#3

of

V4 (switch SI on C.W.) ............................... 27

#3

of

v,

....

..

.

...

..

.

.. .. ..

....

..

.

32

:OM

PLETE

AUGNMENT

Thie

nectssarv

eqo

ioment lot

complete

ali'tnment

of

the

tecelvc-c

includes

.n accura1dy calibralcd sia,nal generator

Md

a

,aood

quality output meter

•p•blc

of

reading

10

milliwa11s

across • 20,000 ohm load.

Proceed as

follows:-

Conncct the

siJZnal

ecneralor,

by

means

of

two sho,1 leads,

10

chassis

,d

the ,erid

of

the

IA7GT

/G

valve at the t-•ng condenser.

TI1e

high side

of

" sii;nal generator should have a

.1

or

.05

.~(. condenser in series

with

'(

k,d.

.

Connect the output meter to pins Nos. I and 4

of

the AUDIO connector

ith lhe Microphone•Hcadsct assembly disconnected.

The

controls should

: sci

as

follows:·

ON-OFF S"•itch in

ON

pcsition.

SEND-RECEIVE switch in RECEIVE oosition.

PHONE-CW.

switch in

PHONE

pcsition.

P•nel volume control full clockwise.

Dial

at

5.8 megacycles.

Center section

of

gang shorted

10

ground.

12

Set the signal generator to exactly

4))

kc and adjust iron cores

in

T4

and

T6

for maximwn output.

The

o,

·craJJ sensitivity

of

the

i,f

ampli6er can

now be measured and should be

70

microvolts for rn milliwatts out,

if

the

signal generator

fs

«liable

and the output meter matched

to

the output

transformer, i.e., approximately 17,000ohms.

The

selecti-,ity

of

the i•f channel

should be such that signals are

40

db

down, at 14 kilocycleJ of! reJonancc.

For checki

ng

purposes the high side

of

the

signal generator may be

tr1nsfcrred

to

the grid

of

the

IP)GT/G

i,f

ampli6cr.

Hert

an input

of

4)00

microvolts should give an output reading

of

10 milliwatts.

After the ,.( ampli6er has been accurately adjusted, the

PHONE.(.W

,,.

·itch should be turned

to

c-w and the core

in

the

BFO

transformer

T)

ad;ust<d to gh·c a 1000 cycle

bdt

with

the

i-f

signd.

This.can best be

adiusud by taking the

modula11on

off the

i-f

signal from the signal generator.

The

r-f detector and oscillator circuits may be adiustcd now.

Connect the high side

of

the signal generator

to

the antenna connector

through a 100

uuf

condenser and the other side

to

any convenient point on

the

chassi$.

Lea,·c controls

as

gi,·cn abovt

but

remove the short from the

gang condenser. ·

Set the receiver dial and signal generator

to

).8

megacycles modulated

30% at 400

~Jes.

Adjust the trimmer condensers C2, C4,

and

C9 for

maximum output: these arc mounted

on

the

gang

condenser. Consideriblc

care

must be

t.aken

in these adjustments to

see

that all three circoit.s arc in

tune. It

will

be found necessary

lo

rock the

gang

condenser back and forth

•cross the signal when adjusting the antenna and detector trimmers C2 and

C4 rcspectiv,ly. Now set

the

signal generator and receiver dial

to

a frequency

of

}.2

mega~les

modulated

30%

at 400 cycles and adjust the iron cores in

lransformm

Tl,

T2, and

T;

for maximum output.

The

•bove adjustmcnlJ should be r<pcatcd until the correct adjustments

of

the

com

do not affect the correct adjustments

of

the trimmer condenscu.

Wh,n

the receiver

h>.s

been correctly adjusted the ovcraU sensitivities

at

;.2.

4.6 and

).8

megacycles should be 4, ) and 6 microvolts respectively

for 10 milliwatts out. These 6gures will varr. however, depending on the

trpe

of

signal generator being used, so

that

,f

the

sensitivities arc approx-

im,telyas abo•e, the

re<:eiver

showd be considered correctly adjusted.

When replacing vah·es

v.,hich

arc used in any part

of

the receiver

circuit

that

has

a

tuning

adjusllncnt associated

with

it-.

that

part

i

cular

adjustment should be checked foi maximum s,nsitivity.

Thi,

may be done

without

a

si,gml

~ncr.toc

by

adjusting

for

maximum

noise

lc\·c1.

However,

the use

of

a signal

gener,tor

is strongly recommended when at all possible.

When the

IA

7GT/G

converter valve

is

changed

it

is

necessary

to

trim

the receiver at ) 8 megacycles,

as

previously outlin<d,

to

compensate for

vui1tions

in

valve

capacities.

13

PARTS

LIST

SISTORS.

,.,,;,

•

NI

Sp~r1'fi,11io11

100.000

ohms

10¾

½

•.lratt

i,.o

ohms

)%

~

.,.,.u

1,.0

ohm.s

)?c, waic

120,000

ohms

l0$°c

I

watt

22,000 ohms

10*

Yz

wan

100,000 ohm.s, t0$.s ½

wan

-17,000 ohms lO'ic ½ watt

30 ohrns

)%

1/J

"-',Ut

47,000 ohms 10'/4 ½

,·-an

J00,000 ohms

10%

½

._,tc

Dual VariabJc-, I section

)00.000

ohms,

othtt

s«tion

2 me-gs.

22,000 ohms

I~

Yi

wau

10,000 ohms

10%

1/.2

wau

1.0 mcgs IO?o ½

wau

}.0

mt8S

)%

½

W.111

220,000 ohm.s JO% ½

-..·au

Dul

Vanablt,

1

s«tion

)00,000 ohms,

nthtr

section 2

me.cs

.)0

ohms

)~

½

Walt

1.0

m.egs

10%

YJ

w,m

470

l.l

mtg,

10%

½

,-.u

"ff'80

ohms

109c ½ watt

10,000

ohms

IO'H

1/J

watt

47,000 ohms

10%

½

wut

40,000

ohm

mulripJitr-

pan

of

M•l

980 ohm

mult

iplier

,nr1

o(

M-

t

2.22

ohm

.shunt

p~n

of

M-1

41,000

ohms

tO'Je,

Yz

...,,It

◄

7,000

ohms

IO'l'et

Vi

watt

1.0 ohms

6.0

oh.m Rhea.stat

)000

ohms >% )

-.·aic

',OfNSERS

001

mf

300

WV

Trimmer, Part

of

Cl

H2.)

mmf

Variable

T,imme-r,

Puc

of

C:S

S«ond

Soction

of

C3

0.01

ml

;oo

wv

100 mm/ S00

WV

IC0 mmf

)00

WV

Trim.mer, Part

o(

Cao

3rd Section

of

CJ

lll0

mmf

1%

)00

WV

0 I

mf

lOO

WV

90 mmf l'?o

)00

WV

.IS

mmf

2%

)00

WV

100

mm/

S00

WV

100

mm/

300

WV

ll0

mmf 2')(,

14

T,p,No.

Marconj 9.11-104

J

R.C.

sw,

.

y,

I.RC

.

BW-½

Marconi

9.11-22

◄

Muron1

9)1-223

Marconi

9ll•I04

Marconi

9ll-47l

IR

.C

.

BW-½

Marconi 9.11-47;

).·

brconi

931-104

M.arconi

9)192

Marconi

9)

1-223

Marconi 9.11-103

Matconi 9.11-10)

I.R.C. BT-•!,

Marconi 931-224

Marconi

9Sl9l

I.R.C.

aw.y,

Marconi 931•

10)

Muconi

9.11-22)

Ma.rconi

9H

Cji? 931-471

Marconi 931-103

Marconi

9.11·

◄73

Marconi 931-

473

Mareoni

9.11•

◄

73

Mmland 107-2)2

Marconi 91084

Marconi

MA

Marconi 914-103

Mutoni

9Sl90

.Mattoni 914-10}

Ma«oni

91

◄

·101

Marcooi

91

◄

·101

At:rovox

14~

Muconi 109•016M

Aerovox

1

◄

69

At:tO\OIC

1469

M.arconi 914,101

Marconi

91

◄ ·101

At:rO'IOX

1469

I;

, i

PARTS

LIST

Ci,,11l1

S1,dol

$Judfua1i

o11

Ct8

7 I

mm/

1%

Cl9

;s

mm/

2%

100

WV

00

90

mm/

2%

)00

WV

01

.L

m(

200

WV

C2l

l000

mm/

100

WV

C2J

ICO

mm(

100

WV

C24 0.01

ml

300

WV

(2)

0.02

ml

400

WV

C26

12

ml

ISO

WV

C27 O2

ml

400

WV

C28

}20

mmf

Variahlt

C29 1000

mm!

100

WV

Oo

1000

mmf

)00

WV

CH

2>

mmf

Vari.able-

CH

LOO

mmf

)00

WV

CH

1000

mmf

SOO

WV

CH

L

◄

O

mm/

Vati.1ble-

C})

L

◄

O

mmf

Vari,blt

C36 140

mmf

Va,iablc-

C

,n

,)

mf 600

WV,

Du.al,

One

Sttrion

}

OB

.I

ml

600

WV.

0th«

S«1ion ol

Cl7

CJ9 0.01

ml

lOO

WV

C40 0.01 mf 300

WV

TRANSFORMERS

Tt Rt<.

At1tC'M:a

TtanJorme,

Tl

Rec-.

Occ«ror Tu.ruformtr

TJ

R«.

Oscillator

Transformer

T

◄

l$t l.F. Transformer

TS

B.F.0.

Transform.tr

T6

2nd

1.F.

Transformer

T8

Tran$mitttr Modulatfoc'I Transformer

T9

Tran1mittcr

Cou.plin_g

Transformer

TIO Transmitter Microphone Tn1uformt.t

INDUCTANCES

LI

l2

Trumniut.r

Loa.d

ing

Jndu<tancc-

R

.f.

Choice

1.;

u

RF

.. Chokc·

Platt.

Ceil

L)

Filamcm

Chok~

SWITCHES

SI

S'1,•itch

-1

Pole 2

Posi1ion

S2

Pari

of

I.,I

SJ

Switch } Pole }

Posit

i

on

54

Switch }

Pole

3

Position

S>

Swnch Tosi:lc D.P.D.T.

VACUUM

TUBES

VI

Tube

V2

Tub~

VJ

Tube

I~

T,p,

No.

AttO\

'OX

1

◄

69

J\trovox, l.f69

Atrovox

1469

Marconi

109-O16M

M.1rconj 914-102

Marcont

914•101

M•rco,,i 914 IOJ

Mu(O(li 911.203

M.rcoc,,

109·0188

M.arconi

911-20

◄

Hamm.tlond

MClll•M

Marconi

91 ◄ ·10?

Marroni

9J4.102

Marconi

109·09)0

Marconi

914--101

Mar

coni 914•102 .

Muconi

109·09.lE

Mar

coni

109-09}1:

Marconi

l09-093E

Man:oni

109-0t7C

Marcon,

914•10)

Mu(oni

914-103

Marconi

9)216

Marconi

9)200

Marconi

9)19l

,Marron!

9)178

Marconi

95211

Mar

coni

9l18l

Muconi 89419

~Car

coni 89418

Muconi 89460

Muconi

90666

M.at

roni

ll0

•097F

:b.br«,ni

ll0•097F

Marconi

90681

M.arCOtli

9)207

Marconi

9)191

•

.Ma.rc-

oni

910~)

Muconi 91053

Muconi 109·0l2B

RVC

IPIGT/G

RVC

IMGT/G

l\VC

IPIGT/G

PARTS

-I.

I S T

':i,r11i1

;.,,,,bol

Sp1ttfor111in

V4

Tube

Vl Tub<

V6

Tub<

V7

Tub<

VS

Tube

V9

Tub<

VIO

Tube

T1ptNo.

RVC

IG4GT/G

RVC

tHSGT/G

RVC

IQIGT/G

RVC

IJW

RVC

tH4G

RVC

IJ6G

RVC

lflG

MISCELLANEOUS

Mtlcr Assembly Marconi 90910

Rel.tr

3)

Ohm

Coil.

Code

#

◄

Conucu C.

P.

Clue

Type

C

Mt

El

CC-I

CC-2

J•I

Audio C,ble

CM<>mor

Sock« Amphenol

PC

◄

F

Powe,

Cable

Connector

Plug M/1/fC.,.NI

♦

ephMol

P€

0.

Ct,3.2.~

1¢•$

Key

Jack

Marconi

12)-108

Microphon,c

,

HHd..Kr

.Aucmbly

Marconi

91184

Ker. Moue Sigrul

T1~

R-48

Crystal

Sockrts

Marconi

a,1.oUD

•Valve

Sock:et.i

Ma«-oni 109·061A

Tube Shield ··eo.c

#G-122

2K

Shitld Ring ··c;o.1•

#G·691D

Sh

ield Ground Clip

'"Goof"

#G-1004

Grid

Clips

Marcon.i

l09•D78A

Li.tht

Duty

Battery

Cable

Marconi

11

t-277

C,bl•

for B•1terr Box (When Usod) Mucoctl 90906

Koy

C,ble Anembly M,rcom 909H

C Battery

C.

N. C,rbonTypc 771

·Heavy Duty P,ck Batt•rr (When Usod) General 120D8L2

S,,1tery Box Ass,mbly (Wh<n Used) Muc:ooi 88476

THE

FOLLOWING ITEMS ARE USED

WITH

PNIA

EQU

IPMENTS

ONLY

S6

Swit<h

Marconi

99829

n Transfonncr

Marconi

89:S28

Hatnesl Muconi

90:S91

Antenn.a

Aucmbly

Mmoni

9938)

~ight Duty'Padt

Battiery

Gmc-ral

t20A412

THE

FOLLOWI

NG

ITEMS

ARE

USED

WITH

PN18

"EQUIPMENTS

ONLY

S6

Switeh Toggle .DPST Marconi 109-0J2A

S7

Switch Toggle

DPDT

Marconi · 109-032B

T7

Trans:formtt

Marconi

116-7

◄

,

Spkr.

Speak«

Oxford

3-CM

-S

S · k

Co

I

lTIP

J,ck

I.CA

. #889-B

;,ea

er

nniec

au

Pl

ug.

Solderltss

IC

.A.

#88)

-B

Oautry

Gable

Asst-mbly

Muconi 110.

H4

"'A"

Batter)·

(2

recfd)

£,..ie,tadr

#6

Orycie

ll

..

B..

a,uery

(4

mfd)

"madr

#386

L

16

--

~

•

.,

·,

·,(

.

i:

,'l-/

/:I

/l'S'i7/c,

V•I

·,

.'

~

C-.JJ

-

.,,·

r

I,

I

c

'i;•

11:7_cylc.

"11

'

C·/4

.A.

·c·

"

o"

-,,

;-

·

7"

,(

•2

2.

·I

:,·

!P5i,T/G

V-3

M-1 .

DNONl'V

l'l~fllRJIY.

.

~flf/0

R)

,,,.,,.,,

..

.,·

-,,.

l9~T/G

V·4

.,

..

i;'

/

7

·f

.J.

·,·

4.iV~,

q·

·p:

DIAGRAM

OF

CONNECTIONS

PN

IB

TRANSMITTER

RECEIVER

TYPE 118-9·80

··

c

·o·

!

H5'iT/G

VS

s;-

0,4·

ii'

IG.5<jT/G

V·6

..

,..

R·l1<R-U

0

.

,,,_,,._u

.

/

/J

,<LCLI//Dl

tlYTUMLtJI//TL

,F~LOL/Ol"C7'

-4-SS

KC

.

r;IJ..., L>L.Norz:s

CHAS.SIS.

.

(J/,.~rO-ll

,(LS/.f7l}.,Z

&

CONP£N.5c,(

LIST

.5£E

.!JJ.lf!'

/4/

·Zol.-L

(-4-}

c,

NHOTZ:S

P,5(ML"94IUT7

Tl/ME

O. · .

WI~£

U§ft(D

,<;LL

lv

fff

:

JZ!L

,-

;U7

FL£){

, ,

VNLLf

S d7"KL,JI.WQ£

f~

·15

--

-L!LVE

..

c·-~'°'\lE

-

·o· -

LIL//CK

- ·

"

£.

"

-q,ULI-/

-

-,-

-

e.\.l\C\(•

e.Q.o'Nt\ -

..

(i

..

-~D-0~1'\N~'-

-

-w

•

-Bl.x-

4ft.U

.H -

•J

• -

AU-9.t.At:K

-

-,c

• - CJ.J\N.·

e.R

ov,J

t,\-

..

L.:.

-

~\.Ul·C,.R.t.E

tt

-

..

M

..

-

UQ..U

.N

-RE

O-

•w.

. .

"

o·-;yg

/4-.iR.QE

TI/YNGCt/.

W//f.£

CR'EEN

..

"llla

·

V.S

•p·

·h

! :li1

••

..

.,

.•

.,

-a

·· -

f\f..C)-

l?,.~o""4"4.-

-

R-

-

B\.\Je.

-Rt:.

D

SP><R.

.

ntLAd

·II

EAPSL:T

.-

/

✓

/-.5/A

CA4L£

A-"l'X.,.///·Z??

I

;'.KK

14',1!7

£U.

L_

-

:.CCAA.

VICW4/~f

~o~

BbTTOM

V/£W

OF

,'/LL

Vt9LVc

SOCJ<£r.s

~~~

~

tltJ771JM

V/£.lr'

tJr

;f.CC

CO/LS

,·

__j _

····

·

....

.. · -

··

..

.

-·-

··

-·

·-

···

-··--

---·

---

- -

ADDENDUM

#I

TO

FOLDER

#131-666

JNSTALUNG

AND

OPERATING

INSTRUCTIONS

FOR

MARCONI

TRANSMITTER-RECEIVERS

TYPES

PNIA

and

PNIB

The

following modifications have been incorporated in the late,t

productions of the PNIA -PNIB Transmitter-Receivers.

This

has bccn

done to further improve the stability and performance or these equip-

ments.

The

changes

jn

question have bctn

m.3de

in

the receiver

sc<"lion,

.and

will

appear in all equipments manufact~rcd after Septemb<r 21,

1949.

The

modifications arc as

follows:-

·

I. Condenser C

12

becomes 0.05 ml + - 20% 400 W. V., Marconi

#911-503.

2. A connectin~ link has been added between Pin

#6

on V5,

a.nd

Pin :j:5 on T4. This link

is

used

as

a regeneration adjustment,

being bentslightly to increase

or

decrease sensitivity.

3. Transformcn

T4

and

T6

have each been replaced by

Ma

rconi

Type #

134-952

connected

as

shown below.

,..,

al

fJI

'Wt

f(t

M.

COM«-

f0

1M

•J

0,

f•

IT

sM

~

<-'-"'•C-.-,...

..... ..

...

a.-

..

aa........,._

.t.DDF.I

•

'Dmr

#'2

TO

FOIDER

#131-666

Il!STALLil!G

MID

OPERATH/G

IHSTRiJCTIONS

FOR

l!ARCONI

TR.~JSlil'ITER-RECEIVERS

TYPES

PNlA

AJID

PNlB.

The

follouing

shO'~ld

be

noted

,·men

ordering

sp;.re

or

re?lace:nent

components

for

PNlA

and

PNlB

eqaipr.ients-:

In

equipnents

manufactured

prior

to

Sept

.

21

, 1949,

in

•.1!'.ic:1

the

transfcrner

T4

is

;1arconi

type

95

178,

and

the

transformer

T6

is

llarconi

type

95183,

the

condensers

Cl3

and

C20

aro

9Crn.'llf

+~

,

50CNN

,

Aero-

vox

type

1469

,

Cl4

and

Cl9

are

35mn.f

+21'

,

500.'N

,

Aerovox

type

1469

, C25

is

o.

re

nf,

+4oowv

,

Harc,mi

type

#911-203,

and

the

regenerati

ve

coupling

link

referred

to

in

!iodification

#2

of

Addendum

4f,1

to

these

Instructions

is

not

used

,

In

equipnents

i;,.anufacturod

after

Sept.21,

1949

,

in

\·;hich

transforuers

T4

and

T6

are

liarconi

type

·

lx;-S.~2,

as

described

in

llodification

#3

of

Addei-

,-

du:n

#1

,

the

condensers

Cl3

,

Cl4

,

Cl9

and: C20

are

all

120

c.uf

±51,,

5'XT.N,

liarconi

type

914-121

, C25

is

'

el.iminated

, a.'ld

the

regenerative

lir,k

is

added

.

When

spare

nr

replacement

parts

are

being

ordel'-

e1

for

the

condenser

Cl2,

llarccr.i

type

#9ll-50;5

,

re

f

erred

t'>

in

~odificaticn

,f.l

of

Addendtn

,f/,l

r.ia.y

be

specified

and

used

in'

all

PNL~

and

PNlB

equir>-

aer.ts,

1lar~rni

typP. 1Cl,L016.!

is

suitable

as

a ·

rcpl

..

~er.:ent

for

Cl2

c-nly

in

tho:;')

equip:ients

nanu-

factured

prior

t'>

Se;,t

.

21,

1949

,

hm:ever

.

Apr.

18

,

1950

,

Marconi PN1A Wiring diagram

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