Quad FM3 Brochure

Page 1

The purpose of VHF/ FM broadcasting is to provide
reception. within the service area of the transmitter
(normally 50 to 100 miles), free of interference and
capable of reproduction at very high quality. The
OUAD FM3 tuner will completely fulfil this pur-
pose with any transmission which arrives at the
aerial in a condition capable of full quality recovery.

Outside the service area of the transmitter it is
the nature of VHF/FM for signal strength to fall
rapidly and there will be a tendency to fading but
the high sensitivity of the FM3 tuner enables it to
receive such signals with two reservations: (a) no
tuner can improve the signalsnoise ratio of the
signal as it arrives at the aerial and (b) the con-
siderable bandwidth essential for low distortion
reproduction means that a weak station can be
resolved only if it is sufficiently separated (i.e. by
at least 400 kHz) from any other more powerful
signal.

In most areas the local VHF/FM services are

normally receivable at reasonable signal levels.
Between these stations on the tuning scale. among
the background noise. there will usually be distant
stations spilling over from other areas. Because the
FM3 inter-station noise suppression circuit is
adjustable the owner can decide where to set the

suppression level between complete silence
between one strong station and the next. on the

one hand, and no suppression at all so as to rake
in every scrap of signal (and noise) on the other.
Also as the suppression system provides muting
until the station is correctly tuned, not only is back»
ground "hash suppressed but the unpleasant
noises associated with tuning through the side»
bands of the station are also avoided, and with
strong stations it is possible to proceed from one
perfectly tuned programme through silence to the
next perfectly tuned programme,

Operating the FM3 is simple. the only control
on the front of the FM3 tuner being the tuning
knob (which is also used for setting the station
markers) and no others are required. The noise
suppression adjustment is a pre-set control at the
rear of the tuner and all other controls, volume
stereo-mono switching, mono hold, on/off, are
provided by the associated QUAD 33 control unit.

The positions on the scale of any five stations
may be indicated by pre-set markers. These are
positioned by pressing the tuning knob to engage
its pointer with each marker in turn, tuning to the
stations to be marked and releasing the knob. The
markers then stay in position for future reference.

The tuning indicator is the original QUAD twin
lamp system which provides for simple, positive
and highly accurate tuning.

The tuner is self powered.

First developed by QUAD in 1955.

Page 2

QUAD

STEREO
TUNER

CIRCUIT DETAIL The RF and frequency changer stages use protected, dual gate
MOS FET, and the IF stages and decoder section |.C. devices. Tuning is by means of a
three gang capacitor and the stability is such that AFC is unnecessary.

To achieve (and maintain) the desired bandwidth and shape the tuner employs
ceramic filtering.

The audio output is via a 5 pin DlN plug on which pins 3 and 5 carry either mono or
left and right stereo channels respectively, according to the incoming programme. In
addition pin 1 carries a separate mono output, useful if an over-ride facility is required.

Specification

Frequency renue: Eli-103 MHz Dietertien: It i lrllt end :40 ltllz deviation Ill-2%
Sensitivity: "a graph Output: IOOmV per chennel for 30% meduletien

Aeriel input: 75 Q casxrel Seuree rrepedence: 5k!)

300 L2 balanced MIMI-um

loetl impedance: Greater then inkil

Full limiting: lrorn less then ZpV Recommended

I . . 5 Ined cup-city: Less then lliOllpF

In". relectron. W8 De-ernplteeis: 50 u 5:: or 75 Sec 3: required
'F "Wm 3 Pull! input: IlJli-lZS/ZDl'l-ZSOV

50-80 Hz
m Itlir SVA

selectivity: 46:18
Dimensions: Width NH" (280 trim)
Cepture retro: 3118 Height 3|" (91 mrnHree stendinq

tr Irendwidlh: less than -:as all no kHz 3* l" """l W" 'V
greater then-60d! at i 400 ltilz Depth 6}" (165 mm) tree stendinp
5;" (HI) mm) ltehind cehinet penel
Output et 3! It": when mounted (ellew
end elmre: -§Od8 H" (84 mm) beyond

reer panel ler
Frequency response: i MB 20 Hz - 15 kHz gonngctnu)

chennel eeplretien: 40:13 at 1 kill 8 lb. (2-7 Kn)

. QUAD

for the closest approach
to the original sound

ACOUSTICAL MANUFACTURING CO. LTD.,
Huntinudon. England
Telephone Huntingdnn (0480) 2561/2

OUAD is a registered trademark. Manufacturers reserve the right to alter specification without notice.