Regency MCA-611 User manual

R
SERUIGE MAilUAL
01{ GALI ATERT RECEIVER
M(IDET M0A.6II
*g{a G0ilMut{lcATl0l'ls lJlc.
1227 S.PATRICK DRIVE
SATELLITE BEACH FLA

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TABLE OF CONTENTS
SESTION 1 GENERAL INFORMATION
1-l Description
L-2 Specifications
1-3 Egui-pment Supplied
1-4 Equiprnent Not Supplied With Unit (Accessories)
1-5 fnstal.lation
1-6 operation
L-7 Crystal Specifications
SEqTION 2 CIRCUIT DESCRIPTION
2-L Crysta1 Select Circuit
2-2 RF Front End
2-3 OscilLator/Multiplier
2-4 r.F..
2-5 auaio
2-6 two-Tone Sequential Decoder
2-7 Larp logic and Igniter Drives
2-8 Decoder Reset
SECTION 3 ALIGNMENT PROCEDT'RE
3-l Final Test Procedure - TP-L4-254
3-2 Test Procedure - Two-Tone Seguential Decoder - TP-14-2I9
3-3 Schenratic
3-4 Top View
3-5 Bottom View
SECTION 4 PARTS LIST
v-
3r-

l
TABLE OF CONTENTS
SECTION 1 GENERAL INFORMATION
1-1 Description
L-2 Specifications
1-3 Equipment Supplied
L-4 Equipment Not Supplied With Unit (Accessories)
1-5 fnstallation
1-6 Operation
L-7 Crystal Specifications
SECTION 2 CIRCUIT DESCRIPTION
2-L Crystal Select Circuit
2-2 RE Front End
,. 2-3 Oscillator/Multiplier
2-4 r.F.
2-5 audio
2-6 Two-Tone Sequential Decoder
2-7 Lanp Iogic and Igrniter Drives
2-8 Decoder Reset
SECTION 3 ALIGNI{ENT PROCEDURE
3-1 Final Test Procedure - TP-L4-254
3-2 Test Procedure - Trro-Tone Sequential Decoder - Tp-14-2I9
3-3 Schernatic
3-4 Top Vi-ew
3-5 Bottom View
+L. '- _,
SECTION 4 PARTS LTST

SECTION 1 GENERAL INFORI'IATION
1-1 DEScRIPTIoN ^ "'
The MCA 6L1 is a two channel crlstal:controlled Fll Receiver. The channel
frequencies Day be selected frcm any of three public service comuni.cations bands;
Iow VHF band (30-50) ltltz, Iligh \rEF band (146-174) MHz and UEF band (450-512) MHz.
fhe bands are juuper pin selectable and the tro charurels need not be in !fus srqe
band.
. the prinary use of this receiver is as + tone alert device; it can also be used
to nonitor uncoded traffic on your alert'channel at the use!'s discretion. In the
alert rcde the recej.ver is held in the squelched condition until its special coded
signal is received.,
there ire trro di.fferent tno-tone codes that will activate each recei.ver. ?he
codes are nade up of three tones A, B and C. The first tone called A for eonvenience
nust be the lead tone of the tno-tone sequence, the second tone can, be eitber B or
C but not both. This will allow all radios to have a comon code as well as an
individual code. (A,B) can be a cosron code and individual call codes can be (A, c),
(A,D) r (A,E) ' (A'F), etc.
The nunber of possiSle conbinattons of codes can be greatly increased by the
installation of an uA 301 option. Thi.s essentj.aLly doubles the nrnber of tones that
can be received and allows for trrc first tones, or A tones which can be either the
sane or d,ifferent depending on the owner's requireaents.
the MCA 611 utilizes silicon transistors for reliability as well as ten integrrated
circuits. the tone decoder is a digital device unlike older modelg that used reeds.
In add.ition, both a c::ystal first I.!'. filter and a ceramic second I.F. filter are
eryloyed. This provides superi.or perfotmance in areas where there argmany closely-
spaced channels.
In addition, this radio featrrres both carrier controlled reset and timer con-
trolLed reset. Either one or the other nay be used to reset the digital filter and
retur:1 the radj.o to a squelched condition. The timer rcilI run fron 3O sec to 3
mi-nutes and the other systen resets and sguelches the radio when the carrier stops.
In order f,or the carrier reset to work, the radio nust be squelched
An exteraal sPeaker iack a.nd connectors for an AC or DC igniter have also been
included on the back panel. The user has the option of ej.ther a pulsed or r:npulsed
igniter (jursper pin selectable).
L-2 sPEcrFrcATroNs
See page 2
L-3 EOUIPMENT SUPPLIED
a. Receiver Unit
b. DC Power Cord
e. TeJ.escopi.c Antenna
d. Carrying Handle
e. Or*nersr Instruction Manual
f. Warranty Card
g. AC Power Cord
1-4 EaUTPMENT NoT sUPPLIED wrrH
h. Antenna clip
i. !{obile l,tor:nting Bracket
a. Antenna Splitter - MA-5
b. Battery - MA-181
ci DC Igniter - WA-24
d. Remote Speaker - MA-108
tlcA 611 -1-
UNIT (RccEssoRIES)
SECTION 1

I-2 sPEcTFIcATIoNS
GEIiTER;AL
Channels. ... 2
operating temperature.... ....q.. -3OoC to 60oC
Operating duty cycle.... ... I hr 10* alcrt
Size. .. 6 L/z"W x lO 3/4nL x 2 5/8"8
16.5 x 27.3 x 5.7 cn
Weight. 3.12 Lb/L.42 kg
Voltage Beq.. .... 117 vac, 12-17' \rDC.
8att. 10.8 vDC
current drain. ... @ 13.8 vDc
Seceiver squelgh. 55bA
Receiver nax audio .... 145nA
Antema. ... . 50 ohn
RECEI\'ER
sensitiviry... ... 2odB. QgrETn$G/ldB s$IAn
Lr 30- 39 !4Hz-. .. .. .. .5 / .4
LH 39- 50 MEa.. ...... .5 /.4
rrr 146-160 !tHz. . - ,5 /.q
rrH 160-170 lrEz .5 /.4
Ur" 450-470 MEz. .55 /.qS
uH 475-500 MHz. . .55 /.45
Audio sq. sensitivity -
Ehreshold . .3 Uv I'EF
light. .34Uv trtP \
Adjacent channel
Low Vtll' 30- 50 MEz-- ..... 60
High VIIF 145-170 !{82.. ..... 65
uIrF 450-500 MEz.. ..... 45
Spr:rious rejection (except primary inage) . sOdB
Inte:anodulation attenuation... .. 2mB QUfETXNG,/12dB SINAD
/43
/65
/5e
/4s
/ss
/46
MAB.. .. 8.5 KHz
Freq stab teup. .0006t \fHF
Freq stab volt. .001t VIIF
Audj.o response .. EIA +2/-e 6dBloctave de-emphasis
Audio out power (nax). .5!{
Squelch blockj.ng. Meets EIA specs
Receiver attack time. . I50ns (nax)
Receiver sq. closi-ng.... ... 250ns (nax)
Hum & noise ratio 3gdB unsqrrelched, 50 squelched
Undesired condutted (AC) . .. -85d8 n (max)
Undesired conducted (RF) . .. _94d8 rn (rnax)
Undesired radiated. ... FCC
Icw VIIF 3C- 50 !!H2.. . .... 55
rligh vHF 146-170 wtz,.. ..... 55
UIIF 450-500 !tHz.. ..... 45
I
I
1
:d
SECTION I ,J
31
it
MCA 611 -2-

DECODER
Frequency range. :"" ' ?ll"ll";i3i 5,""tabre)
Audj.o input irnpedance ..... . gneater than LOK ohn
6dB baadrddth..
Inputs -
A0 audio i.nput. ...._..... .2 - lvlus
D12 RST i-agut (!,tCA-611 onlyl .. 9V nax.
K5 lticrophone hang-uB.. .. r. . . O\, (enable) open (reset)
Outputs--
DO MSG:,:laq) driver (!{ICAO{O}i 2-rray only) 30na sink
D1t MSc latch Q output (1.!CA-6L1 only) ... l3ua source
K7 sq- conteol (MrcRo{oM 2-r.qy ody) .. l5oa sorgce
Sensitivity (decoder ryjth ar:dio)... ..l2dB sinad, IOO* detecr
6dB sinad 75t detect I'
l'lcA 611 -3- SECTION 1

1-5 TNsTALLATToN
Mobile 12 VDC Installation:
The !{C,A 611 is designed for nobile lnstallation in any vehicle that has
a 12 VDC negrative grround systeo. The red lead sith the fuseholder mrst be
corurected to the positi.ve tsm,inal side of the battery. In tlre event that
the battaij, is renoteLy located, it nay be necegsa:ryr to install additional
wires or Bick up +v froa sone other locatlon in the vehicle's electrical
systeq. Grorrnd Eay be picked uB from the optional rcunting hardnare but a
hard wj-red ground to the phj.llips head screr on the back of tlre chassis ls
preferred.
Renove ttre aatenna by rotating it counter clockrrise. Install an !{A-5
antenna splitter so tlre r\CA 611 can share the velr:icLe|s built-in antenna
with the existi.ng radio. Mormt the bracket MA-63 to any convenient location
and screw ttre radio into position with the two lsrurled. knobs-
Batterv Xnstallation:
Reuone ttre antenna bl' rotating it corrnter cloclnriser remove the tro
knurled knobs and puIL tlre case of,f. Place tlre coanector end of the
battery (MA-191) gently betrrreen the spring retainers and slide it fonsard
r:ntiJ. it trakes good contact. Then attach tbe battery retaining bracket cn
the back of the battery and "snug" it forrrard untIl the battery is held
firmly; tighten tlre bracket screw.
C:rzstal Installation:
The follorring Regency Part Nurnber c*ystals are used:
Low VIIF: 3C]-542
High v-HF: 3OL-532
UHF: 301-603
Crysta1 socket )€01 (XIL socket frrrthest from speaker) corresponds to the
"no:laalu position of the front panel frequency select switch. X20Lrs
band select pin is on the anode of CR209. The band is selected by putting
the other end of the jwper pin on one of, the following Bins, depending on
the required frequency.
LL 30- 39!{Hz
LE 39- 50MHz
t{L 146-160!4IIz
HII 160-170MEz
UL 450-470trtHz
UII 475-50OMIIz
X2O2' s jr:mper pin is corurected to the anode of CR21O and cotesponds to
the "alternate" frequency"
After the crystals are installed, it will be necess;rrlt to tqne it up
i.n accordance with the instructions in the service manual.
Ignj-ter Installation :
fvo igniter drivers are provided on the rnain board; a pulsed drive and
an r:npulsed drive. {he later is already wired to the bottom lug of t}re
three tqminal corurector on the back panel of the radi.o. This nakes the
radio immedj.ately compatible rrith the l,lA-24 Igniter Option.
MCA 611 -4- SESIION 1

rf you require an oN-ogF feature for your igmiter, sinply remove A "'"
the fcrale junper connector frmr Q213 and put it on the collector pin
of Q212.
1-6 oPERATToN
Vo1une Control:
Itris control varies the audio output level for the internal speaker.
It also varj.es the level of audio present at the external spealcer corutection.
!{oving the control up iacreases the Volrse level.
Squelch Co:rtrol:
The squelch only works when the radj.o is in the nonj.tor npde. It'
elimiaates backgror:nd noise in the absence of a signal.. Ful1 squelch is al;.
the way down.
AJ.ert Monitor Switch:
In the alert node oaly the proBerly coded sj.gnal can open the squelch.
In the nonitolc oode any traffis, on tlre selected frequency can be monitored.
Frequencv Srritch:
this selects either Fl or F2.
Dutv Switch:
Used only with an MA-3O1 option, othe::vise it is left in the 'rlibtmal"
position. fhis switch'rpuld al1ow an appropriately equipped radio to decode
either AB and AC or ZE and ZF. (An interna.l. corurection will allow the radio
to decode A8, AC @ O, ZF regardless of the duty sritch position.
Alert and Ex. Pwr. Liqht:
Steady light indicates AC Poner ON.
No light indicates radio is on battery.
Slon Elashing - Iow battery.
Fast FLashing - a sj.gmal has been received.
Rear Panel:
For convenience of srcbiLe operation, we have included t'.ro +V connectors
on the back of the radioi one for the vehj.clers battery and one to power the
igniter option MA-24. Ttre bottom connector is for the igniter drive. In
addition' tlrere is an external speaker jack wtrich allows for a remotely
located Epeaker, MA-108, as well as an external antenna jack to go with the
MA-5 y coupler antenna.
L-7 cRYSTAL sPEcr FIcATToNS
Due to the nurnerous freguencies or eh€rnnels j.:rvolved, the crystaLs are
\- not nor3a11y installed by tlle factory, but by the seller or oqrner of the
unit. the Regency part ntrmbers are listed, in Section 1-5. When ordering
from another nanufacturer, the foIlow'ing info::mation shquld be provid,ed:
MCA 5ll -5- SECTTON 1

I" Crystal frequency, detsmiled as follows:
tow Eand:, Cryrstal freguency = chanurel frequenc"y +10.7 t'lgz
Haqr1e:
Crystal frequency=39.5 MHz = 50.2 ltHz - 10.7 MEz
Iligh Barrd: C:ryrstal. frequency = channel fregugPcy -10.7 l'tgz
3
. E:ranple:
Crystal freqt:enc$=155.55 !{Hz -10.7 MEz = 144.85 Mffz=
33
48.2833 ffiz
UHF Band; CtYStal frequency = channel frequ?ncy -lO.7MIIz
9
Exauple:
Crysta1 frequency - 458.'0 MIIz -10.7 l'lHz =_333:lgJS=
49.70000 f,tEz
2. Frequency tolerance of O.00Lt on lligh Band and UIIF Eand, 0.0O2t.on Low Band.
3. UIIF Band - 3rd overtone, load capacity of 18pf; drive level of 2 nillj.qratts.
4. vEl' Bands - 3rd overeone, series resonance minus 450 Hz.
5. Ma:(i.uum i.mpedance of 35 ohms.
6. Ilolder is an He-25N wittr pin leads (plug-in qpe).
MCA 611 -6- SECTION I

SECTION 2 CIRCUIT DESCRIPTION
\_ 2-I cRYSTAL sELEcr ctRcurr
The tliro crystals X201 and X2O2 are selected by jr:npering pins on the anodes
of CR209 and CR210 to the appropriate pln correslnndjng to the frequency divisions
on the device s5ncification page. When a band is selected, bias is applied to the
appropriate front end by causiig the associated d.iodes to conduct througb the
frequency selector switch Sw40l to grrourd
When the ttH Pj.lr is selected, ground is aBplied to R229 and R224 tlrus biasins
the UEF 'qR and mjxer, In all cases exxcept the LE select case, tlre lov band varactors
are held close to gror^ulal by CR223, 222 and 221. when ttre ItL Pin is selected the
tt:rting va:r actors CR205 and CR206 have a varia.ble bias through R243.
By seleeting any other band the AFC rhich is only needed for the IIHF is d,isabled
by diodes CR215 and Cr€18.
Selecting EB atrtplies gror:nd to the EJ.gh \EF RF "'F Q203 and mixer e204 bias
resistors. Varactors CF€03 and CR204 are at +8 volts. Selecting IIL grounds R25O
providlng variable bias to those di.odes, (CR2O3 and CR204).
Selecting LE grorrnds R203 and, R2I6 and puts 8 volts on the cathodes of CR2OI
and CR202. Selecting I& grounds CR2OI and CR202.
2-Z RF FRoNT END
Q201 is the l.ow Band \rHF a4rlifier. varactor tuni-ng is used in the input and
output circuits to detenine wtretlrer the circuits are tuned to the upper or lower
segnent of the low band. The RF signal fron Q201 is coupled to the input of the
low band mixer Q2O2.
Q203 is the lligh Band r/EF RF anplifier. lhe input circuit is dor.rble-tuned.
varactor tuning is used to tr:ne both parts of the double-tuned ci-rer.lits to d,etsmrine
whether the cireuits are hrned to the upper or lower segments of ttre high band.
The RF output signal f,ron 9203 is coupled to the jnput of the high band mixer e2O4.
Q205 is the \i'flF RF anpU.f,ier. varactor tuning is used in the input and output to
detemine vthether the circuits are fi:ned to the upper or Lower segi*ents of the
UHF band.
2-3 osc r LI-AToR/MULT r pLr ER
Q2O8 is the crystal controlled local oscillator. ttre fundanental frequency of
the crystal is taken fror the enitter cj.rcuit for low band VHF injection. The
thiril hanmonic of the crystal frequency is taken fron the collector circuit for high
band injection. When operating on UHF, the third hamonic of ttre c?ystal freguency
at the collector of Q208 is coupled to a frequency t:ipJ.et Q2O7 which nultiplies the
\v frequency by three for UIIF injection. Q2O7 !s tr:rned on only for UIIF operation.
Ihe fundasrental freguency of ttre crystal is nultiplied by nine for UHF injection.
MCA 611 -1- SECTION 2

2-4 LF.
lhe first f.F. frequency 10.7 MEz, fro any one of the nixers, is fed tlrrough u-
F20L (a nonoU.thic crystaI f,ilter) to the ingqt of IC2OI (Pin 18). Bettreen Pins
18 and 3 is the second I.F. nixer circuit. Crystal X203 is used to generate the
second L.'O. frequency (10.245 MHz) used to nix with the 10.7 !4Ez I.F. to produce
the second I.F. frequency 455 fcuz. The 455 KEz signal at Pin 3 of IC2O1 is fed
througb CF201, a nartron band ceranic filter centered at 455 KHz, to Pifi 5 of IC201.
Bebreen Pins 5 and 10 of IC201, there are auplif,iers, U.miters and a qr:adratrrre
detector cj-rcrrit. Ihe adjustable quadrature coil is counected between Fins 8 and 4
of IC201.
Z-5 AUD r o
Ttre denodu.lated audio fro pin 10 is de-euphasized by R262 and C255 and
capacitively coupled through the squelch sritch Q2O9 to the arrdio anplifier 7C2O2.
The squelch amp and squelch switch are inside IC201. A logical low on Pi$ 14 (audio
being recej.ved) sets Pin 16 Higb tneirely providing bias to Q2O9 and, allowing ar:d,io
to pass into IC202. A Higb on Pin 14 of, fC201 (noise) produces a low on Pin 16, IC2O1,
grounding the bias ctrrrent on Q209 and squelching the audj.o. The noise level at which
the squelch switch engages is controlled by R403, the squeleh control.
2-5 TWo-ToNE sEoUENTIAL DEcoDER
Audio enters at AO and is lj.nited by CR3OI and, CR302. Ttre arrdj.o is tlpn
filtered by a high-Q d,iqital filter and the aaplified outirut appears at Pin 1 of IC304.
The voltage has to be 4 rmp in order to trigger the detector in IC3O3. The audio is
fr:rther auftlified by IC304 and the output PiJr 7, IC304 is fed to the ha:monic detector
of IC303 (Pin 5). the ha:monic detector wi].l stop the decoder from detecting any
ha:monics of tlre tone to be decoded
When the correct tone is present, the detector output, after being delayed, fires
a one-shot. The one shot ti.ne constant is set by R316, R317 and C313 and can be varied
by R317 to fit the user's particular inter-tone tj"uing.
The digital f,ilter itself is an 8-5n1e filter. ltre filtered output frequency is
deternined from the clock freguency. The relationship is f"1o.L,/8 = fftlter.
fhe clocks are gated from either Pin 1 of, IC301 or IC302, dependi:rg on whetlrer
j.t is the first or second tone to be decoded. The clock is selected by the oscillator
switch output of fC303.
Tone A (tbe first to be decoded) is selected by the adjustnent of R3O1. Si-urilarly
Tones B and c are set by grounding manually Pirl 7, I.C3O2 rria JO3O1 and settj.ng the
second tone and then ungrror:nding it to set the thid using the trirmj.ng potentiometers
R320 and R318, respectively.
!*ten Tone A is received, the one-shot is fired, oscillator switch 1 is grounded
and oscillator switch 2 goes high (.5v). IC302 is now the clock source and rC301 is
used to alternate between ttre two cLocks for Tones B and C, by alterrrately grounding
and ungrounding Pin 7 of fC302 gating first the clocks for Tone B and the Tone C
into IC303. ltre period of oscillation on Pin 7 of fC302 is 200ns.
MCA 611 aSECTION 2

When the second tone has been received (Tone B or lone C) before the one-strot
has tj-ned out, the latch is set and, Dll i.s gror:nded,. lhis ciuses Pin 14 of IC2OL
to go low turaing off that the squelch switch, which t'r:rns on Q209 ttrus unsquefcfiing
the radi.o.
2-7 LAmP LoGIc AND rGNrrER DRlvEs
!{hea a signal is decoded and Pin Dll goes 1or, it sets the latch Pin 6, IC2O6C
trIotlrlf, Pin 4..I.C2OAB "Iligh", thereby tuza.ing on both ttre high rate'rALgRTo flasher
consisting of IC205D and IC206tr and the two igniter drives. lfie user nay select, via
a juaper pin' which drLve he requires eittrer pulsed or unpulsed. Ehe loqr on Pin 6,
IC2O6C disables both the;A€ on logic consisting of IC2O4A and ttre low battery i-ndicator
consisting of IC204B.
CI2O5F and IC2O5C are the slow light logic circuits for the low battery iJrdlcator..
A11 of the logic eLeneots activate the LED on the front panel by fo:*rard biasing Q2l1
i:rto conduction.
2-8 DEcoDER RESET
Resetting the decoder is accougrlished by driving Pin 13 of IC303 to less ttran lV
for at least 25os. Xhis uay be done in three eraysr the carrier controlled reset, tlre
t:ine out reset and front panel sltiteh Sl{405. The front panel switch j.s t}re only way
to reset botb the signal light and the decoder.
a junper is i.nstalled at the factory fro fiI-Dls to ,IU-D13. Ttrj.s allows the decoder
to reset in the absence of a carrier so tbat. it crn be ready to decode the next nessage.
The flashing ligbt indicating thae the radio has already received a messaEe nf,rst be
reset nanually via Slf405
To nonitor the radio traffj,c for 30 sec to 3 minutes a.fter a :Bessage has been
received, switch the juugter from fi-D15 to JII-D14 and set the RC tiuring net",!ilork R293
for the time you Cesire. when the circuit has timed out, Q214 will stop conducting
making the base of Q304 go high causing it to conduct and tbereby resetting the decoder.
Again the flashing light will renain on rrntil manually reset to let the user know a
message has been received.
!'lCA 6L1 -3- SECTION 2

SECTION 3
ALIGNIiIENT PROCEDURE

A.
FINAT TEST PROCEDUP.E
MCA 611 ON CAI,L AI"ERT RECETVER,
R.F. Alignnent Procedure
r. Test Set-Up
A'. Equipment
1- F.l,t. Signal Generator
2. AC VT\/lt capable of measuring 455 KHz
3. DC Voltmeter
Note: If a radio has two crrirstals in the same banci., a
f::equency:aidway between' them should be used €or the
tune-up procedure so that the RF amp will be broad
tuned. The anode of CR209 mrst be jurnpered to the
spare pin on the anode of CR210 and then jumpered to
the correct band pin (LL, UH, llH, etc. ) . Tf the
radio uses both bands of a given preselector, tune
the.upper range to a niddle frequencr; first, then
switch to the lower range and check the rnid, band
sensitivity there. fn the case of UEF adius{: R243
to achieve rated sensitivity and. for high VIIF' ad.just
R250 to achieve the lower band sensitivity. por the
low VI{F bands tune for the best cornbined sensitivity.
Some compromise in sensitivity rnay be necessarv betrveen
any two bands. f f only one frequencv is bej.nc,r used for
a given preselector then tune up the radio for best
sensitivity on that particular frequency.
nariio Preset
L- Connect DC power suppllr to DC power connection, top nin
of 3-pin connec.tor on the back of the radio. (The DC
'power supply can be substituted by usincr the radio's
own AC su5rply; 117V 60i{2.)
2- Set radio controls as follows:
a. Volume - comfortable listenj.nq level
b. Squelch - upper most slj.de position
c. Alert,/monitor switch - in nonitor position
B.
MATERIAL
APPLICANO}I
g
ln
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. t er co*titu*tcAno*s t'e
{eff,^cy^ slrelLlrE BEAcH, FLoRIDA 3a93?
APPROVALS
UNLESS OT}iENWls€ SP€CIFI€D
orMEilslotrs ARE. ll{ r}icilEs.
TOLERAI{CES AFE
FRAGT. OEC ANG.
! .xxf t
.xxx! FI}IAI ?EST PROCEDURE
I'!CA 511 O}I EALL AIEF.T RECEIVER
lP-14-2s4
DO I.'OT SCALE DRWG.

t
)
i
f
t
d. Duty Switch - in normal position
€. Frequenry slritch.- on frequency to be alicrned ..*,
E. On/Off switch - in ON position
3. Install crystals
a. Put crystal in socket X201 (XTL socket farthest
from speaker), X201 corresponds to "normal', freq.
b. Run band select jrrnrper from anode of cR209 to tire
correct range select pin.
c. X2OZ corresponds to the two
farthest from speaker.
LL 30-39 isz
LF 39-50 YtEz
HL 145-160 tlEz
Quadrature Aligrrment
1. I{ith no signal applied, put the
on Pin 10 of IC201 (A0 Pin) and,
voltage is 3.5 volts.
band select pins
HE 150-170 l{Hz
UL 450-470 !.tHz
ttE 475-500 r,lHz
DC Voltneter's probe
adjust L2L6 until the
f .F. Alignment
1. connect the FM signal Generator to the antenna input
jack. Accurately set the freguency to the center of
the channel bei,ng used. for aligmment. tilodulate the
Signal Generator with 1,000 tlz, 3K KHz deviation.
2. Connect the AC Voltmeter to pin 5 of IC20l (foil side
of board,) .
3. Set AC Voltseter to the 100rnv scale
4. Adjust the signal Generator output until the AC voluneter
reading is mid-range
5' Ad.just L208 for maxinn:m AC voltmeter reading. Re-ad,just
the signal Generator's output to maintain voltmeter
reading near mid-range.
Note: ff the RF segnents refuse to tune up or will not
al1ow fuIl rated sensitivity, check the position of the
band select pin with respect to the frequency of the
crystal and the band select jurnper.
with the frequency select switch sw4cl in the normal
position crystal X201 (farthest frorn speaker) and the
pin cl.osest to speaker are "turned on".
Low VEF Segrment (30-50 ItEz)
1. Connect AC Voltmeter to Pin 5, IC20l.
2. Set AC Voitmeter to the 100 millivolt scale.
3. Make sure band select pins are set up as per Note.
4. set the signal Generator accurately to the frequency of
the channel being used for aliqnment. Connect the
generatorrs output to the antenna input jack. Adjust
signar Generator's output until AC vortmeter reading is
mi.d-range.
5. Adjust L20L and L206 for naxj:num AC voltmeter readino.
Re-adjust signal Generator's output to maintain vortneter
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read,ing near mid-range. Repeat adjustments until no
further improvements can be-made.
High VHF Segrnent (145-170 t!Hz)
l. Connect AC Voltmeter to Pin 5, IC201.
2. Set AC Voltmeter to the t00 nillivolt scaIe.
3. t4ake sure the band select gins are set up as per Note.
4. Set' the Signal Generator accurately to the frecluency
being used for alignnent. Connect generatorrs output
to antenna input jack. Adjust Signal Generator's
. output until AC Volfineter reading is mid-range.
5. Adjust L203 and L205 for maximum AC Voltmeter read5.ng.
Re-adjust Signa.l Generator's output to maintain voltmeter
readS.ng near mid-range.
6. Now adjust L209 and L211 and repeat all adjustments until
no further inprovement can be rnade.
UHF Seguent- (450-500 YHz)
l. Connect AC Voltmeter to Pin 5, IC2OI
2. Set AC VoLtmeter to the 100 millivolt scale.
3. .Make sure the band select pins are set up as per Note.
4. Set the'Signal Generator accurately to the frequency
being used for aligrunent,. Connect generator'f,output
to antenna in5rut jack. Adjust Signal Generator's
output. until AC Vcltmeter readi.ng is mid-ranqe.
5. Adjust C226, C228 and C245 in that order for maximum
AC Voltmeter reading. Re-adjust Siqnal Generator's
output to maj.ntain voltmeter reading near mid-ranqe.
Receat adjustments until no further irnorovemint can be
made.
Note: If sensitiwity is poor (qreater than .7rnv) or if
sensitj,vity varies ntore than 3dB while AFC voltaqe is
varied from 1 to 7 volts, detune L211 two turns CCW.
AFC Aligrunent
1. With the unit on a channel with a UHI' crystal and no
RF input, adjust L2L6 for a voltmeter reading of
approxfunately 3.8 volts at the junction of R253 and
R249. Its setting should be within a turn of the
setting in the quadrature alignment.
B. Carrier Reset Option (See Note on Page 4)
Set alertr/nonitor switch into monitor position.
I.Iitl no RF signal applied, adjust sguelch for desi.red squelching
action.
Return alert/monitor switch back to the alert position.
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1.
2.
3.
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4. Apply enough RF signal to guiet the receiver and sicmal ^. ""
the unit with proper tlto-tone sequence.
5" The squelch should ogen allowing the listener to hear the
remainder of the second toners duration and the message
lamp should flash at a high rate
6. Turn off applied RF signal so that the radio goes into the
sguelched mode. The decoder is now reset and no
signal other than the proper two-tone sequence wil.l open
the squelch
7. The MSG LED should renain fLashinc until, the reset switch
is.moved into the reset position.
C. Time-Out Reset Option
t. Unsolder the factory installed carrier reset junper from Jlt-Dls
and solder it to W-D14 (collector of 9214).
2. Turn up Rr. signal enough to quiet. the receiver,
3. llodulate the Signal Generator with the proper two-tone seguence.
4. The sguelch should open, allowing the receiver to ooerate
normally'for a given perj.od of time. This time period can be
adjusted by varying R293. The llSG LED will be flashing at a
very fast rate and will reqain flashing when the decoder has
been reset.
5, ?he ltSG L.ED can be reset by pushing the reset srritch to the riqbt.
Battery Voltage l{arning AdjusUnent
(for battery equipped models only) \v
1. Place a DC Voltmeter probe on test point ltll and adjust R296
for 4.0 volts. trhe slow flash rate alar:n will trigoer when
the battery voltage reaches ar.rproximately 9.9 volts.
E. Igniter Drive (used with !,IA-24)
1. A junper (factory installed) runs from the bottom solder 1ug
of the three terminal connector on the rear panel to the
eollector of Q2L2.
2. To provide a .pulsed output, simply pull the pin fron e213 and
put j.t on the collector pin of Q2L2.
Acceptable Performance Limits
Sensitivity
Audio power .48yv worst case
. 5 watt
Note: Carrier reset should not be used in areas of low signal
strenqthr BS it will decrease the radio's decode sensitivity
to around 12dB sinad. If thj,s is the case in your area, use
time-out reset.
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RGURE 2
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