Palomar Digicom 100 User manual

885 AM TRANSCEIVER
Owners Manual
ELECiRQn iC1,
cOR?ORATiQn
t - Escondido, Calif.92025 - Telephone: [phone]

I. GENERAL
The DIGICOTd 100 is a 23 chamel M:"~/SSB Class D CitizensBand two-way radio. Featuses include:
- Ail soiid state plug-in modular construction forfast,easyservicing.
- Digitally synthesized frequencycontrolforexcellent stability and tracking.
- Unequallied receiver spurious, intermodulation, and cross modulation performance.
- Internal transmitter ALC to automatically adjustvarying microphone input leveb for
optimumpower output on SSB andmaximummodulation percentageon AM.
- True double sideband AM modulation.
- Unique two control channel selection.
- Filli sized, communications-type speaker.
- Noise blanker, preemphasis type.
The
DIGICOM 100 represents themoststateof theartdesign availablefor the Class D CitizensRadio
Service.
It will provide the ultimate capability in CB comunicationswhile conforming all current
FederalC~municationsCommission regulations. .by user attempt to internally adjust or modify
the transmitter of this unit is not only strictly forbidden by Federal law, but will also decrease its
communication effectiveness, All transmitter adjustments must be made by a qualified technician
with a valid second classor higher radiotelephonelicense.

BEFORE OPERATING THIS UNIT YOU MUST:
A. Obtain a Class D license and cail sign &om the FCC, ~r. applicatban (FCC form 50% is
available from any FCC officeor directly from the FCC, Washington, D.C.).
fd. Read Part 85 of the FCC Rules and Regulations, This is available from the Superin-
tendent of Documents,
U.S. GovernmentPrinting Office,Washington,D.C.
Since the DI@ICB&f 103 is radically different in concept and desig~from other transceivers the user
may he familiar with, some tme will be required to fully appreciate i& operational and pedormance
features. It is a very functional unit with a mininsrlurn of frills or .'flashy9'gadgets, ASI design ern-
phasis has been on shp1iciQ of operation arid absnluk ultianaL5 radio performance, This is a very
carefully engineered radio whichrepresen& a significant investranent by its pwchaser. You should be
careful that any aceessovadded does not detract from the potentially excellent pedormnce of the
DHGICOM 100. Should any question arise concerfing the possible harm of any accessory, conhe% the
factory.
A. ANTENNA
In order to realize optirn*mcorramunicaticn performance, a good arnte~~ais essen-
tial. It must be properly rnatckeb to the Zt' OHM output ~mpedanceof the DIGICOPvI.
&I antenna VSWR of less than 2: 9 on all chasriels is abs,-!utely necessary. Consult
your dealer for antenna installation assistance.
8. MOBILE MOUNTING
Two mounting brackets areprovided, front and rear. All brackets should be attached
to the unit with the Y4" x 20 x 3h9' bolts and Y4" spacers provided. The front bracket
should
be firmly at~ached'lo the vehicle as Lle main radio support. The rear bracket
should
be attached in such a way as to provide a rigid, vibration free radio mount.

This rear bracket could attach to either the transmission tunnel or firewall in a
vehicle mounting. Place themicrophone clipprovided in a convenient place that does
not interferewith vehicle operationwhen themicrophone is in place.
6. ZLECTRiCAL CONNECTIONS
Use xmber twelve or larger wire to connect the unit directly tcj the vehicle 12 volt
battery. For positive ground operation, internal modification is required to insure
proper fuse operation, consult your dealer for assistance. Do not attempt the
modification yourself. For normalnegativeground inshilation; comect the lead with
tie fuse to the positive battery terminal, comect the piair; lead to the negative ter-
minal.
111. IGNITION NOISE SUPPREBION
Xadi0 perfermance will be irilproved greatly by effective ignition noise suppression. Recom-
7s are:
xended ste,
A. Be surespark plugs, distributor sap, rotor, and ignition wiring are cban and In first
rate operatingcondition. Replace anyworn or suspect parts.
B.
Instali resistance type spark plugs and ignition wire if not already present in She
vehicle.
C, If alternator whine (a high pitch tone which changes pitch with engine speed1 is
laeard, install an alternator line filter, Consultyour dealer.
D, Instal? a heavy aekalstrap or braid between the vehiclehood and firewall by the h~od
hinges to insure good grounding that will electrically shield the engine compart-p~ent
from the CB Radio antenna.
E. Be surethat the radio is connected directly lo the vehicle battery and that the battery
is in good condition,
fully charged.

TJ. RADIO OPERATION AYE COKTRWA
A. ON/OFF SWITCH -Turnson power to unit. Lights behind the charnel knobs should
comeon. Locaked
at lower right corner of frontpane!.
Ed. TRA&Sh3IT SWITCH - Located on the side of the
The red iight, in the
iower left
hand cor;aer csrnes on :mdicatir,g the transmitter is operatke. Or, charaels
24 though 99 the transmitter 31.111 not, operate and the red light will not come on.
-.
iransmisaion on these charaels is illegal under ?resent Class a3 FCC Regulations.
Never transmit on anychamelwhen anotherstationisusing
that channel.
C. GHAVXEL S%TTCBES - Two large knobs with clear nubered plastic skirts at the
!eft side of the radio, Each knob sets a digit of the deslreci chafizri n&~.tser.For
exampie, channel 13 would be a 1 on theleft knob and a 3 cn the right knob,
Note that charnel 00 is the same operating frequency aschannel. 1 (01). Also note that
the transmitter
is inoperativefor channels 24 to 519.
D. MODE SWITCH - Located at lower center of panel, just below "Lhe meter. Selects
zade of both transmit and receive operation. The unit must be operated in same
mode
as the other station being c~~municaled with. If the other station is on AM and
the DIGICUM is in the SSB mode !LSB or USB), a background whistle will be heard
on receive.
If the other station is SSB and the DlGICOM is in AM or the wrong SSB
mode, the other station
will be unintelligible. When possible, the SSB mode (either
LSB or USB) gives better range and less crowding of the CB channels (two
simtlltaneous SSB comunications are possible on one channel,one on TUB and one
on USB). However3not ail stations on the air have SSB capability at the present time.

F. Ti- . ]q)-,-7;:- --
,
.,,n..-r. I E-',l$ - .. ,ilj~,,,l., .~~re aid hntellig~biiity of recei.iexi sigraa3s ;I the US3 and LSB
rrto2e. Peaks ,-~a:c.:~~~? ,bfj1!3! sirength.in the AM mode. The classier should normally
he set at ha:?" rotatbm? poirrt (pointer on knob straight up). The clarifier does not
opeasre on transmit 2s &$is is undersirable for clear SSE two way eo~munications
and is iI1~gaF under @resent ~rldany ariticipated future FCC regulations.
F. SQUELCH - Suppresses rlmwanted background noise and weaker signals when the
Fn~ic- .. Ls I-. ,.;,e:ng . 1ise3 to rzt~nltoi- a char:ne1. Increasing clockwise roktion causes in-
sreasifig s:r-,~resaion or" :jtsongc~ signals. To properly adjust, t~gl fully coun-
tercIoc8iwise (r;-izx?l~u~ receiver sensitivity) and &ern turn slowly clockjvlse until
just the point where niiise is first quieted. Any further clockwise rotation beyond this
poir~l will canse unnecessary loss sf receiver sensitivity and thereby many weaker
signals mag not be heard.
6. ~OLUPvfE - Adjust: loudness of speaker audio rsertput.
H. Ni3 SN4FF S"#ITCH - Y8!3nen in the on positaon, the noiseblanker is activated, causing
soppressi~q of ngnltisn noise, static, and other undesirable backgroen~ldnoise during
rece.ve operation.
1. PA /CB SWITCH -Should be in CB position for normal radio raperation. When in the
PA pos~tion, the DIGHCOM will receive normally, however when the transmit switch
IS pushed, the unlt will r,ot transmit and themicrophone voiceinput is cormectedto the
speaker, creating
a pubhc address eapabllity.
J METER -Indicatesrelative power output on transmit and relative signal sbength on
receive.
K. MlCROQHQNE INPUT JACK - Located on left front side of radio. Note that
microphone plug has a tab which must be rotated to line up with the jack before the
two will come c~mpletelytogether. Also be sure to engage he plug lock ring after
connection.

L. EXT SPKR JACK - Located on bottom on unit, next to speaker grill. May be used for
either an external speaker or public address system. Use
4-8 ohm speaker. IM-
PORTANT!Be surecenter conductor of speaker plug isconnected to ungrounded side
of the voice
coil. Audio amplifier will be damaged if abave precaution isnot taken.
EL§ AND FREQUENCIES
MHz channel MHz
channel

channel
channel

TRANSMITTER TUNING PROCEDURES
I. SYNTHESIZER
BOARD (7H001)
A. Complete Aligment Rocedure
1. PRELIMINARY SET UP
a. EQUIPMENT REQUIRED - VOM, high input inlpedance frequency
counter,
13.6 VDC power supply, plas~c hex hing tool, 50 ohm RF dunmy
load
b.
Connect radio to DC supply
c.
Remove PL 1 from R/T board
d. NB switch - off
e . PA // CB switch - CB
f. MODE switch - LSB
g.
CLARIFIER control - ?h rotation (pointer straight upj
h.
Channel switches - channel 01
i. Connect 50 oh load to radio output
j.
Set L3 slug attop of coil (awayfromboard)

k. Connect counter to TP3
2.
Key radio (no RF output should be present as PL1 was removed from R / T
bard).Adjust 645with plastic blade tuning tool for 12.8
MHz at TP3. Setall
frequencieswithin + 10Hz. Unkeyradio.
3,
Set mode switch to USB. Key radio and adjust C55 witfa piasGe blade tool for
12.803000 MHz at TP3. Unkey radio.
4.
Connect VOM to TP1. Check that channel switches are on Q1. Adjust L3 for
2.0VDC at TP1. Tun channel switches to charnel 99 and check that the DC
voltage at
TP1 doesnot exceed 7.5VDC. If it does,adjust L3 f~ra 7.5VDC reading.
5.
Connect freq counter to TP2, Check that mode switch is stiil in USB position.
Adjust C80 with blade toolfor 10.697000
MHZ atTP2.
6.
Turn mode switch to ESB. Adjust C56 with blade tool fix 10.7
7, Function checks
a.
Verify that the radio will not Key (red transmit light does not come on) for
channels 24 through 99.
b.
Verify that the injection frequencies are correct to the R/T unit. Connect
the coilnter to PL1.Note thatthe APJd injectionfreqisthe sameas LSB

OPERATING
CHANNEL
FREQ (MHZj
USB
INJECTION
FREQ
( MHz)
LSB
INJECTION
FREQ (MHz)
8. Reconnect PL1 to R /T board.
10

1. PREEI~~~%'%lNARY SET UP
a. Equipxent rizcjuised - 13.6VDC power supply, 50 ohkFdlmmy load and
~at~eter IOi! ?Y:% oscillcs~fipe wi", high ~~pedance probe ( Tektronix 465
, .
or fq5;,lvaleilY;. 1KC audio gezerator, DC 0-3 ampmeter, plas',ic hex tuning
tool.
b .
Connect radio to DC! supply with ammeter in DC line.
c
.
Connect waltmnekr and dmxy load to radioou$ut comeetor
d. Set R 167 at % rotation
e.
Set R251 fully counter-clocksvise (CCW). No& that all references to trimpot
setEngs are facing ehumbwheel of pot.
f.
Set R150 at M relation
g . Set R293 fu~y ew
h. Set R280 fully CCW
i.
Set R81) (on synthesizer bmrd) fully CCW
j.
Set slugs of L22, L23,L12, L11, and L24 at top d coil (away from board).
k. Be sure synthesizer board has been aligned (see section I of tuning
procedure).
11

ETI . rexiova microphone coriL?ec";i3se
Coxriect scope to T?4 and set R251 for. .5 v P - P audio at TP4
Set R273 at rotation
'JopL<e.c",mo& t&.j T"6 ar,d paref-ilLl3 ~eak LIZ, L11. .zzd fa; i~A.;l..r;.m-~,~ 27.igfj
MHz voltage at TP6
m
iixn moife switch to btYI and adjust RSO (on synthesizer board) for a 913 Fercent,
riodul~%d i KC wa-~eform at TF6
Turn R273 fully CW again
Yote DC ammeter readmg on ;adia slsppiy ii~e and ;her, slowly turn R 280 GW
until c-nrentrisesabout 20 ma (just a slightneedle twitch upward). Do not turn R
280 any farther.
1%

1 Making sure mode switck is still in AM position, set RF output to 3,5w by turning
R273 slowly GCW.
! 2.
Check RF output on channels 1 and 23 for balance. If they aremequal, tweak L:l
slightly for balance.
:3
Set raiiio back on channel 12
14.
Remove audiogenerator connectionand PTT clipleader. Set mode switch to USB
position znd reconnect microphone. Push microphone transmit button and adjust
R 167 for 2 to 3 watts RF output while saying the word "four" into the microphone
in a ccrrnal level volee, Note that as R 161 is t;lrned CCW modulated sutput in-
creases utii a hit pokt is reached beyond which the RF output 2oes not In-
crease. Piis indicates the transmit ALC is operatmgproperly.

DIGICOM 100
RECEIVER ALIGNMENT PROCEDURE
PRELIMINARY SETUP
: Equipment Required - Skble signal generator with A% mdulatien capabiaieq-,
ascilkoscope, hex tuning tool.
2. Set R150, R160, RE8 and Rl3O at
rohtion (pointer straight up).
3. Cramect the signal generator to rear pane! ant.mil,% corn-ectc~a, It is god prsc-
lice to remove the microphone connection to the radio to prevent accidental radio
kansmit into the signal generator causing pokntiai damage to the signal
generator.
ALIGNMENT PROCEDURE;
1 Adjust R298 for S-3 reading or! the front panel S-nekr with the RF generator
input lever hrned fully OFF.
2. nii:iLh, the radio cn ckannel 12 and SB, ai',j.;st signal generato? frequency for a
:K@ ralia audio output tone and 2se ge~erato~ ieveI for a S-9 meter reading. Be
scae the gecerator is set for GW outplrt T,G $2A m&cai!.!atioc,.
3. Peak LP3, L14, LP6, t21 and El7 on &he S-meter. Decrease the signal generator
output during tuning to mainbin a S-9 meter reading. This peaks the entire
receiver
RF signal path.

4. Witdl the squelch per.;, set Iv p-p audio at TP-8 by adjusting R160, This sets the IF
AGC.
5. Farn signal Icvel up to 10 LT and set R278 for a S-9 mekr reamg. This caEbaa%es
he S-meter.
6. "rus;? signal level up to 1000 uv and set Ri%O for 1V DC at TP9. This sets the RF
AGG.
7. With a 1000 uuv signa: (still on channel 12), wow set fie generator on 96) percent
4KC AbI mdulation. Adjust XI30 for a Iv pp audio waveform at TP8. This
bata~lces the AM with the SSB audio oubaat level.