Standard C828M User manual

OPERATING INSTRUCTIONS
C828M
2m FM lOW

We are happy you have chosen our new product STANDARD C828M, the füll
solid State FM transceiver for the amateur radio in 2m band.
The Model C828M has been developed by your STANDARD COMMUNICATIONS
CORP with unsparing applications of its tradltionally held ultraminiaturization tech-
niques and with its personal considerations given from the Standpoint of the users.
It is carefully designed in every respect and manufactured at STANDARD's modern
factory. We are sure that a number of features and excellent reliability will pro-
vide you with great satisfaction.
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TABLE OF CONTENS
Features of C828M 2
Cautions Prior to Use 6
Installation Procedures 8
Communication Procedures 9
Repeater Offset Oscillator 10
"Busy" Indicator Lamp 10
Meter 11
Stand 11
Adjustment of Microphone Sensitivity 12
Microphone Connector 12
Accessory Terminal 13
Channel Increase 14
Accessory Parts 15
Connection of External Speaker 15
Antenna and Coaxial Gable 16
Noise Prevention Measures for Use as Mobile Station 17
C828M Specification 18
Block Diagram 19
Circuit Diagram 20
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1. Features of C828M
We know that lighter and smaller high-performance equipment creates new appli-
cation, and this is quite true of C828M. Such features and many others of this
Model as mentioned below will enable all of you-from beginners to veterans-to enjoy
a broader scope of the usages.
1. small Size and Light Weight:
This new FM transceiver, smaller in volume than a half size of the comparable
products of this Company and as light as 0.96 kg, has succeeded in hnding its
Installation space for mobile Station use at vehicle driver's seat area instead of
assistant driver's which has been exclusively used for this purpose in the past,
ushered in the debut of a new type mounting metal bracket.
2. Push-In/Push-Out Bracket:
This metal bracket has simplified the attaching and detaching processes of
C828M on a Single motion basis. For attaching, just snap your transceiver into
the bracket. The reve/'se consequence can be obtained by simply snapping it off
toward you.
The bracket with the transceiver off therefrom is an evenly faced metal, which
therefore prevents rattling causable during the vehicle Operation and also protects
your feet against a possible hazard from a sharp projection. Such attaching and
detaching processes do not require you to put in your hands on the sides of the
rig. Thus, the attaching process brings the sides of the rig into a dose contact
with their corresponding parts. The rig's occupancy of small space serves for
the efficient employment of the limited interior room of the car. ^ '
3. Single Crystal System Common to Transmission and Reception:
The adoption of the Single crystal system, in which one crystal is used for both
transmission and reception of Signals, has opened the way to an economical In
stallation of additional Channels and the very expedient experiment or Operation
in Joint use of multifarious external oscillators.
4. One Action Repeater Changeover System:
The transceiver has 3 built-in offset oscillators including SIMPLEX. This fea-
ture together with the füll advantages of the single crystal system permits change
over to the repeater Channel with a fi nger action of switch on the front panel.
5. Call switch for Tone Burst Signal Transmission:
C828M incorporates tone burst device (CTN-5). By pressing the call switcb
(momentary switch) for Operation of repeater Channel, a high power tone burst
Signal is transmitted, thus assuring stabilized Operation of repeater.
6. Hi-Low Power Changeover:
By setting the function switch on the front panel from " high " to " low " power
Position, the antenna Output is reduced from lOW to IW with resultant decrease
of power consumption. This prevents radio interference and other disturbances
during local QSO, providing smooth and efficient Operation.
7. Remote Control System for External Oscillator Changeover:
Connection of external oscillator to the transceiver can be made simply by flipp-
ing the evternal oscillator switch on the microphone.
8. Professional-minded Circuit Design:
FET's, Silicon transistors and diodes are abundantly used in the circuitry de-
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signed with Professional minded techniques and latest technicl knowhow.
(a) Receiver
(1) High Sensitivity
High sensitivity design as represented by the ~3dB QS 20dB and the over
23dB S/N at OdB input.
(2) Excellent Cross-Modulation Characteristics
The e3 cellent cross-modulation characteristics are due to the use of FET's
for the radio frequency ampliher and the fi rst and second mixers, also due
to the removal of the fi rst intermediate frequency (IF) amplifier and the gains
distribution made with our new technical approach.
(3) Ceramic Filter
The two ceramic fi lters in the second IF amplifying stage play a role for
the alleviation of ripples within pass band for better selectivity characteri
stics.
_ (4) Integrated Circuits
The second IF amplifying stage consists of 3-stage amplifying unit plus
the integrated circuitry, thus showing very good limiter effect.
(5) Squelch Circuit
The squelch circuit is a noise rectifier type enjoying an established reputa-
tion for mobile Station use, and the circuit operates securely, thanks to the
high gains resulting from the 2-stage noise amplification.
(6) Squelch Time Constant
With the squelch unit (accessory) connected to the accessory terminal on
the rear panel, the squelch time constant can be changed to the best suitable
value for respective uses as mobile and fi xed stations.
(7) 3W of Audio Output
The maximum audio Output is as high as 3W, permitting the Operation of
your transceiver at Optimum sound level even in a noisy expressway.
(8) "Busy" Indicator Lamp
The green lamp turns off and on in association with the squelch circuit,
regardless of the Position of the volume control knob, to clearly indicate
which rig is receiving the signal. This lamp is convenient in a parallel Oper
ation at 50MHz, 430MHz and other bands.
(9) Highly Sensitive Incoming Signal Meter
This incoming signal meter, containing a meter amplifier designed to swing
the pointer in response even to weak incoming signal, can show the exact
change in the input voltage of the antenna.
(b) Transmitter
(1) High-gain, High-efficiency Transistors
Newly developed high-gain, high-efficiency transistors are used. The fi nal
stage is equipped with 2N6082 providing sufficient margin to the Operation.
(2) Offset Mixer Provided with FET
The MOS FET incorporated in the offset mixer of the signal transmitting
section reduces the occurrence of spurious radiation.
(3) Direct FM Modulation System
The 22. OMHz frequency from the offset oscillator undergoes direct FM
modulation. This eliminates the difference of modulation degree between
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Channels.
(4) Twisted Wire
Twisted wire is used for stable impedance conversion and wide bandwidth
characteristics.
(5) Splatter Filter
The RC network filter and the transistor operated splatter filter provide
high clarity and high average level of modulation, and cause no interference
with other Channels through expansion of the band occupancy.
(6) Microphone Gain Control
A semi-fixed resistor for microphone gain control is mounted on the main
printed wiring boad for transmitter.
(7) Transmitter Indicator Lamp and Meter
When the push button on the microphone is pressed, the red pilot lamp
illuminates to show that the transmitter is in transmitting mode. Düring the
transmission, the meter indicates the relative value of the transmitting Output.
(8) Channel Selector With Short-circuiting Ring
The Channel selector of C828M is provided with a short-circuiting ring to
prevent possible interference caused when additional Channels are installed
or when the frequencies of neighboring Channels are adjusted, thereby help-
ing make the frequency alignment much easier during the installation of ad
ditional Channels. The trimmer capacitor for delicate alignment for both the
transmitter and receiver performs accurate adjustment of all the Channel fre
quencies.
(9) Uncasing Possible with No Holp of Tools
Uncasing is possible with the two screws in the rear removed by the fi n-
gertip Operation. This feature lends itself to the addition of the Channel and
other purposes.
(10) Anodized Alminum Chassis
Anodized alminum is used for both the case and chassis. The main chassis
is 2mm thick for an adequate mechanical strengt and designed to show good
heat sink effect.
(11) Antenna Connector
The M-shaped antenna connector screws have their pitches available com-
monly in both inch and millimeter.
(12) Microphone Connector with Speaker Terminal
A 4-pin connector is used for microphone connection. Since audio Output
is connected to No. 4 pin, this connector permits connection of telephone
handset as well as the microphone.
(13) Accessory Terminal (A.T.)
A 9-pin accessory terminal is provided on the rear for connections of ac
cessory units from outside.
(14) Wide Range of Operating Temperature
The operating temperature ranges from —30°C to -)-60°C. This is good
enough for mobile Operation even in severely cold environments.
(15) Microphone with Switches
The microphone is equipped with external oscillator switch and P.T.T.
Switch (microswitch). Sharp switching from transmission mode to reception
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mode or vice verse is assured.
(lE^ Detachable Stand
The detachable stand furnished facilitates the use of C828M as a fixed
Station.
(17) Power Supply Protective Circuit
The power supply circuit is provided with a protective function so as to
keep the internal circuit from any possible damage caused in wrcng connec-
tion of the power supply.
(18) Ant, Protector
Antenna protector circuit Starts to work on, when antenna becomes to open
or Short circuit, or degradation of SV/R. Transmitting LED goes to dark
when there is no more RF output. Ii r^ic occasion try to fi nd out abnormal
point on the antenna circuit and reset • radio to a normal condition of the
transmission. Accordingly the antenna Protector Circuit is automatically re-
leased to its normal condition.
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2. Cautions Prior to Use
The following precautions must be observed for the maximum Performance of
your C828M and for your enjoyment of better ham life:
1. DO NOT Connect or disconnect the power supply cord when the power supply
Switch is in ON position.
2. DO NOT connect or disconnect the antenna or external Speaker when the
power supply switch is in ON position.
3. DO NOT push the microphone switch with the antenna left disconnected.
4. BE SURE to replace the blown-off fuse withe a new one rated at 3A.
5. CHECK to see the polarity of the electrical system prior to the power supply
connection. C828M is designed for negative grounding; the black lead should
be connected to the ground.
Od) (D®
(b d
Figure 2—1
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Figure 2—1
Transmission Indicator
Repeater Indicator Lamp
Mounting Metal Brackel
Auxiliary Mounting
Metal Brackel
Volume Control Knob
Power Switch
® Squelch Control Knob
Channel Selector
EXT-OSC Switch
Antenna Connector
F.T.T. Switch
External Speaker
Terminal
Busy " Indicator Lamp

3. Installation Procedures
Prior to Installation, determine the instaliation position observing the following
Points:
* I fhere any unusual posture required in the Operation of the Channel Selector
and other control knobs?
* Are all the control knobs and meter scale face located in piain view ?
* Isn't the instaliation position of the rig for use as a mobile Station impeding the
general motions of the vehicle driver or the Operator of C828M?
* Specifically for use as a mobile Station, make sure not to place the transceiver
anywhere near a heater duct, air conditioner's exhaust mouth, air intake mouth
and the like.
* Refrain from mounting the transceiver on such places as exposed to rainfall and
sea water. Although there is no restriction as to the Installation posture of
C828M, it is recommended that the body of the transceiver be set upright for
use in yachts, commercial vehicleshetc.
After the instaliation position is determined, install the transceiver according to
the following procedures:
1. Take out the furnished mounting metal bracket (17) and attach it to the body
of the transceiver.
2. Position the mounting bracket in predetermined instaliation place, make a bore
for the bracket with a 5—5.5mm drill, and secure it with the supplied screws
and nuts, preferably at three or more places. Use wooden or tapping screws
according to the mounting plane.
3. Set the body of the transceiver again on the mounting bracket.
4. Connect the power supply. At this time, again make sure of the polarity of
the electrical system.
5. Firmly secure the antenna to the antenna connector (13). Refer to Fig. 2-1.
6. Connect the microphone to the microphone connector (3) on the front of the
transceiver, and fix the supplied microphone hanger on a convenient place for
lifting (see Fig. 2-1).
The above completes the instaliation, and you are now ready to start commimi-
cation.
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4. Commuiiication Procedures
^ 1. Preparation for Communication
First, turn the SQL knob (2) fully counterclockwise, and then set the Channel
selector (11) to the Channel you desireto use.
2. Turn on the power supply switch.
Turn the VOL OFF knob (1) clockwise until it clicks. The Channel selector
lamp and the meter lamp will light up to show that the power is on.
3. Adjust the volume.
As you turn the VOL OFF knob (1) clockwise, you will come to a point where
a rustling noise-or the conversation in the case someone is talking over the chan-
nel-becomes audible. Set the knob for suitable volume while listening to the
noise or the conversation.
4. Set the squelch control.
Turn the Channel selector and set the SQL knob (2) using an empty Channel,
Turn the knob slowly in the clockwise direction until you come to a point where
the noise suddenly goes off.
Set the SQL knob on this point and you will hear no noise but the incoming
Signal alone through the Speaker. In this case, if the signal is unclear because
of the squelch circuit being off and on due to the signal condition of your party's
Station, turn the SQL knob slightly further to the right.
5. Transmission:
Set the repeater switch and hi-low power switch to the desired positions.
Take up the microphone and press the push button on the microphone. Speak
into the microphone slowly and distinctly in normal tone of voice. At this time,
the red lamp in the front illuminates to show the transmitting Status as long as
the push button remains pressed. Simultaneously, the meter indicates the com-
parative value of the transmission power. Now, your voice is out on the air.
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