Midland Sp-400 Series Transceiver Users Guide

							
SP-400 Series User’s Guide  
If a 2-tone or selective Call 1 or Call 2 has been assigned for the 
selected channel, it may be sent by pressing the PTT button then 
pressing the upper (Call 1) or lower (Call 2) function button. 
If your transceiver has been programmed to send an emergency 
call for the selected channel, it may be sent by pressing the 
lower then upper function buttons, and holding them pressed for 
at least two seconds. 
! Please consult your dealer or communications 
coordinator before testing the emergency call 
function. The radio may be programmed to respond 
differently when sending an emergency call. 
Scanning channels 
If you have more than one channel programmed, your SP-410 / 
SP-420 / SP-430 / SP-440 may be programmed to allow you to 
scan them. To activate scan press and release the lower function 
button. If the scan list has at least two channels the radio will 
begin checking all channels in the scan list for activity. The 
status LED will blink amber once every five seconds while the 
radio is scanning. To turn scan off press and release the lower 
function button again. If beeps are enabled a high pitched beep 
will sound when scan is activated and a low pitched beep will 
sound when scan is turned off. 
The default scan list is programmed by your dealer or 
communications coordinator. Your dealer may also have 
designated a particular channel in the scan list as a priority 
channel. The priority channel is checked for activity more often 
than other channels in the scan list. The priority channel may 
also be checked for activity while the radio is receiving on a non-
priority channel. 
The radio may be programmed to wait a period of time after a 
receive signal ends. Once the resume timer has elapsed, 
scanning will resume. This programmed resume timer will also 
be started whenever the radio has ceased transmitting on a 
channel. Your dealer or communications coordinator will 
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 SP-400 Series User’s Guide 
customize the scan options for your particular situation, so the 
following paragraphs detail the available options. 
Busy channel scan 
If no priority channel has been programmed by your dealer or 
communications coordinator, all channels in your scan list will be 
checked for activity, with no preference given to any channel. If 
activity is detected on a channel the radio will stop on that 
channel. Depending on programming, the radio may resume 
scanning after a programmed maximum channel dwell time, 
even though a signal is still present on the channel. While the 
radio is stopped on a channel it may be deleted from the scan list 
by pressing and releasing the upper function button. This 
function may be referred to as nuisance channel delete. If only 
one channel is left in the scan list, the radio will automatically 
turn off scan. When scan is turned off (or the radio is turned off), 
all channels removed from the scan list using nuisance channel 
delete will be restored. 
Priority channel scan 
If a priority channel has been programmed by your dealer or 
communications coordinator, the priority channel will be checked 
more often than the other channels in the scan list. If activity is 
detected on a channel the radio will stop on that channel. While 
stopped on a non-priority channel, the radio may be programmed 
to check for activity on the priority channel. This may be referred 
to as priority channel lookback, and the receive audio from the 
non-priority channel will be briefly interrupted while priority 
lookback occurs. While the radio is stopped on a non-priority 
channel it may be deleted from the scan list by pressing and 
releasing the upper function button. This function may be 
referred to as nuisance channel delete. The priority channel can 
not be deleted from the scan list. If only one channel is left in the 
scan list, the radio will automatically turn off scan. When scan is 
turned off (or the radio is turned off), all channels removed from 
the scan list using nuisance channel delete will be restored. 
22 © 2005, Midland Radio Corporation  
						

							
SP-400 Series User’s Guide  
Transmitting while in scan mode 
If PTT is pressed while the radio is in scan mode, your dealer or 
communications coordinator may have programmed one of the 
following options for the transmit channel: 
1. When PTT is pressed, the radio will generate an error beep 
because your dealer or communications coordinator has 
programmed the radio to not allow transmission while the 
radio is in scan mode. 
2. When PTT is pressed, the radio will switch to and transmit 
on the priority channel regardless of the current receive 
state. This mode may be referred to as priority only transmit. 
3. If the radio has stopped on a channel, or the resume timer is 
active, the radio will transmit on the channel it is stopped on 
when you press PTT. If you press PTT, while the radio is 
scanning channels, the radio will switch to and transmit on 
the priority channel (or the first channel in the scan list if no 
priority channel is programmed). This mode may be referred 
to as (priority) talkback transmit. 
4. When PTT is pressed, the radio will transmit on the channel 
indicated by the channel selector knob. This mode may be 
referred to as channel select transmit. 
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 SP-400 Series User’s Guide 
Advanced Operations 
Operating hands-free 
VOX (voice operated transmit) is a method that allows the 
transceiver to automatically begin transmitting when it detects 
sufficient audio from an optional headset microphone. Correct 
VOX operation generally requires specific headset microphone 
circuitry, and not all headsets that otherwise function correctly on 
the radio may work properly in VOX mode. 
 Please be aware that the PTT button on the transceiver 
is disabled when VOX operation is activated. If you want 
to use PTT operation, but the status LED does not light 
and no error beeps are generated when PTT is pressed, 
you should make sure VOX is turned off. 
Activating VOX 
To activate (or deactivate when already activated) the VOX 
function, switch the radio off, and hold both the upper and lower 
function buttons pressed while turning the radio on. A high 
pitched beep will sound and the radio PTT will be disabled when 
VOX is activated. A low pitched beep will sound and the radio 
PTT button will be enabled when VOX is turned off. 
 Your dealer may have disabled the VOX function. In this 
case, only an error beep will be generated when 
attempting to activate VOX. 
 Two VOX sensitivity selections are possible. The default 
selection is low sensitivity and should be sufficient for 
most headset conditions. For applications where the 
ambient noise level is very low and you desire greater 
microphone sensitivity, you can switch to high sensitivity. 
However if ambient noise conditions are too high the 
radio may transmit constantly indicating the VOX 
sensitivity needs to be set lower. 
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SP-400 Series User’s Guide  
Selecting VOX sensitivity 
When VOX is activated you may toggle between low and high 
VOX sensitivity by pressing the lower, then upper function 
buttons, and releasing both within two seconds. A high beep will 
sound when high sensitivity is selected and a low beep will 
sound when low sensitivity is selected. 
Using the scrambler 
The SP-410 / SP-420 / SP-430 / SP-440 transceivers feature a 
built-in voice inversion scrambler. The scrambler function must 
have been enabled by your dealer or communications 
coordinator before it may be activated. If enabled you may 
activate your scrambler by holding the lower function button 
pressed while you turn on the radio. A high pitched beep will 
sound when the scrambler is activated. While the scrambler is 
turned on, the status LED will blink amber twice every five 
seconds. 
 All SP-400 series radios receiving the scrambled 
transmission must be also have their scrambler enabled 
for the conversation to be intelligible. In other words, for 
intelligible communication, all radios must have their 
scrambler on or all radios must have their scrambler off. 
 The voice inversion scrambler built-in the transceivers is 
a relatively simple form of encryption and does not 
guarantee communication security. 
Editing your scan list 
The SP-400 series radios allow you to edit your scan list before 
scan is turned on. Any channels programmed in the radio which 
are not in the programmed default scan list may be temporarily 
added to the scan list. Additionally, any channels in the 
programmed default scan list, except the programmed priority 
channel, may be temporarily removed from the scan list. 
 The programmed priority channel can not be deleted 
from the scan list. 
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 SP-400 Series User’s Guide 
 If only two channels remain in the scan list, it is not 
possible to delete either of them. 
 When the radio is turned off (not when scan is turned off) 
the programmed default scan list will be restored. 
 Scan list edit is only available when scan is not turned 
on. 
To add or remove the current channel from the scan list press 
and hold the lower function button for more than two seconds. A 
low beep will indicate the channel was removed from the scan 
list. A high beep indicates the channel was added to the scan 
list. 
Care and Maintenance 
Using rechargeable battery packs 
 Before using the battery charger carefully read any 
related warning or caution labels. 
 Do not short battery terminals: this may cause fire, 
burns or explosions. 
 Never dispose batteries into fire as they may 
explode. Strictly follow any disposal regulations in 
your area. 
 Use only recommended batteries and chargers. The 
use of improper batteries and chargers may cause 
burns, fire or explosions as well as causing serious 
damage to the radio or battery or serious injuries to 
people. 
 The recommended battery chargers are for indoor 
use only.  
 Ensure that your AC power source matches the 
rating listed for the supplied battery charger AC 
adapter. 
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SP-400 Series User’s Guide  
 To avoid damaging the power cable of the battery 
charger, do not put anything on it or place it where it 
will be walked on.  
 Do not use the charger if it received a strong shock, 
has been dropped or it appears damaged. Contact 
your dealer or communications coordinator for a 
replacement charger.  
 Never try to disassemble or service the charger 
yourself. Always contact your local dealer or 
communications coordinator for assistance. 
 To reduce the risk of electric shocks disconnect the 
AC power source before performing any cleaning or 
maintenance on the charger. 
 Battery performance will be degraded when exposed 
to temperatures below -20°C (-4°F) or greater than 
35°C (95°F) during their use. The batteries should 
only be charged when temperatures are in the range 
of +5°C (41°F) to +40°C (104°F). 
Recharging battery packs 
 Full battery capacity will only be achieved after cycling 
the battery through 3-4 full charging/discharging cycles. 
 Should you properly use the battery pack, you will obtain 
at least 300 charging/discharging cycles with the smart 
charger. The battery capacity will progressively reduce 
after about 2/3 of its life. 
 Rechargeable battery packs lose their charge over time 
if left unused (self-discharge). This is normal. A NiMH 
(Nickel Metal Hydride) battery can lose 10 to 20% of its 
stored energy in few days. 
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 SP-400 Series User’s Guide 
The battery pack must be charged prior to use. To charge the 
battery pack you should set up the charger and insert the radio 
(or battery) as follows: 
1. Plug the AC adapter into a grounded AC power outlet which 
supplies the specified input voltage for the AC adapter. 
2. Connect the DC plug on the AC adapter to the mating socket 
on the back of the charging cradle. 
3. Make sure the radio is switched off. 
4. Insert the radio into the cradle with the front of the radio 
facing toward the front of the cradle (the three metallic 
contacts of the battery pack must make contact with the 
three contacts inside the cradle). The LED indicator will glow 
red indicating the battery is charging. 
5. The rapid charger will fully charge the 1300 mAH NiMH 
battery in approximately 1.5 hours. The rapid charger will 
change to a green LED and switch to a trickle charge rate 
when a full charge is detected. The standard rate charger 
will charge at a constant rate (requires about 12 hours to 
fully charge a dead battery) and batteries should not be left 
in the charger longer than 15 hours. The LED of the 
standard rate charger does not signal a fully charged battery 
state. 
! Do not leave the battery in the charger longer than 
15 hours. 
 When possible, charge the battery when it is fully 
discharged or, you have used it for the major part of its 
capacity. Otherwise the battery’s capacity could be 
temporarily reduced. Please see the paragraph “Memory 
effect”. 
 Removing the battery before it is fully charged will 
temporarily reduce the duty cycle. 
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SP-400 Series User’s Guide  
Memory effect 
The NiMH (Nickel Metal Hydride) battery pack is made with a 
more advanced technology than a NiCd (Nickel Cadmium) 
battery. For this reason it is virtually free of what is called 
“memory effect”, which affects NiCd batteries. Memory effect 
causes a reduction in the battery’s capacity. However memory 
effect may occur if you regularly charge the battery when you 
haven’t discharged it at least at 50-70%. Memory effect can be 
easily avoided by following these simple rules: 
 When possible, charge battery packs only when they are 
completely discharged.  
 Do not remove the battery from the charger before the 
necessary time to provide a full charge. 
 Provide at least two deep charge/discharge cycles per 
month. 
 The best way to avoid memory effect is to use two 
battery packs and alternate their use with the radio. This 
will allow you to keep your transceiver in operation by 
replacing the battery pack when it is fully discharged. 
Erasing memory effect 
To erase memory effects try applying 3-4 deep charge/discharge 
cycles as follows: 
1. Attach the battery to the radio and leave the radio on until 
the battery runs down and the radio turns off. 
2. Switch off the radio and wait at least one hour and then turn 
the radio back on. Note that some energy remains in the 
battery, if the radio turns on. 
3. Leave the radio on until the battery runs down again. 
4. Repeat steps 2 and 3 up to three times or until the battery is 
well drained. 
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 SP-400 Series User’s Guide 
5. Fully charge the battery and check the battery capacity. If 
you believe some memory effect still exists go back to step 
1. 
 If the battery capacity does not improve after performing 
steps 1-5 three times, your battery pack is faulty or has 
reached the end of it’s life. 
Cleaning your radio 
Wipe the radio with a clean cloth to remove dust. If it is very dirty, 
you can use a damp cloth. 
Clean the battery contacts with a clean, lint-free cloth to remove 
dirt, grease or any other material, which may prevent a good 
electrical contact. If contacts are very dirty you can also wipe 
them using a soft pencil rubber (not hard erasers for ink). If you 
feel that battery contacts still aren’t making good electrical 
contact, please contact your dealer or communications 
coordinator. 
! Do not use liquid, alcohol or aerosol cleaners. 
Optional Accessories 
! When the accessory connector is not being used, 
the radio should be fitted with the supplied dust 
cover. 
The accessory connector uses a 3.5mm speaker jack and 
2.5mm microphone jack. It is designed for the connection of two 
pin accessories. 
Any accessories to be connected to the accessory connector 
should meet the following requirements: 
1. The speaker input impedance should be at least 8 ohms. 
2. The microphone should be a low-impedance condenser 
type. 
30 © 2005, Midland Radio Corporation