Kenwood TK-880 Horn Honk
by Jay Banks
Note: The programming software used for this project is KPG-49D
Table of Contents
A) Pre-install (The Hardware Side)
B) Programming Issues (The software side)
C) Testing out the horn honk on an IFR
D) Vehicle Install (Hardware Side)
A) Pre-install. Parts required: KC-19
and KAP-1 (PA/HA Unite)
Install the KC-19 and KAP-1 board as per TK-880/H Service Manual (see page
Notes: The KCT-19 and KAP-1 will connect as follows:
KAP-1 W2 3-pin connector (green, green, green) connects to CN5 on
the 880 board
KAP-1 W1 3-pin connector (white, black, red) connects to CN3 on the 880 board
KC-19 3-pin connector (brown, red, orange) connects to CN2 on the KAP-1 board
KC-19 8-pin connector (only 8-pin connector) connects to CN1 on the 880 board
Not used in this setup: KC-19 3-pin connector
(brown/white, black, white)
KC-19 2-pin connector with 1 tan (yellow?) colored
wire going to it.
Turn the radio upside down, with the front toward you and the
heat sink away from you.
Remove the panel and VERY CAREFULLY remove resistor R152. R152 is
labeled on the board. R151 and R152 have arrows pointing to them. Remove R152
(the 2nd from the left when oriented correctly).
Notes: Removing R152 will enable the horn honk. The
TK-880 Service manual is not very clear in this area. You may experiment with
the resistor settings, but in our experiments, the horn honk would not
function without R152 being removed.
A fellow tech pointed out that the resistor may actually be
located on slightly different locations on different 880 boards. They should
still be labeled, however.
Issues (The software side)
1. Setup the radio programming in the normal manner.
2. On the KPG-49D menu, go to Edit\DTMF
Here you will find three tabs. Set them up like this:
Screen 1 (Decode)
Notes: The Primary Code will be the unique vehicle code
for the vehicle that this radio will go into. The Primary Decode Response of Alert+Transpond
will honk the horn and send a beep back to acknowledge that the horn was
honked. Setting this to just Alert will only honk the horn. And interesting
side note is that using the Alert+Transpond mode will make the horn
honk function as an extremely rudimentary vehicle location device, because if
you have multiple systems in a radio and you use the horn honk, if you get the
acknowledge beep back on an isolated repeater system, you at least know the
vehicle is in that area. Again, the key words in the last sentence were "extremely
Screen 2 (Encode)
Notes: Setting the first digit to 1000 will make the
first DTMF tone longer. This is optional BUT the reason you might want to do
this is because if the radio is in scan, it may not pull out in time to
receive the entire DTMF tone. Or in other words, you might actually audibly
hear a portion of the DTMF tone, but it will fail to make the horn actually
Screen 3 (DTMF Memory)
Notes: If you want to have the ability it honk horns vehicle to
vehicle, enter all the codes you want to be able to honk on this screen. And
note that it is possible to put an alert on a base radio!
To honk vehicle to vehicle, you have to assign a key to have a
On the KPG-49D menu, go to Edit\Key Assignment:
Note: Keys actually used are optional. Assign desired button the Memory(RCL)
function, as seen above on the "B Switch"
What this does is: When the user hits this key, it will allow them to tab,
using the group up and group down keys on the front of the radio, through the
list of DTMF tones programmed into the radio (see: Screen 3 (DTMF Memory),
pictured above). When the user gets to the Assigned Name (A/N) in the list he
wishes to horn honk, he will stop scrolling and key up using the microphone.
This action will transmit the DTMF tone over the trunking system and cause the
vehicle assigned that DTMF tone to honk...if all horn honk requirements are
met for that vehicle at that time (e.g. vehicle not running, mic on hook,
Options: If you want the horn honk to function while the mic is off
hook, go to Edit\Optional Features and put a check (click in) the empty white
box next to the text that reads, "Off Hook Horn Alert."
If you want a button to enable/disable the horn honk, set a button
(Edit\Key Assignment) with the "horn honk" function. If the customer
does not want the ability to turn the horn honk off, do not set a button up to
Note: With a horn honk button, the 880 display must show "HA" for
the horn to honk. The "HA" means the alert is active.
3) Edit the System Information
On the KPG-49D for Windows menu, go to Edit\System.
Go to each system you want the horn honk to work on and hit the
"System Edit" button.
Change each "Opt Signal" setting from the default of
"None," to "DTMF":
Next, while still on this screen, hit the "Group Data" button at
the bottom of the active window. Make sure the box next to the text
"Horn Alert," has a check in it, as pictured below:
Note: Sometimes this box seems to be checked by default when you set the
Opt Signal to DTMF, however, there are cases where it does not automatically
check this box, so be sure and double check.
Do the above for each system in the 880 that you want to have the horn honk
working on. Note you can have the correct info in the DTMF settings, but if
you do not do the above two items, the horn honk is NOT going to work.
NOTE: When programming the radio, after setting the DTMF information
up the way you want it, make sure and check the little white box that says
"Include DTMF Memory,":
Or optionally, if the programming is already configured for a horn honk,
you can just write the DTMF information to the radio (menu: Program\Write DTMF
Remember that in most circumstances you are going to want a unique DTMF id
for each vehicle, so in most cases, you are going to have the same programming
layout for each vehicle, but edit the DTMF id for each radio as you program
C) To test the horn honk
On the radio, go to a Talk Around or conventional channel with no PL tone.
(You may have to program in a test channel, or optionally, set your IFR up to
handle a PL tone). On the IFR, hit the RF button and program in the frequency
of this Talk Around or conventional channel receive.
Program in the DTMF ID of the radio you are testing by hitting the program
button, the DTMF button, and the 1 on the IFR keypad, followed by the DTMF
code programmed into the radio.
Put the IFR in Generate mode, and hit the Execute Key, followed by the DTMF
button. This will generate the DTMF tone, and if everything is set up
correctly, cause the radio to beep (which will also be honking the horn when
installed in a vehicle.
At this point, you can connect an ohm meter to pin 10 of the KCT-19 and
ground to the body of the 880. When you set the horn honk off using the IFR,
it should Ohm to ground.
D) Vehicle Install
Hook the connector up to the KC-19 (I believe this part is actually a
KC-18, but I could be wrong), with a wire going into pin 10. Run this wire
from the radio, installed in the vehicle, to the horn honk relay on the
vehicle. This is usually located in the fuse box under the hood.
Note: You can find this by pulling relays out and honking the vehicle horn.
When you pull a relay out and the horn no longer works, this is the right
relay. If you are doing fleet vehicles, which are often all from the same
manufacture and same year, make note of the location of this relay, for easy
horn honk installs on future vehicles.
Note: At this time we were unable to locate the relay on a new 2005
(2006?) model Ford truck. If this is the case, get a 5 pin relay, such as a
BOSCH 12V relay (12V 20/30A 0 332 209 150) and purchase a small
horn. Hook up Pin 10 from the 880 to pin 85 on the Bosch Relay, and hook pin
30 of the Bosch Relay, to the horn. Pins 87 and 86 of the Bosch Relay will be
constant 12 volts (run 12 volts to one of them and jumper between pins 87 and
86). See the following diagram:
Note: Make sure you point the horn slightly down, so that it doesn't catch
water, which could damage it.
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