HamGadgets Universal Keying Adapter 3+ User manual

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Universal Keying Adapter 3+
The Universal Keying Adapter Version 3+ kit will allow you to key nearly any
transmitter or transceiver with a straight key, electronic keyer, computer serial or parallel
port or nearly any positive or negative logic signal. It can also be used as a rig-to-
amplifier interface. Active-low and active-high inputs are provided for use with a
straight key, bug, electronic keyer, transmitter or transceiver’s amp output as well as
computer control by either serial or parallel port.
Features of the UKA-3 Kit
Keys solid state, grid block or cathode keyed transmitters or
transceivers up to 400 V DC
Current capacity of 240 mA, AC or DC
Optional high-voltage/high-current relay available
Optical isolation between rig and key input
Works with any electronic keyer, bug or straight key
Computer input for use with contest software
Connects to computer parallel or serial port
Self contained with provision for AC or DC power
LED indicators show power on and keying active states
Compact size, good for integration into other equipment
On board header connection for custom applications or enclosures
Available with or without custom aluminum enclosure

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Parts List
Part Name
Part Description
K1
Optically isolated, MOSFET Solid-State Relay (6-pin DIP or SMT package)
NOTE: May be 4-pin inline with high voltage/current option
Q1
2N7000 MOSFET
C1
10 or 100 µF, 16V electrolytic capacitor
R1
470 Ohm ¼ W resistor (Yellow-Violet-Brown)
R2
220 Ohm ¼ W resistor (Red-Red-Brown)
R4 –R6
1 K Ohm ¼ W resistor (Brown-Black-Red)
R3
100K Ohm ¼ W resistor (Brown-Black-Yellow)
D1
4.7V Zener diode (the larger glass diode)
D2 - D6
1N4148 diode (the smaller glass diodes)
POWER
2.5mm / 5.5mm coaxial power connector
SW1
Pushbutton power switch with round cap
LED
Dual PCB-mount LED indicators
INPUT
PCB-mount 3.5mm stereo jack
OUTPUT
RCA (phono) output connector
PCB
Printed Circuit Board
Assembling the Kit
Always use good static prevention practices when working with static sensitive parts (in this kit,
those are Q1 and K1). This means you should wear a grounding strap when possible, or work on
a static-dissipative work surface. Use a grounded tip soldering iron if possible. When soldering
small parts it is a good idea to use a fine-tipped, small pencil-type soldering iron of no more than
30 Watts or so. Use pliers, clamps or alligator clips as heat sinks to prevent heat damage to parts
while soldering. If you are not fairly experienced with soldering small parts, you may want to
practice on some scrap parts first or get some help from a more experienced builder.
All parts should be installed from the top (white printed) side of the printed circuit board. As you
install each component, bend the leads slightly if needed to help hold the part in place. It’s a
good idea to use pliers, an alligator clip or some other heat sink to keep from damaging
components with too much heat from soldering. Solder the leads in place, being careful not to
use too much solder. Using a pair of fine-tipped diagonal cutters, neatly clip the component leads
close to the solder joint. Except where noted, make sure that the part is seated against the PCB
before soldering. This is especially important for the connectors and LEDs; if they’re not
installed right, the cabinet end panels will not fit properly.
Circuit Board Assembly
Note: You can build your UKA-3 without connectors, switch or LED indicators if you wish to
integrate it into your own gear. An example would be for mounting the UKA-3 inside an existing
or new design tube amplifier or transmitter. The JP1 connector can be used to connect to your
own gear without using the connectors. See the section below entitled, “Using JP1”.

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□Install the 1N4732A Zener diode in location D1.
If you can’t read the part number on the diode, D1 is
larger of the glass bodied diodes. Be sure to
correctly orient D1 so that the band on one end of D1
is on the same end as the stripe on the board.
□Install the five 1N4148 diodes in locations D2, D3,
D4, D5 and D6. Again, make sure the band on one
end of each diode is oriented as shown by the stripe
in the part outline on the circuit board.
□Install the 470 Ohm resistor in location R1.
□Install a 220 Ohm resistor in location R2.
□Install the 100 K Ohm resistor in location R3.
□Install 1K Ohm resistors in locations R4, R5 and
R6.
□Install the 2N7000 MOSFET transistor in the
location marked Q1. Be sure to orient the flat side of
the transistor as indicated on the circuit board.

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□Install the electrolytic capacitor (this part may be
10 or 100 µF) in the location marked C1. Make sure
the capacitor is oriented properly, with the positive
(longer) lead on the side marked “+”. Before
trimming the leads, tilt the capacitor toward the
center of the board as shown so it will clear the top of
the cabinet later.
In the following steps, it is important to make sure the connectors are all fully seated against the
circuit board, and that they are straight both horizontally and vertically. If you are installing the
kit in a cabinet, you may want to slide it into the cabinet to check the fit and make sure the
connectors are properly installed (see “Cabinet Assembly” below for details).
□Install the coaxial power connector in the location
marked POWER. Be sure it is seated flush against
the circuit board.
□Install the 3.5mm stereo jack in the location
marked INPUT.
□Install the RCA connector in the location marked
OUTPUT.
□Install the power switch in location S1. The
pushbutton end faces away from the center of the
board as shown. Push the round pushbutton switch
cap onto the end of the actuator until it snaps into
place, if it is not already attached.

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□Install the LED indicator block in the location
marked LED. Be sure to orient the part so that the
red LED lenses face toward the end of the board.
These will overhang the end of the board and fit
through holes in the end panel of the cabinet (if you
are installing in a cabinet).
□If you are building the standard option of the kit,
install the socket for the solid-state relay K1. The
notch on the 6-pin IC socket should be on the end
closest to the connectors (the right side).
After soldering the socket in place, you can insert K1
into the socket. Make sure the notch on one end of
K1 corresponds with the notch on the socket.
□If you are building one of the optional
configurations with the larger 4-pin K1 relay, bend
the pins 90 degrees to allow the relay to mount
horizontally. The pins or metallic area of the relay
should not be touching any other components,
although the epoxy part of the case may touch C1.
□Check the board for stray leads, solder bridges or other problems and fix as needed. Trim all
leads close to the bottom of the board with a pair of small flush or diagonal cutters. This is
especially important if you will be mounting your UKA-3 in the aluminum enclosure.
Cabinet Assembly
To use the optional aluminum cabinet, first make sure you have trimmed all leads as
close to the board as possible. Test fit the board into the cabinet by sliding it into the
second slot from the bottom. Make sure the board can slide fully into the cabinet. If you
did not get the RCA connector fully seated, they may need to be re-positioned. Make
sure none of the leads contact the inside of the cabinet.

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The cabinet end panels are installed using two flat head screws on each end. If you find
that the connectors don’t line up with the holes, you may have the board in the wrong slot
OR you may have the end panels upside down.
Carefully peel the backing from the supplied label. Carefully line it up with the
connectors, and align it with the lower edge parallel to the edge of the cabinet end cap.
Attach the label to the cabinet, wrapping the ends around the sides of the cabinet. You
can use a sharp blade such as a razor or an X-Acto knife to trim the ends of the label even
with the top groove on the side of the cabinet for the best appearance.

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Using the UKA-3
The Active-Low input is on the tip of the 3.5mm stereo jack. It is used for most straight
keys, bugs, electronic keyers, amplifier keying relays or transistors, foot switches, etc. It
is in series between the input side of the solid-state relay and ground. Shorting the
ACTIVE-LOW input activates the output of the solid state relay K1, keying the attached
transmitter or transceiver. The current through the ACTIVE-LOW connector will be
limited to no more than 20 to 25 milliamps. The ACTIVE-LOW input is protected from
high positive voltages up to 60 V by a diode, but most not be driven below ground
potential (0 Volts). If you only plan to use the ACTIVE-LOW input, you can use a
3.5mm mono plug.
The IN HI input is normally used for computer keying, but can be used for any signal that goes
to a high level when keying and near or below ground when not keyed. This input is pulled low
to ground by 100K Ohm resistor R2. Applying a positive voltage (approximately 3V or higher)
to the IN HI input turns on Q1, which turns on K1’s output and keys the rig. The MOSFET gate-
source voltage is rated for plus or minus 20 Volts maximum, meaning it will easily tolerate
computer parallel or serial port voltages.
Many programs use the standard computer port setup established by NA and CT. When using a
program such as this, the IN HI signal should be a positive logic signal to key the rig. Here’s a
table showing connections for various types of serial and parallel port connectors:
If you are not using the IN HI input, it can safely be either left floating (open) or
grounded.
Alternate Power
Your UKA-3 is designed for a nominal 12V power supply. The acceptable power input
voltage is from 10 to 14 Volts, AC or DC. If your power source varies significantly from
this, you may need to make a couple of minor changes to the power supply circuitry, as
shown in the table below.
LPT
25-Pin Serial
9-Pin Serial
IN HI input
17
20
4
3.5mm plug sleeve (ground)
18
7
5
Supply voltage
Recommended R1 value
Recommended R2 value
3V
None (jumper R1 with wire)
100 Ohms
5V
470 (Omit Zener diode D1)
220 Ohms (unchanged)
6V
100 Ohms
220 Ohms (unchanged)
9V
220 Ohms
220 Ohms (unchanged)
16V
560 Ohms 1/2W
220 Ohms (unchanged)

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Using JP1
You can build your UKA-3 into your own equipment, or in a custom enclosure if you
wish. The JP1 connector can be used to connect to your equipment without using the
connectors. Connections should be made as follows:
JP1 Pin
Function
PWR+ / GND
Power input. This is used to supply DC power only to the UKA-3,
and is not switched. Do not apply AC power to these points.
IN LO / GND
Low keying input, same as the tip of the stereo connector. Ground
to transmit.
IN HI / GND
High keying input, same as the ring of the stereo connector. A
positive voltage of 3V or more will transmit.
P LED / GND
Power LED indicator output; ~ 4.7V DC current limited with a 220
Ohm resistor when power is applied.
K LED / GND
Keyed LED indicator output; ~ 4.7 V DC current limited with a 220
Ohm resistor when the output is active (keyed).
+ OUT
Connected to the center pin of the OUT RCA connector. May or
may not be polarity sensitive, depending on build option selection.
- OUT
Connected to the outer shell of the OUT RCA connector. May or
may not be polarity sensitive, depending on build option selection.

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Support
Should you need support, have questions, have feature requests or bug/problem reports, please
feel free to contact me via email at [e-mail]. I will make every effort to
respond as quickly as possible.
Warranty
All parts in your kit are guaranteed against defects for one year from date of purchase. This
warranty does not cover damage due to incorrect assembly, improper soldering or wiring,
overvoltage, static damage or other misuse or abuse. If you have problems, please contact me via
email to arrange for an exchange or replacement part. If you accidentally damage a part, don’t
panic –just contact me, replacements are not expensive.
Web: http://www.HamGadgets.com
Email: [e-mail]
Phone: [phone]
Specifications
Input power: 12 to 13.8 V nominal, DC or AC
Input current: 40 mA max
IN HI voltage: -20 to +20 Volts absolute maximum, +/- 12 V or less recommended
IN HI impedance: 100 K Ohm
IN LO voltage: 0 to +60 Volts absolute maximum, 0 to +36 V max recommended
IN LO current: 22 mA max
Output voltage: 400 V max (standard build option)
800 V max (high voltage/current option)
Output current: 240 mA max (AC or DC) (standard build option)
700 mA max (high current option, no heat sink)
1.8A max (high current option, with 5°C/W heat sink)
Output ON resistance: ~6 Ohms typical, 10 Ohms max
Turn-ON time < 1 millisecond typical, 5 ms max
Turn-OFF time < .05 millisecond typical, 0.2 ms max
Board dimensions: 81mm x 50.5mm, excluding connectors/LEDs/switch

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PCB Layout Diagram
Schematic Diagram