HRS CW Hotline User manual

Ham Radio Solutions
CW Hotline
Assembly Manual
Version 0.5 1-20-2022
The Ham Radio Solutions CW Hotline is a fairly simple construction project that can usually be built in
about two hours. You will need a low wattage pencil-type soldering iron with a small tip, some thin
solder, a pair of diagonal cutters and a Phillips head screwdriver. Desoldering braid may be required
to correct soldering mistakes. Be sure to wear eye protection when soldering and cutting leads.
Most parts, except for a few at the end, should be inserted into the side of the PCB with the jack
silkscreens J1, J2, J6. Unless otherwise indicated, parts should be flush with the PCB. After
inserting, turn the board over and solder the leads to the pads on the other side. It is often helpful to
just solder one lead, then ensure the component is correctly positioned before soldering the
remaining leads. Be sure to only solder the correct pads, and do not let any solder touch any other
pad or trace. Trim any excess leads with diagonal cutters after soldering each batch of components.
The checklist will be useful to ensure all components are properly assembled.
Build slowly and follow the instructions. Use the images to confirm component placement. CW
Hotline may be built with a straight key, Iambic paddles, or neither. It is recommended to drill the
case first, then use the case to aid in placing some components on the PCB.
Schematic

CW Hotline includes a case, but it must have holes drilled and cut. A drilling template should be printed out at
100% size. Don’t print with “Fit to page”.
Case Parts
CW Hotline case
Printed case drilling / cutting template
4 - M2.6 x 8mm black screws
Vinyl label
Case Tools Needed
Scissors
Tape
X-acto knife / Safety pin
Drill with 5/64”, ⅛”, 5/32” ¼” (2mm, 3mm, 4mm, 6mm) drill bits
Emery board
Case Assembly
Measure the 1” or 2 cm reference square on the template to ensure it was printed at the proper scale.
Cut out the template cross shape on the outer solid lines.
Remove the thin bottom plate of the case and set it aside. Wrap the template around the outside of the
case such that the 4 edges of the template just reach the edges of the case. Use tape to secure the
template to the case.`
Use a safety pin or knife tip to mark/dimple the centers of the holes. There are 10 holes on the top, 3
on the long side, and 2 overlapping holes on the short side.
If including the straight key or paddles on the PCB, use an X-acto knife to mark the location of the
rectangular hole on the other short case side, along the dotted lines.
Remove the template and tape. The template will help to reference hole sizes.
Drill out all 15 holes with the 5/64” / 2mm drill bit.
Enlarge the LED, button, and side holes with the ⅛” / 3mm drill bit. Do not enlarge the 7 speaker holes.
Enlarge the button and side holes with a 5/32” / 4mm drill bit. Do not enlarge the other top holes.
Enlarge the 5 side holes with the ¼” / 6mm drill bit. To avoid cracking the case, step up through
multiple intermediate bit sizes 1/32” / 1mm at a time or use a step bit.
Use an X-acto knife to convert the 2 holes on the short side to an oval that will accept the USB cable. A
Rat tail file may help.
If including the straight key or paddles on the PCB, use an X-acto knife, hacksaw, or nibbler tool to
remove the rectangular hole on the case side. Be careful with this step! Sewing thread can also work
as a cord saw. Smooth with a file or emery board.
After PCB is assembled (see instructions below)
Enlarge holes as necessary to fit the PCB into the
case.
Secure PCB to case with 4 screws in the corner
holes. Do not over tighten or the plastic may crack.
Close case with the removed plate, with the notched
end near the rectangular hole.
Apply vinyl label.

PCB Parts
PCB - CW Hotline Printed Circuit Board
R1, R2, R4 - 680 ohm resistors (blue-grey-brown)
R3 - 10K ohm resistor (brown-black-orange)
R5 - 330 ohm resistor (orange-orange-brown)
C1 - 0.1uf capacitor (marked 104)
Q1, Q2 - 2222A NPN transistors
J1, J2, J6 - 3.5mm stereo TRS jacks
2 1x8 male header posts for ESP8266
ESP8266 in WeMos D1 mini form factor, programmed with
CW Hotline firmware
D1 - green 3MM LED
D2 - red 3MM LED
SW1 - SPST momentary button
1 small speaker
1 small piece foam tape
1 MicroUSB cable
PCB Assembly
Install resistors R1, R2, & R4. For each resistor, bend the
leads near the bulb 90 degrees and parallel and insert into the
PCB. Orientation is not important.
Install resistors R3 & R5 as resistors above.
Install capacitor C1. Orientation is not important.
Install transistors Q1 & Q2. Be sure to match the orientation with the flat side on the silkscreen. Leads
are often very close together so do not let solder contact between any 2 leads.
Install stereo jacks J1, J2, J6. Ensure all jacks are flush with the PCB.
Install 2 1x8 male header posts into PCB. Insert the short sides of the post in the PCB holes. Solder
just one pin each on the other side of the PCB, ensure the pins are perpendicular and flush with the
PCB, temporarily test fit the blue ESP8266 PCB, and then solder the remaining pins.
Insert the blue ESP8266 PCB onto the long sides of the previous header posts, being sure to match the
silk screen orientation, with the reset button nearest the upper left corner. Solder only two diagonally
opposite pins to the hole on the top face of the blue ESP8266 PCB and verify the board is flush. Solder
the remaining pins. Do not trim the remaining exposed posts.
Insert the green LED D1 onto the other side of the PCB. The shorter lead, nearest the flat side of the
LED, should go into the square hole. The LED should not be flush with the PCB, but instead a 5/32”
or 4mm gap between the PCB and the bottom of the LED. If the case has been drilled, you can fit the
LED and PCB in the case to set the position for the LEDs to slightly protrude. Solder just one lead and
adjust until the spacing is correct, then solder the other lead.
Insert the red LED D2 the same way as D1.
Insert button SW1 on the same side of the PCB as the LEDs. It should only fit one way and the 2
middle pads will not be used. The button should not be flush with the PCB, but instead 1/32” or
1mm gap between the PCB and the bottom of the button.
Install the speaker leads into pads marked SP1. If the speaker has a connector on the end of the
leads, remove it and strip the insulation. The red wire should go to the square hole. Solder on the other
side. Use the small square of double sided foam tape to stick the speaker to the PCB above the circle.

Decide if the CW Hotline should be built with a straight key or Iambic paddles and follow the corresponding
instructions. If it will be only used with external keys and paddles, both instructions may be disregarded.
Straight Key Parts
1 Straight Key PCB arm
1 PCB wrench for #4 nuts
3 #4-40 ⅜” screws
2 #4 washers
7 #4 nuts
1 knob & cap
1 #4-40 ⅝” screw
Straight Key Assembly
Insert 2 ⅜” screws into the 2 holes nearest the
center of the main PCB with the screw heads
on the LED side of the PCB. On the other side, insert a washer and nut onto each screw and hand
tighten.
Insert the last ⅜” screw into the hole
nearest the center of the PCB arm, and
lightly secure with a nut.
Insert the PCB arm onto the main PCB
on the ESP8266 side through the 2 first
screws, with the third screw through the
PCB hole marked GND. Secure to the
first 2 screws with 2 nuts.
Add the final nut to the third screw on
the LED side of the PCB. This screw
should be rigidly secured to the main
PCB, and the screw head should only
make contact with the plated ring
around the hole on the arm when the
arm is pressed. Using the PCB wrench,
adjust the 2 nuts on the screw so the
head of the screw is just below but
doesn’t contact the ring on the PCB
arm.
Insert the ⅝” screw to the last hole in
the PCB arm with the head on the
ESP8266 side. Remove the cap from
the knob, add the knob to the other side,
and secure with the last nut. Place the cap back on the knob.

Paddle Parts
2 Paddle PCB arms (1 left, 1 right)
2 #4-40 3/16” screws
1 13/32” #4-40 hex standoff (10.3mm
long)
1 #4-40 ⅜” screws
1 #6 steel washer (9.8mm x 1.1mm thick)
2 #4 nuts
Paddle Assembly
Separate the paddle arms from each other
and lightly sand or file the edge where
they were connected.
Connect the paddle arms to each other
using the hex standoff to create the
spacing. Be sure the paddle arm text is on
the outside, the exposed contact pads are
on the inside facing each other. Use the two
3/16” screws through the two large holes in
the paddle arm corners.
Insert the paddle arms tabs into the main
PCB on the jack side.
Solder just one corner of one of the arm
tabs on the LED side of the main PCB,
ensuring the arm is parallel with but doesn’t
contact the main PCB except at the
soldering pad. Once it is in position, solder
the rest of the tab.
Solder the other arm in a similar manner.
Install the washer to the ⅜” screw and
secure with a nut. This washer will be the
contact point for both paddle arm pads.
Insert that screw into the hole on the main
PCB marked GND with the washer
between the paddle arms. Secure on the
other side of the PCB with a nut.
Adjust and rotate the washer so that it is
equally spaced between the paddle arms.
Optionally push or pull the arms slightly
while melting the solder to fine tune the
arm spacing.