The Tale of a DIY CW Paddle Key

My first DIY Paddle Key 

Way back in 2014 I built a two paddle cw key from basically trash; an empty Tic-Tac box, piece of phone cord, a bunch of popsicle sticks, 3 screws, 3 nuts and a 3.5mm Stereo phone plug. 

With this I attempted to practice morse code sending with the Ham Gadgets Pico-Keyer.

The popsicles sticks levers proved to be too stiff and I swapped them for some FR4 PCB material cut into paddle shapes.

Fast forward eight years and the PCB levers were getting too limber. Squeezing the paddles together cause the PCB levers to curve around the center bolt contact without touching.

In replacing the PCB paddles with a couple pieces of spring steel, I decided to do a redesign and ditch the Tic-Tac box for an open frame key. 

Old PCB levers, trial fit of steel levers
decided to get rid of Tic-Tac box

I used a scrap piece of 1/2 inch plywood for a wood base and a wooden lever mount. I glued and stapled the two pieces of wood together, drilled holes and added a ring terminal and more hardware to the center bolt. I attached the steel levers with a bolt, ring terminal and washer on each paddle. Soldered the three ring terminals to the phone cord, Secured the phone cord with zip ties and placed heat shrink tubing over the paddle ends.   

Finished (?) Two Paddle CW Key

The action is a little stiff, I might have to bevel the sides on the forward end of the wooden level mount to allow the levers to easily touch the center bolt.

As I have the $12 Chinese Paddle as my main paddle this key will serve as a backup.

05 Mar 2022

CW Key - Double Paddles - eBay $12

Made in China 

My G90 has a CW decoder with the built keyer if needed. I tried DIY paddles with some varying success. These were build using all sorts of rubbish, spring clothes pins, biner clips, broken hacksaw blades, an old 2 switch wired computer mouse, popsicles sticks, scraps of copper clad PCB material. etc. I even made a couple touch pad triggered FET switches in an altoid tin. They are not very appealing and tend to break easy and fall to bits. 

On eBay there is a dozen sites that offer what looks like CW paddles off the pages of thingiverse. These are from China and run around $12 as a kit and $25 assembled.

CW Paddles Kit Parts List

3.5mm stereo M-M cable (~4 Feet / 1.5 Meters) 

Plastic Box (6.5cm x 4cm x 3cm) in two parts; box cover and base.

Plastic Paddles (1 left & 1 right)

Red Wire (2.5 inches / 6.4 cm) 2 pcs

Black Wire (2.5 inches / 6.4 cm) 1 pc

Black Heat Shrink Tube (2.5 inches / 6.4 cm) 1 pc

3.5mm Stereo Jack w/ Nut

Brass Ring Terminals - Brass 3 pcs

Brass Bolt 1 cm -  2 pcs

Brass Bolt 2 cm -  1 pc w/ washer brass 2 pc

Brass Nuts - 2 pcs

Steel Bolt 2.5 cm - 2 pcs

Steel Spring 1.5 cm - 1 pc

Magnets - 4 pcs

Steel screws black 1 cm - 4 pcs 

CW Paddle Kit 

Tools I Used:

Soldering Iron w/ rosin core solder

Tip Cleaner

Continuity Checker

Wire stripper 

Hobby knife

Needle nosed Pliers

Flush Diagonal Cutter

Small Phillips screwdriver

Wire Crimper

"Helping Hands"

3X reader glasses

Tools I Used

Build Instructions:

Note: In fitting the Stereo Jack into the Base of the Paddle. I had to clean out the hole and flanges in the base of any excess material with my hobby knife.  Lightly sanding the plastic sides of the jack that sit next to the flanges would improve the fit. I had to gently scrape around the top of all the bolt holes to get the bolts started. Be sure all bolts are square to the part they will thread into.

1. Strip the three wires back 3.5mm/ 0.125" one side only.

2. Crimp ring terminals on wires,  solder ring terminal.

Soldering the crimp connection on ring terminal

3. Cut Heat Shrink into 6 pieces 1cm long. Shrink 1 piece of tubing over each ring terminal shaft. Hold on to remaining 3 pieces for later.

4. On the jack determine which solder terminals are the tip, ring and sleeve with continuity checker or ohmmeter. 

5. Check for fit by placing jack into the flanged hole in base. Sleeve solder lug should  be down. Use hobby knife, drill bit, sandpaper, etc to clear any material obstructing the jack placement. Keep clearing material until jack is a snug fit.

6. On jack gently bend the tip solder lug to the left side of jack and bend the ring solder lug to the right side of jack. (Standard set-up for right handed paddle operators)

Jack wires soldered and jack mounted to flange in base.
(notice I left the black sleeve wire  25mm/1.0" too long.)

7. Check for correct length of black wire to be connect to jack sleeve, place ring thru slit in base and fit into keyhole underside of base.  Black wire only needs to be long enough to reach past the sleeve solder lug.

8. Remove jack from base. Trim off excess black wire leaving enough to strip back 3.5mm/ 0.125". Trim both red wire back 3.5mm/ 0.125".

9. Place remaining cut pieces of heat shrink tube from step 3 on over each wire. Solder red wires to tip and ring. Solder black wire to sleeve.

10. Reinsert jack into flange and orient the jack so the sleeve lug is down be sure ring terminal goes thru slot to underside of base. Secure jack with nut provided.

Underside of base with sleeve ring terminal secured

11. The sleeve ring terminal on black wire is positioned so the ring terminal will fit into the keyhole over screw hole. Place one brass washer under ring terminal. Secure with the 2 cm brass bolt and second washer. The bolt is screwed all the way thru the base to form a post contact between the paddle positions on top of base. Don't over tighten.

12. Take one of the 1 cm brass bolts, place a brass nut halfway down the bolt. Position the tip terminal on red wire outside the left paddle over the screw hole, turn the bolt and washer into the screw hole. The terminal should be captured on the bolt between the nut and the paddle. Set aside for now.

13. Repeat step 12 for the terminal with the red wire connecting the ring of stereo jack and the right paddle. 

14. Use the 2.5mm steel bolts to attach paddles to the base. Do NOT over tighten. Just snug down enough so paddles swing without being lose.

15. Install the steel spring between the paddles, placing ends of spring into the indentation in each paddle. (May want to use a loop of string loosely around paddles to keep spring in place until paddle is adjusted and cover is on)

Adjusting the gaps between the paddle bolts and post contact.
(Notice I used the cover upside down to limit outward paddle travel
and keep from losing the spring, you could also use a loop of string.)

16. Adjust brass bolt in each paddle by screwing in or out to maintain an equal gap between each paddle with the center bolt. Once adjusted tighten brass nuts to keep wires in place next to paddle lever and lock the adjustment.

17. Install a magnet on the underside of each corner of the base by starting  a black steel screw into each magnet hole. 

18. Place cover over the base and secure by fully tightening the black steel screws.

(You may now remove loop of string from paddles as cover opening limits the paddle outward travel and keeps the steel spring secure.

Congrats,

 your $12 Chinese CW double paddle key is now complete. 

Let's celebrate by ordering a big dish of beef chow mein. 

K6ARK Antenna / G90 Back Yard Portable

 23 Feb 2022

With the temperature in the 50 degree F today, I decided to play radio in the yard to see if the K6ARK antenna kit I built as a 9:1 UnUn for an EFRW would tune up on the Xiegu G90 ATU.

AB1OP Minimal Portable Operation Bag

I am happy to report the Xiegu G90 was able to tune the K6ARK 9:1 UnUn EFRW to under 1.5 to 1 on the 80, 40 and 20 meter bands. I didn't do much else I played with the Xiegu G90 CW decoder on a couple transmissions running at 20-25 wpm at that speed my head can only tell that CQ was sent and a few scattered letters here and there.

AB1OP Portable Operations Equipment:

A) A medium capacity tactical style backpack ($40)

B) A 6Ah LiFePO4 battery ($30)

C) Old Android 4.4 KitKat 7" Tablet with VLS logger App ($50 back in 2014?)

D) 6000mAh USB power bank ($10) located between tablet and G90

E) DIY PVC Antenna winder (~$2)

F) Xiegu G90 20W Transceiver & Microphone ($450 new)

G) Earbuds ($1)

H) DIY CW paddles ($1.50 for stereo plug & PCB) on top of G90

I) DIY 9:1 UnUn in 80mm X 50mm plastic box. ($20 in materials)

J) DIY F connectors to Power pole connectors cable ($5)

K) Power Meter with Power pole connectors ($16 meter, $5 connectors)

L) DIY Fused power pole to white male connector cable with clamp on ferrite choke ($10)

M) K6ARK Kit as built to 9:1 UnUn modified for G90 ($20 kit, $5 mods)

Not Pictured:

N) Antenna wire 26awg 41 feet, Counterpoise wire 26awg 17 feet ($13 / 100 feet)

O) Two 7.2 meter (~21ft) telescoping Carbon Fiber fish poles. ($13 + $6 shipping each eBay - up to 4 weeks wait for delivery from China)

P) Strong and light cord 50-100 feet ($4-$7)

Q) Bungee cords to tie poles to stationary objects ($7)

Compare the size difference from the K6ARK and the M0UKD 9:1 UnUn

Here we can see the size difference of the two 9:1 UnUn(s) used for an EFRW antenna.

The K6ARK (attached to G90) extends only 1.25 inches beyond the UHF-BNC adapter.

The M0UKD (atop G90) extends almost 5 inches beyond the UHF-BNC Adapter.

Granted the M0UKD UnUn is built around a T130-2 toroid and a 80mm by 50mm project box. It has a lot of empty space in front of the toroid and the 4mm banana jacks protrude excessively out the front and the side. 

I will keep the M0UKD UnUn if I ever get a small (100W or less) linear amp for my rigs. 

The success of the K6ARK kit build is enough to order a 2nd K6ARK kit to be built as a 49:1 UnUn EFHW antenna to replace a project box built 49:1 UnUn based on a ft140-43 toroid. I already have the ft82-43 toroid, plenty 26 awg magnet wire and 1 inch diameter heat shrink tubing needed to modify the kit to the G90 power level. 

K6ARK Antenna Kit

 17 Feb 2022                                                                                        Ralph AB1OP 

K6ARK Adam is an active SOTA QRP operator. He has developed a small QRP Antenna (Matching) Kit currently sold on Amazon. The kit comes with your choice of either a Male or Female BNC connector as the feed point.

On his web site he has instructions of how to build the kit in one of three different configurations; 

1) 49:1 UnUn for EFHW End Fed Half Wave 

2) 9:1 UnUn for EFRW End Fed Random Wire 

3) 1:1 BalUn for a Dipole.

Website: https://k6ark.com/

My Build: A 9:1 UnUn for EFRW antenna

I decided to purchase a male BNC kit. I need to modify the kit
to handle the maximum power  my Xiegu G90 can produce (20W). I will build it as a 9:1 UnUn for a EFRW antenna to take advantage of the G90 built in ATU. 

K6ARK Kit (Male BNC Version)

 K6ARK Adam suggested for G90 use, adding an FT82-43 toroid to nest the FT50-43 toroid into. The combined toroids would increase the power handling to 30 Watts. 

Adam offered to send me additional 26 AWG magnet wire since the kit supplied 28.25 inches of wire. I had plenty on hand from other projects. I calculated I need at least 36 inches, I cut off 40 inches from my stock as insurance.

Replaced the 3/4 inch heat shrink tubing supplied in the kit with a 1 inch diameter piece of heat shrink tubing and added some additional small diameter pieces to tubing as needed. 

I also purchased some 2mm banana connectors to attach the radiating and counterpoise wire elements.

Additional pieces to modify kit for my G90
The female BNC was used as a heat sink when soldering the male BNC
Notice the 3.5X reading glasses 

 Following K6ARK instructions from his website I was able to complete the kit.

I did have to bring out the "helping hands" to hold on to the PCB while soldering.

a) Soldered the radiating and counterpoise leads to the PCB and pulled the leads thru the strain relief holes provided in the PCB.

b) Wind the 10 turns, twist a tap, wind 20 turns on the combined toroids.

c) Burned off the enamel on the three toroid leads. Arrange the leads to match the holes in the PCB and solder. 

d) Tilt the toroid windings and solder the male BNC to the PCB. 

e) Shrunk Tubing over the assembly to cover and protect the windings. 

f) soldered 2mm banana connectors on the short wires for antenna and counterpoise wires.

I also soldered 2mm banana connectors on a 41 foot 26 awg wire for the antenna and on a 17 foot 26 awg wire for the counterpoise. I shrunk red HS tubing on the antenna connectors and black HS tubing on the counterpoise connectors.

Complete EFRW antenna on a 1/2" PVC wire winder
The short PVC sections can be detached and used as insulators

Compare the new K6ARK EFHW portable antenna system with my portable HB EFHW system used during the 2020 ARRL Field Day.

HB EFHW compared to K6ARK EFRW
Green spool of support cord and UHF(PL-259) to BNC(female) adapter is common to both

HB EFHW consists of 

a) 49:1 UnUn based on a ft140-43 toroid in project box with a female BNC.

b) ~66 feet of 18 awg wire on a 9" spool.

c) 25 foot RG-8X coax with BNC male to male.

d) Large insulator to tie antenna wire to support cord.

e) UHF(PL-259) to BNC(female) adapter.

f) 100 foot spool of strong cord for support line.

K6ARK EFRW consists of:

a) 9:1 UnUn based on a combined ft50-43 & ft83-43 toroids on a male BNC kit.

b) 41 feet 26 awg wire.

c) 17 feet 26 awg wire.

d) 1/2" PVC wire winder, one of the short pieces can be detached and used as an insulator to tie the antenna wire to support cord. 

e) UHF(PL-259) to BNC(female) adapter.

f) 100 foot spool of strong cord for support line.

In Conclusion: With Adam K6ARK antenna matching kit you have the smallest, lightest feed point connector possible, you can leave the heavy coax cables and large gauge antenna wire in your shack. If portable QRP operation is your thing whether atop a mountain summit, sitting of a park bench or just hanging out in your backyard you will enjoy using this kit. 

JDS6600 Signal Generator vs. PLJ-8LED Frequency Counter

Okay here's the thing, two recent purchases, a JDS6600 Signal Generator and a PLJ-8LED Frequency Counter, when connected together display about 42 Hz difference. Which do I believe?
Looks like I have to dig out the Hantek 6022BE USB DSO for the tie breaker.  I hope!

MiniPA 70 watt HF Amplifier Unboxed and Assemble Transformer Cores

22nd of May, 2018  Hope everyone is enjoying Spring!

Watched as much W5KUB coverage of Hamvention 2018 last weekend as was allowed by the XYL and the ever present "Honey Do" list. Been busy in Real Life so bench activity has suffered.

New Project - MiniPA 70 watt HF Amplifier Kit

These kits are current available on eBay for $15-25 USD under various headings.

The Pluses:

• Small 
• Runs on a 13.8Vdc supply.
• Cheap

The Minuses:

• Comes with NO DOCUMENTATION - Need to go online even for the schematic.
• Not Complete - Need to buy several other components to have a working Amp

NOTE: Here are a few youtube videos and websites discussing this kit that I found helpful
.
https://www.youtube.com/watch?v=CeegQYZ25J0

http://pa-11019.blogspot.com/2016/11/diy-kits-70w-ssb-linear-hf-power.html

http://www.oe1cgs.at/wp-content/uploads/2018/02/50W-HF-PA.pdf

https://www.dk9jc.de/blog/equipment/142-diy-kits-70w-ssb-linear-hf-power-amplifier-ft-817-kx2-kx3

Google "SSB HF 70W AMP" key words for latest links.

NOTE: What is NOT included
 (Needed to make a working HF Linear Amplifier for Amateur Radio.)

• HeatSink
• Thermal Paste (Heatsink Compound)
• Bolts / machine screws (6) to mount PCB and TO-220's to Heatsink.
• 12Vdc Fan
• Enclosure
• Panel mount SO-239 connectors
• Power supply connector
• Power Switch
• Fuse and Holder
• Low Pass Filter for desired Ham band(s)
• RCA female panel connector for PTT
• 50 Ohm COAX and Hookup wire
• Power on LED (optional)

MiniPA 70 watt HF Amplifier:  Unboxed

Here is the kit parts all laid out:

As usual with Chinese kits no documentation is included, all parts were loose packed in a bubble wrap bag (no ESD protection for FETs) Two extra TO-220 insulation pads and washers were included. 

The PCB is only about 2" x 4" inches - my kit had all the SMD components already soldered to the PCB,  some of these kits do not so "buyer beware" check auction listing closely, an extra $2 may save you 2 hours of bench time.
The PCB also has Die-cut pieces that are cut out for the T1 & T2 transformer core assemblies.

MiniPA 70 watt HF Amplifier: Assemble the T1 & T2 transformer cores

Here is the Transformer cores ready to solder the tubes to the PCB pieces

Transformer cores after soldering the PCB pieces to the tubes.

Checking PCB for fit on Heatsink I brought

Let's Build Something - Audio Amp

May 9, 2018 

Let's Build Something - Audio Amp

Pete Juliano N6QW co-authored a series of articles for "QRP Quarterly" over three years ago titled "Let's Build Something". The "something" was a beginners Home Brew SSB Transceiver for 40 Meters broken up into two main parts and further sub-divided by each stage.

Part I was a Direct Conversion Receiver and the first stage was a discrete component Audio Amplifier.  Pete's build method was a Manhattan style using W1REX MeSquares.

  

I converted the audio amplifier circuit to K7QO Chuck Adams' "Muppet" style PCB design. I use the free ExpressPCB software (run under WINE in Linux), to design, then print the top copper layer to a PDF.  Import the PDF into GIMP to "flip" the image.  The "flipped" image is then laser printed on glossy photo paper. Ready to do the toner transfer to bare (shiny & clean) copper clad pcb board. Which is then etched.

Sound like a lot of steps but it goes quick after you have the design.

 PCB DESIGN

"FLIPPED" IMAGE

COMPLETED PCB READY FOR SOLDER

K7QO Chuck, uses a thermal laminator to generate the heat and pressure to transfer the toner to the PCB material, He has it down to a science. I use a GE clothes iron than does the job as long as I leave a wide margin with no traces from the edge of the PCB.

The Mouser order is here with the SMD parts so I'll start melting solder in the next couple days. (Real Life has been interfering with bench time!)

73

AB1OP Ralph

Addendum:

LBS_AUDIO_AMP_partslist
part ID for AB1OP PCB diagram
================================
C1  10 NF
C2  100 NF
C3  100 NF
C4  150 PF
C5  10 UF ELECTROLYTIC (observe polarity)
C6  4.7 UF ELECTROLYTIC (observe polarity)
C7  470 UF ELECTROLYTIC (observe polarity)

R1  100K
R2  10K
R3  100 OHM
R4  1K
R5  470 OHM 1/2W
R6  10K POT
R7  100K
R8  10K
R9  10K
R10 1 OHM 1/2W
R11 1 OHM 1/2W
R12 1.3K

D1  1N4148 (observe polarity)
D2  1N4148 (observe polarity)

Q1  2N3904 NPN (observe orientation - flat right)
Q2  2N3904 NPN (observe orientation - flat right)
Q3  2N3904 NPN (observe orientation - flat right)

Q4  2N3906 PNP (observe orientation - flat left)

May 7th, 2018

Converting to 4-pin Microphone Connectors

 Photo above: Diagrams of the connections for each part. (solder lugs side)

On the Bench: 
Decided to standardize my microphone connection for my two Bitx transceivers.  The four 4 pin Foster connector was chosen for ease in converting cheap Baofeng Speaker-Mics or old CB microphones to the task.

Photo above:
Here is my second Bitx Xcvr being prepped for a microphone connector transplant.  The original connector I installed a year ago was an eight pin Foster, (must have been the cheapest on the search!)

Photo above:
My two Bitx Xcvr's sporting the 4 pin microphone sockets. The top one has no internal speaker. It was encased in an old PC-ATX power supply chassis and was an early microphone connector transplant recipient!  Originally I had installed two stereo jacks (2.5mm & 3.5mm) so I could use an unmodified Baofeng Speaker-Mic 2 prong plug.  A problem arose when after leaving the mic plugged in for a long time the jack contacts would weaken enough for the plug to shift out and short the PTT contact through the speaker coil to ground, (No DC blocking cap on speaker+ line in the mic, must have cost too much in production.) This caused the powered on Bitx to transmit uncontrollably. Installing the new 4-pin mic socket and plug took care of the problem and was more secure.

In Summary:
Having the same  microphone connector for both Bitx Xcvrs' is convenient and well worth the time for conversion.