The Charlotte Amateur Radio Club - W4CQ is a general interest radio club serving the Charlotte, NC area. We generally meet on the first Saturday of every month at 10:00 AM at the Salvation Army Divisional headquarters, our served agency. We're located at 501 Archdale Drive in Charlotte, NC. 28217, near I-77 Exit 4 (Nations Ford Road).

Check our Calendar of Events for changes and additions to the meeting schedules.

Feel free to come by and meet the members. We have a working club station on site with active HF, VHF and UHF equipment. This is a secured facility, please arrive no later than 9:35 AM to assure access.

 

Use Safety Wire Pliers to make twisted pair from two strands of #14 THHN.

#16 and #18 bifilar wire can be used for lower power applications, however #14 twisted pair must be used for Legal Limit power.

Twisted pair wire is great for noise canceling and will allow more turns of heavy wire to fit thru the center of a toroid.

(The  needed 15-19 Bifilar windings of #14 will not fit thru a ft-240.)

 

Glue three FT -240-43 toroids together using cut paper bag as a spacer.

The layer of fiber will facilitate a good bond that can be separated with a razor if needed.

As a general rule, a single FT-240 can handle a transmitter capable of 200w, a pair is good for 500w, and three will handle 1500w with reasonable headroom.

True power handling will be determined by the impedance mismatch per frequency.

Wrap toroid using the twisted pair and terminate as follows…

I was able to get 16 wraps of #14 around the toroid.

15 to 19 turns are needed to make the proper transformation.

 

You will need one SO-239 connector which can be can be found here.

I like to use copper strap to tie the ground and SO-239 together.

It can be bought here for $4 per 10′.

Solder your connections and tin the wires to be connected to the SO-239.

I like using a strand of wire from inside the THHN to make a “basket” to accept the tinned transformer connections.

It makes it much easier to get a good bond once the transformer is inside the waterproof box.

Mount in to 4x4x2 watertight box.

I fill the center of the toroid with silicone to help hold it in place.

The silicone dries into a “suction cup” that holds better than hot glue or adhesive, but is easily removable if needed.

I use closed cell foam to brace the sides of the toroid to the box.

This is the finished “Legal-Limit” 4:1 UNUN.

 

I built this 4:1 UNUN to replace my 64:1 UNUN.

The following videos show the 4:1 significantly outperforming the 64:1 on 40m. 

90′ Vertical 4:1 UNUN 100w SDR test Boone

90′ Vertical 4:1 UNUN 100w SDR test Boone

The 64:1 is pictured below.

1. Yaesu 991A with SP-10 Speaker and M-90 Mic
2. ICOM 7610. On top of the 7610 is a Yaesu SP-2000 speaker that works great just not with the ICOM. I am selling it for $125 dollars.
3. Picture of my vertical OCF flag pole antenna @ 16′ shortly being replaced although it tunes great on 80-6M
4. Picture of my Diamond X50A above the shack in the attic.
5. Also pictures is my Yaesu VX-8 mobile transceiver. It is know in the survivalist community as it broadcasts on all VHF and UHF bands.
6. I power the 991A with a Samlex SEC-1235 and the ICOM with an Astron VS-350M
7. You’ll see I am running three monitors to the back of my Macbook Pro. I leverage SDR-Control as seen in the pictures for FT8 (the map), SDR (the specturm) and the far right monitor for my log work.
8. I also took pictures of my RF Filter at the connection point of the 7610 and the common mode choke at the mid-point of my coax wire. I get zero common mode.

Video of 3D printing a balun box

Link to 3D printer files

This is the easiest balun to make.

Simply wrap two pairs of 16ga red and black wires 13 times on  opposite sides of a #31 mix toroid.

Twist the black wires together from each side, and the red wires together form each side.

The attach the black pairs to the shield side and the red pairs to the center conductor of each SO239.

Mount the completed balun in a box.

Note: This particular box required the balun be mounted before soldering.

 

No need to buy a radio or a hotspot!

All you need is a connected Windows PC with a Mic and Speaker. (I use a Bluetooth or USB headset)

Click to download dudestar_x64

The WB4ETF Fusion Room is #02145

Make it official with a Motorola USB Headset for $18.99!

 

Video of me using PC to talk D-Star to KA4YMZ 1.2ghz repeater

Video of me using PC to talk Fusion to WB4ETF 147.060 repeater.

(These are short because I was jamming myself with the echo of my own voice.)

 

NOTE

Your Call sign must be registered with D-Star and you must have a DMR-ID to use DudeStar.

You can register for D-Star here.

You can get a DMR-ID here.

 

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Upcoming Events

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01May2024

W4CQ Trader Net

W4CQ Trader Net

From 7:30pm until 8:30pm

At W4CQ Repeater 444.450mhz +5 / 82.5 tone

Find out more...

04May2024

Monthly Club Meeting

Monthly Club Meeting

From 10:00am until 12:00pm

At W4CQ Radio Room @ Salvation Army Community Services Bldg.

501 Archdale Dr Charlotte NC 28217

Find out more...

04May2024

License Testing

From 11:00am until 3:00pm

At Must Make Reservation!

Find out more...

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