Tuna Inductor Coil Data    


"LCT Coil Set Data"


This is the Data I used from Richard, WW8J to build the Inductor Coil Sets.
All the info from his webpage is copied here to have an alternate source.
You can also reach the original information on his website here.






WW8J Link Coupled Tuner Coil Design

From VE3ERP Hamcalc Software Program

And

W4RNL Recommended Link Coupled Tuner Component Values


I have had several requests for design information of the LCT plug-in coil sets.
I would like to say that the design I have chosen is based upon the layout of the tuner,
as well as readily available materials (including coil forms) and components on hand,
as well as the 0.25" copper tubing used for the inductors L1 L2 coil set.

It is not necessary to clone the coil design specifications shown below in order to achieve the same values.
For example, a coil set for 40 meters, L2 with a True inductance of 12uH could be wound with
7 turns of 0.25" copper tubing on an 8.0" form in order to provide an approx. 12 uH value for L2.
This particular coil would not work with my tuner design because
the male plug-in pins would not align to the female mounting receptacle.
The physical properties of any given value inductor can be manifold.

In my design the 12 turns of 0.25" copper tubing for L2 (40 Meters) was chosen to
accommodate the length of the female plug-in support.
In fact, the length of all three coil sets vary from approx. 6.0-9.5 inches.
You may have a different layout for your tuner, or may desire a different value for coil Q,and
therefore the use of the free Hamcalc software program would be valuable in designing your coil sets.
In the design of each of my coil sets, I have found that the derived Hamcalc software arithmetic values matched
very closely the actual measured inductance meter values of the finished coil sets.

You do not need an inductance meter to build these coil sets!
The information given in the tables below was derived from Hamcalc software available from
George Murphy VE3ERP, and was used in the design of the Link Coupled Tuner shown on the previous web page.

Richard Flake, WW8J



40 meter Link Coupled
L2 – L1 COIL SPECS


L2 Coil Specs


True inductance.........................= 12.000 uH

Number of turns........................= 12.000

Coil form diameter...................fd= 12.700 cm. = 5.000 in.

Coil pitch diameter...................d= 13.335 cm. = 5.250 in.

Wire diameter.........................W= 0.635 cm. = 0.250 in.

Pitch (c.c. spacing of turns)......Sw= 1.250 cm. = 0.492 in.

Coil Length...................Lcm, Lgth= 15.002 cm. = 5.906 in.

Coil Length/diameter ratio...........Ld= 1.13:1

Wire diameter/spacing ratio........W/Sw= 0.51:1

Turns per inch (25.4mm).............Tpi= 2.032

Self-Capacitance.....................Co= 8.960 pF

Added capacity required to resonate..Cx= 34.118 pF

Frequency.............................ƒ= 7.000 MHz

Self-Resonant frequency..............ƒs= 15.349 MHz

Apparent inductance............. ...La= 15.151 µH

True reactance at resonance...........X= 527.788 ohms

Apparent reactance at resonance. ...Xa= 666.397 ohms

Total true resistance................Rc= 0.278 ohms

Apparent total resistance....... ...Rt= 0.444 ohms

True Q...............................Qt= 1897

Apparent Q....................... ..Qc= 1502



L1 COIL SPECS


True inductance.........................= 1.200 uH

Number of turns........................= 3.015

Coil form diameter...................fd= 10.160 cm. = 4.000 in.

Coil pitch diameter...................d= 10.795 cm. = 4.250 in.

Wire diameter.........................W= 0.635 cm. = 0.250 in.

Pitch (c.c. spacing of turns)......Sw= 1.270 cm. = 0.500 in.

Coil Length...................Lcm, Lgth= 3.829 cm. = 1.507 in.

Coil Length/diameter ratio...........Ld= 0.35:1

Wire diameter/spacing ratio........W/Sw= 0.50:1

Turns per inch (25.4mm).............Tpi= 2.000

Self-Capacitance.....................Co= 7.153 pF

Added capacity required to resonate..Cx= 423.634 pF

Frequency.............................ƒ= 7.000 MHz

Self-Resonant frequency..............ƒs= 54.323 MHz

Apparent inductance................La= 1.220 µH

True reactance at resonance...........X= 52.779 ohms

Apparent reactance at resonance....Xa= 53.670 ohms

Total true resistance................Rc= 0.054 ohms

Apparent total resistance..........Rt= 0.055 ohms

True Q...............................Qt= 984

Apparent Q.........................Qc= 968
80 – 75 Meter Link Coupled
L2 – L1 COIL SPECS


L2 COIL SPECS


True inuctance.........................= 22.000 uH

Number of turns........................= 15.000

Coil form diameter...................fd= 15.240 cm. = 6.000 in.

Coil pitch diameter...................d= 15.875 cm. = 6.250 in.

Wire diameter.........................W= 0.635 cm. = 0.250 in.

Pitch (c.c. spacing of turns)......Sw= 1.215 cm. = 0.478 in.

Coil Length...................Lcm, Lgth= 18.225 cm. = 7.175 in.

Coil Length/diameter ratio...........Ld= 1.15:1

Wire diameter/spacing ratio........W/Sw= 0.52:1

Turns per inch (25.4mm).............Tpi= 2.091

Self-Capacitance.....................Co= 10.948 pF

Added capacity required to resonate..Cx= 83.042 pF

Frequency.............................ƒ= 3.500 MHz

Self-Resonant frequency..............ƒs= 10.255 MHz

Apparent inductance................La= 24.900 µH

True reactance at resonance...........X= 483.805 ohms

Apparent reactance at resonance....Xa= 547.587 ohms

Total true resistance................Rc= 0.301 ohms

Apparent total resistance..........Rt= 0.386 ohms

True Q...............................Qt= 1605

Apparent Q.........................Qc= 1418



L1 COIL SPECS


True inductance.........................= 2.200 uH

Number of turns........................= 3.5000

Coil form diameter...................fd= 13.335 cm. = 5.250 in.

Coil pitch diameter...................d= 13.970 cm. = 5.500 in.

Wire diameter.........................W= 0.635 cm. = 0.250 in.

Pitch (c.c. spacing of turns)......Sw= 1.921 cm. = 0.756 in.

Coil Length...................Lcm, Lgth= 7.684 cm. = 3.025 in.

Coil Length/diameter ratio...........Ld= 0.55:1

Wire diameter/spacing ratio........W/Sw= 0.33:1

Turns per inch (25.4mm).............Tpi= 1.322

Self-Capacitance.....................Co= 6.882 pF

Added capacity required to resonate..Cx= 933.018 pF

Frequency.............................ƒ= 3.500 MHz

Self-Resonant frequency..............ƒs= 40.904 MHz

Apparent inductance................La= 2.216 µH

True reactance at resonance...........X= 48.381 ohms

Apparent reactance at resonance....Xa= 48.737 ohms

Total true resistance................Rc= 0.044 ohms

Apparent total resistance..........Rt= 0.044 ohms

True Q...............................Qt= 1107

Apparent Q.........................Qc= 1098
160 meter Link Coupled
L2 – L1 COIL SPECS


L2 COIL SPECS


True inductance.........................= 42.000 uH

Number of turns........................= 18.000

Coil form diameter...................fd= 20.320 cm. = 8.000 in.

Coil pitch diameter...................d= 20.955 cm. = 8.250 in.

Wire diameter.........................W= 0.635 cm. = 0.250 in.

Pitch (c.c. spacing of turns)......Sw= 1.328 cm. = 0.523 in.

Coil Length...................Lcm, Lgth= 23.911 cm. = 9.414 in.

Coil Length/diameter ratio...........Ld= 1.14:1

Wire diameter/spacing ratio........W/Sw= 0.48:1

Turns per inch (25.4mm).............Tpi= 1.912

Self-Capacitance.....................Co= 13.363 pF

Added capacity required to resonate..Cx= 172.780 pF

Frequency.............................ƒ= 1.800 MHz

Self-Resonant frequency..............ƒs= 6.718 MHz

Apparent inductance................La= 45.248 µH

True reactance at resonance...........X= 475.009 ohms

Apparent reactance at resonance....Xa= 511.745 ohms

Total true resistance................Rc= 0.313 ohms

Apparent total resistance..........Rt= 0.363 ohms

True Q...............................Qt= 1517

Apparent Q.........................Qc= 1408



L1 COIL SPECS


True inductance.........................= 4.200 uH

Number of turns........................= 4.000

Coil form diameter...................fd= 18.415 cm. = 7.250 in.

Coil pitch diameter...................d= 19.050 cm. = 7.500 in.

Wire diameter.........................W= 0.635 cm. = 0.250 in.

Pitch (c.c. spacing of turns)......Sw= 1.259 cm. = 0.496 in.

Coil Length...................Lcm, Lgth= 5.035 cm. = 1.982 in.

Coil Length/diameter ratio...........Ld= 0.26:1

Wire diameter/spacing ratio........W/Sw= 0.50:1

Turns per inch (25.4mm).............Tpi= 2.018

Self-Capacitance.....................Co= 12.723 pF

Added capacity required to resonate..Cx= 1848.703 pF

Frequency.............................ƒ= 1.800 MHz

Self-Resonant frequency..............ƒs= 21.772 MHz

Apparent inductance................La= 4.229 µH

True reactance at resonance...........X= 47.501 ohms

Apparent reactance at resonance....Xa= 47.828 ohms

Total true resistance................Rc= 0.064 ohms

Apparent total resistance..........Rt= 0.065 ohms

True Q...............................Qt= 747

Apparent Q.........................Qc= 742



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