Lundahl
anode, grid and power supply chokes




All Lundahl chokes are wound with two separate coils which can be connected in series or in parallel. The inductance and current values given below are for the series connection. Parallel connection will result in one quarter (1/4) of the inductance at twice (2x) the current. This is because inductance has a square relationship to the number of windings. Doubling the windings results in 4 times the inductance.


All Lundahl chokes are wound in basically the same way. This means that chokes labeled "anode choke" can also be used as power supply chokes and vice versa.


Power supply chokes
Type
Coils connected in series
Coils connected in parallel
Weight (Kg)
 
Inductance (Henry)
Design
DC-current (mA)
Resistance
(Ohm)
Inductance (Henry)
Design
DC-current (mA)
Resistance
(Ohm)
LL1638 / 4
4
400
36
1
800
9
1.4
LL1638 / 8
8
200
36
2
400
9
1.4
LL1638 / 10
10
150
36
2.5
300
9
1.4
LL1673 / 10
10
200
60
2.5
400
9
1.4
LL1673 / 15
15
140
60
3.75
280
15
1.4
LL1673 / 20
20
100
60
5
200
15
1.4
LL1685 / 10
10
160
130
2.5
320
33
0.75
LL1685 / 13
13
130
130
3.25
260
33
0.75
LL1685 / 17
17
100
130
4.25
200
33
0.75
 


Anode chokes
Type
Coils connected in series
Coils connected in parallel
Weight (Kg)
 
Inductance (Henry)
Design
DC-current (mA)
Resistance
(Ohm)
Inductance (Henry)
Design
DC-current (mA)
Resistance
(Ohm)
LL1667 / 05mA
810
5
2400
203
10
600
0.78
LL1667 / 07mA
580
7
2400
145
14
600
0.78
LL1667 / 10mA
405
10
2400
102
20
600
0.78
LL1667 / 15mA
270
15
2400
68
30
600
0.78
LL1667 / 25mA
168
25
2400
42
50
600
0.78
                 
LL1668 / 25mA
100
25
680
25
50
170
0.78
LL2743 / 70mA
64
70
400
16
140
100
1.35
LL2743 / 90mA
50
90
400
13
180
100
1.35
 


Grid chokes
Type
Coils connected in series
Weight (Kg)
 
Inductance (Henry)
Standing
DC-current (mA)
Resistance
(Ohm)
 
LL1667 / 5mA
810
5
2400
      
0.78
LL1670 / 0,8mA
540
0.8
5300
      
88 gram
 


Filament chokes
Type
Coils connected in series
Coils connected in parallel
Weight (Kg)
 
Inductance (Henry)
Design
DC-current (A)
Resistance
(Ohm)
Inductance (Henry)
Design
DC-current (A)
Resistance
(Ohm)
LL1694 / 1.5A
0.16
1.5
1.8
0.04
3
0.45
0.83
LL2733 / 1.7A
0.4
1.7
3.4
0.1
3.4
0.85
1.35
 






 

 


Lundahl choke inside the
Thrax Orpheus phono preamplifier