Progressive Receiver Design -
Freq. Low |
Freq. High |
C1 pF |
C2 pF |
C3 pF |
C4 pF |
C5 pF |
C6 pF |
C7 pF |
C8 pF |
L1 uH |
T1 uH |
T2 uH |
0.45Mhz * |
0.46MHz |
10- |
100 |
2200 |
6800 |
6800 |
|
|
|
82 |
|
|
1.8 |
2.0(a) |
10- |
10 |
470 |
1500 |
1500 |
|
|
|
20 |
|
|
1.8 |
2.0(b) |
5- |
10 |
270 |
820 |
820 |
|
|
|
35 |
|
|
3.5 |
3.8 |
5- |
47 |
270 |
470 |
470 |
|
|
|
8.5 |
|
|
7.0 |
7.1 |
5- |
33 |
100 |
330 |
330 |
|
|
|
4.5 |
|
|
9.0 * |
|
9- |
22 |
100 |
330 |
330 |
|
|
|
3.3 |
|
|
10.0 |
10.15 |
5- |
22 |
82 |
220 |
220 |
|
|
|
2.9 |
|
|
14.0 |
14.35 |
5- |
18 |
68 |
220 |
220 |
|
|
|
1.83 |
|
|
18.06 |
18.17 |
5- |
18 |
47 |
180 |
180 |
|
|
|
1.3 |
|
|
21.0 |
21.45 |
5- |
18 |
47 |
180 |
180 |
|
|
|
1.0 |
|
|
24.89 |
24.99 |
5- |
15 |
33 |
150 |
150 |
|
|
|
0.90 |
|
|
28.0 |
29.7 |
5- |
12 |
33 |
100 |
100 |
|
|
|
0.71 |
|
|
50.0 |
52.0 |
5- |
10 |
22 |
100 |
100 |
|
|
|
0.30 |
|
|
Notes:
Suggested winding details are shown below.
The inductance values for T1 and T2 are for the tuned winding.
All frequencies in MHz unless otherwise stated.
Capacitor C1 is shown in the form minimum value -
The values shown for 450-
Coil Assemblies:
If constructors wish to wind their own inductors and transformers there are a variety of new and second hand coil assemblies available from the amateur radio market. The most common types are in ½ inch square aluminium cans, approximately ¾ inch high which are available from rallies and surplus suppliers in the form of assembled PC boards out of mobile radio equipment. Half inch diameter iron dust toroids may be used but will require tuning with trimmer capacitors and only limited details have been provided.
Finished coil assemblies should be tested and then the windings varnished and left to dry for at least 24 hours -
For use in a 50ohm environment transformers T1 and T2 should have a turns ratio of between 8:1 and 10:1 between the tuned winding and the coupling link -
Transformers T1 and T2 form a bandpass filter, slightly overcoupled on some bands in order to cover the whole of each band without retuning.
The following table gives coil details (Toko part numbers where available from one or more UK suppliers) and suggested winding details for use with the ½ inch square assembly -
Frequency Range |
L1 |
T1 |
T2 |
450- |
68t, 7/48# Litz wire plus a pot core |
|
|
1.8- |
65t, 7/48# Litz wire |
|
|
1.8- |
79t, 7/48# Litz wire |
|
|
3.5- |
40t, 7/48# Litz wire |
|
|
7.0- |
23t, 36# wire |
|
|
9.0MHz |
27t, 36# wire |
|
|
10.0- |
KANK 3335 23t, 36# wire |
KANK 3335 |
KANK 3335 |
14.0- |
17t, 30# wire |
|
|
18.06- |
14t, 30# wire |
|
|
21.0- |
12t, 30# wire |
|
|
24.89- |
12t, 30# wire |
|
|
28.0- |
11t, 30# wire |
|
|
50- |
7t, 26# wire |
|
|
Winding wire should be solderable-
Each winding should be close-
Make each winding off to the base pins by pre-
Additional oscillator coil information has been provided by project participants as follows (frequencies in MHz):
Freq. Low |
Freq. High |
C1 pF |
C2 pF |
C3 pF |
C4 pF |
C5 pF |
L1 uH |
6.97MHz |
7.105MHz |
8- |
330 |
110 |
390 |
390 |
13t, 26swg, enamelled copper wire on T50- |
13.6 |
14.4 |
8- |
39 |
56 |
220 |
220 |
KANK3335 1.5uH |
13.95 |
14.5 |
8- |
110 |
56 |
220 |
220 |
KANK3335 1.5uH |
16.8 |
19.5 |
8- |
0 |
56 |
220 |
220 |
KANK3335 1.5uH |