The Output LP/BP Filters for Transceivers GENESIS G****, AVALA-01, AVALA-02….
and CER-01- Make them Simple as Possible with Outstanding Performances
Dipl. Ing . Tasić Siniša –Tasa YU1LM/QRP
All rights reserved, project is free for personal use only
The GENESIS G****, AVALA-01, AVALA-02….ADTRX1….ADTRX9 and CER-01 transceiver transmitter
power amplifier output spectrum have a lot of harmonics. To achieve clear output spectrum according to FCC
regulation -50dBc we need to add LP (low-pass) or BP (band-pass) filter at output. I successfully realized LP-BP
filter as simple peaked LP (low pass) used in transmitting and receiving branches simultaneously (or in TX path
only) with only 2 coils. LP and BP realization is simplified to the end. It is possible next realization for utilizing in
SDR transceiver for all HF bands GENESIS G59, AVALA-02….. For very easy use with AVALA-01 mono-band
transceiver LP/BP-s should be realized as separate block (see picture BP/LP realized for 7 MHz and amplitude
transfer characteristic down). It is possible the classic realization also see table and schematic down in article. I left
for the Genesis series G40, G3020,… at the PCB place for montage all these type filters and some new not publish
here too. I took all real losses for L and C during design.
1. HF/6m BP-LP filters YU1LM version with peaked LP
BAND[MHz]
1.8
3.5
7
10
14
18-21
24-28
50
L1[uH
3.35
1.8
0.91
0.57
0.48
0.286
0.29
0.1
L2[uH]
5.86
3.35
1.64
1
0.84
0.544
0.53
0.16
C1[pF]
2700
1000+330
680
470
330
390
150
100
C2[pF]
240
120
56
47
27
22
12
18
C3[pF]
3300
1800
910
470+150
470
270
180
180
C4[pF]
360
150
68
47
39
12+12
15
22
C5[pF]
91
100
39
27
18
22
3.3
12
C6[pF]
1000
470
270
180
120
100
68
39
Pictures above are example of the BP/LP filter for 7 MHz which is similar to the proposed in article. The
transfer characteristic I obtained at spectrum analyzer screen with function max hold and with swept signal
generator output power +10dBm.
23.9 MHz
-12.65 dB
49.92 MHz
-0.1902 dB
DB(|S(1,1)|)
Schematic 1
54.52 MHz
-0.2732 dB
DB(|S(2,1)|)
Schematic 1
Graph 1
0
DB(|S(2,2)|)
Schematic 1
-20
87 MHz
-66.14 dB
108 MHz
-53.18 dB
143.6 MHz
-49.77 dB
-40
49 MHz
-26.56 dB
-60
-80
-100
0.1
50.1
100.1
Frequency (MHz)
150.1
180
BP-LP response for 6m
14.586 MHz
-6.095 dB
24.914 MHz
-0.2059 dB
29.825 MHz
-0.3714 dB
50.11 MHz
-42.15 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
Graph 1
0
DB(|S(2,2)|)
Schematic 1
-20
56.225 MHz
-82.55 dB
84.85 MHz
-96.52 dB
-40
28.149 MHz
-28.84 dB
-60
-80
-100
1
21
BP-LP response for 12m and 10m
41
61
Frequency (MHz)
81
100
10.34 MHz
-8.21 dB
18.06 MHz
-0.3712 dB
21.39 MHz
-0.2544 dB
31.04 MHz
-25.41 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
Graph 1
0
DB(|S(2,2)|)
Schematic 1
-20
-40
42.75 MHz
-66.24 dB
21.4 MHz
-23.06 dB
64.1 MHz
-83.47 dB
-60
-80
-100
1
21
41
Frequency (MHz)
61
80
BP-LP response for 17m and 15m
7.018 MHz
-9.652 dB
14 MHz
-0.1053 dB
14.4 MHz
-0.113 dB
21 MHz
-23.92 dB
DB(|S(1,1)|)
Schematic 1
Graph 1
DB(|S(2,1)|)
Schematic 1
0
28.36 MHz
-70.25 dB
-20
DB(|S(2,2)|)
Schematic 1
43.58 MHz
-82.71 dB
-40
14.22 MHz
-28.93 dB
-60
-80
-100
1
BP-LP response for 20m
21
41
Frequency (MHz)
61
70
7.042 MHz
-4.598 dB
10.14 MHz 10.96 MHz
-0.1838 dB -0.1949 dB
14.64 MHz
-14.06 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
Graph 1
0
DB(|S(2,2)|)
Schematic 1
-20
20.91 MHz
-51.26 dB
30.6 MHz
-85.51 dB
-40
10.18 MHz
-28.55 dB
-60
-80
-100
1
11
21
Frequency (MHz)
31
40
BP-LP response for 30m
7.0636 MHz
-0.36507 dB
7.1243 MHz
-34.746 dB
14.013 MHz
-49.863 dB
Graph
1
28.666 MHz
-53.787 dB
43.302 MHz
-48.893 dB
0
-20
-40
-60
DB(|S(1,1)|)
Schematic 1.$FPRJ
DB(|S(2,1)|)
Schematic 1.$FPRJ
-80
DB(|S(2,2)|)
Schematic 1.$FPRJ
-100
0.1
10.1
BP-LP response for 40m
20.1
30.1
Frequency (MHz)
40.1
50
1.825 MHz
-8.468 dB
3.501 MHz
-0.2103 dB
3.706 MHz
-0.2187 dB
DB(|S(1,1)|)
Schematic 1
Graph 1
0
7.145 MHz
-71.91 dB
-20
10.53 MHz
-72.99 dB
DB(|S(2,1)|)
Schematic 1
14.18 MHz
-52.01 dB
DB(|S(2,2)|)
Schematic 1
3.7 MHz
-24.02 dB
-40
-60
-80
-100
1
6
11
16
17
Frequency (MHz)
BP-LP response for 80m BP-LP response for 6m
1.784 MHz
-0.2363 dB
2.059 MHz
-0.3104 dB
DB(|S(1,1)|)
Schematic 1
Graph 1
0
3.501 MHz
-60.94 dB
-20
5.488 MHz
-73.43 dB
DB(|S(2,1)|)
Schematic 1
7.145 MHz
-50 dB
DB(|S(2,2)|)
Schematic 1
-40
1.808 MHz
-27.13 dB
-60
-80
-100
1
BP-LP response for 160m
3
5
Frequency (MHz)
7
8
2. HF/6m LP filter classic design
This is classic design and values for L and C are given in table down. I added also transfer characteristic for
each filter bellow. This filter type will not be enough for clear spectrum for second harmonics according to the
FCC regulation several dB will be miss in some cases. Unwanted signals will be much lower than normal 100W
transceiver has at output. Unwanted signals will be lower than proposed 1mW. This type LP filters
performances are good enough for harmonic suppression especially in the case push-pull RF amplifiers. The
advantage of this design is simplicity and very good replication. This is a really uncritical realization.
Band[MHz]
1.8
3.5
7
10
14
18-21
24-28
50
L1[uH
5.15
2.62
1.45
1
0.74
0.517
0.355
0.196
L2[uH]
5.15
2.62
1.45
1
0.74
0.517
0.355
0.196
C1[pF]
1200
680
330
220
180
120
100
47
C2[pF]
2700
1000+330
680
470
390
240
180
100
C3[pF]
1500
680
330
220
220
120
82
56
1.804 MHz 2.005 MHz
-0.4323 dB -0.504 dB
3.508 MHz
-20.46 dB
7.018 MHz
-53.68 dB
Graph 1
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
1.803 MHz
-28.3 dB
2.002 MHz
-25.11 dB
-40
-60
-80
0.1
2.1
4.1
Frequency (MHz)
6.1
7.2
LP response for 160m
4.066 MHz
-0.322 dB
3.508 MHz
-0.2759 dB
7.018 MHz
-20.64 dB1
Graph
10.51 MHz
-40.64 dB
0
14.02 MHz
-53.95 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
3.494 MHz
-23.16 dB
-40
4.075 MHz
-25.15 dB
-60
-80
0.1
4.1
LP response for 80m
8.1
Frequency (MHz)
12.1
16
7.006 MHz
-0.1242 dB
7.4 MHz
-0.153 dB
14.02 MHz
21.26 MHz
-43.08 dB
-23.16 dB1
Graph
0
28 MHz
-55.61 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
-40
7.309 MHz
-26.86 dB
-60
6.987 MHz
-48.08 dB
-80
0.1
10.1
20.1
28
Frequency (MHz)
LP response for 40m
10.19 MHz 14.49 MHz 20.22 MHz 30.21 MHz 42.23 MHz
-0.1461 dB -5.758 dB -22.54 dB Graph
-41.73 dB1 -56.91 dB
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
10.11 MHz
-34.39 dB
-40
-60
-80
0.1
20.1
40.1
Frequency (MHz)
LP response for 30m
56
10.19 MHz 14.49 MHz 20.22 MHz 28 MHz
-0.1107 dB -0.1902 dB -10.44 dB
-27.86
Graph
1 dB
42.23 MHz
-47.56 dB
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
14.35 MHz
-20.71 dB
10.11 MHz
-24.06 dB
-40
14 MHz
-26.63 dB
-60
-80
0.1
20.1
40.1
56
Frequency (MHz)
LP response for 30m
18.1 MHz 21.51 MHz
-0.1222 dB -0.1672 dB
36.19 MHz 42.04 MHz 54.11 MHz
-19
dB
Graph
1-26.63 dB -38.78 dB
0
63.08 MHz
-45.89 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
18 MHz
21.36 MHz
-22.92 dB -22.16 dB
-40
-60
-80
0.1
30.1
60.1
Frequency (MHz)
LP response for 17m and 15m
84
24.83 MHz 30.01 MHz 49.7 MHz 56.1 MHz 75.14 MHz
-24.641dB -38.94 dB
-0.134 dB -0.1725 dB -18.32 dB
Graph
0
115.6 MHz
-58.71 dB
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
24.95 MHz 30.02 MHz
-23.14 dB -22.3 dB
-40
-60
-80
0.1
40.1
80.1
120
Frequency (MHz)
LP response for 12m and 10m
100.4 MHz
49.95 MHz 54.1 MHz
-24.43
-0.1229 dB -0.1501
dB
Graph
1 dB
150 MHz
-43.97 dB
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
54.11 MHz
-24.37 dB
50.02 MHz
-28.85 dB
-40
-60
-80
0.1
50.1
100.1
Frequency (MHz)
LP response for 6m
150
3. HF/6m LP-BP Filter Design Simple as Possible
This design is derivate of classic LP (low pass) to BP (band-pass) with minimum built in components
two L and five C. The values for each band are given in table down. I added also transfer characteristic for each
filter below. The idea for this realization comes from RSGB Radio Communication Handbook eight edition BPLP from DJ8ES for 2m [page 9.37].
Band[MHz]
1.8
3.5
7
10
14
18-21
24-28
50
L1[uH
6.8
4.7
2.2
1.8
1.5
1
0.47
0.27
L2[uH]
6.8
4.7
2.2
1.8
1.5
1
0.47
0.27
C1[pF]
1500
560
470
330
240
100
120
82
C2[pF]
1000
330
240
150
82
56
68
39
C3[pF]
1000
220
150
68
22
33
56
18
C4[pF]
910
330
240
150
82
56
68
39
C5[pF]
1500
560
470
330
240
100
120
82
DB(|S(1,1)|)
Schematic 1
2.073 MHz 3.476 MHz 4.028 MHz 7.2 MHz
dB 1-34.17 dB -61.99 dB
-0.3593 dB -26.21
Graph
1.004 MHz 1.828 MHz
-4.533 dB -0.3152 dB
0
DB(|S(2,1)|)
Schematic 1
DB(|S(2,2)|)
Schematic 1
-20
2.095 MHz
-23.37 dB
1.806 MHz
-23.99 dB
-40
-60
-80
0.1
2.1
4.1
Frequency (MHz)
6.1
7.2
LP response for 160m
1.827 MHz 3.476 MHz
-9.347 dB -0.2625 dB
4.028 MHz 7.063 MHz 10.16 MHz 14 MHz
-0.2887 dB Graph
-27.89 dB
1 -45.58 dB -60.12 dB
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
DB(|S(2,2)|)
Schematic 1
-20
-40
3.486 MHz
-28.41 dB
4.008 MHz
-29.04 dB
-60
-80
0.1
5.1
10.1
Frequency (MHz)
LP response for 80m
14
1.793 MHz 3.811 MHz 6.957 MHz
-15.74 dB -7.847 dB -0.378 dB
7.301 MHz 10.16 MHz 14.04 MHz 21.08 MHz 28 MHz
-0.398 dB -18.93
dB 1-38.02 dB -57.98 dB -71 dB
Graph
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
DB(|S(2,2)|)
Schematic 1
-20
7.02 MHz
-23.3 dB
-40
7.298 MHz
-35.58 dB
-60
-80
0.1
10.1
20.1
28
Frequency (MHz)
LP response for 40m
3.811 MHz 7.063 MHz 10.16 MHz 14.35 MHz
dB 1
-15.19 dB -4.856 dB -0.4333 dB -21.95
Graph
20.21 MHz 30 MHz
-41.82 dB -61.02 dB
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
DB(|S(2,2)|)
Schematic 1
-20
10.15 MHz
-26.98 dB
-40
-60
-80
0.1
10.1
20.1
Frequency (MHz)
LP response for 30m
30
3.811 MHz 7.063 MHz 10.16 MHz 14.04 MHz 14.51 MHz 20.21 MHz 28.13 MHz 42 MHz
-25.42 dB -18.75 dB -11.24 dB -0.3411 dB -0.3416
dB 1-23.77 dB -44.23 dB -64.14 dB
Graph
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
14.36 MHz
-32.55 dB
14.01 MHz
-32.64 dB
-40
-60
-80
0.1
10.1
20.1
Frequency (MHz)
30.1
40.142
LP response for 20m
6.97 MHz
-15.29 dB
10.19 MHz 18.05 MHz 21.51 MHz 25.35 MHz 36.2 MHz 42.23 MHz 56 MHz
-5.524 dB -27.22 dB -34.98 dB -48.19 dB
-9.919 dB -0.3122 dB -0.3536 dB
Graph
1
0
DB(|S(1,1)|)
Schematic 1
3.505 MHz
-22.44 dB
DB(|S(2,1)|)
Schematic 1
-20
DB(|S(2,2)|)
Schematic 1
21.55 MHz
-23.85 dB
18.09 MHz
-27.93 dB
-40
21.05 MHz
-39 dB
-60
-80
0.1
20.1
40.1
Frequency (MHz)
LP response for 17m and 15m
56
14.35 MHz 21.51 MHz 24.62 MHz 30.58 MHz 50.12 MHz 56 MHz
75.21 MHz 84.01 MHz
-6.478 dB -1.223 dB -0.2532 dB -0.2685 dB Graph
-29.03 dB
1 -35.18 dB -50.08 dB -55.35 dB
0
DB(|S(1,1)|)
Schematic 1
3.562 MHz
-18.25 dB
DB(|S(2,1)|)
Schematic 1
-20
1.853 MHz
-23.81 dB
DB(|S(2,2)|)
Schematic 1
28.08 MHz
-20.66 dB
24.89 MHz
-22.84 dB
30.36 MHz
-30.02 dB
-40
-60
-80
0.1
30.1
60.1
90
Frequency (MHz)
LP response for 12m and 10m
14.35 MHz 30.37 MHz
-16.72 dB -9.434 dB
50.1 MHz 52.06 MHz 100.5 MHz
-0.245 dB -0.2569
dB -41.49
Graph
1 dB
144 MHz
-59.63 dB
0
DB(|S(1,1)|)
Schematic 1
DB(|S(2,1)|)
Schematic 1
DB(|S(2,2)|)
Schematic 1
-20
-40
50.23 MHz 52.45 MHz
-27.84 dB -40.64 dB
-60
-80
0.1
50.1
100.1
Frequency (MHz)
LP response for 6m
150
Summary
It is possible realized very simple LP or LP-BP filter at the output of SDR transceivers Genesis G****,
AVALA series, HF CER-01 transceivers or any other transceiver as minimal number component approach. The
number of turns on ring cores or air coils can be easy calculated with freeware software written by Wilfried
DL5SWB. Please take care about component quality build in these filter because un-adequate component lead
to output transistor destruction!!! Some details you will be able read in references and in the articles which are
in preparation and they will be published very soon at these WEB pages. The filters are with 3 equal coils! For
BP filters are very important component accuracy to obtain good RF specifications!
I wish you successful BP realization and I apologize for some possible mistakes. I made great effort to
share my projects with all who are interesting for. Anyway, send me your comments positive or negative,
results or photos of your realization please.
August 2008, rewritten July 2009
VY 73/72 and GL in homebrew Tasa YU1LM/QRP
tasayu1lm@gmail.com
tasa@insimtel.com
References:
1. www.yu1lm.qrpradio.com
2. www.genesisradio.com.au
3. http://www.linear.com/designtools/software
4. M.Martin DJ7VY :A New Type of Preamplifier for 145 MHz and 435 MHz Receivers/UKW berichte
1/1978
5. www.dl5swb.de
6. Ed Wetherhold W3NQN – Clean Your Signal with Band-Pass Filter –part1 ), QST May 1998(pages
44-48) ,
7. Ed Wetherhold W3NQN – Clean Your Signal with Band-Pass Filter –part1 ), QST June 1998(pages
30-42),
8. Lew gordon K4VX-Band-Pass Filters for HF Transceivers-QST 09/1988(pages 17-23)
9. http://www.bavarian-contest-club.de/projects/bandpassfilter/100W-BP.pdf