swr freq

swr freq

Antennas : 40M

• ZMV Spiral antennas - An experimental antenna similar to the TAK spiral antenna was evaluated for SWR response over the frequency range of 7.0 to 7.3 MHz, or the 40-meter band.
  [ Hits: 3431 | Votes: 8 | Rating: 5.37 ]

• Fan Dipoles 10/15/20m and 12/17/30m - How to build Fan-Dipoles by DK7ZB. Experiences with various band combinations. Not all combinations are working properly. If the frequencies are to close together the impedances will lead to a very bad SWR. This happens with the bands 10-12-15m or 15-17-20m.
  [ Hits: 488 | Votes: 2 | Rating: 9.5 ]

• Transmission Lines - Whenever you choose a coax feedline, the frequency of operation is a very important consideration. Over the operating bandwidth of the coax the VSWR is low, typically 1.2:1 or better. Insertion loss is also an important parameter. It is usually specified in dB/foot and is a linear relationship.
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• Build An LF Antenna Analyzer - A Portable Low Frequency Antenna Analyzer, For those of us who like to play with antennas on the ham bands, one of the handiest tools to have around the shack is an "antenna analyzer". These gadgets combine a signal generator and standing-wave ratio (SWR) sensor in a small battery-powered unit.
  [ Hits: 4567 | Votes: 2 | Rating: 5 ]

• Antenna Impedance measurement - When experimenting on an antenna it's often important to determine its feedpoint impedance at various frequencies across the operating band. It's easy enough to measure SWR, but sometimes we need to know more detail than this
  [ Hits: 1426 | Votes: 6 | Rating: 2.67 ]

• 20m Indoor Loop Antenna - This antenna can gets you on the air on 14MHz, and it has a useable frequency range. The VSWR is almost perfect at the centre-frequency abd the design uses no expensive components.
  [ Hits: 668 | Votes: 4 | Rating: 6.75 ]

• Vertical antenna for Vacation - Vertical Vacation Antenna for 80, 40 and 20 Meter-Band, by Herbert OE3BMB This antenna is a full size λ/4 for 20m and 40m band, and a shortened λ/4 for the 80m band. Generally on the 40m band the SWR is under 1,6. In 80m and 20m band at the resonant frequency the SWR is about 1,1.
  [ Hits: 5037 | Votes: 4 | Rating: 8 ]

• Balcony Mounted Buddistick Antenna by KP4MD - The antenna handles 250 watts and covers 40 through 10 meters, with an optional add on coil for 80 and 60 meters. The author in this pages includes an interesting video in which describes the antenna setup, and the importance of the shunting coil on lower bands like 40 and 80 meters. SWR curves diagrams are also included and demonstrate the influence on resonating frequency of the shunting coil.
  [ Hits: 281 | Votes: 3 | Rating: 10 ]

• T2FD Antenna - Terminated and twisted folded dipole - T2FD is a 600-900 ohms folded dipole, terminated with resistor. Feed impedance is coupled with 50/600 ohms voltage balun. It is a wide band antenna with rather low SWR over the full designed frequency range: antenna tuner is seldom needed.
  [ Hits: 487 | Votes: 0 | Rating: 0 ]

• A & A Engineering - Smart Battery Chargers, WeatherFAX, Color SSTV,GPS-Based Frequency Standard, Power/SWR Meter, , Digital Frequency Synthesizers
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• Radio & Communications - Info about many aspects of Radio & Communications. Antennas, signals, frequencies, codes, swr, scanning etc.
  [ Hits: 18494 | Votes: 13 | Rating: 3.32 ]

• Simple 2.4 GHz SWR Meter - This is a simple 2.4 GHz SWR meter which is based around surplus microwave hardware which can be easily found. The main component is a MECA -20/-20 dB Directional Coupler which has a frequency range of approximately 700 MHz to 2.5 GHz.
  [ Hits: 144 | Votes: 2 | Rating: 6 ]

• What is SWR - standing-wave ratio - Article about Standing-wave ratio (SWR) defined as a mathematical expression of the non-uniformity of an electromagnetic field on a transmission line. SWR is the ratio of the maximum radio-frequency (RF) voltage to the minimum RF voltage along the line.
  [ Hits: 191 | Votes: 0 | Rating: 0 ]

• Antuino - Antenna Test Equipment - Antuino is an accurate instrument that can be used in the field to measure SWR, field strength, modulation, etc. In the lab, it can be used to sweep filters, measure gain, distortion, frequency response, etc. It works upto 150 Mhz. On the third harmonic, it is usable on 435 Mhz band as well (with reduced sensitivity).
  [ Hits: 305 | Votes: 0 | Rating: 0 ]

• SARK-100 Pc Scan - A windows program that scans the SARK-100 and plot the SWR Vs frequency. The data can also be stored as an Excel file. The min and max match frequency is calculated. Donationware
  [ Hits: 1904 | Votes: 3 | Rating: 8 ]