AV-640 MULTIBAND VERTICAL ANTENNA 8-BANDS (6, 10, 12, 15, 17, 20, 30, 40m) / HY-GAIN
E-shop: 1 pc, Praha: 0, Brno: 0, Ostrava: 0, Plzen: 0
On 8. 9. 2017 we expect
14 690 Kč / pc incl. VAT (12 140 Kč exc. VAT)
code: GES08901210, MOQ: 1 pc
HY-GAIN 8-Band vertical 6/10/12/15/17/20/30/40m; 3dBi; 1500W PEP; 7.6m; 11kg; 125km/h
HY-GAIN's new AV-640 Patriot HF Vertical is the best built, best performing, low radiating angle and best priced multiband vertical available today. Need no external radials.
Hy-Gain is proud to deliver the AV-640 Eight Band Vertical. Drawing on our many years of Amateur Radio HF and VHF antenna design experience, we have produced a well-engineered antenna capable of maximum efficiency, unmatched performance, and superior construction.
Computer optimization of the AV-640 design yields the most efficient 3/8 wavelength electrical design with maximum gain and low angle of radiation for long distance communication. No traps are used to achieve eight band
performance. The AV-640 is resonant on 6, 10, 12, 15 and 17 meters with individual 3/8 wavelength radiators. The center radiator resonates on 20, 30 and 40 meters using parallel end loaded Teflon wire coils. Capacity hats on these bands give wide 2:1 VSWR bandwidth and the antenna is kept to a height of 26 feet by the low inductance coils. There are no "tricks" or "mystery resonances" used for impedance matching on any band.
No long-wire radials or counterpoise kits are necessary for operation of the AV-640. The AV-640 is self contained for simple, convenient portable or fixed operation.
Mechanical construction of the AV-640 is designed for extreme light weight and high wind survival. Aircraft grade 6063-T832 aluminum and high strength fiberglass are used for the entire radiator. The trap-free design presents a very low wind surface area. Bulky tubing is not required to support unwieldy traps.
The broad 2:1 VSWR bandwidth on all bands lessens large frequency shifts seen in other antennas when the antenna is wet or iced.The AV-640 is covered by our Hy-Gain Warranty and supported by our customer
service team. We would like to thank you for purchasing this product from us and ask that you let us know of any suggestion you may have. With proper assembly, installation, and maintenance, your AV-640 will provide years of faithful service.
Theory of Operation
The AV-640 HF Multiband Vertical antenna consists of an end fed radiator that is resonant in the 6, 10, 12, 15, 17, 20, 30 and 40 meter amateur frequency bands. Resonances on each band are the result of impedance matching a 3/8 wavelength element with a broadband RF transformer. The characteristic impedance at the base of the 3/8 wavelength radiator is in the order of a few hundred ohms.
To match this impedance two tools are employed. First a counterpoise of 72" spokes is mounted at the AV-640 base. The capacitance from this ground plane helps lower the base impedance. Second, a 4:1 toroidal transformer (voltage balun) steps the base impedance down to 50 ohms. This transformer uses (2) ferrite cores for high power capability. Also, the windings are made of twisted pair wire to improve coupling and reduce loss. A second high power transformer is configured as a 1:1 current balun to help stop RF from traveling back on the feedline shield. The radiator of the AV-640 is at DC ground potential for static drain. This is accomplished by a radio frequency choke in The center radiator of the AV-640 supports 1/4 wavelength stubs for 6 , 10, 12 and 17 meters. The stubs are placed approximately one tenth of a wavelength (electrically 1/8 wavelength) above the AV-640 base. At the top of each stub the impedance is very high at the frequency the stub is tuned. This high impedance stops, (chokes) RF at this point creating a resonant 3/8 wavelength radiator. There is minimal loss using this method as compared to standard trap circuits. Also, VSWR bandwidth is not restricted by the °Q" of trap components. On 15
meters, the center radiator is terminated with a capacity hat to form a 3/8 wavelength radiator. No stub or coil is used on 15 meters. For 20, 30 and 40 meters, a coil and capacity hat are used on each band to create a 3/8
wavelength radiator. The coils are mounted at the top of the center radiator. These three coils are connected in parallel. Parallel connection separates each band to allow individual band tuning and has less loss than does series
connection. Also, the AV-640 coils have significantly less loss than a standard trap because the AV-640 capacity hats exhibit greater capacitance than a typical trap, therefore, less inductance is required.
VSWR at Resonance: Less than 1.5:1 at antenna typical
Gain: 3 dBi nominal
Height: 25 ft 10 in
Weight: 22 lbs
Horizontal Radiation Angle: 360 degrees
Vertical Radiation Angle: 16 degrees at 1/4 wavelength high
Wind Surface Area: 2.5 sq ft
Wind Survival: 80mph