Vhf Skeleton Slot Antenna Parts
Vhf Skeleton Slot Antennas
Vhf Skeleton Slot Antenna System
Vhf Skeleton Slot Antenna For Sale Introduction
The RSGB VHF/UHF Manual (1st edition, 1970's) had a section and diagrams on skeleton slot antennas for VHF (2 meters / horizontal polarization). There was a UK manufacturer of these J-Slot antennas in the 1970's and 1980's. About VHF Skeleton Slot Antenna The resource is currently listed in dxzone.com in a single category. The main category is Skeleton Slot Antenna that is about Skeleton Slot Antenna. This link is listed in our web site directory since Saturday Nov 19 2016, and till today ' VHF Skeleton Slot Antenna ' has been followed for a total of 799 times. You have already flagged this document. Thank you, for helping us keep this platform clean. The editors will have a look at it as soon as possible.
This paper was presented at the 40th Annual West Coast VHF/UHF conferenceheld on May 5-7 in Cerritos, California. Some editing was done to make itsuitable for this web page.
Abstract
Slot antennas can be used for fixed stations, satellite ground stationsand beacons. With proper mounting, a slot antenna can also be used for 'microwavemobile'. With a 16-slot total, the antenna can have 10-12 dbi gain.
Slot antennas can be built from surplus waveguide sections, which will givean ominidirectional pattern (and horizontal polarization). This paper offersa computer-aided method to calculate the proper dimensions for the slotsand their locations.
Spooky slot canyon hike california. Spooky Gulch is a short slot canyon hike in the Grand Staircase-Escalante area, located on the Hole-in-the-Rock Road, 26 miles south of the town of Escalante. Spooky is well-named and pretty famous for how dark it gets when deep in a slot, and for the panic-inspiring quality of its extremely narrow walls. See full list on alltrails.com.
Because the antenna is of one-piece construction, it is rugged and can bebuilt cheaply, requiring only access to a reasonably precise drill pressor milling machine.
Getting Ready
Vhf Skeleton Slot Antenna Parts
The first step in construction of the antenna is to select a section ofwaveguide which covers the desired frequency. Approximate waveguide dimensionsfor several microwave bands are listed in table 1. If your waveguide doesn'tmatch the dimensions exactly, go ahead and run the program. It will tellyou if the waveguide is too small (if you attempt to operate a waveguidebelow its cutoff frequency, it will have unacceptable SWR and losses).
Table 1 - Waveguide Dimensions Usable Frequency (Ghz) Typical Waveguide Long Dimension 'a', inches Short Dimension 'b', inches 1.12 - 1.7 WR650 6.5 3.25 1.7 - 2.6 WR430 4.3 2.15 2.2 - 3.3 WR340 3.4 1.7 2.6 - 3.95 WR284 2.84 1.34 3.3 - 4.9 WR229 2.29 1.145 3.95 - 5.85 WR187 1.872 .0872 4.9 - 7.05 WR159 1.59 .0759 7 - 11 WR102 1.02 0.51 8.2 - 12.4 WR90 0.9 0.4 10 - 15 WR75 0.75 0.375 18 - 26.5 WR42 0.42 0.170
Running the Computer-aided Design File
Once the waveguide has been selected, just enter its cross-sectional dimensionsand the desired operating frequency into the Mathcad program file slot_ant.mcd or slot_a2.mcd. In order to edit the file and make the calculations, you must have a copyof Mathcad, running under Microsoft Windows.
The program file references the slot antenna dimensions shown in Figure1. Note that all calculated dimensions are given in both inches and millimeters.For the best pattern, a pair of ground planes (wings) can be added to eitherside of the antenna. The wings should be flush with the top of the waveguideand extend at least a half-wavelength below the bottom slot. The wings needto protrude out from the sides by several wavelengths, if possible.
Machining the Slots (2 methods)
Drill Press - Just drill many overlapping holes, then file out the slots to the desireddimensions.
Milling Machine - The ideal method: fast and accurate, and less prone to an accident of drillingor filing.
Note that the front -face and rear-face slots are exactly across the waveguidefrom each other. You should be able to 'see through' any front/back pairof slots if the antenna is constructed correctly.
Feeding the Antenna
The simpliest feed for the slot antenna is to use a coaxial-to-waveguidetransition. These transitions are also available (sometimes) on the surplusmarket, having BNC or Type N connectors.
Parx poker room review .
There are two versions of the Mathcad slot antenna program. It was discoveredthat the original program running on Mathcad 3.1 had some problems whenusers tried to run it on later versions, namely version 6.0, etc. For usersof the older Mathcad, use slot_ant.mcd, otherwise use slot_a2.mcd. Many thanks to Steve Muther, WF6R, for getting the program running inMathcad 6.0.
Some worked examples
About Mathsoft's Mathcad
Download Mathsoft's Mathcad browser
Return to W6BY Home Page
020597
I am always interested in trying different antenna designs, especially if they are simple to construct and provide increased functionality. While perusing some old issues of QST magazine online I found a series of articles that discuss a design called the Folded Skeleton Sleeve. The design is a unique way to build a dual-band resonant dipole or groundplane vertical. The articles appear in the May 2011, October 2011, October 2012, December 2013, and March 2015 issues of QST magazine.
I was particularly interested in this antenna design because a simple resonant dual-band antenna could be very useful for deployment at Field Day or for EMCOMM purposes. Other multi-band antenna designs exist and can perform quite well (windoms, off-center-fed dipoles, G5RVs, non resonant end feds, dipoles fed with window line, etc.), however, most of these require a wide range antenna tuner to achieve a decent SWR on multiple bands. Other designs, such as trap dipoles, can be heavy and cumbersome with multiple points of failure. The folded skeleton sleeve design exhibits non of these limitations.
Design
The folded skeleton sleeve at first looks like a standard folded dipole, however, the top radiator is not continuous. Two notches are cut along the top of the window line to create the parasitic element that allows for operation on the higher frequency band.
A 75M / 40M antenna should be perfect for both EMCOMM (these are the most common HF bands used for emergency communications) and Field Day. A 40M / 20M antenna is equally perfect for Field Day and the combination of the two provides a lot of operating versatility from two simple antennas that cover the three busiest Field Day bands. I also decided to construct a 40M / 30M antenna for use as a portable antenna for digital communications.
Dr henrik slots reno . Nov 07, 2020 Henrik Slots, MD is a Renown physician that specializes in Family Medicine and is located at 10085 Double R Blvd, Reno NV 89521. Henrik Slots, MD is a Family Medicine Specialist in Reno, NV. He is affiliated with medical facilities Renown Regional Medical Center and Renown South Meadows Medical Center. He is accepting new patients. Be sure to call ahead with Dr. Slots to book an appointment. Slots is a family medicine doctor in Reno, Nevada. He has been in practice between 6-10 years. Slots graduated from the American University of The Caribbean School of Medicine in 2010. He works in Reno, NV and 1 other location and specializes in Family Medicine. Slots has been my primary care physician since I moved to Reno in 2013, and he is the best. He's so friendly, smart, thorough, and caring. Those are exactly the character traits I want my doctor to have.
Construction
I built the antennas using 18AWG stranded copper-weld 450 Ohm window line (Wireman 553) and folded dipole insulator kits (Wireman 804) which make fantastic strain reliefs for securing the window line. I also made my own 1:1 baluns in a similar design to what I have done before, except this time I used FT-150A-K toroids and 18AWG wire which allowed me to make the baluns smaller in size while still being adequate to handle 100W. To house the baluns I used Bud Industries PN-1322-DGMB NEMA 4X enclosures. These are well made boxes and they feature convenient mounting tabs that are easily bolted to the center insulator.
75/40 Bandwidth
75 Meter Band
2:1 SWR: 3.68-3.785
3:1 SWR: 3.63-3.86
40 Meter Band
2:1 SWR: 7.18-7.238
3:1 SWR: 7.1-7.3
While the bandwidth of this antenna is not particularly wide, it is easily matched to the radios 50 ohm output with practically any antenna tuner. Vhf Skeleton Slot Antennas
My ham radio club used the 75/40 at our Field Day site for the duration of the event. While obviously intended for use on 75 40 meters, the antenna was used on the higher bands as well with the help of a wide range antenna tuner. Over the course of field day this setup resulted in over 350 CW contacts.
40/30 Bandwidth
40 Meter Band
2:1 SWR: 7.158-7.33
3:1 SWR: 7.073-7.448
30 Meter Band
2:1 SWR: 9.93-10.24
This antenna exhibits better bandwidth than the 75/40 and even reaches an SWR of 1.1:1 on 30 meters.
40/20 Bandwidth Vhf Skeleton Slot Antenna System
This antenna is by far the best design of the bunch. This configuration results in an SWR of under 2:1 across the entirety of both the 40 and 20 meter bands.
Antenna Winders Vhf Skeleton Slot Antenna For Sale
Since ladder line can be annoying to work with since it doesnt coil easily, I decided to build some winders from 1/2 inch PVC pipe to keep the finished antennas organized. I built a larger one for the 75/40 antenna and smaller ones for the 40/20 and 40/30 antennas. I am really pleased with how these turned out and plan to build more for use with other antennas; they are a fantastic way to avoid a tangled mess.
Vhf Skeleton Slot Antennas
Vhf Skeleton Slot Antenna System
Vhf Skeleton Slot Antenna For Sale Introduction
The RSGB VHF/UHF Manual (1st edition, 1970's) had a section and diagrams on skeleton slot antennas for VHF (2 meters / horizontal polarization). There was a UK manufacturer of these J-Slot antennas in the 1970's and 1980's. About VHF Skeleton Slot Antenna The resource is currently listed in dxzone.com in a single category. The main category is Skeleton Slot Antenna that is about Skeleton Slot Antenna. This link is listed in our web site directory since Saturday Nov 19 2016, and till today ' VHF Skeleton Slot Antenna ' has been followed for a total of 799 times. You have already flagged this document. Thank you, for helping us keep this platform clean. The editors will have a look at it as soon as possible.
This paper was presented at the 40th Annual West Coast VHF/UHF conferenceheld on May 5-7 in Cerritos, California. Some editing was done to make itsuitable for this web page.
Abstract
Slot antennas can be used for fixed stations, satellite ground stationsand beacons. With proper mounting, a slot antenna can also be used for 'microwavemobile'. With a 16-slot total, the antenna can have 10-12 dbi gain.
Slot antennas can be built from surplus waveguide sections, which will givean ominidirectional pattern (and horizontal polarization). This paper offersa computer-aided method to calculate the proper dimensions for the slotsand their locations.
Spooky slot canyon hike california. Spooky Gulch is a short slot canyon hike in the Grand Staircase-Escalante area, located on the Hole-in-the-Rock Road, 26 miles south of the town of Escalante. Spooky is well-named and pretty famous for how dark it gets when deep in a slot, and for the panic-inspiring quality of its extremely narrow walls. See full list on alltrails.com.
Because the antenna is of one-piece construction, it is rugged and can bebuilt cheaply, requiring only access to a reasonably precise drill pressor milling machine.
Getting Ready
Vhf Skeleton Slot Antenna Parts
The first step in construction of the antenna is to select a section ofwaveguide which covers the desired frequency. Approximate waveguide dimensionsfor several microwave bands are listed in table 1. If your waveguide doesn'tmatch the dimensions exactly, go ahead and run the program. It will tellyou if the waveguide is too small (if you attempt to operate a waveguidebelow its cutoff frequency, it will have unacceptable SWR and losses).
Table 1 - Waveguide Dimensions Usable Frequency (Ghz) Typical Waveguide Long Dimension 'a', inches Short Dimension 'b', inches 1.12 - 1.7 WR650 6.5 3.25 1.7 - 2.6 WR430 4.3 2.15 2.2 - 3.3 WR340 3.4 1.7 2.6 - 3.95 WR284 2.84 1.34 3.3 - 4.9 WR229 2.29 1.145 3.95 - 5.85 WR187 1.872 .0872 4.9 - 7.05 WR159 1.59 .0759 7 - 11 WR102 1.02 0.51 8.2 - 12.4 WR90 0.9 0.4 10 - 15 WR75 0.75 0.375 18 - 26.5 WR42 0.42 0.170
Running the Computer-aided Design File
Once the waveguide has been selected, just enter its cross-sectional dimensionsand the desired operating frequency into the Mathcad program file slot_ant.mcd or slot_a2.mcd. In order to edit the file and make the calculations, you must have a copyof Mathcad, running under Microsoft Windows.
The program file references the slot antenna dimensions shown in Figure1. Note that all calculated dimensions are given in both inches and millimeters.For the best pattern, a pair of ground planes (wings) can be added to eitherside of the antenna. The wings should be flush with the top of the waveguideand extend at least a half-wavelength below the bottom slot. The wings needto protrude out from the sides by several wavelengths, if possible.
Machining the Slots (2 methods)
Drill Press - Just drill many overlapping holes, then file out the slots to the desireddimensions.
Milling Machine - The ideal method: fast and accurate, and less prone to an accident of drillingor filing.
Note that the front -face and rear-face slots are exactly across the waveguidefrom each other. You should be able to 'see through' any front/back pairof slots if the antenna is constructed correctly.
Feeding the Antenna
The simpliest feed for the slot antenna is to use a coaxial-to-waveguidetransition. These transitions are also available (sometimes) on the surplusmarket, having BNC or Type N connectors.
Parx poker room review .
There are two versions of the Mathcad slot antenna program. It was discoveredthat the original program running on Mathcad 3.1 had some problems whenusers tried to run it on later versions, namely version 6.0, etc. For usersof the older Mathcad, use slot_ant.mcd, otherwise use slot_a2.mcd. Many thanks to Steve Muther, WF6R, for getting the program running inMathcad 6.0.
Some worked examples
About Mathsoft's Mathcad
Download Mathsoft's Mathcad browser
Return to W6BY Home Page
020597
I am always interested in trying different antenna designs, especially if they are simple to construct and provide increased functionality. While perusing some old issues of QST magazine online I found a series of articles that discuss a design called the Folded Skeleton Sleeve. The design is a unique way to build a dual-band resonant dipole or groundplane vertical. The articles appear in the May 2011, October 2011, October 2012, December 2013, and March 2015 issues of QST magazine.
I was particularly interested in this antenna design because a simple resonant dual-band antenna could be very useful for deployment at Field Day or for EMCOMM purposes. Other multi-band antenna designs exist and can perform quite well (windoms, off-center-fed dipoles, G5RVs, non resonant end feds, dipoles fed with window line, etc.), however, most of these require a wide range antenna tuner to achieve a decent SWR on multiple bands. Other designs, such as trap dipoles, can be heavy and cumbersome with multiple points of failure. The folded skeleton sleeve design exhibits non of these limitations.
Design
The folded skeleton sleeve at first looks like a standard folded dipole, however, the top radiator is not continuous. Two notches are cut along the top of the window line to create the parasitic element that allows for operation on the higher frequency band.
A 75M / 40M antenna should be perfect for both EMCOMM (these are the most common HF bands used for emergency communications) and Field Day. A 40M / 20M antenna is equally perfect for Field Day and the combination of the two provides a lot of operating versatility from two simple antennas that cover the three busiest Field Day bands. I also decided to construct a 40M / 30M antenna for use as a portable antenna for digital communications.
Dr henrik slots reno . Nov 07, 2020 Henrik Slots, MD is a Renown physician that specializes in Family Medicine and is located at 10085 Double R Blvd, Reno NV 89521. Henrik Slots, MD is a Family Medicine Specialist in Reno, NV. He is affiliated with medical facilities Renown Regional Medical Center and Renown South Meadows Medical Center. He is accepting new patients. Be sure to call ahead with Dr. Slots to book an appointment. Slots is a family medicine doctor in Reno, Nevada. He has been in practice between 6-10 years. Slots graduated from the American University of The Caribbean School of Medicine in 2010. He works in Reno, NV and 1 other location and specializes in Family Medicine. Slots has been my primary care physician since I moved to Reno in 2013, and he is the best. He's so friendly, smart, thorough, and caring. Those are exactly the character traits I want my doctor to have.
Construction
I built the antennas using 18AWG stranded copper-weld 450 Ohm window line (Wireman 553) and folded dipole insulator kits (Wireman 804) which make fantastic strain reliefs for securing the window line. I also made my own 1:1 baluns in a similar design to what I have done before, except this time I used FT-150A-K toroids and 18AWG wire which allowed me to make the baluns smaller in size while still being adequate to handle 100W. To house the baluns I used Bud Industries PN-1322-DGMB NEMA 4X enclosures. These are well made boxes and they feature convenient mounting tabs that are easily bolted to the center insulator.
75/40 Bandwidth
75 Meter Band
2:1 SWR: 3.68-3.785
3:1 SWR: 3.63-3.86
40 Meter Band
2:1 SWR: 7.18-7.238
3:1 SWR: 7.1-7.3
While the bandwidth of this antenna is not particularly wide, it is easily matched to the radios 50 ohm output with practically any antenna tuner. Vhf Skeleton Slot Antennas
My ham radio club used the 75/40 at our Field Day site for the duration of the event. While obviously intended for use on 75 40 meters, the antenna was used on the higher bands as well with the help of a wide range antenna tuner. Over the course of field day this setup resulted in over 350 CW contacts.
40/30 Bandwidth
40 Meter Band
2:1 SWR: 7.158-7.33
3:1 SWR: 7.073-7.448
30 Meter Band
2:1 SWR: 9.93-10.24
This antenna exhibits better bandwidth than the 75/40 and even reaches an SWR of 1.1:1 on 30 meters.
40/20 Bandwidth Vhf Skeleton Slot Antenna System
This antenna is by far the best design of the bunch. This configuration results in an SWR of under 2:1 across the entirety of both the 40 and 20 meter bands.
Antenna Winders Vhf Skeleton Slot Antenna For Sale
Since ladder line can be annoying to work with since it doesnt coil easily, I decided to build some winders from 1/2 inch PVC pipe to keep the finished antennas organized. I built a larger one for the 75/40 antenna and smaller ones for the 40/20 and 40/30 antennas. I am really pleased with how these turned out and plan to build more for use with other antennas; they are a fantastic way to avoid a tangled mess.