Manufacturer of Antennas
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Ground Independent Antennas
When we think of a vertical antenna, what usually comes to mind is a 1/4 wavelength mono-pole antenna mounted on the ground or on a ground plane. These antennas, because of their close proximity to ground have a fairly high (30+ deg) angle of radiation. This is not acceptable for maximum VHF or UHF communications range. If we desire to mount an antenna on a non-metalic (plastic or fibre-glass) vehicle it becomes necessary to use an antenna that will function totally independent of ground.A ground mounted 1/2 wavelength antenna will likewise have a high radiation angle. However when a 1/2 wavelength antenna is mounted 1/4 wavelength (or more) above ground, it has a radiation pattern close to that which would occur in free space.
Because of the high (> 1000 Ohms) feed impedance at the end of a 1/2 wavelength antenna, it is necessary to provide a means of tranforming this high impedance to the 50 Ohm impedance of the co-axial cable normally used in communications work.
A co-axial stub match will perform this impedance tranformation very nicely. It is conveniently just slightly longer than 1/4 wavelength long. When this is placed at the base of a 1/2 wavelength antenna, the antenna will be elevated a little over 1/4 wavelength above ground when mounted on a metal vehicle. When mounted on a non-metalic vehicle it really shines - no other antenna will match it's performance.
In either case, it has a low angle of radiation and will give a noticable increase in range when compared to a 1/4 wave whip mounted on the ground plane of a metal vehicle roof.
Antenna Gain
There are many ways that antenna gain can be expressed:dBi - Gain over an 'Isotropic Source' (a theoretical antenna with no dimentions).
dBd - Gain over a dipole (an antenna 1/2 wavelength long).
dBq - Gain over a quarterwave monopole.
dBadv - Meaningless random large numbers generated by advertizing departments.
A dipole antenna has 0 dBd gain or 2.15 dBi gain or 3 dBq gain or (large number) dBadv gain. It's the same antenna only the numbers are different. Unless you really understand antenna theory, the numbers become meaningless.
Unless you know that the gain numbers published by a particular manufacturer are accurate, don't believe any of them. The only accurate measure of antenna gain is size - the bigger the antenna, the more gain. There are a few exceptions to this; the most notable being the 5/8 wavelength antenna; it is really a 1/2 wavelength antenna fed with 1/8 wavelength of single-wire feedline.
Remember: it is physically impossible to increase the gain of an antenna without increasing its size.
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Mobile Antennas
While designed primarily for use on non-metalic vehicles, these Ground Independent antennas will give superior performance when used on any vehicle.Works great for packet
Can be mounted on the railing on the balcony of an apartment.
For base station operation - just slip it into a 1" TV mast. These antennas work extremely well where others work poorly or not at all.
This is the perfect antenna for mounting on the mirror of a semi-truck.
| Impedance | = | 50 Ohms. |
| Power Rating | = | 200 Watts. |
| Connector | = | SO-239. |
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* Supplied with TM-1 mount. See Other Products for details.
Prices are in U.S. Dollars. Foreign orders add $10.00 S & H.
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Portable Antennas
These antennas are similar to the 2 Meter mobile antennas. They feature a telescoping whip that is easily removable for transport.These antennas are Supplied with a unique mount which allows for a wide variety of mounting options.
Impedance = 50 Ohms. Power Rating = 200 Watts. Connector = SO-239.
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Base Station Antennas
Restrictive covenants or ordinances got you off the air? Want to put up a very effective antenna that even the XYL will like?The ultimate in STEALTH! This very efficient disguised antenna looks like (and is) a fully functional WEATHER VANE. The deception is so totally effective that anyone looking for your antenna will have trouble finding it. It is so attractive that the neighbors will want one!
Specifications and performance are the same as the GIA-XXX series antennas. With its great performance and effective disguise, this is the best clandestine antenna available.
Just in case the neighbors want a Weather Vane like yours, there is a special model just for them. It looks exactly like the STEALTHY antenna but is only a weather vane.
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Prices are in U.S. Dollars. Foreign orders add $10.00 S & H.
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75 Ohm Hardline Accessories
ConnectorsInexpensive connectors for the low-loss, 1/2 inch and 13mm, semi-rigid, aluminum shielded 75 Ohm co-axial cable used by the cable TV companies. These connectors mate with standard UHF series connectors.
Installation of these connectors is quite easy and can be accomplished in a few
minutes without the need for special tools. Each order is shipped with complete
step-by-step installation
instructions.
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Cable Splices
Joining two pieces of 1/2 inch or 13 mm, semi-rigid. aluminum shielded, 75 Ohm
co-axial cable is a snap with these cable splices. No special tools required.
Each order is shipped with complete step-by-step
instructions.
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Linear Matching Transformers
Will allow you to use your
50 Ohm radios and antennas with the low-loss 1/2 inch or 13 mm
semi-rigid, aluminum shielded, 75 Ohm co-axial cable used by
the cable TV companies. These LMTs connect directly to the 75 Ohm
co-ax and mate with standard UHF male connectors.
Installation of these LMTs is quite easy and can be accomplished in just a few minutes with no special tools. Each LMT is shipped with complete step-by-step installation instructions.
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| Read this before ordering. | Application Notes | GO TO TOP |
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Other Products
SWR and Power Calculator
The perfect accessory for your directional watt meter.Quickly and easily calculates:
- Standing Wave Ratio
- Return Loss
- Power Gain and Loss
- Feed Line Loss
- Effective Radiated Power and more.
Price - only $5.95 + $0.75 (S&H)
Antenna Mount
Here it is! The low cost solution to the problem of how to put a big antenna on top of a van, truck or SUV and still be able to keep it in the garage.These antenna mounts will hold your antenna up in a 100+ MPH wind (driving 75 MPH into a 30 MPH head-wind). If the antenna hits an obstacle, the mount will allow it to be deflected down to a 45 degree angle. When 45 degrees of deflection is exceeded, the antenna will be quickly brought down to the 'full down' position, thus protecting the antenna and vehicle from damage.
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Ordering Information
We do, however accept cash, personal checks, money orders, etc.
When paying by personal check, please allow 4-6 weeks for delivery;
other forms of payment, please allow 2 weeks for delivery.
Click here for a printable order form:
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After printing the order form, click on back to return.
| More Info | Custom Antenna Info |
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