Commonly asked questions
Q – Do you offer any other types of shipping besides registered??
A – We have made the decision to make all of our orders registered delivery to protect both our buyers and ourselves which as such keeps product prices as low as possible due to less complications if in the event of a postage issue. If in the event you have a special delivery request or type please feel free to contact us before placing an order for further information.
Q – Can I return something?
A – If you receive a product with manufacturing or materials defects, please send an email to info@fivefourcommunications.com and we will make it right. This applies to the original purchaser and is non-transferable. We reserve the right to request proof of purchase when processing claims. For any other reason, we’re happy to return or exchange unused, undamaged, defect-free products still in their original packaging within fourteen (14) days of the shipping date. You will be required to pay all shipping charges back to us as well as cover all shipping charges of the new product back to you. There will also be a 10% restocking fee for any items that are returned to cover the cost of restocking and inspecting returned products. Older version of products cannot be exchanged for their newer versions!Q – Do you sell to Military and/or private security?
A – We certainly do and if you are interested in a large quantity or custom order please send an email to info@fivefourcommunications.com in which we will respond to ASAP to help you fulfill your needs.
Q – What kind of components do you use?
A – All products are built with the highest quality parts, sourced in the United States and the European Union.
Q – Do you stock replica/Reproduction items?
A – All items on this website are original. Unless otherwise stated all items are original.
Q – Is the VMAS suitable for civilian radios?
A – With the correct connection, power and frequency settings yes.
Q – Why use a vest mounted antenna?
A – The antenna is designed to keep the antenna from becoming a distractor in the field of view to the radio operator. Primarily for inter squad communications and not for reach back communications. It provides limited tactical advantage to the operator as to not mark him as a radio operator at typical tactical engagement ranges.
Q – What is the correct way to connect my VMAS into my kit?
A – We find that the vest mounted antenna works best when routed over the operators shoulder and then back up towards the shoulder moving over at least one webbing receptacle on molle webbing.
*Antenna tested in this configuration.
Q – How does the VMAS compare to other antennas?
A – The vest-mounted antenna is going to provide you greater flexibility; especially when operating in restricted urban or natural terrain. It will also provide you the ability to walk on extended patrols without the distraction of an antenna whipping about in your field of view, it will never replace a long whip for long range communications.
Q – What type of adapter do I need?
A – Check out this link for some information on radio connections.
https://www.campbellsci.com/blog/ins-outs-rf-connectors
If that doesn’t answer your question, please feel free to contact us via the Contact page and we can help direct you to what product to order.
Q – Is there a lead time on products?
A – On custom products there is a lead time which is determined by the availability of parts or complexity of the work. However, we strive to turn custom and basic repair work around in a short timeframe. Contact us is you require further information on this.Q – Are there locations you will not ship to?
A – All, if any, locations that we will not ship to are currently located on our Terms & Conditions page.
If you have any further questions and/or require assistance to have an item delivered to the areas we do not currently ship to, please send us a pre-request via our contact us page for us to contact you for further information.
Q – What is the effective range of the vest mounted antenna?
A – Most operators will notice an immediate increase of reception of faint signals. Transmissions depend on radio output and a variety of factors including terrain, atmospherics and weather. The antenna has seen good transmit ranges in open and restricted terrain.
It is not going to give you the same ranges as a fully extended long whip antenna. It is not a “magic” antenna.
This antennas VSWR will change drastically due to configuration. This is not a problem with modern transeivers operating at the approved power of less then 10watts. Most radios will automatically adjust output power to compensate for any user error or incorrect application.
Q – What is antenna gain?
A – In electromagnetics, an antenna’s power gain or simply gain is a key performance number which combines the antenna‘s directivity and electrical efficiency. In a transmitting antenna, the gain describes how well the antenna converts input power into radio waves headed in a specified direction.
In a receiving antenna, the gain describes how well the antenna converts radio waves arriving from a specified direction into electrical power. When no direction is specified, “gain” is understood to refer to the peak value of the gain, the gain in the direction of the antenna’s main lobe. A plot of the gain as a function of direction is called the gain pattern or radiation pattern.
Antenna gain is usually defined as the ratio of the power produced by the antenna from a far-field source on the antenna’s beam axis to the power produced by a hypothetical lossless isotropic antenna, which is equally sensitive to signals from all directions.[1]
Usually this ratio is expressed in decibels, and these units are referred to as “decibels-isotropic” (dBi). An alternative definition compares the received power to the power received by a lossless half-wave dipole antenna, in which case the units are written as dBd. Since a lossless dipole antenna has a gain of 2.15 dBi, the relation between these units is
For a given frequency, the antenna’s effective area is proportional to the power gain. An antenna’s effective length is proportional to the square root of the antenna’s gain for a particular frequency and radiation resistance.
Due to reciprocity, the gain of any reciprocal antenna when receiving is equal to its gain when transmitting.
Directive gain or directivity is a different measure which does not take an antenna’s electrical efficiency into account. This term is sometimes more relevant in the case of a receiving antenna where one is concerned mainly with the ability of an antenna to receive signals from one direction while rejecting interfering signals coming from a different direction.
*from Wikipedia
Q – What is VSWR?
A – In radio engineering and telecommunications, standing wave ratio (SWR) is a measure of impedance matching of loads to the characteristic impedance of a transmission line or waveguide. Impedance mismatches result in standing waves along the transmission line, and SWR is defined as the ratio of the partial standing wave‘s amplitude at an antinode (maximum) to the amplitude at a node (minimum) along the line.
The SWR is usually thought of in terms of the maximum and minimum AC voltages along the transmission line, thus called the voltage standing wave ratio or VSWR(sometimes pronounced “vizwar”[1][2]). For example, the VSWR value 1.2:1 denotes an AC voltage due to standing waves along the transmission line reaching a peak value 1.2 times that of the minimum AC voltage along that line. The SWR can as well be defined as the ratio of the maximum amplitude to minimum amplitude of the transmission line’s currents, electric field strength, or the magnetic field strength. Neglecting transmission line loss, these ratios are identical.
The power standing wave ratio (PSWR) is defined as the square of the VSWR,[3] however, this deprecated terminology has no physical relation to actual powers involved in transmission.
*from Wikipedia