Lightweight & Strong

Cost Effective Solutions

New Innovation for Commercial users

The HF Spectrum (2 > 30MHz) has many communication users around the world including commercial/marine and others, most end users use wideband/broadband antennas which in many designs are very inefficient the tilted folded dipole being the most common unit.

The radiation losses on this type of wideband HF antenna are huge due to the matching network part of the antenna being a mega load resistor and impedance matching transformer, however, to increase RF power radiation requires the use of a more efficient design on the frequency/frequencies to be used.

Many radio/antenna suppliers always seem to recommend a 2 to 30MHz antenna which is 30 mtrs long and requires 2 mast fixing points, in many cases this is not convenient especially in sandy conditions, also the whole spectrum of 2 to 30MHz is never used by commercial operators and there are many reasons for this.

Our technical notes and propagation book is available free (COMMERCIAL USERS ONLY), this shows how to get the most out of your equipment for day time and night time use during the forthcoming 11 year Sunspot Cycle as of 2020.

Radio Amateurs use the whole spectrum but that is because they want to communicate Worldwide and achieve vast distances, the commercial user does not want to do this, the user needs to communicate IN country only and so a few thousand kilometres is sufficient. 

The commercial user needs 2 or 3 daytime and 2 or 3 nightime frequencies probably between 3 to 16MHz as radio propagation changes between daylight and night time due to the reflection angle of the earths layers. ALE in the commercial radios do the required link exchanging to find optimum frequency operation.

Diagrams showing and explaining how signal distances and frequencies change from day light to nightime

There is a solution and RFCOMMS have been successful in this field for the past decade in using a newly designed hybrid matching transformer that has negligible insertion losses (0.5db) and can be resonant on any spot HF frequency or HF segment and has good efficiency, just a single wire is used with the matching unit. Several different impedance matching units have been developed for frequency ranges, harmonic resonance and power levels.

The hybrid matching unit does not contain any resistors or active components and is constructed using up to 5 special custom made ferrite cores wound with Mil Def 210 PTFE wire which is then housed in a UV protected enclosure and fully resin potted to protect it from the elements (IP68). The transmission line used is Kevlar based for strength and durability and is terminated with a UV protected insulator. The whole package is what you see below on the spool.

We can make a custom antenna offering a major increase on any wideband antenna using the above techniques, the length of the transmission line will depend on the lowest frequency that is required but is usually around 25 mtrs in length, specific higher daytime frequencies will use shorter transmission lines. Mounting is simple using very low cost installation items.

Spectrum coverage can be custom made

Wideband spectrum sweep showing VSWR under 1.5/1 @ 50 ohms, giving more E.R.P. than a terminated folded dipole (TF2D)

Tables show operating frequencies versus time of day but is solar activity dependent

The units are VERY cost effective, small, lightweight and totally IP68 rated as they are resin filled. All external parts are Marine A4 Stainless and the kevlar wire has a breaking strain of 90 kgs, other transmission lines can be offered like Phosphor Bronze multi strand pre stretched @ 300kgs BS. Many other options can also be offered.

Power handling is normally 125 watts pep which suits most commercially made HF transceivers and can handle ssb, (data, subject to lower power) ALE etc. Higher power units also available on request.

More ERP

Ultra low cost

Samples available

Available as just a matching unit or as a complete antenna built to your frequencies.

Commercial users only.