WWW.RFCOMMS.CO.UK is an R&D advisory to Commercial organisations requiring RF antenna matching solutions. With over 50 years of HF/VHF Communications knowledge we design and manufacture the highest quality HF (2 > 30MHz) RF matching transformers using up to 16 cores per unit and made to Mil 810G specification. Power levels of up to 5 kw can be offered on some configurations. We offer Current & Voltage baluns, and Un/Uns plus custom made RF chokes for optimum attenuation required in the HF spectrum for noise and returned RF. Commercial enquiries only.
PLEASE NOTE THAT TO PROTECT YOUR SECURITY & PRIVACY WE DO NOT USE OR HAVE ANY SOCIAL MEDIA ACCOUNTS OR LINKS
VHF Matching Units
Above: New 125 watt 30 > 70MHz Matching unit (higher power units available), low through loss (1.3db), 50 ohms, uses half-wave length of wire for required banded frequency range. 4 banded frequency ranges 30 > 45, 35 > 50, 45 > 60 and 55 > 70MHz, extremely efficient, no grounding required. BNC or “N” type connectors suggested. Commercial enquiries only.
NEW HF ANTENNA TECHNOLOGY!
“A new Generation of 2 > 40MHz Wide-band HF Antennas”
Above: New core technology!. Multi HF frequency matching units: Developed in 2016 offering single, multiple or wide-band frequency operation from one single wire and dispensing with old style inefficient TFD commercial antennas. Maximum insertion loss of 1.2db, no matching resistors, no masts needed, NEW multi Ni/Zn/Mn cores wound with Def Std 210 PTFE wire, stainless steel fittings, spring loaded line connector, line strain relief, back or top mounting hook, UV protected enclosure which is resin potted and full IP68, Commercial enquiries only.
2 > 40MHz, lightweight and top commercial quality. Options of BNC/SO239 or “N” type sockets.
UPDATED TEST RESULTS 2019
Test results of the new hybrid core tri-mix which offers superb matching over the HF spectrum. This new Wideband multi core HF matching unit offers a maximum insertion loss of 1.2db and maximum HF spectrum usability from one single transmission line.
Superb return loss: @ 2MHz -21db increasing to -34db:
Maximum insertion loss 2 units back to back = 2.4 db /2 = 1.2db per unit
The VSWR plot can be a single spot frequency, or multi frequency as above for EG: 7/14/18/21/28MHz with 20 mtr line & 3 cores, or, can be plotted as required using either harmonic related frequencies or a frequency segment EG: 2 > 16MHz or 8 to 18MHz and even 2 > 36MHz, this is all dependant on the line length and cores used. EG: 4/6/8/10MHz = 35 mtrs & 4 cores, a unique device.
Helically wound verticals and Loops using hybrid matching units.
Undergoing trials are RFCOMMS 2 mtr tall 50mm diameter fibre glass helical vertical with stainless steel top radiator, the unit uses no earth or radials as it is a single or multi resonant frequency end fed and matched using a near zero loss Hybrid combination of Zn/Ni/Mn cores and silver plated PTFE wire resulting in multi frequencies and/or wide-band (2 > 40MHz) high power operation, also under trial is a 1 mtr (26mm dia tubing) and a 1.5 mtr diameter helical loop (50mm dia tubing) which uses similar technology of the above matching units with low loss.No tuning capacitors, no matching resistors, and high power operation. No tuner/matcher required for either unit. Perfect matching (2 > 40MHz) for transmission and reception (TX/RX) single or multi-band with no adjustments required. Loop can be turned to eliminate interference. Commercial enquiries only.
Guanella Current Baluns
Above: The 4/1 Guanella Current balun, multi-core, extremely high quality: Other versions include un/un and voltage versions, all fully resin potted.
NEW CORES-NEW IDEAS
We are currently studying the use of FSCP (Fully Sintered Crushed Powder) which is a loose powder available in Zinc/Ni/Mn, this can be mixed with a polymer such as nylon and compounded to produce non breakable cores with irregular shapes, it also offers the choice to make high precision HF/VHF cores.
After many months of experimentation with new core materials and new designs we have now produced outstanding results offering superb balance and excellent return loss. The new designs are mostly multi-core units using PTFE Mil spec wire in PTFE tube and are available in both voltage & current configurations with different ratios available.
New custom made cores with a new Ni/Zn mix has given us ultimate control of return loss and provides a perfect solution for the ultimate unit. 2 to 16 cores are used depending on the ratio, I or V configurations, and power requirements.