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FAQFrequently Asked Questions
Do I need a tuner?
No need to use an ATU with the G4TPH Magloops. The Magloops is a tuned resonant circuit once tuned for the frequency of operation. A ground or counterpoise is not needed for the same reason.
How do I tune the Magloop?
To tune the Magloops for the frequency you move the tuning unit knob to the position where the noise on receive is the greatest. Once this is done, check the SWR and adjust the tuning knob for best SWR. Moving the tuning knob just a very small bit will make the SWR worse or better so use very small adjustments until you get the best SWR. I usually tune for the middle of the band and get an SWR of about 1:1 to 1. This will provide an SWR of usually 1:5 to 1 across the whole of the band without having to retune. This is one of the major features of the G4TPH Magloop antennas.
Can I use the Magloops in the loft?
They can be used in the loft however to change bands requires access to the manual tuning unit. The antennas were designed to be portable, and fold down for convenient travel and to keep the price down they have manual tuning.
Can I use the Magloops in a horizontal position?
The Magloops will work in an Omni-Direction if placed in a horizontal position and will work fine. I quite frequently use one hung horizontally from the ceiling of my workshop
How high off the ground should the Magloop be placed?
In a vertical position place the bottom of the antenna about 1 foot (400mm) above the ground. Height doesn’t really make much difference but position to other objects such as metal pipes or metal support will affect the SWR.
Will the Magloop work inside a house or apartment?
The antennas will work placed in front of a window providing the building does not have a large amount of steel beams in its construction. I have used the antennas lying on the bed in a hotel room since there was not a suitable curtain rail to hang it on. It worked fine. I have also tried to demonstrate the antennas at the RSGB’s National Hamfest but the building had so much steel in its construction I couldn’t receive hardly anything let alone work any stations. Be aware of “faraday cages”
Will the Magloop work as well as a dipole or Yagi?
Magloops antennas are known to be very good especially for their size. However: any antenna smaller than a dipole will not perform as well as the dipole cut for the frequency of operation. Some very high percentages for Magloops compared to a dipole are achievable. Obviously Magloops will not work as well as a directional multi-element antenna such as a yagi or quad antenna.
I have heard that Magloops are quiet. Is this true?
Magloop antennas are receiving magnetic RF not electrical and magnetic RF thus electrical inference can be a couple S points down on other types of antennas. At times I have not been able to hear a station with a dipole and have switched to the Magloop showing 2 S units down thus the noise was less and I was able to copy the station better.
Is the length of the feed cable critical?
I have used various lengths during development but have not noticed any problems with all of the different lengths used.
Does the tuning unit have to be at the top or can it be on the side or at the bottom?
The Magloop will work with the tuning unit top, bottom or on the side. Just remember to mount the Load unit directly opposite the tuning unit.
What power will the Magloop antennas handle?
The ML MKII models will handle 50 Watts SSB/25 Watts Data modes. The new ML40 HP will handle 100 Watts SSB and CW and 60 Watts Data modes. Any more than this may cause arcing in the capacitor and possibly damage the output of your rig.
How do the G4TPH Magloop antennas handle such high power when the capacitor tuning unit is so small?
I have designed a capacitor that is not really air spaced but is using a dielectric material between the plates and rotors. These are being specially manufactured for my antennas.
Why are the G4TPH Magloops able to cover a Ham band without re-tuning?
I have spent a great deal of time and money experimenting with the inductive loading units. The new designs act a bit like a unun bringing down the inductance of the resonant circuit. This allows a wider tuning range with a low SWR across the band. The tuning is still very sharp at the actual resonant frequency. The results is a very low SWR at the resonant frequency (1:1 to 1) and a reasonable SWR across the whole of the band (usually around 1:5 to 1, band edge to band edge).
Why do I need to change the number of rails used to cover all bands from 40m through 10m with the new ML40 HP model?
The frequency range of a Magloop antenna is dependent on the capacitance and the diameter of the loop. If the range of the capacitor value is too high the lower range will be too high to tune the higher frequency bands. If the capacitor value range is lower it will not cover the lower frequency of the larger loop but cover the higher frequency with the smaller loop. (The instructions outline the size of loop to use for the various bands).
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