MGL Avionics User Forum

Is there anyone who I could approach to buy an aerial for a V6?
Regards

Any avionics shop, Aircraft Spruce, many online retailers - or simply make your own:

Buy a simple straight whip car Arial (no fancy curlies etc). Cut the length as measured from the base where it would mount onto the car to about 64cm. That is about mid-band for 1/4 wave.
Replace the cable with RG58 or RG400.

Done.

You now have a perfectly serviceable airband 1/4 wave stub antenna. Make sure you mount it on a properly dimensioned ground plane (metal skin aircraft is the easiest of course - the entire fuselage makes a great ground plane).
If wood, fabric, composite of any sort then it can get tricky. You MUST use a SWR meter in line to your antenna to tune it. If the base can be mounted on metal struts or tubes it may perform the function of the ground plane - the SWR meter will tell you. It may be a bit directional but often is quite OK.
If you can't - a little trick I used often (like on a glass fiber fuselage) - take 4 lengths of ordinary electrical flex cable (as thick as you can get is helpful) of 64 cm length plus a bit - connect the 4 lengths to the base electrically. Now spread them along the inside of the fuselage (use tape or similar to hold in place). OK for the wires to follow the contour of the fuselage. When viewed from above it would look like an X. Two pieces going forward and two aft at about 90 degree angle in between.
This fakes a solid piece of metal for RF of the same size.

The above tends to produce a very good SWR usually better than 1.4 at any frequency. You can tweak the SWR for best match at a particular frequency by clipping small pieces of the antenna using a side cutter and following the SWR until you are happy. To make this possible start with the antenna a bit longer and clip no more than 0.5cm at a time.

Aim for SWR below 1.5. Literature suggests anything up to 2.0 is good but not in the confined space of our small aircraft - here we want as little reflected energy as possible and anything not radiated by the antenna gets radiated partially by your cable (and that gets close to sensitive equipment) and tends to enter your electrical ground wiring where it is free to go to all equipment. The voltages concerned can be quite high so do not ignore this.