392M 80-10 meter antenna coil

Great Lakes Antennas

392M 80-10 meter antenna coil

This coil is designed for use on any frequency between 35-30 MHz. What makes this coil different than the others is the ability to operate on any HF ham band as well as MARS, CAP, MARINE and any other service in this range. Set up is simple; the coil uses any standard 3/8 x 24 thread mobile type mount. But it is very important to use a good ground system or counterpoise. Depending on the installation you may need some matching at the base of the antenna such as capacitance or transformer to achieve the lowest SWR possible. Many times a simple hand wound choke made of 16 AWG wire works great and gives you total coverage without having to change caps when changing bands. Start with 10 turns at 3/4" diameter and connect from the base of the antenna to ground. You can spread the turns apart until you get the best results. Included with the coil is a picture with the tap points listed. I have given the approximate tap points for each of the US ham radio bands. The tap points will vary depending on the installation. This testing was with an 80" whip and the coil at the base using the "choke coil" matching method. Remember, this is a starting point only! To make tuning simpler always remember when you bypass more of the coil with the tap wires it will raise your frequency. When you expose more of the coil you lower the frequency.

The large tap wire will always connect between 1-13 and A-F and sometimes C-1. The shorter tap wire will always connect between C-1, C-2 and C-3. 1-13 are your “fine tune" taps. A-F and C-1 are your course taps. The coil between C-1 and C-2 is a half-step between the coarse taps. The coil between C-3 and C-2 is only used to bring you down below 5 MHz. To some this may seem like a lot! Others may not even need these directions! Either way it should become very simple to you with use.

• 80 meters (3.8 MHz) Start with all coils open and use tap A with 1-13
• 60 meters (5.35 MHz) C3-C2 and D-8
• 40 meters (7.2 MHz) C3-C1 and D-8
• 30 meters (10.125 MHz) C3-C2 and F-7
• 20 meters (14.3 MHz) 03-01 and C1-10
• 17 meters (18.14 MHz) 03-01 and 01-6
• 15 meters (21.35 MHz) 03-01 and 01-4
• 12 meters (24.95 MHz) 03-01 and C1-2
• 10 meters (28.5 MHz) C-3-C1 and C1-1

This is a good starting point for your antenna system. We are always glad to help in any way we can.