Ignition shielding, electronic ignition shielding, two stroke aircraft engine ignition shielding.

 Ultralight News
Covering the World of Ultralight Aviation


(by appointment ONLY)

Click For  
Rotax Aircraft Engine Parts Info

The L'il Buzzard, L'il Hustler, and L'il Hustler SS two place ultralight trainers and light sport aircraft.

Top 10 reasons to consider a
 L'il Buzzard, L'il Hustler or
L'il Hustler SS!

The World's first Lightsport and Ultralight Aircraft weekly web video webcast!

If you have high speed internet and Windows Media Player installed you can watch our weekly Light Sport and Ultralight aircraft webcast!

Each issue is 25 to 35 minutes in length and is live on the web for 7 days.
Click here for more information!

 Click here for this months specials!


Have you updated your Bing Carb! Failure to do so could result in an engine out! Click here for more information!

Click HERE to receive Ultralight News EXTRA!
Our monthly newsletter
packed full of information about ultralight aviation!

Ignition shielding for Rotax aircraft engines.

This information is provided as a guide for shielding your aircraft for the successful installation and operation of any AM radio system.

Engines used in ultralight aircraft are traditionally two stroke 20 to 75 horse-power units which use a magneto to generate electric current in order to produce a high energy spark for ignition. This type of ignition is reliable and effective and used on most aircraft utilizing gasoline-fueled engines.

However, this set-up interferes with radio broadcasting. The problem with high energy spark ignition is its inherent characteristic of broadcasting a complete spectrum of radio signals in the form of static, especially on the AM band.

Years ago, when aircraft communication was initiated, the only radios available were of the amplitude modulation (AM type). Since that time, no major changes in aircraft radio design have been made.

Engine ignition noise (static) has always been a problem for aircraft communication systems, and it remains so today. With the advent of the all-metal airplane, the problem has been reduced for a number of reasons. Most important of these is the complete shrouding of the engine in a metal cowl with a metal firewall between the engine and radio installation. But even shrouding the engine in metal does not remove all of the interference. By shielding the actual source, most unwanted signals can be suppressed.

High tension wires should be shielded with wire braid, spark plugs jacketed in metal, and the magnetos housed in a metal case with all of these grounded to the engine block. As a final measure, the antenna for the radio should be placed some distance from the engine and connected to the radio with a shielded coaxial cable which has its outer braid grounded at j each end.

AM communication equipment installed in an ultralight aircraft will operate satisfactorily if properly installed and protected from the high energy ignition system.

The following steps should be taken in order to assure clear communication to and from your ultralight aircraft:

1. Obtain and install resistor spark plugs of the same type you are now using. May be located at your auto parts store.

2. Install metal spark plug covers. (Covers can be purchased from Parts Unlimited - 204 West Lawton Street - Edgerton, Wisconsin 53534)

3. Shield your spark plug wires with wire braid. The end closest to the spark plug end should be grounded to the metal plug cover. (The braid can be obtained from your local electronic supply store).

4. Fabricate a sheet metal cover (.020 aluminum is sufficient) to fit over the spark coil or coils. This cover should fit tight to the engine block and should be grounded there. All wires should emerge through rubber' grommets set in the cover. The wire braid should be grounded inside the cover. (See Figure 1 and 2).

5. Last and probably most important, fabricate a bracket attaching your antenna to the wing tip, jack post, or vertical fin of your aircraft.

6. Install the antenna on the bracket and connect it to the radio transceiver' using a coaxial cable. (Both the antenna and cable may be purchased at your nearest aircraft radio shop.

Secure the coaxial cable from the antenna to the radio using duct tape or similar material. The coax should be secured to a structural member every 18 to 24 inches.

Remember, shielding an ignition system for radio communications is more an art than a science. What may work in some cases, may not in others'. This srticle, is intended to be a guide to you the user. You may find that you'll have satisfactory results using any one or a combination of steps shown here.

Radio Shack is a source of supply for most of the above parts.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19  Index for this section.

Make yourself visible to others when your flying...... Strobe lights make you visible! Click here for more information!

Ultralight News
Covering the World of Ultralight Aviation

Click here to contact us via email.

Use this box to search our sites or the web!

Web UltralightNews.ca
UltralightNews.com UltralightFlyer.com

Ultralight Aircraft News Web Magazine Covering the World of Ultralight Aviation . You may link to these pages or print them out for your own personal use, but no part of this publication may be copied or distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language, in any form or by any means, electronic,  mechanical, manual, or otherwise,  without the written permission of Ultralight News. By copying or paraphrasing the intellectual property on this site, you're automatically signing a binding contract and agreeing to be billed $10,000 payable immediately. Copyright Ultralight News