|
Re HT leads for Ford coils on the Leburg system.
I have always supplied Lemark Hotwire leads (PE24 and PE36) with no problems reported. These have the added benefit the the plug connectors can be bent to have a straight or angled entry.
If you have the heavier coil with turrets you will need the X-kit also.
Halfords and Partco have supplied them, otherwise try Martins Motor Supplies Swindon.
I suggest that you stick to the distributed resistance type of HT leads, which are probably best at damping down the "ringing" that is the main source of the RF interference.
Also, we had persistent problems from one user, who had supplied his own leads with low resistance cores. When I supplied the usual set, all problems of blowing up output transistors dissappeared.
Also, I avoid the type with coiled conductors. I don't see how having extra inductance in the plug leads has any benefit, and I suspect that these increase the stress on the driving transistors. The transistors I use have overvoltage protection built in, but I would prefer to avoid the source of the stress rather than rely on the protection.
The Leburg system worked well from the start, and the controllers have changed very little. However users are full of bright ideas, some of which are good, some bad. Much as I wanted to avoid damping down the ideas of others, I found that I had to become more prescriptive in defining the installation.
The installation recommendations are as much a process of evolution as engineering, in that where an individual recommendation is made, at least one snag was solved, although I might only be able to explain vaguely why, in engineering terms. As the system now seems reliable, that process has worked, so we have probably combed out the snags.
I suggest that each user takes advantage of learning from earlier mistakes and follow the recommendations, otherwise he risks stepping into an area where a snag lurks.
Re radio noise.
The first step is to fit a halfway decent aerial as far from the engine as possible. If you have a rubber duck stuck on the top of a handheld clipped to the instrument panel, then you can expect a noisy and ineffective radio.
Re the Leburg system, there are two sources for "radio" noise.
One is due to radiation from the ignition system. The distributed high resistance leads are very effective at reducing the radiated noise, and grounding the engine, engine mount, firewall, instrument panel etc helps.
The second source is alternator noise in the form of spikes on the +12V supply from the rectifier/regulator, which is cheap (which users like), effective, but crude. A cheap 12V, LDO, 3 terminal regulator on a bit of Vero board will get get rid of these spikes.
David Mickleburgh
|