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techie49

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  1. techie49
    As the proud owner of a new IPad, bought by my lovely wife for my birthday. ( Can you let go of my arm now dear), can anyone using the Oz Runways package give me an unbiased opinion as to whether it's any good. The website makes it look very good but a user's view is a little better. What is good? What if anything is not so good? Paul Toone
  2. techie49
    More to the point, have you mended it yet? If so what was the problem? If you haven't and want some help, give me a shout Paul
  3. techie49
    Sorry saw the comment about resistance and assumed you meant the sender. OK it still applies in the reverse sense. The gauge needs to respond to a variable resistance from the sender which as you said is 240 Ohms which will be the 'empty' end of the sender. The low value you measure, probably either 70 Ohms or 10 Ohms will determine the 'full' measurement. Measure the minimum value with your meter. If you feed 12V through a resistor of that value, any suitable gauge should indicate 'full'. I'd go to a motor shop with a couple of resistors and a battery and have a play, or ask if they have the spec of the sender for any particular gauge and buy one that matches your sender. Paul
  4. techie49
    It's only a variable resistor, so as long as the resistance value at each end is the same, the brand shouldn't matter. Before you fit one to the tank, I'd connect it up and move the float to each end of the travel. One end should indicate 'full' and the other end 'empty'. If it doesn't either the gauge is broken or the sender resistances are incorrect. Hope that helps...................... Paul
  5. techie49
    Hi FD, It does sound like RF feedback. If the battery voltage is pushed up by the alternator, the output of the radio will be higher than on idle and may get into the headset. First change your headset as it's unlikely all the users of the aircraft will have experienced the problem and not said anything. If it isn't your headset why has it suddenly started? Again, others would surely have noticed the problem if it's the radio. I'd go for a problem with the antenna next but you'll need to test with a SWR meter to check that what's going up the aerial lead is actually being radiated and not coming back down the feeder. Be interested to know the cause if you find out. Paul
  6. techie49
    Yes I saw that one too. Perhaps the gentleman concerned might like to enlighten us as to why that is........................ Paul Toone
  7. techie49
    Hi RD, Your KR2 wouldn't be the one slightly bent at Leongatha recently??? It's certainly a case of 'right place, right time' for hanger space. I have enquired at Tyabb too but the only space at the time available was ridiculously expensive, it was an aircraft hotel by the sound of it!!!! I suppose ultimately I might have to assemble it on a patch of mud. At least I can get both wings on at the same time. Paul
  8. techie49
    Thanks Darky, I'll certainly follow that one up. What's the situation with jumpers? Don't they do a fair bit at Lilydale? Paul
  9. techie49
    Cheers RD. Funnily enough I spoke to them today but no result. I was hoping to do my testing there due to the runway and the wide open space. What are you building? Paul
  10. techie49
    Does anyone know of, or have any suggestions as to where I might do the final assembly of my Zodiac 601XL(B)? I need somewhere preferably not too busy and within 1-2 hours of Bayside, Melbourne. Ideally I'd like to rent space in a hangar for a month around the end of November. I'd need to do taxi testing so a good runway would be a bonus. Although I've built the aircraft in my double garage, it's difficult to get the wings on there and put the aileron rods in the wings. Also it would then need to be dismantled for transport. Any offers ???? Paul Toone
  11. techie49
    I seem to remember the 601 landing gear weighs about 45lbs. That's just the metal w/o the brakes and wheels.........................
  12. techie49
    Hi John, Don't know if you'll know the answer to this. I've managed to snap plug#1 off leaving the thread and all attempts with an extractor have failed. Looks as if the head will have to come off. Can the main nuts be taken of and it all falls into your hands or is it an epic job? Regards Paul Toone (techie49) One step forward, three steps back !
  13. techie49
    Cheers Bruce. The only bit I may have trouble with is if parts need close tolerance machining, although there's plenty of small outfits round here I suppose. I generally make most things myself, certainly in the electronics line. Just waiting for the components for an electronic ignition. Hopefully will draft the circuit board tomorrow night.
  14. techie49
    Thanks Jim & John, Points noted (oh dear - what a pun!) You've given me plenty to think about. I think I'll get the engine running on the existing points and build an electronic ignition with the ability to take any firing input. Ultimately I want a dual system for redundancy probably using a coil joiner as Jim suggests. The difficulty in converting the Hitachi dissy seems to rest with the shaft mounted magnet assembly or whatever. There seems to be a number of possibilties with modules if you only want to use them for a firing signal, but the operating magnet needs to fit the shaft correctly. Jim's idea of the Mitsubishi distributor is a good possibility as is the ND unit. I read an article yesterday about converting both types. It seems to be a case of seeing what modules are available and what will fit the shaft of the dissy. Your system looks interesting 'ARRON 25'. What about some pics, although the mention of milling makes me run away, having a drill stand as my only major tool. Paul Toone
  15. techie49
    Hi Jim, Many thanks for that. I joined the group and had a look at the article you suggested. If you have the after-market part nos. it might help the local parts place to find them. I like the idea of dual ignition but I'll bet someone suggests it's twice the kit to go wrong! Are the coil joiners available in Oz? I'm getting p**ssed off paying the rip-off currency conversions when I order from Spruce et al. Regards, Paul
  16. techie49
    As far as I know, the only time there are any magnets in the distributor is when it's a point-less one using hall-effect switches or the reluctor coil system. I think the later EA81 engines had an electronic distributor with all the works under the cap and no separate electronics anywhere. After putting the question on the forum, I found a comment elsewhere that with a point operated electronic ignition they last for a long time as the current through the points is only a 'wetting' current and doesn't erode the metal. The plastic heel on the points is good for hundreds of hours so the article stated. I'm a believer in keeping things simple so my first thought is to keep the points and go for a good CDI multi-spark system. Next would be a processor controlled adjustable system to adjust timing according to RPM and loading. I'd still like to hear what actual flying Subie users have got though. Paul Toone
  17. techie49
    Hi Fly, Yes I've seen the spec. There's various units about. What I'm after are opinions from users who have fitted some of the options and would care to share their views. Paul Toone
  18. techie49
    I'm about to complete the installation of an EA81 on my Zodiac 601XLB. The current ignition system is the standard points driven coil. Has anyone tried either CDI, multi-spark CDI or TAI? I'm looking towards a multi-spark CDI system as I made several CDI systems years ago. My one concern is the longevity of the points at high RPM for long periods. Anyone converted to optical, reluctors, etc? What performance and results have you had? Regards, Paul Toone
  19. techie49
    Allan Barton at Zenair Australia is the man to ask. He's got a 601XL(B) (i.e. fully modified as per FAA and UK mods). He's done thousands of K's around the country. I'd be interested too as I'm getting my engine on next week and hopefully will be flying around Christmas / NY. Regards, Paul
  20. techie49
    Darky, Try Dr Raoul de C. Tunbridge at Moorabbin, 03 9596 0012. Last time it cost me $120 + GST. He's a nice chap too. His comment last time when I took off my glasses to do the eyesight test was 'Oh yes. Your eyesight's s**t isn't it' !!! I should add it's OK with specs................ Regards, Paul
  21. techie49
    Hi Adrian, Pitch 40 or whatever is simple. that's the spacing between rivets,i.e. drill a hole every 40mm. Looks like you have plenty of work to do. I'm re-doing wings on my 601XL. Paul
  22. techie49
    It's splitting hairs but no I'm not talking about thermal overload, it's thermal runaway. I don't understand the reference to Xenon strobes in this context at all. To duplicate the action of a Xenon strobe you need to pulse a 1W+ LED at a current above that used for normal running. The way you do it is to use a very short pulse of 80 to 100mS with a long gap, around a second, in between. That way the LED does not overheat and you get maximum light output. Have a look at any commercial aero lights. Do you see any relays? The short pulse provides an intense flash not unlike the xenon tube but you would be unwise to use a mechanical component. A flasher relay is designed to provide pulses roughly 1s on and 1s off. If you overdrive a LED in this manner it won't last long or you would have to use a lower driving current. You may as well use a globe. It's quite easy to use a power MOSFET instead of a relay. The circuit I have on test is working quite happily using a small microprocessor to provide whatever flash sequence you want - with no flapping relays. The circuit's easy, the casing is the difficult part. Paul Toone
  23. techie49
    I don't disagree you can string LED's in series like a Christmas tree but you are talking about LED's that are 1.2 V devices and give off as much light as a poorly glow worm. The ones to act as a strobe are high intensity 2.0 - 3.0 V devices that get hot. When they get hot they draw more current and get hotter and so on to destruction. If you are trying to duplicate a xenon strobe, these are the devices to use. They need to be pulsed for a short duration to be allowed to cool in between pulses or you work out a method of heat-sinking. Any that are on for any length of time need a current limited supply and heatsinking. You can pay up to $10 each for these so I wouldn't be thinking of using a car flash unit to operate them. Paul Toone
  24. techie49
    ---- I meant Aveo flash or whatever. Still bloody expensive ................ Paul Toone
  25. techie49
    Unfortunately guys you can't treat a LED like a globe. A LED works on current, a globe works on voltage. If you feed a LED with 12V it will last about 1mS before it says goodbye. A strobe light needs to be fed with short duration pulses of 80 - 100mS if it's made of LEDs and the pulses have to be current limited. You can use a LED like a globe if again you limit the current passing through it. The circuitry to do this is easy. The hard bit is getting it all into a package that is streamlined and looks good, not to mention waterproof. I'm doing one that's a cluster of six 1W LEDs for the strobe, a pair of reds for one side and greens for the other and in each lamp, a high intensity white to face the rear. $US700 for the Aerolight (?) is too rich for me. Paul Toone
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