techie49

Hi Luke,

Contact the EAA -experimental aircraft association. I'd bet there's a group near you. You'll probably find someone who'd take you up for a flight. Don't worry about your health problems at this point. Just see if you can get into the air and enjoy it. Even if you are not able to fly commercially, there's always the chance you might fly for a hobby, depending on how your conditions develop. Good luck mate and let us know how it's going.

Paul

If you need fuel flow sensors, have a look at Futurlec Electronics. They sell a variety of flow sensors for under $20. They are generally a three wire device, open collector and you will need to calibrate them yourself but it's quite easy. You end up with a 'k factor' which reflects the number of pulses output from the flow sensor when you pass 1 litre through it. I use one on a MGL fuel gauge.

Paul

On closer inspection ( first read on my phone) I can now see a rather better set up having completely missed the copper strips in the pic ! ! !

So I didn't pass first time !

One point however. What is the material used for the 'washer'? I'd have gone for tinplate and soldered the copper strips to the washer. If it's aly, you are setting up for future problems with dissimilar metals in contact.

Paul

Well a little narrative would be good !

The pics seem to show a comms antenna inside a structure with an enlarged washer beneath it. If it's a normal VHF antenna, I'd be interested to know what sort of a match was achieved in s.w.r terms. I'm fairly sure you could transmit and receive using it, but the performance could probably be improved. Do I pass?

Paul

Buttons definitely pushed I'd say...........!

Skips reply illustrates what I said about not stressing over the size of a ground PLANE (!). Whatever works for you is ok. Decent wiring and antenna connections are as important.

Paul

I too was going to comment on how gliders have become so advanced they have ejection capabilities. When I did some gliding with the kids when they were in the Scouts in the UK, the instructor briefed me by saying " If I say out, don't say what because I won't be there" .

I prefer an engine ..........!

Paul

Hey Skip,

I was brought up on feet and inches but since some look at you blankly when you mention those units I thought I ought to put measurements in terms some would understand!

BTW If you do want to be pedantic, it's a ground 'plane' .........(!)

Paul

I think I got my copy years ago from Abebooks. If they're still around it may be worth a try. The book was to accompany the BBC series of the same name, which you can watch on 'YouTube'.

Ok Nev. So based on your comment we shouldn't report murders in case someone copies it !

I'm interested to learn from where the alleged offender obtained the means to commit the offences.

Paul

Be interesting to find out what kit he was using. Base station and external antenna or hand-held?

Paul

The article in the first post misses the great quote supposedly from a wartime report which states ' .....deploying a parachute as they departed which enabled him to descend into the sea still seated in the simple tubular fuselage. He then released his seat straps and drowned in the normal way'. That was quoted from the brilliant book, now sadly out of print I'd guess, 'The Secret War' by Brian Johnston (BBC).

Paul

Hi Tim,

Glad to see you're using a 'proper' engine !

My cowling came from Zenith and is listed for a Rotax 912. Depending on the mount, you may have to fibre glass two bulges for the rocker covers. I didn't need to but as I've used a Weber carb I had to put a bulge in the top instead.

Paul

I perhaps should have added, my engine is an auto conversion, a Subaru EA 81, so no magnetos involved. Suppressed leads aside, the principles are the same. Look up Occam's Razor..........

Paul

This may be of some help to anyone struggling to cure residual radio interference on an aircraft. I'm at the 'about to fly' stage in my build but was not happy about the ignition interference on the radio, which is a Flightline 760, very similar to a Microair. I've got suppressed plug leads and even went to the extent of building a filtered input socket ( 15 way D type) for the radio. Still no joy. The antenna is well earthed to the aluminium fuselage and the connections are good on both ends of the coax cable. What I had forgotten to check was where the interference was getting into the radio ! Yes blindingly obvious I know, from someone who is supposed to be very experienced with radio from HF to Microwave !

I quickly established that that filters aside, the interference was getting in via the antenna. I was getting into band pass filters on the antenna, etc, when the thought struck me. The cowling is fibre glass and thus transparent to RF. Imagine a car bonnet - metal (usually anyway ).

So what to do? I had similar screening problems years ago on noisy switched mode power units in plastic cases and had cured it by the use of nickel screening spray.

I carefully sprayed the upper cowling and used copper flashing to create a connection to the frame of the aircraft via the cowling fixing screws.

The result - silence apart from normal radio traffic.

The moral of the story - don't be too clever. Look for the glaringly obvious.

Paul

Hi Biggles,

There's something no one has touched on. You mention hum in the headset. Is the aircraft antenna ok? I know you said you changed the coax to the antenna but it might be worth getting a SWR meter on the antenna. If for some reason it's poorly matched, you can get RF feeding back into the radio which can distort the audio. If you've changed the radio, it's obviously the installation at some point. Just a thought.......

Paul

Hi Bruce,

I wouldn't get hung up on the size of the ground plane. As you correctly state, anything larger than a quarter wave at your operating frequency will be ok. As big as is convenient would be my measure. It only serves to allow the antenna to 'match' with the transponder and also helps a quarter wave antenna avoid having only high angle radiation. To get maximum range, your antenna needs to radiate at a lower angle. The learned books will show in polar patterns what I mean. Make sure you follow any guidelines for cutting the antenna to resonance at the transponder transmit frequency as I doubt you'll be able to measure the SWR of the system. Hope this helps a bit.

Paul

P.S If you want an absolute measurement, I'd take the highest, (transmit) frequency of 1090 MHz, the wave length at that frequency being 27.5 cm, so a quarter wave would be 6.9 cm. I'd go for about 10 cm for ease of measuring and cutting. Think about mounting an antenna on a normal car. The ground plane is a little bigger than a quarter wave, certainly at VHF and UHF !

Hi Methusala,

I was going to abbreviate you to Meth but perhaps not.

Very interested how you did efi. Is it single or multipoint?

Share some details if you would. It's the way I'd like to go. The EA81 is good but any carb is a pain.

Paul

I think all carb systems can be prone to icing given appropriate conditions. I wasn't going to bother with carb heat but chickened out when thinking of the million and one things that could go wrong. So now we're down to a million things to go wrong ! I take it Paul, since you're in this thread, that you're using a Suby. Wonder if it's the EA 81 or EJ22. I know the 22 is an injection engine but some do go back to a carb for simplicity. One day I'd like to get a EJ22 to play with as I think in spite of the added complexity injection is the way to go. Plus around 130hp would be nice.

Hi Paul,

What a coincidence. Just got in earlier from Tyabb. It's finally finished ( until I find something else to adjust ! ). I ended up with a Weber 32/36 carb and unfortunately a speed hump on the cowling as the inlet adaptor sits a little proud of the top. It'll do for now but I do want to fit dual ignition that's independent of the distributor timing. I'll use a second Suby to do that though or this one will never fly. I made a 'hot box' to provide carb heat and it seems to work. Just have to complete the paperwork and get it inspected by the CASA AP.

Paul Toone

That picture is nowhere near Rochester airport. The airport is in a built up area bounded by industrial units and also a very nice Holiday Inn. I used to fly into there from Leicester as it was quicker than driving to business meetings. Rochester is a lovely airport to drop into with grass strips, or it was 10 years ago.

Paul

It seems to me there is more to this than meets the eye.

Someone has dismantled the instrument panel in an aircraft, or at least extracted the instruments, on an airfield or within a hanger (?) and nobody has seen anything ?

Then another or the same someone has taken out the engine and no one has seen anything or passed comment. You would need to support the fuselage of the aircraft to stop it tilting backwards and require the use of an engine crane to physically move the engine. This all takes time but no one has noticed an aircraft being dismantled?

Very strange..........

And no mention of this episode being reported to the Police ?

Paul

Give us some more info John.

It takes more than a few minutes to steal all that surely. Where was it and what was actually pinched?

Paul

Hi Ian,

Just reminded me. I've just put the rebuilt soob in the aircraft, a bit of wiring to do.

Where in relation to TDC does the magnet sit on the flywheel ?

I wanted to put in a second ignition and thought about that as a trigger.

The engine with the Hirth gearbox runs lovely on the test stand so fingers crossed.....

Regards,

Paul

I only saw the details, such as they were, about one person being banned, purely by accident.

What are the criteria for getting a ban on this forum? I know it's not very nice if someone is attacking you as a person as opposed to an attack on the point you are making, but when am I going to get a ban for disagreeing with someone?

If I publicly call someone an ar$ehole on here, I might expect to be penalised, even if it's true ( and I have come close ! ) but am I under a mistaken impression that this forum is for a free and perhaps frank exchange of ideas?

Why are these people being 'banned'?

Paul

Good reply John.

Couldn't have put it any better mate.....!

Paul Toone.