Messages

31

Control Line / Re: "Home International" 2017 in Dublin next weekend

« on: May 25, 2017, 09:44:00 AM »

Fred (and anyone else who needs them): Directions below.

John: The original plan was to kick off early on Saturday, but the weather forecast is not good for Saturday (rain). Having said that, Saturdays forecast has changed every day this week, so I can't really give you a straight answer. There will be a pilots briefing Friday evening and the final call on a start time will be made then.

The competition depends on the best team flights from both days, so if team A flies and team B does not on one of the days, even mediocre scores for both days can be enough to produce a winner.

Chris

32

Control Line / "Home International" 2017 in Dublin next weekend

« on: May 22, 2017, 21:36:20 PM »

Boys and girls, ladies and gentlemen,

This coming weekend (27/28 May)sees the Home International Control Line competition (aka Triple Crown) being hosted by the Fingal Model Flying Club, take place in Ring Common Sports Centre.

At this years event we will have some of the best control line aerobatics pilots in this part of the world, with members of both the Welsh and English teams having participated in the British Team at last years Control Line World Championship in Australia.

This year three teams are competing, representing Ireland, England and Wales, with Scotland being a no show.

In general, these models are beautifully finished and expertly flown, with many high tech features, such as carbon re-inforced bulkheads, custom bolt on wing joiners (not dis-similar to full size). It also looks like most models will be electric at this years event.

As national pride is at stake it will take or gales or lightning to stop flying from taking place.

The event proper kicks of on Saturday morning at Ring Common Sports Centre, just off the M1 with flying taking place all day Saturday and Sunday, weather permitting.

Chris

33

How to... / Re: Vinyl covering

« on: April 27, 2017, 09:23:01 AM »

Fred,

I'm getting "Error 404" for the link: http://www.gliderireland.net/index.php/techniques/vinyl-covering.

Chris

34

Club Talk / Re: Glider A & B Crets.

« on: February 15, 2017, 21:52:41 PM »

I've stepped back from this one Fred.

I'm easy either way with how you want to handle it.

35

Club Talk / Re: Glider A & B Crets.

« on: February 10, 2017, 18:34:18 PM »

Keith,

You started the rot!

I asked  a simple question about an acronym I'd not come across before and you introduced antennae with gain!
I thought you'd pick up me having named the yagi as for most people it's a TV aerial. Tongue firmly in cheek.

Not that any of it makes any difference when we're struggling with the sticks, or the pinkies are freezing off on the big L.

I still hate acronyms though

Chris

36

Club Talk / Re: Glider A & B Crets.

« on: February 10, 2017, 10:24:04 AM »

Lets leave it there. My antenna theory is very (very) rusty and was never used in anger (except during the relevant exam).

Still, the human body is not a great conductor and weirdly, neither is the ground (it helps that there's a lot of it though), so if the shoes were conductive(ish) there would be a kind of reflector behind the antenna.
Remember that some antennae are designed with a built in ground plane to shape/redirect the radiation pattern.

Having said all of that you're right though. When I'm flying I'm usually too busy trying to keep my airplanes out of the ground (and trees...) and away from everybody elses airplanes, not wondering about this stuff.
And besides, my models would probably be invisible long before I reached the extremes of the default theoretical radiation pattern anyway, never mind seeing if it was extended in any direction.

Looking back over this dicussion I'm reminded of a VHF radio operators course I did many years ago. One of the participants (not me)  insisted on stating that at VHF signals would go 'over the horizon' Whilst in the extremes of Maxwells Equations he may have been technically correct, for all practical purposes they don't, which was all that was important to everybody else on the course.

I'll shut up now and let people get back to posting about A and B certs. 

37

Club Talk / Re: Glider A & B Crets.

« on: February 09, 2017, 22:47:48 PM »

Don't think I've ever seen a Yagi fly well. They seem to have centre of gravity and control surface issues...
John: Best left for really strong wind conditions (force 10 and above)

Keith:
Moving slightly back towards the original topic I wonder whether the radiation pattern really is omni-directional.
I'm not arguing about the radiation pattern of the dipole, because there is nothing to argue about there.

When we're flying though we tend to be standing behind the tx, (I've only ever seen one pilot sit) so effectively there is a 'mirror' (in terms of RF energy - i.e. the human pilot - even if we're not great rf mirrors) on one side of the antenna, distorting the textbook donut shape of the field. I know I'm long since past being able to do the calculations on this - the exam was passed and promptly forgotten about - but does the pilot not distort (extend) the lobe and effectively add some gain in front of the pilot (and reduce the size of the pattern/donut/lobe behind the pilot)? i.e. better/more range (stronger signal at the model) if we always turn and face the model, assuming the antenna is vertical. Of course, standing on a slope will realign the radiation pattern too as the ground is no longer horizontal...

I'd better shut up before anyone starts to think I know anything about this stuff. It was a long time ago in a galaxy far far away.

I hope none of my old lecturers see this....

38

Club Talk / Re: Glider A & B Crets.

« on: February 08, 2017, 21:19:27 PM »

Keith,

You mean like my satellite dish or the Yagi Uda we used to watch TV with?

I just love TLAs (Three Letter Acronyms). Created by professionals, who don't know what they're talking about, to obscure that fact from everybody else.

Chris

39

Club Talk / Re: Glider A & B Crets.

« on: February 08, 2017, 07:59:09 AM »

Thanks John. Now I know.

Effective radiated power (ERP), synonymous with equivalent radiated power, is an IEEE standardized definition of directional radio frequency (RF) power transmitted from a theoretical half-wave dipole antenna. It is differentiated from effective (or equivalent) isotropic radiated power (EIRP) mainly by use of relative antenna gain instead of absolute gain in the calculation. In the case of ERP, antenna gain is calculated as compared to the maximum directivity of a half-wave dipole antenna, whereas EIRP is calculated using antenna gain referenced to an ideal isotropic radiator, otherwise known as "absolute" gain. The term "antenna gain" is assumed to be absolute (referenced to isotropic) unless specifically stated to be relative. The gain is then multiplied by the power actually accepted by the antenna to result in the actual ERP value (or EIRP). Power losses which occur prior to the antenna, e.g., in the transmission line or from inefficiency in the generator itself are therefore not included in the calculation of ERP or EIRP.

courtesy of wikipedia...

40

Club Talk / Re: Glider A & B Crets.

« on: February 07, 2017, 21:52:46 PM »

Folks,

Please forgive my ignorance, but I don't recognise this acronym "ERP", and neither does google in the context of a transmitter.

"Power output as 100 mW ERP for any radio type and the requirement to use equipment only with a “CE” approval stamp. 5.8 Ghz Video equipment is usually limited to 25 mW ERP."

I can have a guess, but its not one I've come across before.

Chris

41

Scale / Re: Annother Islandmodels 1/3 Scale Ka8b build log

« on: January 23, 2017, 20:38:50 PM »

I'm hesitant to recommend anything as I find painting a royal PITA, but when I am not using rattle cans I use a touch up gun.

My one is a Draper gravity feed (i.e. cheap) and works well enough for my needs, although these days it's mostly used for fuel proofing after I rattle can the colours.
Having said that, I don't build scale models.

42

Events / Re: 2017 ISREvent Dates

« on: January 23, 2017, 20:28:47 PM »

Thanks lads, visa applications duly submitted...

43

Events / 2017 ISREvent Dates

« on: January 19, 2017, 09:14:36 AM »

Lads,

Do we have any proposed dates for 2017?

I need to make sure I have no 'visa' problems, so it helps to put the dates in the calendar as early as possible.

Chris

44

Misc / Re: MPX Green plugs mold from Steckerform

« on: December 11, 2016, 09:05:39 AM »

I'm obviously a tightwad. My preferred power connectors are Deans (T style) and I use 12.7 mm heatshrink. If the wires are a bit thin a few slivers of hot  glue into the back of the connector before applying the heat gun fix that. 12.7 mm heatshrink is just big enough to fit over the body of a Deans connector.

12.7 mm is the diameter before shrinking just so there's no confusion. In my opinion, since the heatshrink is snug around the body of each connector half, it provides good strain relief when 'pulling the plug'.

I can see the attraction of the MPX green connectors for that big glider I keep building in my dreams though.

45

Slope Soaring / Re: Mt Leinster 24/25 Sept 2016

« on: September 25, 2016, 22:26:08 PM »

Saw John Fireball setting up his middle phase at the western slope when I was heading home. Plenty of lift, so I took my P6 out. Vertical takeoff. It flew like a homesick angel. Plenty of lift but very bumpy. 30  minutes later all of my tricks flown, plus a few I didn't know I could do, and hadn't planned on doing either. Got my fix and model still in 1 piece. A successful dsys flying so.