self adhesive foil versus 2.4ghz reception ?

[richard cohen]

Evening all. just bought a HK skipper waterplane but wondered if i could add protection to the lower hull/fuselage to protect the foam on grass landings. glass cloth/epoxy will add weight, so wondered about adding thin self adhesive metal foil tape to underside of the step. Anyone used it and know how 2.4ghz reception is affected ? or other suggestions for a lightweight durable covering for foam.?

cheers

Rich

[Martin Whybrow]

Metallic foil tape will have an adverse effect on 2.4GHz signals; are you able to place the antennae well away from the area you want to tape? Incidentally, the foil tapes I've used are quite fragile and would add liitle to the strength of a foam fuselage.

[Simon Chaddock]

richard

2.4 travels more or less in a straight line between Tx and Rx aerials so if the foil area (assuming it is true metal foil) ends up between them (flying overhead?) you are likely to seriously effect the signal.

I think you will find it is only the keel that suffers on landing so really only a narrow strip from the step forwards needs reinforcing so glass/epoxy (make sure it is foam safe!) might not add that much weight..

[scott finnie]

Hi I've used reinforced fibre tape from Amazon with a 90 second epoxy brushed on before. Works a treat with the parkzone icon and Dynam Catalina. Use it only at the most vital points and weight gain is not noticeable. Good luck

Scott

[Ian Jones]

I've got an HK catalina, the seal on the hull was virtually non existent so mixed some epoxy with meths to produce a thick liquid and poured that into the floor of fus then tilted the fus around to work the mixture the required places. That sealed it. The foam for the hull was quite thin and I had the same fears as you Richard so I made up the same mixture and painted it on the inside. The epoxy turned a strange sort of pinky red colour so had to painted afterwards.

The mixture takes a very long time to harden, hours to go sticky and weeks to set properly but it does do the job. I also know someone that went one step further and used the same mixture with silk cloth to make a very tough underside to a Kavan Partanavia (no wheels)

Ian.

 

Edited By Ian Jones on 01/02/2015 00:37:13

[Former Member]

[This posting has been removed]

[Dave Hopkin]

0.6oz Glass Tissue available here - **LINK**

Bonded with Ezecoat or Poly-C which ever you prefer

1 Layer of Glass Tissue - stipple on the first coat then two or three coats later sand off excess - lightwieght and ding resistent

[bouncebounce crunch]

We have all heard the whispers of no metal, no fog, no mist,no rain or the 2.4ghz is unreliable, but I wonder if this is truly proven or just mythical wishful dreaming of those that have lost a model inexplicably.

do the manufacturers make clarity on this subject or is it just flying field mythology?

[Gary Manuel]

Even lighter fibre glass cloth available here:

Very cheap 18g fibre glass cloth

[Dave Hopkin]

Fog, Mist and rain are all (in RF Propogation terms) effectively the same - "Wet Air" and will attenuate the radiated signal - the higher the proportion of wetness the higher will be the attenuation

A decent estimation is that compared to normal (dry air) free space losses , moderate rain is twice as "dense" to RF, and heavy rain is three times as "dense"

I would ask the questuon however - why would you be even thinking of flying in mist or (god forbid) fog?

A discussion document here (**LINK**

[bouncebounce crunch]

Thanks Dave,

I am a conservative type flyer wind and drips of rain are ok, but as you know there are a few fruity types out there flying in all weathers, snow, sleet or light rain and they have been pictured in RCM@E over the years.

[Chuck Plains]

A quick cure would glass reinforced tape. It's tough and sticks really well. I have several rolls of it here from speedpacking on Ebay. It's nearly one third of the price you'll pay locally.

[Stevo]

Blimey Chuck.

Good call, just bought some!

[richard cohen]

I have to say the glass tape looks like a winner

cheers for all the input

[Codename-John]

Actually Flite-metal did some testing with their product, - © is .0018 inch thick self-adhesive aluminum for replicating a full size aircraft finish.

with different manufacturer sets and had no discernable change in reception whether

1- the aerials were placed fully inside a covered fuse,

2- the aerials outside of a covered fuse and

3- an RX on a wooden tray out in the open

Walk away comparisons were conducted to a distance of up to 800+ feet without "any" change in spread spectrum system performance. That is to say no change in system performance whether a system configuration was (1), (2), or (3) with the systems set to normal flight power mode

when you look at the calibre of some of the models using the stuff I doubt they would risk loosing one to radio failure caused by its covering- examples

I don't know about thicker ali duct tape type materials though

Edited By Codename-John on 01/02/2015 20:36:36

[Martin Harris - Moderator]

A clubmate re-covered a model in a silver metallic heatshrink covering - I suggested a range check and there was virtually no range at full transmission strength! This was with either a Spektrum or Orange receiver - I can't recall which.

Edited By Martin Harris on 01/02/2015 20:51:44

[Chuck Plains]

Posted by Stevo on 01/02/2015 11:28:55:

Blimey Chuck.

Good call, just bought some!

You won't regret it Stevo, both the quality and the width are excellent!

[john stones 1 - Moderator]

Ah the Cohen brothers..never mind the quality feel the width

P.s I recommended packing tape last week and they stomped on me and said it was rubbish

John

[Dave Hopkin]

Just read that Flite Metal test report and to be honest, whilst I dont doubt their results I dont understand how they happened!

Surrounding a reciever antenna with a conductive material shouldl form a Faraday Cage and block the vast bulk of RF signals - so range tests ought to fail miserably...

the only thing that springs to mind (and it might be irrelevant) is the grounding of the faraday cage - mosy are well grounded (earthed) a plane wouldn't be (but then nrt is a real 747 in flight, but that acts as a faraday cage anyway)

[Chuck Plains]

Posted by john stones 1 on 01/02/2015 23:59:04:

Ah the Cohen brothers..never mind the quality feel the width

P.s I recommended packing tape last week and they stomped on me and said it was rubbish

John

Got it in one!

Yes, cheap packing tape is generally hopeless if it gets really wet. But the nose and belly of my old Bixler were covered in the reinforced tape and weren't affected by it's many landings in wet grass and flights on showery days. Actually, I've just recalled that I left the old tape on when I did the hot water trick in the kitchen sink a couple of times when the nose was bent out of shape. I'm not saying it was a pretty sight, because the edges of the tape did start lifting from the curved surface, but the parts that remained in contact with the fuselage also remained stuck.

[Bucksboy]

I was interested in covering a balsa plane with the cheap aluminium foil to replicate metal and was worried about the reception. I made a small box and covered it entirely with the tape. Inside the box was a receiver, battery and servo, the only hole in the box was to allow a long arm fixed to the servo arm to escape. The arm had a small flag on it so that I could see movement. I use a Hitec Aurora and the receiver was a standard 6 channel one. I did a range check with the system with only a small difference in range. I could get full control with the reduced power output out to 50-60'. Taking the lid off and exposing the receiver and its single aerial meant I could go an extra 10' or so. I decided to use a 9 channel receiver that has 2 aerials and place one inside the latex rubber pilot and the other sticking out from the bottom of the plane in the free air. This would give me the best 'belt and braces' installation. Like all of us, the plane is 3/4 built and has not flown yet and has been like that a while. Despite my test, I'm still a little cautious about it.

 

 

Edited By Bucksboy on 02/02/2015 09:48:16

Edited By Bucksboy on 02/02/2015 09:48:53

[Dave Hopkin]

I wonder how much difference the thickness of the aluminium on the tape makes?

Perhaps this is a case of the cheaper the better as athe thickness will tend to be thinner

Edited By Dave Hopkin on 02/02/2015 09:45:12

[Codename-John]

A conductive enclosure used to block electrostatic fields is also known as a Faraday cage. The amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic field.

RF shielding enclosures filter a range of frequencies for specific conditions. Copper is used for radio frequency (RF) shielding because it absorbs radio and magnetic waves. Properly designed and constructed copper RF shielding enclosures satisfy most RF shielding needs, from computer and electrical switching rooms to hospital CAT-scan and MRI facilities

Seems Material matters more to RF shielding, thin Aluminium seems ok but don't try covering a model in copper

Edited By Codename-John on 02/02/2015 19:10:30

[Codename-John]

Umm, don't know what happened there, but my post seems to have thrown a wobbler

[Daithi O Buitigh]

I have memories of working inside a Faraday Cage. The firm I worked for back then used to have annual 'grading tests' (to see if you deserved a pay rise). Anyway, I had to do the practical inside a cage (made from what looked like chicken wire mesh) and was going strong when the examiner bumped into the aerial and promptly blew all the fuses inside the set, a section of the mains dropper resistor (AC/DC TV sets back then) and the main rectifier. I managed to repair all of it (after giving him a lot of very dirty looks) and got a score of 99%. He told me after that he never gave 100% because that would mean I was as good as he was.

However, my point really is that it is possible to receive signals inside the cage, albeit attenuated