Antenna position

[pierre1111]

The stripped part of the antenna cable - is it supposed to be in the antenna tube or sticking out the top?

The spektrum instructions show it above the tube exposed but by default from Arrma it’s in the tube with the rubber cap on top to seal it off.

I left mine sticking out and sure enough it eventually broke off flush with the tube. No wonder range was shortened and it took off at speed twice when it went too far out.

 

[Big Kid]

I keep them INSIDE the tube so a break off of tip etc is not an issue.

As one who Raced R/C Boats for many many years where Crystal receivers were the norm, we needed the antennas UP out and above the models .. so taking care of placement and vulnerability was always on your mind

 

[pierre1111]

That’s what I want to do now after my latest experience and that’s what Arrma does stock. But spektrum clearly has it above the tube and says to leave it unshrouded by metal or carbon fiber, and have it at the highest possible point.

Breaking off the stripped 31mm part clearly has an effect. Maybe having it stripped and protected lower completely in the tube is better then stripped above the tube?

It’s bound to break off again if I leave it sticking out.

 

[Relimar]

That’s what I want to do now after my latest experience and that’s what Arrma does stock. But spektrum clearly has it above the tube and says to leave it unshrouded by metal or carbon fiber, and have it at the highest possible point.

Breaking off the stripped 31mm part clearly has an effect. Maybe having it stripped and protected lower completely in the tube is better then stripped above the tube?

It’s bound to break off again if I leave it sticking out.

The stripped back area at the end of the antenna is a carefully measured size for the type of signal it's receiving, not that you were, but don't mess with that. It's also a coax cable, so ensure the inside filament and exterior braided ground don't touch each other. All my spektrum receiver antennas are inside the plastic tube and protected, or fully under the body. It hasn't effected signal distance or fidelity whatsoever. What they're showing is how to get the antenna away from materials that block the signal, metal, CF etc to ensure maximum performance. This is standard practice for a business, they're giving you the ideal scenario for setup. I'd rather have 95% function and not rip off the antenna every 3rd crash.

 

[pierre1111]

The stripped part broke off completely. I cut a few mm down to get a clean slice then stripped it back again the prescribed 31mm

If the stripped length is so critical isn’t burying it in a tube just as bad? I guess in my mind I can’t see the difference between the outer wire jacket vs being in a tube.

 

[Relimar]

The stripped part broke off completely. I cut a few mm down to get a clean slice then stripped it back again the prescribed 31mm

If the stripped length is so critical isn’t burying it in a tube just as bad? I guess in my mind I can’t see the difference between the outer wire jacket vs being in a tube.

It's the ability of the signal to pass through various materials that they're on about. All they claims they make about performance and range are based on testing with zero interference from anything and as tall on the vehicle as possible. They can't guarantee what material a random RC antenna tube will be made out of, so they tell you to have it out in the open. Remember, Spektrum sells these as standalone receivers for any application, it could be a full metal RC tank or a CF helicopter, they need to specify how the antenna should be placed vs having some hapless end user trying to identify what materials are surrounding it and how those may effect range.

If your antenna end was ripped off, just make sure the interior filament and outer braid aren't touching at the "new" end where the tear happened. *oh yup, you made a new clean cut, just read that.

 

[pierre1111]

Ok, so the grey wire jacket will block the signal vs the antenna tube that lets it mostly pass through, roger that.

I’ll try to get a magnifying glass to verify the inner conductor isn’t touching the outer braid before pulling it back in the tube.

 

[Relimar]

Yep, I'm like 92% sure that's how it all works. Either way, in actual practice, I've had the antenna in a tube with a rubber cap on the end and stuffed under the body of my Typhon for over two years and have had no issues with range.

One of these cheap-o USB microscopes is handy to have.

 

[razorrc]

I honestly didn’t think you could cut back the sheathing on a broken antenna wire, so I’m curious if this ended up fixing it.

 

[pierre1111]

I honestly didn’t think you could cut back the sheathing on a broken antenna wire, so I’m curious if this ended up fixing it.

Apparently you can - the critical length is the stripped part, not the overall length of the wire. So long as there’s enough length left to get reasonably high up. I’ll report back the next time I take it that far out


Duh… that was silly of me. I realized when you strip the outer jacket the 31mm you’re also supposed to remove the shielding braid. The inner conductor has its own sheath you leave alone. It’s the braid that would block anything, not the outer grey plastic. Now there’s no worry either of the center conductor touching the outer braid

Use a 22-24awg wire stripper to get the outer grey part. This leaves the braid intact. Slide it down so it bunches up at the base then use a flush cutter to cut the bunch off. This way there’s less risk of cutting through the braid and damaging the center conductor.

 

[Big Kid]

I honestly didn’t think you could cut back the sheathing on a broken antenna wire, so I’m curious if this ended up fixing it.

The antenna is tuned to a specific length ... as i understand it. If you loose 2" you can add 2" back and be ok.
If length changes ( permanately ) so will the effect tune of the receiver change in correctly listening to the trasmitters signals.

 

[pierre1111]

It’s the stripped length that matters. Not the overall length. The stripped length prescribed for 2.4ghz is 31.2mm. So as long as you have at least that much you can keep cutting it back.

You can buy antenna wires in different lengths.

 

[Big Kid]

Never heard of a radio signal of any frequency or modulation that mattered if surrounded by a thin non conductive sheathing ?
If true .. just learned something new about 2.4 gig systems

 

[pierre1111]

It’s not. I made the mistake thinking it was.


Strip the outer sheath 31mm, remove the braid, leave the center conductor alone, protect it with the antenna tube, and go.

 

[razorrc]

And... have you tried driving it yet?

 

[slick2500]

I honestly didn’t think you could cut back the sheathing on a broken antenna wire, so I’m curious if this ended up fixing it.

I fixed one of my old Spektrum receivers this way, before I fixed it I had like 20-30 feet of range if I was out in the open now I have at least 100 yards of range with it.

 

[Diem Turner]

I honestly didn’t think you could cut back the sheathing on a broken antenna wire, so I’m curious if this ended up fixing it.

You can indeed. In fact, you can continue the process of "refreshing" your antenna when it breaks over and over again so long as you have at least 31mm of antenna left that you can strip the mantle and outer braided shield off of (though you should probably just replace the antenna entirely before you arrive at the base of your Rx case...frugality is one thing but that would be borderline Petarded).

 

[slick2500]

You can indeed. In fact, you can continue the process of "refreshing" your antenna when it breaks over and over again so long as you have at least 31mm of antenna left that you can strip the mantle and outer braided shield off of (though you should probably just replace the antenna entirely before you arrive at the base of your Rx case...frugality is one thing but that would be borderline Petarded).

Not all receivers have replaceable antenna though. I think I might have 3 or 4 receivers out of my entire collection that have replaceable antenna.

 

[Diem Turner]

Not all receivers have replaceable antenna though. I think I might have 3 or 4 receivers out of my entire collection that have replaceable antenna.

The antenna is still replaceable. There's just a spare receiver connected to the other end. But you're right of course. This all obviously only pertains to receivers that have antennas with IPEX connectors. I do think all of my receivers have them though. Pretty sure anyways. I guess there's only one way to find out.

 

[pierre1111]

I can confirm I was able to successfully take the truck out as far or maybe a few yards further then where I lost control of it twice before I realized the antenna was damaged

You have 3… maybe 4 repairs before the wire is too short to get up to the top of the tube. If/when I get to that point I’ll open it up and solder a new wire or maybe a connector to the board if the pads are in the right place. They are pretty cheap on Jenny’s if you wanted to stick with spektrum.