Futaba receiver antennas getting hot?

[Terry Keeley]

Ya, those switches are junk for our application. I ran them years ago, had one of them that wouldn't turn off so I opened it up and there's only one tiny contact point on a little teeter-totter mechanism that was all pitted & corroded.

I asked Gary Preusse about it as he was in that field and he said they are definitely not made to take the vibration we give them, slide type switches are, that's why all the major radio manufacturers use them.

I told Bill McGraw at Speedmaster about it and he immediately stopped selling them.

The manufacturers supply SPST slide switches, those Noble units are DPST, they're like running two switches in parallel.

 

[Daniel's Racing]

Ya, those switches are junk for our application. I ran them years ago, had one of them that wouldn't turn off so I opened it up and there's only one tiny contact point on a little teeter-totter mechanism that was all pitted & corroded.

I asked Gary Preusse about it as he was in that field and he said they are definitely not made to take the vibration we give them, slide type switches are, that's why all the major radio manufacturers use them.

I told Bill McGraw at Speedmaster about it and he immediately stopped selling them.

The manufacturers supply SPST slide switches, those Noble units are DPST, they're like running two switches in parallel.

The high quality locking switches I sell have been 100% bulletproof.

I have sold thousands of them and continue to sell them every day.

I would be hearing about it if they were having problems.

Like I said the same switches I use are available in two pole. I could wire the poles in parallel for redundancy but I have never needed to go there.
If I was having problems I could immediately cut the chance of failure in half. It has never happened.

 

[Daniel's Racing]

Daniel, don't you "pot" the soldered terminals prior to heat shrinking them?

Yes sir I do so the wiring doesn't fail from fatigue at the solder joint. Once it hardens up that last 1/2" where the heat shring is stiffens it up so the only bending is where clean wire comes out of the shrink wrap.

 

[Daniel's Racing]

Well looks like my question is causing an uproar . Sorry Terry, didn't mean to disrupt your thread . Daniel, I guess I'll be labeled asinine then . My reasoning is I wanted to be sure I got my antenna as high as possible , kinda like a VHF radio antenna on a boat. Line of sight system so you want it as high as possible. No coax was harmed in the installation. At the race site now

You will be fine. I think you treat things with more care than most.

I just see what so many do with the short ones the last thing you want to give most people is more coax to get damaged.

About 50% of peoples receivers I see have some damage to the coax. Seen so many people still pushing them out top of tube folding over and capping them. I mean you name it they will find a way to nick or kink up the delicate wire.

Now we have 12" sticking out. Nice.

 

[Grimracer]

one thing to remember..

The marine market is super small to the land market (which is smaller than the air market).. VERY SMALL.

Just to help put this in perspective if marine was a larger market they would make marine transmitter systems.. but.. they don't to that.. in that they also don't make a "marine RX" the car guys have little use for a long antennas.. so quantity wins this battle.

Water challenges 2.4 and the further away you can keep the coax from the water the better. A redundant antenna like those used in a Diversity RX add to this insurance.

Be well

Grim

 

[Daniel's Racing]

one thing to remember..

The marine market is super small to the land market (which is smaller than the air market).. VERY SMALL.

Just to help put this in perspective if marine was a larger market they would make marine transmitter systems.. but.. they don't to that.. in that they also don't make a "marine RX" the car guys have little use for a long antennas.. so quantity wins this battle.

Water challenges 2.4 and the further away you can keep the coax from the water the better. A redundant antenna like those used in a Diversity RX add to this insurance.

Be well

Grim

Same reason our surface receivers have the second internal antenna instead of a second coax antenna.

You want to extend the range add a second coax antenna. That now will do something with two up out of the boat. They plug right in.

The reason you see two coax antennas on all Futaba's aircraft receivers is to increase range.

 

[Bill Eilers]

Clean pins and sockets. A dab of dielectric. Rcv mounted high allowing Antenna to exit full length. Also Antenna exit on right side.. my opion most radio issues are a result from not looking at your radio inst. As the most important part of your build. Damn things r 2 fast to half *** your control system

 

[Daniel's Racing]

The most bullet proof switch you can make is to use a gold plated XT30 30 amp male plug and wire it in series to be your switch and epoxy it end side wall of the box.

Then you take a female plug with the two pins connected together with 18 gauge wire. When you plug it in it is on. Yank it to go off. Bullet proof 100%.

Problem is no one can wire that properly without having the wire fail at the solder joint unless you know how to prevent it. Same with those long slide switches is they are worthless for most people for same reasons. Not easy to how to properly solder and pot the connections and shrink wrap it so there is no fatigue of wire at solder joint.

 

[Hydro Junkie]

Okay guys, I think you are overthinking all of this. For starters, all boats are different and require different set ups. When I look at my 2000 Elam, for example, the radio gear has worked pretty much flawlessly for the 9 years I've had it. With that said, my set up is simple:

• a Futaba 4PLS transmitter
• an R304SB receiver with standard length antenna
• an S9156 high torque digital rudder servo that's now discontinued
  
• an S148 standard throttle servo
• Futaba/Sanyo 4.8 volt receiver packs

IF I was dealing with a boat that has carbon fiber in its layup, I would definitely be looking at a 400mm antenna. Since I'm not, the 304 works fine just the way it is. If you look at the picture of my boat, you will also see the antenna tube doesn't come out the top of the radio box, but out the side, with a 90 degree bend:
https://static.wixstatic.com/media/...1/1fdd7a_80b95370a7ea469a83539c8d0a973d93.jpgThis means the antenna is even lower, and is on the left side of the boat. Even with that, it still works at the furthest parts of the course. Yes, I know the picture shows a long 75MHz antenna but that was swapped out years ago. The present 2.4 antenna doesn't reach the last third of the tube.

 

[Terry Keeley]

Clean pins and sockets. A dab of dielectric.

I used dielectric in the past but found this stuff is amazing, it solved a noise issue with one of my 3EGX conversions. Pricy but one bottle lasts forever, if you do some research some very highly respected electronics folks say it makes contact points (switches, plugs etc.) act as good as soldered joints.

https://www.stabilant.com/TechNote02_EN.html
https://www.amazon.com/Stabilant-5ml-Kit-Makes-30ml/dp/B001E50GQS
Twice the price at NAPA: https://www.napaonline.com/en/p/ECHCE1?impressionRank=1

 

[Bill Eilers]

Cool!.

 

[Ray Sametz]

Andy Brown's bulletproof switch, first saw in the baitbox of a Mongoose he ran in Fl. He used 5/16 nuts to tighten and loosen connection, same as glow plug.

 

[Roxyflash]

Be careful with dielectric grease if you use too much It can spread the female pin to open causing a bad connection .

 

[Daniel's Racing]

One more issue I see with running long antennas.

The extra length going up the tube is just folding over at speed anyhow.

The receiver antenna works considerably better and is meant to be vertically polarized. You ever watch a long antenna tube at 60 mph.

The long antenna tube is bowed over and your long antenna is not an iota taller than the shorter one was and it is laid over flat not sticking up vertical like it should be.

The tube is laid back with the end horizontal and back over or closer to the prop roost.

4-6" straight up or a 8"-12" folded back to the same 4-6" height but now it is laid flat.

The straight 4-6" one is going to give you the better range.

Noticed I haven't almost poked the ole' eye out since we got rid of those long stranded wire antennas the FM radio used to have to have.

The short antenna was all the rave of the 2.4 GHZ. Now you want to go back long for no reason whatsoever.

Decrease your range and maybe poke your eye out too. Nice.

The short vertical antenna will have better range than a long antenna when underway at speed.

 

[Tom Foley]

Happy to report no issues with the system
Had an 85 MG servo go crazy when someone else turned on a Spektrum transmitter close by . Turns out it was a servo problem not a system problem .

 

[Wally Marsh]

Okay guys, I think you are overthinking all of this. For starters, all boats are different and require different set ups. When I look at my 2000 Elam, for example, the radio gear has worked pretty much flawlessly for the 9 years I've had it. With that said, my set up is simple:

• a Futaba 4PLS transmitter
• an R304SB receiver with standard length antenna
• an S9156 high torque digital rudder servo that's now discontinued
  
• an S148 standard throttle servo
• Futaba/Sanyo 4.8 volt receiver packs

IF I was dealing with a boat that has carbon fiber in its layup, I would definitely be looking at a 400mm antenna. Since I'm not, the 304 works fine just the way it is. If you look at the picture of my boat, you will also see the antenna tube doesn't come out the top of the radio box, but out the side, with a 90 degree bend:
https://static.wixstatic.com/media/...1/1fdd7a_80b95370a7ea469a83539c8d0a973d93.jpgThis means the antenna is even lower, and is on the left side of the boat. Even with that, it still works at the furthest parts of the course. Yes, I know the picture shows a long 75MHz antenna but that was swapped out years ago. The present 2.4 antenna doesn't reach the last third of the tube.

I’m

 

[Wasted wages]

I've always run FM systems without failures..
When I finally made the jump to 2.4, I bought a very nice PK4 with a dozen or more recievers...
First time I ran a boat with the new gear, the boat got half way across the course and I lost radio...luckily it did some doughnuts and eventually rolled over.
I pulled everything apart, the reciever I chose for the installation had a long antenna on it.

When I popped open the reciever I found the antenna not even attached to the board, and some green corrosion on the IC...

That reciever now resides at the bottom of the lake. That's how I fix radio problems.

I also subscribe to Daniel's method of switches...I've used toggles for years.
Pot the wiring, heat shrink for strain relief on the wires. When I put the switch in the radio box, I cover the toggle with a dubro pushrod seal, put a dab of shoe goo on the tip to seal it shut. Bulletproof setup.
Never use silicon anywhere near or in a radio box! That stuff gasses off corrosive gas that will eat up every contact in the box.

 

[Bill Eilers]

Andy Brown's bulletproof switch, first saw in the baitbox of a Mongoose he ran in Fl. He used 5/16 nuts to tighten and loosen connection, same as glow plug.

That's a switch that won't come loose

 

[Bill Eilers]

One more issue I see with running long antennas.

The extra length going up the tube is just folding over at speed anyhow.

The receiver antenna works considerably better and is meant to be vertically polarized. You ever watch a long antenna tube at 60 mph.

The long antenna tube is bowed over and your long antenna is not an iota taller than the shorter one was and it is laid over flat not sticking up vertical like it should be.

The tube is laid back with the end horizontal and back over or closer to the prop roost.

4-6" straight up or a 8"-12" folded back to the same 4-6" height but now it is laid flat.

The straight 4-6" one is going to give you the better range.

Noticed I haven't almost poked the ole' eye out since we got rid of those long stranded wire antennas the FM radio used to have to have.

The short antenna was all the rave of the 2.4 GHZ. Now you want to go back long for no reason whatsoever.

Decrease your range and maybe poke your eye out too. Nice.

The short vertical antenna will have better range than a long antenna when underway at speed.

Keep the exposed coax high thru the first turn rooster tail

 

[Terry Keeley]

Ever notice how some people will go on and on to try and sell their point of view?

Here's a politician explaining how it works: