Source for Futaba 400 mm RX Antennas

[Mark Stein]

One of the reasons I point that out is to note the center wire is very small and not stranded like 75mhz antenna. If it is bent say 90 degrees over and over it could break anywhere.

 

[Grimracer]

Yes Mark.. hope you are well... ya NEVER want to bend the end of the coax... so.. I just place it in the tube and shove a small zip tie in the bottom.. (zip tie tongue in the entry point of the tube).. and wala.. she is good to go.

Grim

 

[Hydro Junkie]

If you ever assembled your own tv cable like I did years ago you know about the shielding and center wire.. same here just smaller

If you think that single conductor coax was fun, you should try to do a quadrax. Four conductors of 22 gauge or smaller inside a shield braid. Can we say "Good Times"?
Actually, I see stranded coax cables all the time. The difference is that the center conductor is larger, in the 18 to 20 gauge range. That said, those are for airborne radio systems where the cable has to be bent for installation. Those also have a pin either crimped or soldered onto the end of the center conductor.

 

[Brian Spitzer]

DING! DING! DING! We have a winner, give that man a cigar. Remember only the last inch is the actual antenna and needs to be above any metal and carbon fiber for best reception, this has been known from the beginning. And BTW this is true of any 2.4 system not just Futaba. I still run the Futaba 4PKS-R 2.4 FASST system with all 603FS RXs and will continue to do so as they have been nothing short of excellent. As far as the "experienced racers" that had issues at the Nats I heard there was confusion over the best RX with the newer T-FHSS system they were using and there was a better RX to use for marine applications?? Maybe Mike Z. can chime in on that story..........

Don,
The receiver you are referring to I believe is the R324SBS Diversity Receiver. I have these in all my boats on the T-FHSS protocol and have exceptional range, far superior to the R304SB.

 

[Grimracer]

DING! DING! DING! We have a winner, give that man a cigar. Remember only the last inch is the actual antenna and needs to be above any metal and carbon fiber for best reception, this has been known from the beginning. And BTW this is true of any 2.4 system not just Futaba. I still run the Futaba 4PKS-R 2.4 FASST system with all 603FS RXs and will continue to do so as they have been nothing short of excellent. As far as the "experienced racers" that had issues at the Nats I heard there was confusion over the best RX with the newer T-FHSS system they were using and there was a better RX to use for marine applications?? Maybe Mike Z. can chime in on that story..........

Any of the Futaba "Diversity" receivers are best for Marine Applications. Again.. the installation is important to fully utilize the diversity feature.

Grim

 

[Mark Bullard]

I did lose a boat the week before the Internats. It was a transmitter problem. As I did not have fail safe turned on in none of my boats. The D hydro I was testing for straight away was clock with the gun at 85 mph when I lost it. So turned on the fail safe before I tested the twin and the problem showed again. Could not get over a 100 ft. past the bouys and the motors would shut down. So must have had RF problem with my 4PK. But was running R603FS's with long antennas.
Talk with Futaba Monday morning about 8:30 and talked radios. They say that the R334SBS has very good range out of the box. It has a little longer antenna than the other receivers. But can not be run with another side by side like I do in the twin of two batteries, two switches and two receivers. But the R614FS will. So I ordered a new 7PX, four R334SBS receivers, and two R614FS receivers. Click the little button to pickup at the center, since the center is only 20 miles from me. Jumped in the truck and was back at the shop by 10:00. Good service.
I had long antennas for the R614FS so installed them for the twin and installed the R334SBS in all the other boats. I could drive the boats anywhere I wanted to go on our lake. Outstanding radio system.

 

[Mike Hughes]

I heard some very experienced Futaba sponsored racers lost control of their boats at Hunstville this year.

For over water use Futaba recommends getting the antenna up high, away from the water, pipe and any CF parts on the boat.

Most of those issues at Huntsville this year were from transmitter issues. We dont normally run that long on the left and right side of most lakes. I believe a lot of the issues were outstanding before people showed up. Tramsmitter antennas were compromised. The boats were just pushed outside of the range they normally run in. You werent seeing them lose the boats close just far left and right. I had radio issues too on my twin. I was getting too much radio in my water box so I parked it. LOL Was nice to take it home in one piece.
Mike

 

[BobBonahoom]

I used to know an expert radio design engineer who designed spread spectrum systems for homeland security applications. He told me that with 2.4 systems it is very important to get the antenna above the ground plane (water for us) as far as possible. But he also said that it was just as important to keep the antenna perpendicular to that ground plane (straight up).

I fitted my boats with some 400 mm receiver antennas which are sticking up above the radio box about 12". As you might guess, when I go down the straight away at full speed these long antenna tips are almost parallel with the water due to the air flow and only about half the static distance from the water. That means it may be better to have a shorter and/or stiffer antenna in order to remain perpendicular to the ground plane at speed. Just thinking out loud here...Any thoughts?

 

[Hydro Junkie]

Your memory is on the money. The issue with a long antenna that is unsupported is that, as you stated, it will lay down due to the air flow. While this isn't a problem for most of the straight, at the far end and in part of the corners, you are hitting the antenna almost straight on the end or running up the length. This puts a serious attenuation on the signal since you're only getting a fraction of the signal strength you would get with a vertical antenna. At the same time, however, you don't want it to be so rigidly supported that it can't flex since that can cause issues as well if the supporting structure or tube breaks.

 

[gilbert galli]

I use futaba T 10 cg fasst model, the boats are équiped with the rx futaba 6106hfc in hydro 40 and hydro 21 or 6008hs in mono 15cc and fsr v 15cc with 400mm long antenna, i have not any probléms

 

[Hydro Junkie]

We never said you would. Bob stated a POSSIBLE issue that can come up with the long antenna and I agreed, both of us using known information to base our posts. You may never have a problem as being at long range with an antenna that's laying over is only one thing that can affect receiving range.

 

[Grimracer]

Bob.. I suspect you will not have any issues.. I have (I dont anymore) laid the antenna down in my Tunnel boat so the end was parallel to the water.. never an issue and it was 5" off the water.

Then.. I know they are not close to the ground all the time.. BUT.. most airplanes.. JETS included.. will be on the ground several hundred feet from the pilot and the antennas are never vertical.

Grim

 

[DougSick]

Racing IMBRA in Europe in 2016, two of us Canadians had the same issue in the exit of the left turn with the Futaba receiver. We would loose radio for a second causing our boats to continue around the corner and inside the course. After a couple of occurances, we concluded there was some external standing interference in the area and the locals ran the longer antenna. We bought a bunch from Ians Boats (http://www.iansboats.co.uk/) who had a shop at the site, installed them and had no more problems. He had a handful of them at the 2018 IMBRA in France. I have since purchased additional ones from him to run in Europe and home. They are not listed on his website but you can email him for availability.
No real issues with the shorter versions at home except when the tip broke off of one and I didn't see it. No radio after 10 ft out. Ouch. The longer ones do give more flexibility with placement of the receiver and being able to get the tip away from the tuned pipe.

 

[Walt Barney]

I used to know an expert radio design engineer who designed spread spectrum systems for homeland security applications. He told me that with 2.4 systems it is very important to get the antenna above the ground plane (water for us) as far as possible. But he also said that it was just as important to keep the antenna perpendicular to that ground plane (straight up).

I fitted my boats with some 400 mm receiver antennas which are sticking up above the radio box about 12". As you might guess, when I go down the straight away at full speed these long antenna tips are almost parallel with the water due to the air flow and only about half the static distance from the water. That means it may be better to have a shorter and/or stiffer antenna in order to remain perpendicular to the ground plane at speed. Just thinking out loud here...Any thoughts?

Bob,
I have one 400 MM antenna in stock and have more on the way,If you want me to send the one out let me know
Thanks
Walt Barney

 

[moe1117]

Try Radio South

 

[sailr]

Here ya go.

https://www.ebay.com/p/Futaba-Repla...PZ_XqCiC1blOjPJDu_vjgphS-ItiOLjhoCZ0wQAvD_BwE

 

[Grimracer]

Those do not appear to be the 400mm units...

 

[Walt Barney]

I agree they do not look like 400mm in length
Walt Barney

 

[Daniel's Racing]

Those are most likely short.

A short antenna that stays vertically polarized in the wind will have better range than a long one the wind has bent back and now is horizontally polarized.

Long antennas serve almost no purpose just more wire to get damaged. Mount receiver under the lid with Velcro and the entire antenna can be pushed right straight up the antenna tube. It don't get any better than that.

If you need more range take the second internal antenna and disconnect it and run a second antenna instead. Same exact connector. You can take that whole flat circuit board(antenna) sticking up completely out so the receiver closes up easily too.

 

[Grimracer]

Poor advice above folks.. I think you all can see that.. please do not follow his advice..

it has ZERO to do with direction polarization and everything to do with distance from the obstruction. Its JUST that simple.

Grim