747drvr

My Feedback: (5)

Mick ,

I would love to see the hanger mod . I thought of growing a bigger transmitter tray (belly) but my girlfriend doesn't like that option !

Marc

Julez

Spektrum TXes have a clearly stronger RF output in the states, this is correct. But here in the EU, the laws concerning the ISM band are more stringent. The power density is limited to 10mW/MHz for DSSS, and 100mW/MHz for FHSS.
Thus, more power is allowed for Fasst.
The Spektrum radios also use 100mW here, and got away with it until now...

Region code means, that you cannot operate a german module in a US transmitter, for example. And I think you can only choose MHZ frequencies which are legal in the country you bought the transmitter in.
You cannot choose 72MHz in a TX with german region code, for example.

Cheers,

Julian

FILE IFR

Got it.

Thanks for the explanation Julian.

GrayUK

Many thanks Julian.

You say "until now....."

Can you cllarify?

Paul

DelGatoGrande

My Feedback: (23)

so how many mW is usa 14mz modul??100?[X(]

Moerig

"The power density is limited to 10mW/MHz for DSSS, and 100mW/MHz for FHSS. "
I am willing to bet not even the manufacturers understand the implication of this spec...... I bet everyone assumes that means 10mW for DSS and 100mW for FHSS. BTW this spec is almost universal except for France ( probably because authorities there dont understand it either...)
the CE (!) mark. What does the (!) mean, bet nobody on this forum knows...

mick15

Pics of the little bracket to shift the cg.

m

DelGatoGrande

My Feedback: (23)

nice!!

747drvr

My Feedback: (5)

Very clever ! What did you fabricate it from ?

Marc

Julez

Hi!

First, your question, Paul:

Answer: I have no idea

Well, having about 2MHz of spread, the Spektrum system would only be legal with 20mW of power according to EN 300328.
Somehow, the importer halfway declared it as FHSS system because it "hops between 2 channels", but 2 channels are not enough to fall under the FHSS regulations. Authorities are currently investigating, AFAIK, but the mills of them grind slowly.
There has been some kind of meeting of the authorities, dealers and RC assosiations recently, and it was discussed to allow 100mW for all kinds of RC use.
In a nutshell, noone knows nothing, as usual. Until things get cleared up, we will have DSM3 and Fasst MK2.

Best thing is to go flying and not worry about anything. I have yet to see any kind of RF Gestapo.[8D]

Cheers,

Julian

afterburner

My Feedback: (18)

If there are any to be seen, you guys should see them first.

Marty

schroedm

My Feedback: (1)

[X(] Can you say that?!?!

FliteMetal

I can shed light on the EU meetings and provide online summary of what has been resolved thus far. This is simply addressing the power
differential which exists within many of the EU countries and a group that has been striving to have all countries permit use of 100MW. The
report defines what countries are considering permiting this and those whom further discussion has to be conducted.

On May 14th. there will be a http://www.cept.org meeting solely dedicated to this TCAM issue. Delegates from several European versions of
AMA/BFMA will attend. EFRA assessment of the meeting: http://www.efra.ws "get the latest news here" text in greenish yellow

afterburner

My Feedback: (18)

I just did!!.

Nothing against Julez. Appreciate all the info he has provided in this thread. Just his location and the term he used brought up some thoughts[].

Marty

FliteMetal

Not to get too specific...but a friend purchased a Futaba 7G with two receivers to handle all the servos
in a multi engined aircraft and was confused when he saw no reference in the owners manual to a dual
receiver set up. He called asking if I could advise and I set out online to see what was documented.

I was amazed to see no return to my searches which were Dual receiver 2.4 Futaba. Sure there were a
number of incremental returns but absolutely none which addressed dual receivers.

My specific question is relative to the fact the 2.4 gig receivers are transceivers which in traditional terms
would typically have a distance between each restriction to prevent cross talk, etc. Knowing that even at
2.4 this is still an issue in industrial applications I deal with every day...I would have thought I'd found at
least one post dealing with the use of multiple 2.4 Futaba receivers in a single airframe. NaDa...

1). Can anyone indulge me for a moment or two to shed light on any issues related to the distance between
each receiver and antenna pair?

2). The other question is related to using a Y harness in a channel slot so a second battery can be plugged
in for additional capacity. If there is no switch on the battery side of the "Y" are there active elements in
the system which will draw down the additional battery attached in this manner?

Thanks in advance for your feedback as the new Futaba 7G owner is placing this into an expensive exotic &
doesn't want to gamble with what worked in his original 72 narrow band configuration.

altacom

My Feedback: (3)

Regarding the spikes in the images, I believe they are showing the 2 channels being used by a Spektrum Radio. The one with one spike I believe to be a XPS signal on one channel and non-hopping.

Juan Garcia

My Feedback: (7)

I performed a similar test with JR/Spectrum system, I mean insert the receiver in a S.S. ware then in a S.S. pipe and couldn't disrrupt the signal either .
Every servo behaves as normal.
Also I'd to mention that JR recommends 2.4 Ghz systems for jets as well for any other type of aircraft.
JR and spectrum's 2.4 Ghz are the same technology "Spred spectrum". The only difference is the method employed, DSSS Vs. FHSS.
So both systems might be good for jets.
Have not tried 2.4 system with jets yet but will do it soon. I can let you know my resultas.

Juan.

altacom

My Feedback: (3)

I have the same question. My Son-In-Law wants to put FAAST in his 35% Carden. It presently has 2 PCM Receivers, and we want to put in 2 FAAST RX.

I have tested and found that any 2 receivers will operate when bound to the same transmitter. But not willing to jeopardize a $6000 plane without some guidance and some assurance that it's safe. And how should it be done to be safe and effective.

Any help will be appreciated.

mick15

I have two 6014 rx in a model. The receivers are back to back, ie. one aerial points rear one points forward one points up and one points down, all seem to work just fine.

m

gerhardp

Hi Mick15,
If you have some patience, another option will be available later this summer. Check out another forum that discusses 2.4 GHz system with dual receivers with and without power management system.

http://www.rcuniverse.com/forum/m_7461687/tm.htm

Gerhard

FliteMetal

Cross thread marketing there...Gerhard??? The sheriff in these here parts frowns on a
marketing program built on cross threading...

The market has flattened out a bit with people tired of promises and delivery short on
fulfillment. Getting the EU to accept 100mw will be a continuing challenge with Belgium
and Spain as obstinant as they are.

Mick: Its interesting to read the two receivers were "back to back" without interop issues.
My friend's considerable investment in his bomber(s) warrants being a wee bit paranoid
amidst the fluff of marketer's wild claims these days.

I know Futaba shows a right angle to the vertical example of antenna placement in their
manual. I suppose this is of no differential if the two were at right angles to each other
in the vertical plane as well. Anyone have twin receivers with the antennas mounted like
this? That would be two veritical "Y's", one parallel to fuse, the other at right angles to it.

If one is to believe half the BS claims made by people trying to dump their SS inventories
it takes a real leap of faith these days. One marketer claiming their system has a 2 million
chipping sequence... talk about latent response times if that were true. But still they claim
it...

Gerhard's product will find a place where people are throwing big bucks at multiple receiver
DS systems...however the growth money is down in the trenches with 10 channel newbees.

ceecrb1

WELL i´ve been reading a lot of posts and issues for the past few weeks and finaly ordered my 6EX and 2 RX´s 2 days ago.

A few things that maybe I can add, being an electrical engineer and computer scientist.

As 2.4Ghz is the same frequency as WIFI and the futaba system uses the same coaxial antenna and connectors as laptop and small wifi systems.... This information can be carried accross to the RC world.

A. The computer style WIFI enclosed ariels (the same style as on the TX) are, internally, identical to the 2 rx ariels, this could be usefull for anyone wanting a more "protected" option or external options.
B.General rule of thumb.. 0.5dB loss of signal on the RC ariel for every Meter of cable added (if your thinking of buying wifi ariels and extending etc). This is often quite funny when you buy a 7db gain antenna for WIFI which comes with a 2mtr cable.... your only buying a 6db "system"
C. DONT open up the coax more to achieve a greater "working length" of ariel on the cable..... Unlike with low frequency systems (ie 35mhz etc...) the length of bare wire is very important in relation to its performance in converting the waves in the air into the signal inside the cable..... Think of it as a very basic filter, where the length of bare wire will change the frequency...


Once my system arrives I´ll be installing one RX in a plane and the other will be used for testing before instalation in my funjet.... I´m hoping to test the gains that may be available by placing a good quality wifi ariel on the main RX antenna (diversity systems always work with a primiary and secondary... Ie we can mod-up the primiary and leave the 2nd as is for "backup" but if a modification is done well.. the 2nd will NEVER be used).
I´m sure this would make jet and large scale flying FAR more relaxed affair... however it would resort back to a big black external ariel poking out the plane.... or in the case of laptop antennas (basically a flat copper sheet) These could be mounted flush on a wing surface or tail fin etc.......

Once I get this done i´ll come back and update

Edit for spelling

GrayUK

Fliemetal
I see no problem with using 2 rx’s, either split to control half the plane each or through the Royal Powerbox which selects which is best and uses it.

The Powerbox has been reported else where in the thread (recently) and functions well.
Also on another thread I have seen reports of this option. In both cases the owners report no switching ! which once again says a lot for FASST as a secure data RF system.

Using 2 RX’s I would probably use 2 Y aerial setups one in the vertical plane and one in the horizontal.

Ceecrb1
I would not change the aerials, they work perfectly as they are, more range than you will ever want.
Also, on the FASST I do not believe there is a primary and a secondary.
If you read the Futaba patent the way it works is that at the beginning of each ‘packet’ there is a ‘preamble’, which looks like data but has no value as such. Both aerials read this and the computer looks at the quality of each signal. On that basis it selects on which one to receive the data.
So it decides on each packet which aerial to use.
It is very clever, hence the patent and this is one of the reasons why Spektrum has to use multiple rx’s to do what Futaba can do with one.

Juan
The fact that JR recommends Spektrum for jets does not mean anything really, the proof is in the users hands. I know that Spekrum can work reliably in jets, I have seen it and it is good. However, because of its complexity and install requirements (3 pages on RCJI) it is more prone (in my opinion) to problems as a result of bad installs and its own complexity, it also seems to be inconstant when linking, which I find scary!
I have never had my FASST system fail to link, normally less than 1 second.

I watched a guy at our field last week; switch from 35meg PCM to FASST in 15 minutes. He positioned the rx in mid air hanging on Duck tape! and 2 pieces of 1/8th ply strip! Not what I would call a good install….but he them flew his Flash all day with absolutely no issues, I hope he has now done a proper install but it shows the robust nature of the system.

Paul

FliteMetal

Paul:

That's encouraging to hear. So you don't anticipate any interaction between the two receivers in close proximity
as a final resolve... : )

GrayUK

I think with all electronics it is a good idea to keep them a little apart to avoid 'electromagnetic crosstalk' but a couple of inches should do.
Here is a pic of a double FASST instal.

[link]http://www.rcuniverse.com/forum/fb.asp?m=7547574[/link]

Paul