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Old Aug 17, 2012, 09:29 AM
Radio? Screwdriver!
United Kingdom, England, Bristol
Joined Aug 2011
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Quick update on hop channels. It appears that the transmitter hops over 31 channels. Interestingly S-FHSS only seems to transmit between 2400MHz to 2450MHz. I assume this is so that France can be accommodated without having a separate hardware revision for both transmitter and receivers.

However this may be of interest to FPV'ers who may want to use 2.45GHz to 2.48GHz for their video transmitters. Obviously you'd have to be careful that as your fairly near the band that you don't get any harmonics or the sidebands hitting the main Tx signal - and saturating the receiver front end.

Cheers,
Si.
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Old Aug 17, 2012, 01:53 PM
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Joined Dec 2007
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Simon,

All that info is available in the FCC docs for the Futaba S-FHSS system.
Go here: http://transition.fcc.gov/oet/ea/fccid/

Doug.
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Old Aug 17, 2012, 02:15 PM
Radio? Screwdriver!
United Kingdom, England, Bristol
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Originally Posted by DougV View Post
Simon,

All that info is available in the FCC docs for the Futaba S-FHSS system.
Go here: http://transition.fcc.gov/oet/ea/fccid/

Doug.
Hi Doug,

Some of it is on the FCC docs, but not all (such as servo bit resolution, etc). However I've found that the FCC docs often doesn't always line up with what the transmitter is actually doing (even though it should).

For example, the FCC docs say that the transmitter hops on 60 channels. However with my transmitter example its only commanding the RF chipset to switch between 31 channels! Also FCC docs specify that FSK modulation is used, but not 2-FSK - which like saying I drive a Honda - I do - but there are many different types/sizes/etc of Honda.

Also the resolution and update frequency is something that may be of interest to someone who is deciding on a transmitter.

For comparison the Aurora 9 has 10bits resolution and a transmission update frequency of ~19ms.

Cheers,
Si.
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Old Aug 17, 2012, 04:32 PM
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Keep it coming I really enjoy this type of information. it helps make a more informed decision.
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Old Aug 20, 2012, 07:44 AM
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Help please!

Hi,

I've been flying for a few years on a really old & basic 35mhz and finally took the plunge a few weeks ago and bought an 8j.

I'm struggling to programme it though and although the manual might be easy to decipher for people with some programming knowledge I'm finding it difficult unless I want to do exactly the same thing as the examples show - sadly I don't usually.

I've tried setting the failsafe but it doesn't seem to be working. Apart from going into the failsafe menu and setting the channels to f/s + 0% (with the throttle channel on f/s 15% ACT) I'm unsure how to get this working. I've tested it on the ground with a bit of throttle and the control surfaces at maximum and then turned off my radio and nothing changes - they all stay in the same place as when I turned it off. Anybody got any idea where I'm going wrong please? Also how do I set it to shut the throttle off totally instead of just to 15%.

Does this rely on a suitable receiver or should it work on any - I'm using one of the cheap FTR rx's that my local model shop takes out of the acro wot foam-e kits when people don't want them and they then sell them on cheap!

Any help or advice would be greatly appreciated.

Cheers

Sam
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Old Aug 20, 2012, 08:24 AM
Radio? Screwdriver!
United Kingdom, England, Bristol
Joined Aug 2011
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Quote:
Originally Posted by ozzieparky View Post
Hi,

I've been flying for a few years on a really old & basic 35mhz and finally took the plunge a few weeks ago and bought an 8j.

I'm struggling to programme it though and although the manual might be easy to decipher for people with some programming knowledge I'm finding it difficult unless I want to do exactly the same thing as the examples show - sadly I don't usually.

I've tried setting the failsafe but it doesn't seem to be working. Apart from going into the failsafe menu and setting the channels to f/s + 0% (with the throttle channel on f/s 15% ACT) I'm unsure how to get this working. I've tested it on the ground with a bit of throttle and the control surfaces at maximum and then turned off my radio and nothing changes - they all stay in the same place as when I turned it off. Anybody got any idea where I'm going wrong please? Also how do I set it to shut the throttle off totally instead of just to 15%.

Does this rely on a suitable receiver or should it work on any - I'm using one of the cheap FTR rx's that my local model shop takes out of the acro wot foam-e kits when people don't want them and they then sell them on cheap!

Any help or advice would be greatly appreciated.

Cheers

Sam
Hi Sam,

I've never used one of the FTR receivers, so I couldn't say for certain that it supports a failsafe - however I would be surprised if it didn't.

A couple of things to check:
- Make sure the transmitter is in SFHSS mode, not FHSS mode
- I have found that the failsafe can take 10-20 seconds or so before any changes are updated to the receiver. Unlike most systems that you make the receiver save the failsafe positions - Futaba seem to like to do it through the transmitter. So the failsafe data gets sent from the transmitter to receiver every so often. Quite how often I haven't worked out exactly yet.

To set the failsafe position, on the Failsafe screen, use the jog dial to select which you want to change. Put that stick or channel into the relevant position and then push and hold the jog dial down until the screen updates. The throttle channel never goes below 0%, as its doesn't really have a centre point. If you want it to go lower than the default 15%, set the bottom position (i.e. Carb fully closed on a glow engine) with the End Point Adjustment screen, then use the throttle trim to move the carb to the shut off position. Now once in that position, you can set the failsafe position as above.

To get 0% on the throttle, you'll need to set the EPA (End Point Adjustment) to 140% and also put the throttle trim to minimum. However I would imagine you'd never want to get that low - better setting up the linkages to allow throttle cut off at 100% EPA.

Hope this helps.

Cheers,
Si.
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Old Aug 20, 2012, 08:37 AM
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Joined May 2012
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Quote:
Originally Posted by ozzieparky View Post
Hi,

I've been flying for a few years on a really old & basic 35mhz and finally took the plunge a few weeks ago and bought an 8j.

I'm struggling to programme it though and although the manual might be easy to decipher for people with some programming knowledge I'm finding it difficult unless I want to do exactly the same thing as the examples show - sadly I don't usually.

I've tried setting the failsafe but it doesn't seem to be working. Apart from going into the failsafe menu and setting the channels to f/s + 0% (with the throttle channel on f/s 15% ACT) I'm unsure how to get this working. I've tested it on the ground with a bit of throttle and the control surfaces at maximum and then turned off my radio and nothing changes - they all stay in the same place as when I turned it off. Anybody got any idea where I'm going wrong please? Also how do I set it to shut the throttle off totally instead of just to 15%.

Does this rely on a suitable receiver or should it work on any - I'm using one of the cheap FTR rx's that my local model shop takes out of the acro wot foam-e kits when people don't want them and they then sell them on cheap!

Any help or advice would be greatly appreciated.

Cheers

Sam

I have Futaba R2008SB (about $60.00 on Ebay) IMHO works just fine. As far as the throttle shut-off/throttle-hold/cut-off percentage is set via the throttle stick. Go to the throttle cut menu and move the stick, the percentages will change and then choose the one best suited for you.

As far as the failsafe, I'm not familiar with your receiver, however for most systems it doesn't cut instantly, takes a couple of seconds.

Hope this works
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Old Aug 20, 2012, 08:53 AM
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UK
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Thanks Si,

I've checked the S-FHSS setting and that's ok. I think it's down to me not waiting long enough for the failsafe to kick in - I assumed it would be instant!

So when testing it I should wait for 10 - 20 seconds once I've turned the tx off and then it should activate - is that correct? I don't fly anything really fast yet but I reckon it could still go a long way away / deep into the ground within 10 seconds!

I'm sorry but I've got a few other questions that you may be able to answer for me:

The tx came with a 4 cell 1200mah nimh 4.8v battery pack which charges through the tx charging jack. The charger that came with it (ripmax futaba) should have lights that come on when you plug different aspects into it but they don't now (they did briefly for the first couple of charges). I can return it to Ripmax or the shop I got it from but I'm not too bothered if it's just the lights not working and it still charges all the same.

I've got the tx set up as a 4 cell battery type but the tx screen is showing 5.0v - is this correct as I'd assume that it wouldn't go over 4.8v? What should the value be if it's fully charged?

Cheers

Sam
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Old Aug 20, 2012, 08:59 AM
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Thanks Felix,

The rx I've got comes in at roughly $30 which helps on a tight budget - I'll head on to the full blown rx once the funds recover but the tx set me back a bit!

If I got to the throttle cut menu and set the mode to ESC then I get the option to change the mix, rate and thr and posi - are they important when flying electric?

Cheers

Sam
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Old Aug 20, 2012, 10:14 AM
Ron - AMA 1025
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USA, FL, Largo
Joined Aug 2005
304 Posts
rx

You can get the Futaba R2006GS SFHSS 6 channel rx for the 8J for $35 from helidirect.
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Old Aug 20, 2012, 10:20 AM
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Quote:
Originally Posted by ozzieparky View Post
Thanks Felix,

The rx I've got comes in at roughly $30 which helps on a tight budget - I'll head on to the full blown rx once the funds recover but the tx set me back a bit!

If I got to the throttle cut menu and set the mode to ESC then I get the option to change the mix, rate and thr and posi - are they important when flying electric?

Cheers

Sam
ESC is for electric, (Electronic Speed Controller)
These are my settings as they appear on the screen. All of my electrics are set up like this which works for me.

Mode ESC
Mix INH
Rate 0%
Thr 0% (0%) (as I've set it to with the sick)
Sw SWF (Like the long neck and it's location, above the collective/throttle)
Posi UP (towards me) I 've standarized my switches down or towards me turns things off. In this case (the throttle-cut is on making the throttle itself off) when the switch is towads me.

Hope this helps
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Old Aug 20, 2012, 05:15 PM
Radio? Screwdriver!
United Kingdom, England, Bristol
Joined Aug 2011
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Hi Sam,

Quote:
Originally Posted by ozzieparky View Post
So when testing it I should wait for 10 - 20 seconds once I've turned the tx off and then it should activate - is that correct?
No, no. Wait for 10-20 seconds once you have setup the Failsafe for the transmitter to send the failsafe settings over the receiver. After that time, then try turning off the transmitter to test the failsafe.

Quote:
Originally Posted by ozzieparky View Post
The tx came with a 4 cell 1200mah nimh 4.8v battery pack which charges through the tx charging jack. The charger that came with it (ripmax futaba) should have lights that come on when you plug different aspects into it but they don't now (they did briefly for the first couple of charges). I can return it to Ripmax or the shop I got it from but I'm not too bothered if it's just the lights not working and it still charges all the same.
Our UK models come with a Peak-Detection Fast charger. I slow charged my pack first (as for the first few charge cycles it's always recommended to charge Ni-Mh gently and not fast charge them), and haven't used the supplied charger yet. Anyway I haven't read the destructions, but I'm guessing the LED will extinguish when the pack is fully charged and it stops charging. Try plugging another Rx pack in (doesn't matter if its 4 or 5 cell) and see if the light comes back on again.

Quote:
Originally Posted by ozzieparky View Post
I've got the tx set up as a 4 cell battery type but the tx screen is showing 5.0v - is this correct as I'd assume that it wouldn't go over 4.8v? What should the value be if it's fully charged?
I did notice that Ripmax never setup the transmitter to use a 4-cell pack rather than a 5-cell. You can change this in the parameter menu on the 3rd screen under "Batt Typ". This will lower the voltage cut off, as on a standard 4-cell Ni-Mh pack, 4.8v is a bit high for a voltage cut off. Going on the voltage that the transmitter basis its alarm for a 5cell pack, I'm assuming on a 4-cell it'll go off at ~3.9v.

As typical for a transmitter, the alarm voltage goes off at a very low voltage level. At that level, you probably only have 2-5minutes absolutely maximum before you have to land. For general flying use, I would consider charging it at around 4.4 to 4.6v. Infact if it was 5v or below before going flying for the day, I'd charge it again to be safe. After all, as it takes a cheap Rx pack, it's easy and cheap enough to replace it every 2 years to be on the safe side and not have to worry about it not holding a charge.

The packs included aren't the new Low Self Discharge packs (e.g. Sanyo eneloop), so don't forget that you'll need to charge it if not used for a couple of weeks. Again, as its only a simple Rx pack, it wouldn't cost much to put in a new Low Self Discharge 5 cell pack. These also have a almost twice capacity of the included packs, so moving to a 5cell pack, you can expect nearly twice the use on a single charge.

Out of interest, where did you get your transmitter from? I personally got mine from Phoenix Model Products, as it was only a little more expensive than Slough RC, but the owner is a nice guy and I prefer to support the smaller shops! Not that I have it in for the larger companies, just when I can I do like to support the little guys.

Cheers,
Si.
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Old Aug 20, 2012, 05:18 PM
Radio? Screwdriver!
United Kingdom, England, Bristol
Joined Aug 2011
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Quote:
Originally Posted by ozzieparky View Post
Thanks Felix,

The rx I've got comes in at roughly $30 which helps on a tight budget - I'll head on to the full blown rx once the funds recover but the tx set me back a bit!

If I got to the throttle cut menu and set the mode to ESC then I get the option to change the mix, rate and thr and posi - are they important when flying electric?

Cheers

Sam
Just had a thought, didn't you get a R2008SB, plus a free R2006GS with your transmitter? The R2008 should be standard in the box and the free R2006 is an offer that Ripmax are doing at the moment if you buy a T8J.

Both my R2008SB and R2006GS both have set-able failsafe's on all the channels.

Cheers,
Si.
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Old Aug 21, 2012, 07:09 AM
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Quote:
Originally Posted by SimonChambers View Post
Just had a thought, didn't you get a R2008SB, plus a free R2006GS with your transmitter? The R2008 should be standard in the box and the free R2006 is an offer that Ripmax are doing at the moment if you buy a T8J.
I got mine through Inwood Models - they were doing a special show price at LMA Cosford for tx only. I sometimes use Phoenix and like you I think the owner's a good guy but I'm driven by price in most of my purchases and also Inwoods are pretty close to my parents place if I ever need to drop in...

Quite like the idea of some eneloops for the tx - any advice on what brand / where's best to get them?

Cheers

Sam
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Old Aug 21, 2012, 07:10 AM
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Quote:
Originally Posted by Felix the kat View Post
These are my settings as they appear on the screen. All of my electrics are set up like this which works for me.

Mode ESC
Mix INH
Rate 0%
Thr 0% (0%) (as I've set it to with the sick)
Sw SWF (Like the long neck and it's location, above the collective/throttle)
Posi UP (towards me) I 've standarized my switches down or towards me turns things off. In this case (the throttle-cut is on making the throttle itself off) when the switch is towads me.

Hope this helps
Cheers Felix - will have another look...
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