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Spektrum DX18

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Old 09-10-2012, 09:33 PM
  #501
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Default RE: Spektrum DX18


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ORIGINAL: madmodelman

What the 18 actually does is assign the most important controls, flying surfaces, in the first available channels.
Like you I used to use Aux2 for ucu control. This is a complete waste of time and a channel, I advise you to forget it.
If you are worried about killing the turbine fast simply assign a throttle cut switch, I use switch H.
Gary.
Gary - Thanks for the information on how the flying surfaces are assigned. It just seems strange that if you change them you lose a channel. My first radio was a Heathkit GD 47. I have traversed through a number of radios over the years, my last one is the JR 11X. This DX-18 is a whole new breed of cat. It's a fantastic radio. I also appreciate your concern about me waisting time. I have been retired for 14 years now and I just waist time whenever I want to. Also at this age forgetting things is not a problem.
Thanks again,

Galen

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Old 09-10-2012, 11:57 PM
  #502
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Default RE: Spektrum DX18

Hi Galen,

Sorry about the wasting time, badly phrased that. When I got into turbines about three years ago I religously used the aux ecu as per the JC manual then èventually got a Wren and realised that I was the only one in the UK throwing a channel away. This was on a JR DSX 9 so I hÃ*d to use a matchbox or two sometimes.
When first using the DX18 I got confused because it kept throwing out the gear channel which annoyed me initially, but then I realised that gear is just a non proportional switch so the Tx just chucks it out so the early crucial channels get priority presumably for latency, common sense I guess. I quickly got used to it though.
I can't quite understand how you can lose a channel though especially as one of the battery inputs is actually a 10th channel, simply plug the battery into any spare port.
I started off on a Macgregor single channel reed set more years ago than I care to remember!
Gary.
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Old 09-13-2012, 06:48 AM
  #503
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Default RE: Spektrum DX18

I am about to set up my old CARF Lightning on my new DX18, using a 12020 Rx and PB Sensor switch.

Any advice (or general usage) on channel asignment? Or do you let the Tx assign default channels?

And which switches do you use for what? (Mode 2 fliers only please)

I am thinking :- switch A for retracts
D for 3 position flaps
Right slider for wheelbrakes
Left slider for airbrakes (if/when fitted)
G for engine cutoff instead of pulling trim back
C and F are rates

How about smoke? switch B maybe (when I connect it up)
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Old 09-13-2012, 06:59 AM
  #504
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Default RE: Spektrum DX18

its s smorgasbord radio.. my setup is Basically the same as 12X..I use E for smoke, because it was Aux2 on the 12x and learned it that way.. some guys use sliders or B or the button for smoke.. Its cool that you can do it anyway you want... Make it like you learned your old one because you will have less chance for a switch error at a critical time.With the 12chan, it doesn't matter what channelization you use.. The pain of setting it up helps you learn it and learn what you want..

As far as throttle trim, you can use the digital trim and the kill button, or the slider.. I prefer the slider..because the kill button is also the trainer button... , which is also why its not smoke or brakes...

I put my gyro and smoke on 11/12 because i dont look at them in the monitor .. the first 10 show on the first monitor page...11+ show on the Xplus page..

Once you get a baseline model setup, then just copy it over and over and change the config... do that before you bind to a new model because if you change wing config, it will steal channels...it takes some trial and error to get it done...
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Old 09-13-2012, 08:43 AM
  #505
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Default RE: Spektrum DX18

I suggest you use H for throttle cut, easier to find in a panic situation!
Gary.
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Old 09-13-2012, 11:05 AM
  #506
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Default RE: Spektrum DX18

Has anyone used the TM1000 telemetry module to check out their Rx's minimum input voltage reached during a flight?

I had nine 7-8 minute flights today and after every flight I found that my so-called voltage-stabilized Powerbox Sensor switch showed a minimum voltage of 5.4V compared with the resting voltage of 5.8V. Evidently the current draw of the servos was sufficient to pull down both linear regulator voltages by 0.4V each, which suggests to me that the max current capacity of the regulators was being approached. There is no mention of any voltage drop to be expected under load in the Sensor Switch user manual. The provided Sensor output leads connect directly into the Rx so there's no extra resistance in circuit.

Since I was only wringing out a li'l Wren 44 Gold powered Boomerang Nano for which I wouldn't expect the servo current draw to be particularly heavy, I'm wondering if my Sensor Switch is somewhat below par. Or perhaps this voltage drop is simply a feature of linear regulators under any sort of load.

The flight log data showed only minimal numbers of fades on the AR9000 and two remotes and no frame losses or holds, so it was good to confirm that the radio link was secure at all times.

Gordon
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Old 09-13-2012, 11:59 AM
  #507
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Default RE: Spektrum DX18

Alisdair,

If you think of the channels as 1 to X and stick them in where you logically want them to go then you'll get along much better. Then in the system menu you assign the channels to the functions you have connected them as.

The only exception to this rule is the inbuilt mixes, such as flaperon or 4 chan aileron etc as these have specific channel assignments.

Cheers,

Colin
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Old 09-13-2012, 12:04 PM
  #508
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Default RE: Spektrum DX18

Hi Colin,
Are you home at the moment?
What aircraft have you installed onthe DX18? And which Rx?
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Old 09-13-2012, 12:08 PM
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Default RE: Spektrum DX18

Gordon,

A linear reg is basically a variable resistor with heat being the waste product so I'm guessing that coupled with the fact that they are not very efficient might explain the 0.4v drop when under load?
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Old 09-13-2012, 12:30 PM
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Default RE: Spektrum DX18

Alasdair,

Back from France tomorrow (Fri) and I have all aircraft that i own on the DX18, including viperjet, boomer and my 110cc ultimate with smoke.

Give me a phone/pm if you have any questions.

Colin
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Old 09-14-2012, 10:08 AM
  #511
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Default RE: Spektrum DX18

.4 is actually alot for a Nano, for regulator drop.. hook up an ammeter and check all your surfaces and gear/brake servos.. the most common culprit is the gear servo being not set right..
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Old 09-15-2012, 12:56 PM
  #512
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Default RE: Spektrum DX18

The 0.4V is more than I expected. With this telemetry system it's necessary to reset the min Rx volts reading after switch-on and before flight as otherwise it will read low to begin with. The micro retract servo only operates a Clippard SMTV-3 air switch and there's no binding at servo endpoints. I remember seeing a servo current ammeter advertised somewhere but can't remember where.
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Old 09-16-2012, 12:53 PM
  #513
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Default RE: Spektrum DX18

You can use a watt meter, just plug between battery and reg.. might have to make some adapters.... I just use my watt meter most of the time and do trial and error.. just to make sure.. most jets are around .2 to .6 amps at idle. depending if there are gyros and such.. Flaps are also a common culprit at the full up, there is often high current if the settings are over driven to the stops.. brakes too.. just cycle everything and eliminate that from the equation and then you will also know the idle current..


Story: I was helping a buddy set up a jet with 1 A123 2300. on a fully charged battery, we set up all the flight controls, but I assumed the other stuff was set.. the jet wasn't buzzing or anything.. we had it on for a bit... we went and flew it once.. all well... After that, we charged it and the battery held 2000mah.. we were about to lose the jet.. culprit: binding servo, but not enough to buzz.. idle amperage was 2.4 amps... we were lucky.. keep troubleshooting.. you will find it..

Additionally, I would recommend you plug a Cricket into the Box.. it has a voltage tell tale and its really accurate..cheap.. fromeco.org... I use the cricket on most new jets.. it blinks at the lowest voltage seen... I have seen descrepancies between the telemetry min V and the cricket.. I believe the cricket...
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Old 09-17-2012, 10:12 AM
  #514
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Default RE: Spektrum DX18

Thanks Goose. I've used a Super Whattmeter for years for electric flight but never thought that it'd be particularly accurate for low currents. Looking at the specs on the Astroflight website I see the resolution is 10mA, so it should give a worthwhile estimate of current draw and I'll give it a try.

Best regards

Gordon
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Old 09-19-2012, 02:11 PM
  #515
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Default RE: Spektrum DX18

Still talking about PB regulators, the Gemini in this instance, I flew my GP Ultimate 160 today with telemetry installed for the first time. The plane has a pair of 2S 2200 lipos into the Gemini and it has seven 20kg servos on the surfaces (overkill I know and not overworked in this plane with a Saito FG-36 gas engine, but I wanted titanium gears) and a low-power digital on throttle. After all three of the flights during which it was aerobatted quite hard, the telemetry indicated that there had been a 0.4V voltage drop on load during each flight. No more than 0.4V, and no less either.

So its beginning to look as if the 0.4V volts drop on load is a feature of the PB circuitry.

I'm really liking the telemetry. It told me that even with the flea-power of the Saito compared with the 50cc 2-strokes most guys fit in this plane, it would perform a 600ft vertical climb, and I was astounded at the way the plane kept on clawing its way upwards.

I have the airspeed sensor and will try that on my 44-Gold powered Nano and Hawk .

Good ol' Spektrum!
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Old 09-24-2012, 03:30 PM
  #516
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Default RE: Spektrum DX18

Couldn't resist, got myself one of these last week

For some reason, in one of the models, I don't have "gear" selection (from wheel to everything else) in Gear channel under Channel Assignment within System menu, what am I doing wrong? I don't have any program mix associated with that channel either.

Thank in advance,
Barry
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Old 09-24-2012, 03:54 PM
  #517
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Default RE: Spektrum DX18


Quote:
ORIGINAL: marquisvns

Couldn't resist, got myself one of these last week

For some reason, in one of the models, I don't have ''gear'' selection (from wheel to everything else) in Gear channel under Channel Assignment within System menu, what am I doing wrong? I don't have any program mix associated with that channel either.

Thank in advance,
Barry
Barry - I had some what of a simular problem. If you read posts 496 - 499 on this forum It should answer your questions. If not, I'm sure others can chime in and explain it further.

Regards - Galen
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Old 09-24-2012, 08:17 PM
  #518
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Default RE: Spektrum DX18

What would be a good voltage low limit to set the RX battery telemetry at for A123 6.6 packs? My past experience has been that A123 will start out at 7.20 volts. I know that they have a flat discharge curve and that A123 don't respond well to load testing but they do drop off some and that around 6.2 volts or so they fall off the cliff really quick. I am thinking that setting the low limit alarm at 6.4 to 6.5 would be adequate.

Any thoughts?

thanks
mike
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Old 09-24-2012, 08:22 PM
  #519
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Default RE: Spektrum DX18

Thanks Galen, but I have confirmed that this has everything to do with my wing type selected with 2 Ail and 2 Flaps, which bumps the Gear and defaults Gear channel as L Flap, without gear selection. Anyone has this problem?
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Old 09-24-2012, 10:40 PM
  #520
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Default RE: Spektrum DX18

Reading these posts I am wondering if this radio has issues or whether it is just people learning a new system with lots of channels etc ?
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Old 09-25-2012, 12:00 AM
  #521
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Default RE: Spektrum DX18


Quote:
ORIGINAL: marquisvns

Thanks Galen, but I have confirmed that this has everything to do with my wing type selected with 2 Ail and 2 Flaps, which bumps the Gear and defaults Gear channel as L Flap, without gear selection. Anyone has this problem?
Like you I'm using the 2 ail and 2 flap which uses the gear channel as L flap. For the gear I plugged the retract servo into Aux 4 and assigned switch A to operate that channel. To get the where you assign which switch, go to Channel Assign in the setup menu, scroll to next, then in my case scroll down to aux 4 assign it to switch A.
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Old 09-25-2012, 12:07 AM
  #522
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Default RE: Spektrum DX18

Quote:
ORIGINAL: TimWatson

Reading these posts I am wondering if this radio has issues or whether it is just people learning a new system with lots of channels etc ?
In my case it was learning that all switches are assignable and you can assign any switch to do anything. Example, I don't like the digital trim on the throttle channel so I assigned the left slider as the throttle trimmer.
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Old 09-25-2012, 12:11 AM
  #523
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Default RE: Spektrum DX18

Barry, it's not a problem. If you select a wing type other than normal the tx automatically assigns the necessary channels and mixes needed.
Gear gets booted further down the line as the flight surfaces get priority. When all is said and done gear is not even a proportional channel so does not take priority.
Simply assign gear to a spare aux channel and the switch of your choice.
The whole idea is that the tx sorts it out for you when you tell it your wing set up, this can be appreciated more when things start getting really complex, I.e. multiple servos per surface etc.
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Old 09-25-2012, 05:11 AM
  #524
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Default RE: Spektrum DX18

Barry, If you activate dual aileron and dual flap it will use the gear channel. You can go into the channel assign under System set up. The first screen that comes up is RX port Assignments. In the lower right corner is next. The next screen is Channel Input config. You can assign one of the unused channels to switch A which is the typical gear switch. I hope this helps you out.
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Old 09-25-2012, 08:14 AM
  #525
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Default RE: Spektrum DX18

Hi guys,
im setting up a Bobcat with the Spektrum 18X and a Spektrum12020 receiver, TM1000
power supply is thru a Powerbox Gemini with 2 x 2300 mA LiFe packs.
ive plugged the TM1000 telemetry module into the data/bind port and batt 1 into batt port and batt2 into the srxl port
Ive selected the Powerbox option on the transmitter telemetry menu , but I get only a single battery voltage readout.
there is a single Rx batt voltage option with alarm options which I can't ddisable how do I get both pack voltages on my Tx ?
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