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Spektrum DX7 voltage

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Old 09-23-2012, 04:09 PM
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edjahar42
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Default Spektrum DX7 voltage

My DX7 on one model memory shows low voltage ( falls as I'm watching) and on all other model memories it shows good voltage. This is after a full charge and I've checked it with a volt meter. The charger is working right and the battery in the tx shows 12+ volts. This model memory is one that was started to program exponential on my plane to cure it's twitchiness. The problem with this is that the tx shows low battery and shuts down. I can of course fly on the other memory, but I don't like unknowns.
Any help appreciated,
Ed
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Old 09-23-2012, 04:37 PM
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Default RE: Spektrum DX7 voltage

G'day Ed,
First I would copy that model to another memory slot, rebind, & check the voltage.
When I had a DX7 it didn't matter what memory I was on, the voltage showed the same.
Also, If your plane is twitchy, forget Expo, for a minute, reduce the throws with dual rates, use the low rate, at 10% less than you have now,
& fly it, if it's still too twitchy reduce the rate by a bit more, then when it's comfortable to fly, maybe then you might introduce a small amount of Expo.
Expo is a fine tuning adjustment, it is not a cure all, because when you reach the Expo point, you have full travel & it's even more twitchy.
If you start with reduced thows, you can easily go to a high rate, with flick of a switch, if you set it that way.

Cheers
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Old 09-23-2012, 04:50 PM
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Default RE: Spektrum DX7 voltage

Thanks for the reply Alan,
I already had another memory position for this plane, I went back to it and rebound and no voltage drop. That one model memory is the only place that the tx shows a ( false) voltage drop all other memories show true voltage readings. I just don't like that my tx shows this false voltage drop and shuts down. You need to be able to trust your tx, right?
Ed
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Old 09-23-2012, 04:58 PM
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Default RE: Spektrum DX7 voltage

G'day Ed,
Too right, I have been having trouble with my radio lately, or at least I thought I was, turned out to be a faulty switch, in the plane.
I checked batteries, replaced leads, then the penny dropped, & I bypassed the switch, full voltage to RX.
I know that is nothing like your problem. Just venting. LOL.
Have you thought about contacting Horrizon Hobbies?
It might be worth sending in, for a checkup.

Cheers
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Old 09-23-2012, 07:23 PM
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Default RE: Spektrum DX7 voltage

Yep, tomorrow I'll give HH a call
Later, Ed
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Old 09-23-2012, 10:07 PM
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Default RE: Spektrum DX7 voltage

What you may be seeing is that your Tx pack may be getting weak.If you setup a model and are playing with the programming and havent actually bound it to a DSM2 Rx it may be operating in original DSM mode.DSM is alot more power hungry on the Tx than DSM2.If the pack is less up to the task and it is in DSM mode it may suck the voltage down quite a bit more rapidly.This is likely why you see a difference in power use from one memory compared to another.The pack may be handling the DSM2 load reasonably adequately but just isnt up to the task of feeding the DSM demand anymore.
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Old 09-24-2012, 02:11 AM
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Default RE: Spektrum DX7 voltage


ORIGINAL: edjahar42

My DX7 on one model memory shows low voltage ( falls as I'm watching) and on all other model memories it shows good voltage. This is after a full charge and I've checked it with a volt meter. The charger is working right and the battery in the tx shows 12+ volts. This model memory is one that was started to program exponential on my plane to cure it's twitchiness. The problem with this is that the tx shows low battery and shuts down. I can of course fly on the other memory, but I don't like unknowns.
Any help appreciated,
Ed
If you connect a Trainer Cord, or a 1/8" Audio jack, to the Trainer port, the Tx powers up and does not transmit RF. It draws less current in that mode. Do you see the same difference in voltage, with that setup, when you change from one Model Memory to another?
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Old 09-24-2012, 08:02 AM
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Default RE: Spektrum DX7 voltage

Thanks for the reminder Rich.I had kind of forgotten that trick to disable the RF section.
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Old 09-24-2012, 09:07 AM
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Default RE: Spektrum DX7 voltage

Thanks guys, Rich I plugged my simulator cable into the trainer port and turned the tx on and it showed the same voltage as on the other model memories. What does this mean?
Ed
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Old 09-24-2012, 12:07 PM
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Default RE: Spektrum DX7 voltage


ORIGINAL: edjahar42

Thanks guys, Rich I plugged my simulator cable into the trainer port and turned the tx on and it showed the same voltage as on the other model memories. What does this mean?
Ed
I am not sure but it is data that may shed some light on what is causing your Voltage difference.
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Old 09-24-2012, 03:39 PM
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Default RE: Spektrum DX7 voltage

Thanks again, guess I'll go ahead and call Spektrum tomorrow.
Ed
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