Go Back  RCU Forums > RC Airplanes > Beginners
Reload this Page >

anything bad about the dx7?

Notices
Beginners Beginners in RC start here for help.

anything bad about the dx7?

Old 09-23-2007, 07:51 PM
  #1  
ken420
Senior Member
Thread Starter
 
Join Date: Jan 2006
Location: winchendon, MA
Posts: 140
Likes: 0
Received 0 Likes on 0 Posts
Default anything bad about the dx7?

hey guys,ive been thinking about buying the Dx7 and was wondering if there is anything bad about it?i would really like to get the jr 9303 2.4 but its alot of money..lets here your thoughts on the Dx7..
Old 09-23-2007, 09:14 PM
  #2  
Rbart
 
Rbart's Avatar
 
Join Date: Apr 2006
Location: The Great NorthWEsT
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

The only thing "bad" about the DX-7 is the battery supplied with the radio... dont trust it!
There have been a few crashes at my local field by DX-7 owners.. just about every one of them was a battery issue.
If the voltage drops down enough, the reciever "resets" and it can take 4 or 5 seconds for it to sync up with the transmitter again...
which is way more than enough time for a tragedy!
Most of the guys at our field have taken to using either Lipos with a voltage regulator, or just going with a 5 cell 6 V pack.

Old 09-23-2007, 10:54 PM
  #3  
hogflyer
 
hogflyer's Avatar
 
Join Date: Mar 2005
Location: Wichita, KS
Posts: 2,036
Likes: 0
Received 1 Like on 1 Post
Default RE: anything bad about the dx7?

There have been several guys in my club with the DX-7 and they have seen the radio spend more time in the shop than anyplace. They've had nothing but trouble with it. If it was one bad radio I wouldn't worry about it, but this is several very experienced fliers who have 2 or 3 of these radio's and they are not very reliable for them right now. Two guys lost planes to DX-7 radio issues this week (one radio was just returned at the beginning of the week from Horizon), one pylon racing and the other practicing - both suddenly no control and had 110 mph missiles slowly nosing into the ground.

Hogflyer
Old 09-24-2007, 02:25 AM
  #4  
alan0899
 
Join Date: Apr 2006
Location: Warialda NSW, AUSTRALIA
Posts: 2,275
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?


ORIGINAL: ken420

hey guys,ive been thinking about buying the Dx7 and was wondering if there is anything bad about it?i would really like to get the jr 9303 2.4 but its alot of money..lets here your thoughts on the Dx7..

G'day Ken,
I have a DX7, & I fly it every weekend & sometimes through the week as well, I have had ZERO problems with mine, absolutely none, it is a great radio system.
The only problems I have heard about, stem from guys using high power digital servos, & not allowing enough battery capacity. Or from fellas using electric planes with the DX7, & having ESC or BEC problems, & again, not the radios fault if the power aint there, it won't work.
They would have had the same problems with "normal" radios.
Since I got my DX7, 6 other members in our club have bought them, & none of them has had the slightest problem.
Old 09-24-2007, 05:20 AM
  #5  
nobodytwo
Senior Member
 
nobodytwo's Avatar
 
Join Date: Jun 2007
Location: North Little Rock, AR
Posts: 164
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

Ken420:

Had a student give me a Spektrum 2.4 DX7 the first of July. Have flown the radio at least once, EVERYDAY, without a problem. That said: I've upgraded the transmitter radio to a NIMH 1650 mah (comes with a NIMH 1500), and all receivers have a 6 volt NIMH 1500mah. I have on order a 9303 and I see another DX7 in the near future.

Happy Landings!
Old 09-24-2007, 06:01 AM
  #6  
CGRetired
My Feedback: (1)
 
CGRetired's Avatar
 
Join Date: Sep 2004
Location: Galloway, NJ
Posts: 8,999
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

I also have the DX7 system and use it frequently. I am in the process of replacing all of my 72 MHz receives with the DX7 7 channel receiver (I believe it's the AR7000 RX). I am totally pleased with it.

I do use a 1200 mah 6 volt battery in all receiver applications with voltwatch, but that's not the fault of the radio, that's just a personal choice.

Flawless performance as far as I am concerned.

CGr
Old 09-24-2007, 07:23 AM
  #7  
TxDiveBomber
Member
 
Join Date: Sep 2007
Location: LJ, TX
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

I average 15-25 20-minute flights on multiple airplanes a week with my dx7. Absolutly zero problems thus far. I never used the reciever battery I went with 6V nimh from the start. This controller has been nothing but rock solid for me.
Old 09-24-2007, 08:30 AM
  #8  
jvino
Senior Member
 
Join Date: Apr 2007
Location: Woodburn, OR
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

The only problem with the DX7 is that it only has 7 channels and lacks some mixing ability. Otherwise I have only heard great things about it. I just picked up the JR X9303 2.4. I will have my first flight with it this week. Seems to be a rockin radio but so it the DX7.
Old 09-24-2007, 08:54 AM
  #9  
-pkh-
Senior Member
My Feedback: (2)
 
-pkh-'s Avatar
 
Join Date: May 2004
Location: Emmaus, PA
Posts: 3,354
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

At my club there are at least 8 guys, including myself, with DX7's, and we've had no problems with the transmitters so far. My receiver battery seemed to have a bad cell, so I didn't use it. I also had a couple receivers that would lose bind after they were shut off, but Horizon took care of things there. I haven't used the servos yet.
Old 09-24-2007, 08:00 PM
  #10  
ken420
Senior Member
Thread Starter
 
Join Date: Jan 2006
Location: winchendon, MA
Posts: 140
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

thanks for the info guys..the dx7 is looking pretty good.i dont really need dsm as i dont fly with many people and my channel is always free,would i be better off going with the original jr 9303 vs. the dx7?
Old 09-24-2007, 08:55 PM
  #11  
A6Ordie
Senior Member
 
A6Ordie's Avatar
 
Join Date: Jan 2007
Location: Sparks, NV
Posts: 115
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

I would go with the DX7 for the model match. Plus 72mhz will slowly fade away and be hard to find as demand falls off. 2.4 prices will go down as demand increases just like HD TV's, brushless motors, ESC's and the like. It isn't going to happen all that fast, but you might as well plan on the future and 2.4 is going to be the most used eventually. I also have a Dx7 and love it. I've had no problems with it so far.

Just my 2 cents
Old 09-25-2007, 12:16 AM
  #12  
bigedmustafa
My Feedback: (2)
 
bigedmustafa's Avatar
 
Join Date: Jun 2005
Location: Omaha, NE
Posts: 4,107
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?


ORIGINAL: ken420

thanks for the info guys..the dx7 is looking pretty good.i dont really need dsm as i dont fly with many people and my channel is always free,would i be better off going with the original jr 9303 vs. the dx7?
If nothing is driving you to purchase a 2.4Ghz radio system in particular right now, you can only help yourself by delaying the purchase as long as is practical. Prices will drop, the technology will continue to improve, and more manufacturers will enter the marketplace with new and exciting products. Rest assured that all of the radio manufacturers are working on new whiz-bang designs for next year that will help seperate all of us from our money.

If you just have an urge to buy a new radio system, the DX7 is a very solid choice for most sport fliers. You can always sell it here on RC Universe or elsewhere once something nicer comes along.

Good luck and good shopping!
Old 09-25-2007, 07:25 AM
  #13  
MasterX
Junior Member
My Feedback: (6)
 
Join Date: Aug 2004
Location: Ingleside, IL
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

Hello Guys.. One of the big problems with the DX7 is that once you get this radio you will fall in love with it.. There is nothing like it...

I can say that when I get to field I am stress free of anyone knocking my planes out of the sky. That is worth the cost of the radio right there.

Be careful with this technology it is very addicting!

Have fun.

Later.
Old 09-25-2007, 07:30 AM
  #14  
BobMaine
Senior Member
 
Join Date: Aug 2005
Location: Midcoast, ME
Posts: 169
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

The DX7 manual leaves lots to be desired. If you want to do more programming than just the basic stuff you won't find it in this manual. Lots of criticism of the manual in the DX7 forum on RCU -- take a look.
Old 09-25-2007, 07:33 AM
  #15  
BobMaine
Senior Member
 
Join Date: Aug 2005
Location: Midcoast, ME
Posts: 169
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

Also lots of places are out of AR7000 receivers in case you want to set up a second plane. "Sometime in Oct..." they say. I assume they mean this year.
Old 09-25-2007, 08:23 AM
  #16  
Fastsky
 
Fastsky's Avatar
 
Join Date: Dec 2001
Location: Calgary, AB, CANADA
Posts: 2,989
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

I forwarded the info about the possible battery problems to our clubs email list yesteday. I checked my email this morning and have and all ready received a reply from one of our club members that he has encountered the same battery issue!! Thanx for the heads up![8D]
Old 09-25-2007, 08:29 AM
  #17  
-pkh-
Senior Member
My Feedback: (2)
 
-pkh-'s Avatar
 
Join Date: May 2004
Location: Emmaus, PA
Posts: 3,354
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?


ORIGINAL: BobMaine

The DX7 manual leaves lots to be desired. If you want to do more programming than just the basic stuff you won't find it in this manual. Lots of criticism of the manual in the DX7 forum on RCU -- take a look.
Just curious, what programming are you finding difficult with the DX7?

I've found the DX7 manual to be as good or better than the 9C manual, which isn't saying much.
Old 09-25-2007, 09:41 AM
  #18  
RCKen
RCU Forum Manager/Admin
My Feedback: (9)
 
RCKen's Avatar
 
Join Date: Jul 2002
Location: Lawton, OK
Posts: 27,284
Likes: 0
Received 17 Likes on 15 Posts
Default RE: anything bad about the dx7?

There is a lot of people talking about the "problem" with the Spektrum receivers and low voltage. If everybody would stop and think about this it's not a new problem that has just occurred with the Spektrum equipment. ALL receivers have a voltage cutoff point where they quit working. It's just basic electronics that the receivers are designed for a range of voltages. Before the Spectrums hit the market the same thing would happen with our older radios, if the voltage dropped too low the receiver would quit working. Now introduce the Spectrums into the picture and you have the same problems, just with a different voltage level. It does appear that the Spectrums are a little more sensitive about the voltage than older equipment. But in reality there is nothing new here just because it's a new radio. It all boils down to the fact that you need to ensure that you have a battery large enough to provide adequate power to your on-board radio system. And throughout the flying day you need to monitor your battery to ensure that it's got enough juice left to fly with. It's been the same procedures that have been used for the last 30 years (or more).

Now with that in mind I will say that I think that Spectrum made one mistake, and that is providing too small of a battery to realistically run their equipment. Since they are supplying digital servos, which have a higher current draw than standard servos, with the DX7 they probably should have included a larger battery pack than they did. But that's something that can be dealt with before the radio gets in the air.

Ken
Old 09-25-2007, 10:53 AM
  #19  
Insanemoondoggie
 
Insanemoondoggie's Avatar
 
Join Date: Nov 2006
Location: Altamont, MO
Posts: 2,475
Received 1 Like on 1 Post
Default RE: anything bad about the dx7?

Ken ,I picking up a DX7 this week. My ? is. When the battery drops under 4.8 volts , while a load is on it, the reciever goes to safe mode ? A battery can show more voltage than the 4.8 but drop under that when under a load. Is this what they are talking about ?
Old 09-25-2007, 11:17 AM
  #20  
hdsoar
Member
 
Join Date: Nov 2005
Location: Toledo, WA
Posts: 53
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

I disagree that there is no difference between the 72mhz systems and the Spektrum when it comes to low voltage. Here's the scenario:

Let's say your servos put a momentary load on the battery that drops the voltage below the critical voltage for the receiver. We'll assume that the voltage drop lasts for a very short time, 300ms or so. This is probably a real world scenario when entering a high g manouver. You will have a spike in load as you move several servos all at once, then the load will come back to "normal". Now with the 72mhz analog or PCM receivers you will have a 300ms interuption in signal/connectivity. You may not even notice the drop in connection. You only lose connectivity with the plane for the length of time the voltage is below the critical level. With the Spektum and I assume the other 2.4ghz receivers, when your RX voltage drops below the critical level,(even for just a couple milliseconds), you go into a re-boot and re-handshake with the TX. This can take seconds, not milli-seconds. Seconds of lost connectivity can be too much to recover from. I beleive these are the scenarios where planes are lost with "good" power systems. Quique had this happen at SEFF this year. I'm sure they thought the power system employed was adequate, and probably was pre-Spektrum. Check this article.

[link=http://www.horizonhobby.com/Articles/Article.aspx?ArticleID=1674]Horizon Article[/link]

BTW I've had my DX7 since December 2006 and put it in all my planes by Jan. I've had no issues with it and love it.
Old 09-25-2007, 12:20 PM
  #21  
RCKen
RCU Forum Manager/Admin
My Feedback: (9)
 
RCKen's Avatar
 
Join Date: Jul 2002
Location: Lawton, OK
Posts: 27,284
Likes: 0
Received 17 Likes on 15 Posts
Default RE: anything bad about the dx7?

hdsoar,
You are missing the point of my post. I am not talking about specific voltages and such, but rather about safe PRACTICES that you as an RC user does. Let me ask you a question. With an pre-spectrum radio did you just keep flying all day long?? Of course you didn't. You monitored the voltage of your batteries and when they were low you quit flying. You put a battery in your plane that was capable of handling the load put on it by your system. It's the same thing with the Spektrum radio as well. You should monitor your battery and when it starts getting down to the point that the voltage could drop below the reset point you should quit flying. You should also make sure that you have a battery in your plane that can handle the loads placed on it during flight. Plain and simple. It's the same practices that have been in place since RC started. They still apply today just as they did 30 or 40 years ago.

Ken
Old 09-25-2007, 12:36 PM
  #22  
-pkh-
Senior Member
My Feedback: (2)
 
-pkh-'s Avatar
 
Join Date: May 2004
Location: Emmaus, PA
Posts: 3,354
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?

I don't think anyone is trying to get more flights out of a battery pack after switching to a Spektrum system. I do believe that the Spektrum reboot issue comes about because many guys were flying with packs that dropped severely under load, and didn't know it before, since the analog receivers would mask the problem.
Old 09-25-2007, 12:51 PM
  #23  
RCKen
RCU Forum Manager/Admin
My Feedback: (9)
 
RCKen's Avatar
 
Join Date: Jul 2002
Location: Lawton, OK
Posts: 27,284
Likes: 0
Received 17 Likes on 15 Posts
Default RE: anything bad about the dx7?


ORIGINAL: -pkh-

I don't think anyone is trying to get more flights out of a battery pack after switching to a Spektrum system. I do believe that the Spektrum reboot issue comes about because many guys were flying with packs that dropped severely under load, and didn't know it before, since the analog receivers would mask the problem.
I absolutely agree. And like I said in my previous post I think that Spektrum should include a bigger battery with this radio. But I don't consider the reboot as something bad about the radio as the original post asked. I consider as something that needs to be done in operating the radio. For all us "old farts" it just means that we need to shift what we know about monitoring the radio battery and quitting at a higher voltage than we would have before the Spectrums came out. But as people learn they need to cared for in a slightly different way it's not going to be an issue any longer.

Ken
Old 09-25-2007, 01:12 PM
  #24  
Rbart
 
Rbart's Avatar
 
Join Date: Apr 2006
Location: The Great NorthWEsT
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
Default RE: anything bad about the dx7?


ORIGINAL: RCKen

I absolutely agree. And like I said in my previous post I think that Spektrum should include a bigger battery with this radio. But I don't consider the reboot as something bad about the radio as the original post asked. I consider as something that needs to be done in operating the radio. For all us "old farts" it just means that we need to shift what we know about monitoring the radio battery and quitting at a higher voltage than we would have before the Spectrums came out. But as people learn they need to cared for in a slightly different way it's not going to be an issue any longer.

Ken
Actually.. I think the best solution would be for Spektrm to make the DX-7 receivers operate off of TWO battery packs!
A 4.8 V pack just to maintain the recievers connectivity to the transmitter, and a second pack of whatever voltage nessessary to operate all your gear.
the amount of juice used to maintain connectivity is near negligable.. a fully charged pack could last for a week (maybe ).
This would eliminate 99% of the "loss of control" tragedies (not that there are actually that many to begin with) from the DX-7.
Another idea might be to use exclusively 5 cell packs.. even a "discharged" battery has some residual charge left on it.. .5 V ?
so even if your pack is more or less discharged there is still enough juice to maintain the connectivity between TX and RX.
This solution will cause problems with some mechanical retract servos that can not deal with 6 V.. thats why I think the first idea is best.

Rick
Old 09-25-2007, 01:36 PM
  #25  
RCKen
RCU Forum Manager/Admin
My Feedback: (9)
 
RCKen's Avatar
 
Join Date: Jul 2002
Location: Lawton, OK
Posts: 27,284
Likes: 0
Received 17 Likes on 15 Posts
Default RE: anything bad about the dx7?

I have the JR X9303 radio but all the receivers I have are Spektrums. My solution was to simply go to high Mah (1500 -2000) 5 cell 6 volt packs. I've never even come close to dropping down the 4.8v yet. But if a user wanted to use dual 4.8v packs that would take care of it as well. As I said, I think that Specktrum should ship the radio with a higher capacity receiver battery. In this day and age of battery technology there isn't any reason why they couldn't. High capacity batteries are cheap.

Ken

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.