I am wondering if you are having problems because you have a long run of
control cable. Paralleling the control cable might be a useful experiment.
If your voltage at the motor is really low will the motor take excessive
current and trip out the power supply current limit.
I presume that you are not running a transmitter and coupling rf into the
control cable in the long conduit run.
I know that these are off the wall suggestions but something is causing your
problem and it may not be an obvious thing.
Mark N1UK G3ZZM
----- Original Message -----
From: "James C. Garland" <4cx250b@muohio.edu>
To: <towertalk@contesting.com>
Sent: Sunday, 10 June, 2007 5:12 PM
Subject: Re: [TowerTalk] SteppIR problem
> Bill, that's quite an interesting mystery! Evidently, you're overloading
> the
> power supply and it's shutting down, so I agree with Jerry's assessment.
> However, from what I understand, the stepper motors are current driven,
> not
> voltage driven. That means that even a short circuit in a pair of wires to
> one of the stepper motor windings shouldn't overload the power supply. And
> if you've checked all the resistances between pairs and they'r okay, and
> if
> there's no resistance across pairs, then that pretty much rules out any
> problem with the antenna. If there was an antenna problem, then the
> shutdown
> would occur always when the same motor was energized. But that's not what
> you're seeing.
>
> Did you check to make sure there's no resistance between any of the
> control
> cable pairs and the control cable shield?
>
> Have you checked your AC line voltage? Your symptom could be explained if
> the voltage is too low. Also, by any chance is your power supply plugged
> into a GFI, UPS, or surge-protected circuit? One simple test would be to
> measure your AC line voltage when you power up the controller and see if
> the
> voltage sags. Also, if the power supply is plugged into an outlet strip,
> then you could try changing it: it might be a faulty surge suprressor or
> switch in the outlet switch with some resistance that's dropping your line
> voltage.
>
> Let us know what you learn, and good luck!
>
> Jim W8ZR
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of Bill Carnett
> Sent: Sunday, June 10, 2007 9:42 AM
> To: towertalk@contesting.com
> Subject: [TowerTalk] SteppIR problem
>
> Greetings to all Tower Talkers,
>
> A very wise man and fellow TT (K7LXC) suggested I post
> my challenge here to the group...maybe somebody will
> have a new idea that I've not explored.
>
> Last week we put up a new 4L SteppIR with a 40/30
> dipole. The antenna is approximately 500 feet from
> the shack. SteppIR control line is used, continously
> without any accessories inserted, running through 3
> inch conduit (not that that makes any difference).
> Prior to lifting it in the air I found that a problem
> existed. When attempts were made to change bands or
> even frequency on the same band, the control box went
> dead. Simultaneously, as the box died, the "on"
> indicator light on the pwr supply went out. A second
> later the pwr light came back on; the led "lights" on
> the control box flashed once but the box remained off.
> The box could be turned back on, but the same
> sequence occurred if a band/freq change was attempted.
>
>
> Immediately all of the wiring and continuity was
> checked with the antenna...all ok. Spoke with Jerry
> at SteppIR and we proceeded to change first control
> box....before I realized the pwr supply was
> faltering....no change.
>
> The next step was to attempt to run each motor
> individually and in groups. Each motor ran
> individually without problem. Adding the 2nd and 3rd
> motor caused no problems....the yagi functioned fine.
> The addition of the 4th motor (didn't matter which
> sequence), consistently killed the antenna. On
> occassion it would all seem to work for a couple of
> band changes but never more than 1 or 2 minutes - with
> all 4 motors running. So, with up to 3 motors
> running...all ok, with all 4, no go. However, this is
> a 4 element yagi. After speaking again with Jerry, I
> was reassured that the problem was simply a power
> supply and all will work fine....thus the long
> scheduled antenna raising event went forward as
> scheduled. Needless-to-say, the replacement power
> supply did not correct the problem.
>
> Prior to erecting the yagi I extended the elements to
> 14150 so it can be used as a monobander...but that
> will only bring temporary happiness. A power supply
> (3rd) was "hand picked" by the SteppIR engineers,
> sent, and tested this morning. Basically the same
> problem. It did seem to work briefly then shut
> down....exactly the same as before.
>
> So, I'm looking for ideas that have been overlooked.
> Yes, I should have listened to my gut, rather than the
> "experts" and canceled the raising until all problems
> were fixed, but that can't be undone. If this beast
> must be lowered, I'm a bit reluctant to put it back up
> after this experience. Yes, all antennas have
> problems but it would be less $$ to replace it at the
> time of lowering rather then taking down, bring the
> crane back and forth, etc.
>
> Sorry for the long-windedness of this but any and all
> thoughts are appreciated!
>
>
>
> 73, Bill
>
>
>
>
> ____________________________________________________________________________
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