[TowerTalk] [VHF] Rotator problems

[Donn]

Sometimes, power supplies like to have a minimum load on 
themselves.  Its possible that 85 watts isn't enough of a 
load for the 400 watt inverter and the output voltage is 
moving around.  This could be confusing the position sensor 
(voltage off of the pot) enough that it can't ever settle 
down.

In any case, good luck !

73 Donn
WA2VOI/0

----- Original Message ----- 
From: "Dan Evans" <dan.evans at insightbb.com>
To: <towertalk at contesting.com>; "VHF Reflector" 
<vhf at w6yx.stanford.edu>
Sent: Monday, June 20, 2011 9:00 PM
Subject: [VHF] Rotator problems


>I have an odd Rotator problem.
>
> In my Rover setup, I have an old Hygain AR40 rotor.   For 
> the past several years I have been having an annoying 
> problem.  Whenever I turn the antenna the rotor moves to 
> the desired position but instead of stopping, as it 
> should, it keeps "bouncing" back and forth several 
> degrees.  And it will keep bouncing until it over heats, 
> or until I shut off the power.
>
> My "work around" has been to switch off the power when it 
> reaches the correct heading.
>
> While preparing for the June VHF contest I discovered it 
> doesn't do this when plugged into the household 120v 
> outlet.   But it does do it when I use my deep cycle 
> battery and inverter.  So it seems to be a power issue.
>
> I don't believe the inverter is the problem.  The rotator 
> is rate at 85 watts.  My old inverter was a 100 watt 
> model, and my current inverter is a 400 watt continuous / 
> 800 watt surge.   So it really shouldn't be much of a 
> load...
>
> Any ideas?
>
> The reason I had it on the bench was to take it apart, 
> check the pot, clean and grease the bearings, check the 
> connections, and replace the rotor cable.  None of which 
> seems to have helped.   I'm a bit stumped.   I am 
> considering just wiring up a box with momentary switches 
> for left rotate, right rotate, and a meter for 
> direction....
>
> Oh, load on the rotor for my application is a push up 
> mast, and 3 VHF yagis, and cables.  Altogether maybe 30~35 
> lbs...
>
> Scratching my head,
> 73
>
> Dan
>
> -- 
> Amateur Radio Emergency Service, Clark County Indiana. 
> EM78el
> K9ZF /R no budget Rover ***QRP-l #1269 Check out the Rover 
> Resource Page at:
> <http://www.qsl.net/n9rla>    List Administrator for: 
> InHam+grid-loc+ham-books
> Ask me how to join the Indiana Ham Mailing list!
> ------
> Submissions:                    vhf at w6yx.stanford.edu
> Subscription/removal requests: 
> vhf-request at w6yx.stanford.edu
> Human list administrator: 
> vhf-approval at w6yx.stanford.edu
> List rules and information: 
> http://www-w6yx.stanford.edu/vhf/