You said: "The center of the pot is connected to the rotor bell housing
so any resistance between the top and bottom of the rotor will allow
current to go thru the pot."
If the center of the pot is grounded to the top bell housing, how is the
potentiometers resistance "seen" across the gap between the top and
bottom of the rotor housing? Are the ends of the pot connected to the
bottom housing, putting the pot in parallel with the top and bottom of
the rotor casing?
I'm trying to understand the failure mode.
73 de Bob - KØRC in MN
On 5/26/2011 2:00 PM, towertalk-request@contesting.com wrote:
> ------------------------------
>
> Message: 3
> Date: Wed, 25 May 2011 22:18:09 -0400
> From: "Gary Schafer"<garyschafer@comcast.net>
> Subject: Re: [TowerTalk] Rotator Question
> To:<k0rc@citlink.net>, <towertalk@contesting.com>
> Message-ID:<28A8E0D3A500443080D1447CEE36A699@garyPC>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Faraday shield with an antenna going into it, the mast.
> There is never a good ground between the mast and the tower as there is a
> rotating joint there. You may be able to measure a short with your ohm meter
> but it is not a good connection to high current lightning. The center of the
> pot is connected to the rotor bell housing so any resistance between the top
> and bottom of the rotor will allow current to go thru the pot. It is a
> common cause of failure.
>
> Bonding the top to the bottom of the rotor is good practice for keeping
> everything on the tower at the same potential when lightning does strike.
>
> 73
> Gary K4FMX
>
>> > -----Original Message-----
>> > From:towertalk-bounces@contesting.com [mailto:towertalk-
>> > bounces@contesting.com] On Behalf Of Robert Chudek - K0RC
>> > Sent: Sunday, May 22, 2011 2:41 PM
>> > To:towertalk@contesting.com
>> > Subject: Re: [TowerTalk] Rotator Question
>> >
>> > Please tell me what this #2-#4 wire is going to do that the Faraday
>> > shield effect of the tower legs around the rotor is not going to do? Or
>> > the metal of the rotor bell-housing itself? That pot is buried several
>> > layers deep, covered with metal. Does a #2-#4 wire have some priority
>> > for lightning? I really need to know, as I have been extremely lucky to
>> > escape any rotor damage, even with several lightning direct hits to my
>> > tower.
>> >
>> > 73 de Bob - K?RC in MN
>> > ------------------------------------------------------------------------
>> >
>> > On 5/21/2011 2:00 PM,towertalk-request@contesting.com wrote:
>>> > > Message: 2
>>> > > Date: Fri, 20 May 2011 15:58:30 -0400
>>> > > From: "Gary Schafer"<garyschafer@comcast.net>
>>> > > Subject: Re: [TowerTalk] Rotator Question
>>> > > To: "'K. Alan Robbins'"<lnmoose@chartermi.net>,
>>> > > <towertalk@contesting.com>
>>> > > Message-ID:<30AFC9A2F47C4C3E990DAA8B668AB726@garyPC>
>>> > > Content-Type: text/plain; charset="us-ascii"
>>> > >
>>> > > You may have had lightning take out the pot. Place a heavy #2-#4
>> > jumper from
>>> > > the top of the rotor to the bottom.
>>> > >
>>> > > 73
>>> > > Gary K4FMX
>>> > >
>>>>> > >> > -----Original Message-----
>>>>> > >> > From:towertalk-bounces@contesting.com [mailto:towertalk-
>>>>> > >> > bounces@contesting.com] On Behalf Of K. Alan Robbins
>>>>> > >> > Sent: Friday, May 20, 2011 3:08 PM
>>>>> > >> > To:towertalk@contesting.com
>>>>> > >> > Subject: [TowerTalk] Rotator Question
>>>>> > >> >
>>>>> > >> > To everyone who responded off-list with gracious help, copies
>>>>> > of
>> > owner's
>>>>> > >> > manuals, etc. Thank you very much.
>>>>> > >> >
>>>>> > >> >
>>>>> > >> >
>>>>> > >> > It seems I am the victim of bad luck with this rotator,
>>>>> > and/or I
>> > need
>>>>> > >> > lots
>>>>> > >> > of exercise climbing up and down the tower this year.
>>>>> > >> >
>>>>> > >> >
>>>>> > >> >
>>>>> > >> > 73 de W8VCK
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