We get plenty of lightning in Wisconsin, but in my case the shunt around
the thrust bearing (and rotator) is mainly to prevent harmonic
generation when shunt feeding the tower. If the tower gets a direct
hit, damaged bearings will be the least of my worries.
73,
Scott K9MA
On 8/16/2021 9:43 PM, Eddie Edwards wrote:
As long as you don't get a lot of lightning up in Wisconsin, the impedance of
your entire ground protection system probably doesn't matter as much either.
But isn't that the point of all the bonding and grounding just in case?
YMMV
73, de ed -K0iL
-----Original Message-----
From: RFI <rfi-bounces+eddieedwards=centurylink.net@contesting.com> On Behalf
Of K9MA
Sent: Monday, August 16, 2021 17:42
To: donovanf@erols.com; rfi@contesting.com
Subject: Re: [RFI] DFing intermittent connection
Hi Frank,
That makes sense. All I ever used it for was as a shunt around the thrust
bearing, for which the impedance probably wasn't that critical.
73,
Scott K9MA
On 8/16/2021 4:44 PM, donovanf@erols.com wrote:
Hi Scott,
Braid is always a poor choice outdoors unless its under pressure and
protected from moisture such as inside jacketed coax cable
When its no longer under pressure and protected from moisture the RF
resistance of braid goes up dramatically because the crossovers in the
braid no longer conduct effectively.
That's why the appropriate choice for an outdoor conductor is stranded
wire or solid wire and never braid
73
Frank
W3LPL
----------------------------------------------------------------------
--
*From: *"K9MA" <k9ma@sdellington.us>
*To: *donovanf@erols.com, rfi@contesting.com
*Sent: *Monday, August 16, 2021 9:27:16 PM
*Subject: *Re: [RFI] DFing intermittent connection
Gee, it's worked for me for years. Not much salt spray in Wisconsin.
73,
Scott K9MA
On 8/16/2021 12:32 PM, donovanf@erols.com wrote:
Jim,
Please ignore Scott's advice, it will cause tower corrosion and
quickly fail
73
Frank
W3LPL
------------------------------------------------------------------------
*From: *"K9MA" <k9ma@sdellington.us>
*To: *jimk8mr@aol.com
*Cc: *rfi@contesting.com
*Sent: *Monday, August 16, 2021 4:30:35 PM
*Subject: *Re: [RFI] DFing intermittent connection
Or just use the braid from some RG8 and a couple hose clamps.
----------
Scott Ellington. K9MA
--- via iPhone
> On Aug 16, 2021, at 9:27 AM, jimk8mr--- via RFI
<rfi@contesting.com> wrote:
>
> The kit is basically a very heavy, very flexible cable, six
feet or so, with lugs on both ends, and clamps with a large flat
surface to attach to the mast and to the tower leg. I'd think that
the bottom lug could be attached to a tower bolt, or some other
low resistance connection to the tower.
> It would seem to also be simple to homebrew something a bit less
rugged, perhaps using a piece of RG-8, shield and center conductor
connected together.
>
> 73 - Jim K8MR
>
>
>
> -----Original Message-----
> From: EDWARDS, EDDIE J via RFI <rfi@contesting.com>
> To: RFI List <rfi@contesting.com>
> Sent: Mon, Aug 16, 2021 9:09 am
> Subject: Re: [RFI] DFing intermittent connection
>
> Just FYi...They told me they only have the bypass kits for
standard Rohn towers, but not for the BX or HDBX series towers.
Need to make your own for other non-rohn configurations.
>
> 73, de ed -K0iL
>
> -----Original Message-----
> From: RFI On Behalf Of jimk8mr--- via RFI
>
>
> You might look into DX Engineering's Bearing Bypass Ground Kits
DXE-BBGK-2-25-P.
> I installed one yesterday for K8AZ. I'm not sure if Tom had a
particular problem or it was just as a precaution. It easy to
install, the only issue in my case was that the tower had been
painted, so some paint scraping was in order. But much easier than
replacing a thrust bearing!
>
> 73 - Jim K8MR
>
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Scott K9MA
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--
Scott K9MA
k9ma@sdellington.us
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