On 7/4/2012 8:06 PM, Rick Kiessig wrote:
> The tower will be 8.5m above immediate ground level, near the top of a hill
> on a relatively steep slope facing the ocean. 10m away, the ground drops to
> 16m below the top of the tower.
>
> The location is at the inside corner of my house and garage, with the open
> 90 degrees facing a driveway, so there's not much room at the base. There's
> open space either on the roof (which has a metal roof) or in the yard on the
> other side of the house. The antenna has adjustable element lengths with
> coverage from 6m to 40m (UltraBeam, similar to SteppIR). I'm looking for
> extra coverage on at least 20m, and hopefully on 15m and 40m as well.
>
> I should have been more explicit in my question. While a vertical is an
> option, due to the steep slope and where I would have to put it to have room
> for radials, it wouldn't have very good coverage on the other side of the
> hill. So I was thinking of a wire-type antenna that could be hung from the
> tower. A multi-band inverted-V was my first thought, but EZNEC shows it
> would couple with the Yagi when they're pointed in the same direction, while
> also adversely affecting SWR (I've also heard from a few hams who say
> they've tried such a thing, with bad results; Jim W5IFP's comments to the
> contrary are encouraging). The Inv-V is appealing in part because I could
> also feed it out of phase to increase high-angle coverage.
>
> I'll take a look at a sloper as Mark N1UK suggested. Maybe with a long
> enough stand-off cable from the tower, it wouldn't couple as much.
I've had very good luck with a half sloper on 160 and you could so this
with a multi-band center fed dipole following the slope of the hill.
Half slopers are a some times thing, depending a lot on the height of
the tower and what's on it.
That will still leave the back of the hill a weak spot. Does the hill
fall away to the back as well, or continue on up? If it falls away and
your property line is far enough back you could again support the end of
a center fed dipole , but support it with 20 or 30 feet of synthetic
rope to get the dipole away from the antenna on the tower.
Then there are always the Cushcraft R5 and R 8 along with the Hygain
AV640. The matching networks are the same but the AV640 uses no traps
and the bands tune independently. Mine at 32 feet was on par with a
center fed, half wave dipole on 40 meters when it came to DX including
ZLs and VKs from Central Michigan.
Just some thoughts,
73
Roger (K8RI)
>
> 73, Rick ZL2HAM
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of K8RI
> Sent: Thursday, July 05, 2012 7:54 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Second antenna options?
>
> On 7/4/2012 12:59 AM, Rick Kiessig wrote:
>> With a tower in-place that doesn't have enough height to stack a
>> second beam, and without another high spot to use for something like
>> an elevated dipole, what are some good options for a second antenna
>> that covers one or two of the same bands as the primary beam?
>
> How tall it the tower and how much free space around it?
>
> 73
>
> Roger (K8RI)
>
>
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