Topband: Rohn 25 Vertical questions.

[Tim Duffy]

Hello Ron:

As Frank explained, micro-arcing can be an issue when using a tower as the
antenna element (in fact it can happen on any tower supporting Yagi's too).
Anything that is not firmly bonded together can create noise (diode effect)
on both TX and RX. I believe it is worth the effort to do everything
possible to minimize problems like micro-arcing. There is no filter to fix
arcing issues - if they occur - after the fact.

Several good 160 stations have in band RX capability. The success of those
stations ability to in band RX is related to how well they control their
environment. 

Remember "hope" is not a strategy. 

Wishing you luck and looking forward to hearing you on 160 this season.

73
Tim K3LR

-----Original Message-----
From: Topband [mailto:topband-bounces+k3lr=k3lr.com at contesting.com] On
Behalf Of Ron WV4P
Sent: Wednesday, August 19, 2020 4:04 PM
To: Mail 10
Cc: 160
Subject: Re: Topband: Rohn 25 Vertical questions.

Thanks for all the replies and willingness to share hard earned wisdom.

Tim, When you say "May cause noise" Is that on TX ? or ?
I am setting the antenna up to run the 4 parasitic elements like yours, but
it will be phase 2 as the radials for them elements will be tricky on my
very unlevel terrain.

Frank, I do anticipate the use of an inband station although it's not
likely to be utilized much I would not think.  All RX will be on a mix of
Beverages, rx vertical arrays and loops 700 - 1200 foot from the TX tower.

I am a welder, but I can't foresee any safe / reliable way of attaching
anything to Rohn 25. Maybe putting lugs on each of the 5/16 bolts and
running an unbroken #6 copper up each leg and bonding together at the top.
A lot of effort for a likely minimal if any change in scores though.

Ron, WV4P




On Wed, 19 Aug 2020 at 03:56, Mail 10 <mail10 at barefoothorse.com.au> wrote:

> I am planning a similar installation, using Deeco mast sections (6' x
> 10"). I have 20 of these, used of course. I don't think they have been
> manufactured for decades. Sections interface with pin and socket, with 3
> x 1/2" bolts between plates on each end.
>
> Will also be strapping across the joints, as I know what a PITA
> intermittent connections are.
>
> It will be a radiating mast with no other antennas on top, apart from a
> parallel wire for 80 m operation.
>
> Erection won't commence until at least later in Spring, as the ground is
> just so wet now, after one of the wettest years we've had.
>
> 73, Luke VK3HJ
>
> On 19/08/2020 4:06 am, Ron WV4P wrote:
> > Howdy All,
> >
> > I'm getting ready to put up a Rohn 25 Insulated Base ~1/4 wave vertical.
> > (115') and I'd like to get some advice if possible.
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