In commercial (cellular, LMR) services, the decision of where to put the power
stage (in the equipment hut or on the top of the tower) depends on the cost to
generate enough power to compensate for dB loss in the coax. At today's
mm-wave freqs for 5G operation, e.g., Freq Range 2 from 24-52 GHz, it would be
costlier to put a PA of sufficient power in the hut at the tower base to yield
the necessary ERP at the antenna than it would to put a smaller PA stage at the
tower top and run a fiber/copper cable assembly to it from the hut.
It's a different story at HF and even V/UHF. The coax losses are significantly
less in this freq range than at mm-wave so the advantage (coax loss reduction)
of remoting the RF components is not as great. For us Hams it becomes a matter
of personal taste - how loud do I want to be? - vs how loud MUST I be?
On another hand, running fiber vs coax to the tower could eliminate much of the
danger from lightning strikes. The problem then becomes (a simpler?) one of
protecting the power feed(s) going to the electronics from inside the Ham
shack.
73 deGene Smar AD3F
-----Original Message-----
From: Chuck Dietz <w5prchuck@gmail.com>
To: Kelly Taylor <ve4xt@mymts.net>
Cc: Steve Maki <lists@oakcom.org>; TowerTalk@contesting.com
Sent: Tue, May 17, 2022 12:34 pm
Subject: Re: [TowerTalk] Fw: Feeding single band HF yagis 500+ ft from the shack
I was wondering the same thing. I’m surprised that no amp company makes an
amp to go at the tower. Maybe remote a rig and amp close to the towers?
Chuck W5PR
On Tue, May 17, 2022 at 11:23 AM Kelly Taylor <ve4xt@mymts.net> wrote:
> Curious… at what point, given the cost of hardline, does one consider
> running code-compliant power out to the towers, putting the RF components
> there and using either ethernet or fibre between the control heads in the
> shack and the rf components?
>
> Just a question. Flames will be ignored.
>
> 73, kelly, ve4xt
>
> Sent from my iPhone
>
> > On May 17, 2022, at 10:59, Steve Maki <lists@oakcom.org> wrote:
> >
> > Very little 7/8" either.
> >
> > We use thousands of 1/2" short jumpers, but we buy them pre-made, so
> there's very little bulk surplus 1/2" available anymore :-(
> >
> > -Steve K8LX
> >
> >> On 5/17/2022 10:41 AM, john@kk9a.com wrote:
> >> Connectors are really not expensive, especially surplus N style. It is
> >> unfortunate for us that the cell towers no longer use 1 1/4 and 1 5/8
> >> Heliax, it was much easier to get surplus than it is now.
> >> John KK9A
> >> Grant Saviers KZ1W wrote:
> >> One thing I observed in the past (>3yrs ago) looking for surplus
> >> hardline was that the larger diameters (>7/8) are sold at a bigger
> >> discount. Connectors get expensive, but only two are needed.
> >> A factor impacting the market is new cell towers don't use much hardline
> >> any more, all the RF stuff is at the top in the antennas.
> >> Grant KZ1W
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