[TowerTalk] Re: flexible coax

i4jmy@iol.it i4jmy@iol.it
Fri, 16 Mar 2001 12:17:50 +0100


A very good (but expensive) solution is to use RG393, a double shielded 
teflon insulated coaxial cable similar in size to RG214.
In any case (this is an idea "stolen" from VHF and UHF contesters) a 
low loss LDF4-50A coiled horizontally in few turns realizes a sort of 
spring that doesn't suffer with 180° of rotation on either sides.

73,
Mauri I4JMY



> ---------- Initial message -----------
> 
> From    : owner-towertalk@contesting.com
> To      : towertalk@contesting.com
> Cc      : 
> Date    : Fri, 16 Mar 2001 07:38:43 +0100
> Subject : [TowerTalk] Re: flexible coax
> 
> 
>       Think RG214 is marginal for 1500 W, at least on the high bands.
>       The RG217 cable is an excelent choice, however connectors might
>       be a problem, if you want to use UHF that is, I only know of N
>       and C connectors for that cable. However if you know how to
>       solder you can apply an old fashion UHF solder type connector
>       to it, works excelent.
>       For cables up and down towers and interconnections betwen 
>       antennas RG217 is perfect. I always use RG217 on tower down
>       to ground and from there 7/8 " hard line.
>       By the way, RG217 is rated for around 1000 W on 144 MHz, if
>       I remember correctly.
>       I would say that even the Andrews Super Flex can be used, at
>       least if you dont make the rotor loop too tight, however below
>       30 MHz I see no need for Super Flex, RG217 will take many many
>       KW´s on 28 MHz and down.  
> 
>       73, Jim SM2EKM
> ----------------------------------------------------------------------
--
> -------------------------------
> -----Ursprungligt meddelande-----
> Från:	jreisert@jlc.net [SMTP:jreisert@jlc.net]
> Skickat:	 den 16 mars 2001 00:57
> Till:	billwall@bellsouth.net; k4rv@mindspring.com; 
> towertalk@contesting.com
> Ämne:	Re: [TowerTalk] flexible coax
> 
> Tom,
> 
> I prefer RG214 coax for rotor loops. It's not cheap (although very 
> common 
> on the surplus market-especially in short lengths and affordable). It 
> is 
> relatively flexible but also has two shields making it much sturdier 
> than 
> RG 213. I get several years of tough service out of it. Usually the 
> connectors fail before the coax.
> 
> Andrews so called flexible cables to me are a misnomer. True, they 
can 
> be 
> flexed, but only a few times! They are great during installations 
where 
> the 
> cable must be bent in peculiar shape but NOT FOR CONSTANTLY MOVING 
> ROTORS!
> 
> 73,
> 
> Joe, W1JR
> 
> 
> 
> 
> 
> 
> At 09:39 AM 3/15/01 -0500, bill wall wrote:
> >Hi all:
> >Andrews has a cable named flexible and I would also ask Press.
> >                                Bill KC4UZ
> >----- Original Message -----
> >From: "Sain'T Tom" <k4rv@mindspring.com>
> >To: "tower talk" <towertalk@contesting.com>
> >Sent: Thursday, March 15, 2001 8:36 AM
> >Subject: [TowerTalk] flexible coax
> >
> >
> > > What is the biggest, lowest loss coax that is flexible enough to 
> use in a
> > > rotor loop?
> > >
> > > What coax is typically used in a rotating tower installation, and 
> how is
> >it
> > > installed so as not to drag along the ground.
> > >
> > > Thanks
> > > Tom K4RV



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