Antenna Cable

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criten
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Antenna Cable

Post by criten » Tue Nov 10, 2009 11:24 pm

Three questions about fitting an external antenna and the cables involved...

I'm considering fitting a discone. Or alternatively fitting 4 ants and 4 scanners to service 70-80mhz, 118-137mhz, 400mhz & 800mhz. I presently use my radio scanner in a room thats effectively a radio blackspot on all bands. However the roof is about 4 floors up, and we're on the top of a mountain... can't ask for much better.

Whats the best cable to use? I'd prefer to stick to products sold by Jaycar since I'm a wholesale customer. Where do you get RG213 in western syd? Is RG213 better than RG6?

What are the best connectors to use? Why?

Would a 20-30m cable run be too long for a discone? Or say a 6db 400Mhz ant (already have this one on hand)? Unfortunately the roof is fairly distant when running through the cable conduets already in place for ethernet.

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alphamike
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Re: Antenna Cable

Post by alphamike » Wed Nov 11, 2009 8:33 am

I'm also going through a similar process at the moment.
RG213 seems to be the go, however you can't use RG6 as its 75 Ohms, I don't think jaycar sells 213, do they?

If not, Prestige Communications sell it.
http://www.prestigecom.net.au/index.php ... ts_id=1925
There're in WA but there service is great and postage times fast. Selling for $4.90 p/m

ivahri
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Re: Antenna Cable

Post by ivahri » Wed Nov 11, 2009 11:21 am

RG6 is 75 ohm, RG213 is 50 ohm. If the antenna is designed to be terminated in to 50 ohms you should be using 50 ohm cable. RG213 should be widely available (DSE used to stock a junky grade of it) & RFI would definitely be the best source. They are at North Rocks (9630 0655) or talk to one of their many agents in western Sydney.

Why would someone in Western Sydney talk to a WA seller... that really is nuts! They probably source it from RFI in Sydney anyway!

I've answered the connector question already.

If you are on top of a hill & already have good signal levels then RG58 may not be such an issue. So what if you have an extra 10dB of loss if you have signals better than -80dBm? I would always recommend better quality cable but if you don't need it why use it?

Regards,

Richard

Farsouthscanner
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Location: Far South Coast NSW

Re: Antenna Cable

Post by Farsouthscanner » Thu Nov 12, 2009 5:36 pm

Hi Criten
I went through the same sort of thing last year and earlier this year.
Have a look at my setup and pics on this forum.
I basically have a discone with LDF4-50 cable into a Multicoupler. Its a great setup and even with out the pricy coax would work well.
Mark

centralcoastscanman
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Re: Antenna Cable

Post by centralcoastscanman » Thu Nov 12, 2009 7:09 pm

if anyone is after any coax and are considering the coax that RFI stock give me a pm and I might be able to help out with a very competitive price...

criten
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Re: Antenna Cable

Post by criten » Thu Nov 12, 2009 10:41 pm

Thanks for the advice guys, I'll be getting some RG213 from RFI and looking into their discones. And for the record, don't bother looking for any decent radio gear from Jaycar - its all crap and they don't have RG213 - only RG59, RG58 & RG6.

vk2fear
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Re: Antenna Cable

Post by vk2fear » Sat Dec 12, 2009 10:18 pm

Also guys try Rojone for cable very cheap ask for Berine(owner good mate of mine) i run LMR 400/600 at home its great
Call sign:VK2FEAR
SCANNING WITH:
FT8800 x2 - FT60 - UBC245XLT - UBC120 - UBC72XLT - UBC780xlt - UBCD396T -
UBCD996T x2 - TX-3800 x2 - T-2020 66/88mhz X 4 - T-2010 66/88mhz x4 - TS-480 sat

ivahri
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Re: Antenna Cable

Post by ivahri » Sun Dec 13, 2009 8:17 am

LMR is good cable but the only problem is that you need the connectors to suit. That is why Andrews cable remains more popular as the connectors are more widely available.

Richard

vk2fear
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Joined: Sun Aug 24, 2008 5:25 pm

Re: Antenna Cable

Post by vk2fear » Sun Dec 13, 2009 9:31 am

Hi all

LMR400 uses the same connectors as RG213

U can get LMR400 Solid core or Ulltra flex i run both,

LMR600 runs a different plug.

Nate
ivahri wrote:LMR is good cable but the only problem is that you need the connectors to suit. That is why Andrews cable remains more popular as the connectors are more widely available.

Richard
Call sign:VK2FEAR
SCANNING WITH:
FT8800 x2 - FT60 - UBC245XLT - UBC120 - UBC72XLT - UBC780xlt - UBCD396T -
UBCD996T x2 - TX-3800 x2 - T-2020 66/88mhz X 4 - T-2010 66/88mhz x4 - TS-480 sat

criten
Posts: 270
Joined: Mon Nov 09, 2009 10:21 am
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Re: Antenna Cable

Post by criten » Thu Dec 31, 2009 12:13 pm

Well I've been broke over christmas. However I ended up fixing my 1.3m ant and mounting it on the roof. The BNC crimp had broken so I got some crimpless plugs. Works much better than my 30cm whip ant in my radio blackhole!

Now getting VHF from Shooters Hill and GRN from Kurrajong.

One thing that surprised me... I made a 5m extension lead out of 75ohm TV coax. There seems to be no difference having the lead connected or not. I think past experiences with 802.11 gear had gotten the fear in me.

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