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what are you guys using for antenna / coax

This forum is for the discussions targeted at converting various models of Motorola equipment to operate in the 900MHz Amateur Band.

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gopher
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what are you guys using for antenna / coax

Postby gopher » Wed May 14, 2008 8:36 pm

Im wondering what you guys are using for your mobile setup... I currently have a 900mhz NMO motorola antenna, and I am wondering what to use for coax / antenna mount. Most of the mounts i see online already have crappy coax connected. I want to use a real low loss coax... Does anyone know where i can get a good through-the-sheet-metal NMO mount with or without good coax ?

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n7maq
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Re: what are you guys using for antenna / coax

Postby n7maq » Wed May 14, 2008 10:42 pm

gopher wrote:Im wondering what you guys are using for your mobile setup... I currently have a 900mhz NMO motorola antenna, and I am wondering what to use for coax / antenna mount. Most of the mounts i see online already have crappy coax connected. I want to use a real low loss coax... Does anyone know where i can get a good through-the-sheet-metal NMO mount with or without good coax ?



Larsen NMOKDS

http://www.tessco.com/products/displayP ... ventPage=1


Jim

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Re: what are you guys using for antenna / coax

Postby gopher » Wed May 14, 2008 10:51 pm

RG58A/U for 900???

WB6DGN
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Re: what are you guys using for antenna / coax

Postby WB6DGN » Thu May 15, 2008 1:16 am

Times Wire and Cable has a cable specifically designed for higher frequency mobile antennas. It's called LMR200MO or MA or something like that; I know it's LMR200. It is the same physical size as RG58 and can use connectors designed for RG85 but, where 58 has losses of 16 to 20db/100ft. the LMR200 is around 8 to 9db/100ft (remember, you will only use about 15 to 20 feet of it in a normal mobile install.). I'm going from memory on all of this but the specifics should be close enough to get you in the ballpark. Even though it can use RG58 size connectors, you would want to stick with the best quality ones and, in my opinion, avoid the UHF type all together. As chintzy as it looks, the MiniUHF is a true 50 ohm connector and is rated to 2.0GHz, or, obviously BNC, TNC or N are all good choices, but, again, use good quality ones, NOT the nickel plated cheapies. I'm even pretty picky about brand and, pretty much, stick with RF Industries Silver/Teflon types (I have NO connection with that company or it's dealers, I just like the product) and, (HORRORS!!!) I use exclusively crimp-on types. NEVER had a problem. So, that's my opinion. As someone I used to work with used to say, "That and a dollar will get you a cup of coffee just about anywhere."
Tom

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n7maq
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Re: what are you guys using for antenna / coax

Postby n7maq » Thu May 15, 2008 5:37 am

gopher wrote:RG58A/U for 900???


Yes, this is dual shield coax.

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motorola_otaku
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Re: what are you guys using for antenna / coax

Postby motorola_otaku » Thu May 15, 2008 9:51 am

I use LMR195 or Teflon RG58 with Amphenol or RF Industries crimp Mini-UHFs. I also use standard 3/8-3/4'' hole NMO mounts; the ones that terminate into SMAs are definitely better, but I don't notice much additional loss in everyday use and all of my playing on 900 is in simplex.

The antenna is where you can really help yourself. Use a "pigtail" or, if feasible, one of these. Quarterwaves and low-profile antennas are okay if you're talking into a high-site repeater or SMR system, but if simplex is your game then you'll appreciate the extra gain.
When exposed to Rapid Fire Growth or Thermal Emergency, two things are lost:
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Jim2121
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Re: what are you guys using for antenna / coax

Postby Jim2121 » Fri May 16, 2008 1:00 pm

I've already been using http://www.pacwireless.com/products/mobile_900mhz.shtml for a year now... good results! for mobile ops.
Lost my catalog for http://www.timesmicrowave.com/wireless/index.shtml
which has a few Amateur operators in 900mhz. In the company (been looking & sending emails back & forth) still thinking!
motorola_otaku post has some very good info and the Tessco post on there is good!
theres supposed to be a new LMR with a low loss for 900Mhz? I'm still waiting for the details.
grab a catalog from timesmicrowave...
Messages can't be intercepted if they aren't sent, can they?
Erwin Rommel

WB6DGN
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Re: what are you guys using for antenna / coax

Postby WB6DGN » Sun May 18, 2008 5:53 pm

theres supposed to be a new LMR with a low loss for 900Mhz? I'm still waiting for the details.


Not specifically for 900Mc; just a high performance low(er) loss, RG58 TYPE cable, designed specifically for mobile antenna use. Their designation for it is LMR-200MA. See the latest (Vol. 26) Tessco Catalog, page 574, right column, last item in subcategory "Flexible Low Loss RG58 Cable". Tessco P/N is 34936.
Tom

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Jim2121
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Re: what are you guys using for antenna / coax

Postby Jim2121 » Sun May 18, 2008 9:49 pm

Right Tom... I should have corrected myself, thanks for the input! better yet I should have waited for the details out of CT. because it was a phone QSO btw. a tech. at timesmicrowave & myself -- then posted the details! But I'm sure theres enough info here to answer the orignal question...what we use for 900-coax/antenna...ect... later Jim
Messages can't be intercepted if they aren't sent, can they?
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