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Re: [TowerTalk] Crimped PL-259's

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Crimped PL-259's
From: Les Kalmus <w2lk@bk-lk.com>
Reply-to: w2lk@bk-lk.com
Date: Thu, 14 Oct 2010 17:28:14 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
  Jim (VE),

Where can I find this RFS corrugated cable (in red below)? The prices I 
have found are triple what you mentioned.
I need to find some before the cold weather sets in.

Les W2LK

On 10/14/2010 4:23 PM, Jim Thomson wrote:
> Date: Thu, 14 Oct 2010 08:41:08 -0700
> From: Jim Brown<jim@audiosystemsgroup.com>
> Subject: Re: [TowerTalk] Crimped PL-259's
>
>> Almost no one except amateur radio and CB uses UHF (PL259) connectors 
>> anymore.
>>
>> Therefore you will mostly find them in ham and CB shops (and ebay).
>>
> The inference here is that UHF connectors are somehow outmoded.
>
> ### They ARE outmoded.  There is no standard for UHF connector's.  If there
> was, they would all be useable, and they are not.  The quality of UHF 
> connector's
> varies from superb to pure junk.  A lot of them are not 50 ohms.   They can't 
> be 70 ohms
> for RG-11  and  50 ohms  for RG-213....at the same time.
>
>
>
> Nothing
> could be further from the truth.  The FACT is that they are entirely
> satisfactory for systems operating below about 500 MHz, and
> mechanically, they have some significant advantages over most other coax
> connectors when installed on most coaxial cables .
>
> ###  what mechanical advantages?   They are not even waterproof !
>
>
>
>
> Those other newer connectors DO have advantages above 500 MHz, where
> their constant impedance characteristic  matters, and where their small
> physical size takes up less space.
>
> Why is so much new equipment coming with N connectors, or with other
> smaller connectors?  Mostly because that equipment operates at those
> higher frequencies, where their advantages DO matter.
>
> ### The only connector's  offered  for  7/8"  and  1.25"  heliax is
> type N... and 7-16 DIN.      Andrew stopped making   UHF males  for
> 7/8"  heliax back in the early 90's.  The only connector you can get
> for LMR 1200 /1700 is  type N  and 7-16 DIN.
>
> ##  7/8"  heliax and  1.25" heliax is the 2 x  most common sizes you see
> in the cell industry.   7/8"  RFS brand 7/8"  heliax with a corrugated  CU
> center conductor + outer conductor is aprx $2.35 per foot...cheap.  Andrew
> doesn't even offer  7/8" heliax with a corrugated center conductor...only
> a  copper tube.  Ditto with 1.25" heliax.
>
> ##RFS also makes both 7/8"  and  1.25"  heliax  with a corrugated Aluminum
> outer conductor..and corrugated copper inner conductor.   Now this stuff is 
> all
> the rage in EU/Asia/China/India..and now NA.    The 7/8"  version is aprx 
> $1.48
> per foot !  it's only 22 lbs  per 100'  [ vs  45 lbs  for LMR-1200DB] . The 
> spec's are
> 99.8% as good as the stuff using CU  for the outer conductor.   Having a 
> corrugated
> center conductor  means it  is a LOT more flexible than Andrew heliax  [with 
> it's rigid
> copper tube / kink prone].   From an install point of view,  flexible, 
> light,cheap heliax
> is the way to go.Braided cables  will suck water up on their braids via 
> capillary action.
>
> ##  The cell industry  has completely swapped over to 7-16 DIN.  All the new 
> gen 3+4
> eq is 7-16 Din. Type N is obsolete.   7-16 Dins are plentiful on the surplus 
> market.  You can't
> blow up a 7-16 Din on HF.
>
>
> Methinks that the poster of this comment needs to go back to study the
> fundamentals of transmission lines.
>
> ## I did.  RG-213  won't  work from the bottom of a tower to the top of a 
> tower on 15M,
> and that assumes you have BIG stuff between house and base of tower]   Hams 
> have been
> brainwashed into thinking RG-213 + UHF connector's is some sorta 'standard'.  
> Have folks
> ever put a wattmeter at the top of their tower's..and measured their 
> power..... with
> exactly 1 kw CXR applied in the shack ??    They will get an eye opener, and 
> then some.
>
>
>
>   The ARRL Handbook and ARRL Antenna
> Book are a good place to start.
>
> ##  The ARRL  handbook and Ant book  both need a serious re-write.    Did 
> they finally
> figure out how to build a balun ?
>
> Jim   VE7RF
>
>
>
> 73, Jim K9YC
>
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