[TowerTalk] Fwd: Attach a PL-259 to a 1/2" hardline

[K8RI]

On 11/7/2012 9:20 PM, Missouri Guy wrote:
> FWIW...I needed connectors for the 1/2 aluminum coax
> quite a few years ago.  I didn't think of K8RI's neat idea
> of the brass fittings back then.  What I did was to make
> an adapter-sleeve with a ~1" length of 1/2" i.d. aluminum tubing.
> The tubing fit over the standard PL-259 connector
> and the coax.
>
> I found a thick steel washer in the junk box
> that is about the same size as the CUTTER WHEEL in a copper tubing
> cutter.
> I rounded off the edge of the washer and installed it in the
> cutter.  I then used the "cutter" to ROLL two indented rings
> on each end of the aluminum tubing (4 rings total).  That worked, but I
> found that the aluminum coax was TOO SOFT to "fuse"
> to the aluminum sleeve.  I solved that problem by making
> some hard plastic inserts that "just fit" inside the coax.
>
> I removed the foam inside the coax with a homebrew
> hollow "drill" made from a chunk of mild steel so the
> inserts could slide in.  It worked well and the connections
> are still good many years later.
>
> Yeah, you may have to use a small lathe to make the inserts, but I know
> some of you have one in your shop.  Those inserts may be needed
> *IF* you find that the brass compression fittings that Roger used
> are somewhat loose when compressed over the soft aluminum
> coax.

I like your idea and I'm trying to picture it a bit better.  It has a 
certain elegance to it, but unfortunately takes a bit more work and I've 
noticed a lot of us are not extremely gifted on ambition...at least I'm 
not. OTOH I can't resist a challenge, particularly if it doesn't cost much.

I wonder if a swagging tool couldn't be built to fit the jacket tightly 
onto the PL-259 Barrel? This would give a large area of contact and 
might be strong enough to hold well.  The problem with swagging onto the 
barrel is the Aluminum tends to spring back.  OTOH swagging to an ID 
slightly undersize with a bit of a bell on the end of the jacket and 
then pressing the PL-259 into the end of the coax jacket might work 
well.  Now some one just needs to make the tools to do this well. <:-)).

As in writing computer programs, there are usually far more than one way 
to get the same result.  My approach was neat and easy, but you are 
correct in that using the compression fitting the coax is a bit small 
for the fitting. It will tighten down fine, but it takes care to keep 
things straight. Of course if you have a good lathe and a bit of skill, 
you can build the equivalent of of a 7-16 DIN. With some brass rod of 
the proper size you can also build the connectors used on Heliax. Those 
are fairly simple, but it takes about a 4" rod and that brass rod is 
kinda pricey!

73

Roger (K8RI)


>
> 73,
> Charlie, N0TT
>
> On Wed, 07 Nov 2012 18:01:07 -0500 K8RI <K8RI-on-TowerTalk at tm.net>
> writes:
>> On 11/7/2012 5:32 PM, Tom KD8DEG wrote:
>>> I use standard copper pipe compression fittings if the cable is
>> the
>>> aluminum 75 ohm cabel tv line. They work great.
>>
>> A couple ways of making adapters.
>> http://www.rogerhalstead.com/ham_files/conn.htm
>>
>> 73
>>
>> Roger (K8RI)
>>
>>>
>>> Tom KD8DEG
>>>
>>> ----- Original Message ----- From: "Steve Maki"
>> <lists at oakcom.org>
>>> To: "towertalk" <towertalk at contesting.com>
>>> Sent: Wednesday, November 07, 2012 10:00 AM
>>> Subject: Re: [TowerTalk] Fwd: Attach a PL-259 to a 1/2" hardline
>>>
>>>
>>>> Well, they do make female F connectors for anything up to .750,
>> but
>>>> normally it's terminated with pin connectors. The pin connectors
>>>> though are useful as a starting point to transition to UHF.
>>>>
>>>> -Steve K8LX
>>>>
>>>> On 11/7/2012 9:49 AM, Jim W7RY wrote:
>>>>
>>>>> Is this 75 Ohm CATV cable?
>>>>>
>>>>> If so, there are NO standard adapters or connectors. The cable
>> TV
>>>>> industry does not use "connectors" on this type of coax. The
>> cable
>>>>> connects directly to the device through a hole in the side of
>> the
>>>>> device.
>>>>>
>>>>> 73
>>>>> Jim W7RY
>>>>
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