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RE: Pressurize LDF5-50?
To: "'CRTech'" <crtech@crtech.org>
Subject: RE: Pressurize LDF5-50?
From: "Bill Hurne" <billhurne@pilgrimradio.com>
Date: Fri, 14 Jul 2017 12:27:49 -0700
Content-language: en-us
In-reply-to: <CAHL64sE7p-xZ_vuGv3MgefRYWM8iMBae=McYKQ57UWgOqs+jSg@mail.gmail.com>
References: <003801d2fccb$41182df0$c34889d0$@pilgrimradio.com> <CAHL64sE7p-xZ_vuGv3MgefRYWM8iMBae=McYKQ57UWgOqs+jSg@mail.gmail.com>
Thread-index: AQJdrXkLyc6SGEt5I5wUJHHuZnfRgQGPvxldoTHRvmA=

For the L45R connector I thought about making a very small gas groove inside the center conductor where the self-tapping center screw piece threads into the center.   Use a very small file.   Of course the bullet needs the small holes in the Teflon, and feed gas into a 7/8 EIA adapter such as https://www.rfparts.com/adapters/adapters-eiaflange/eiaflange-78/eiaflange78-adapt/rla050-16.html






From: Kevin Kidd [mailto:kkbroadcastengineering@gmail.com]
Sent: Friday, July 14, 2017 12:00 PM
To: CRTech
Subject: Re: [CRTech] Pressurize LDF5-50?



It at least has been done in the past but I don't know of any recent systems built like that.  Foam type flange connectors "should" seal well enough to hold pressure but probably not as well as the connectors on air line.  I do recall reading somewhere that some modifications had to be made to the foam connectors to get a good flow of gas out of the hollow center conductor.  There may be (or may have been) a special foam connector for the purpose.


Kevin C. Kidd, CSRE/AMD
Lawrenceburg, TN
AM Ground Systems Company  -  WD4RAT
kkidd@kkbc.com  --  866-22-RADIO -- 866-227-2346


On Fri, Jul 14, 2017 at 1:01 PM, Bill Hurne <billhurne@pilgrimradio.com> wrote:

We’re replacing an antenna fed by LDF5-50 coax up the tower.   At the antenna is a 1 5/8 EIA connector, with a reducer to 7/8 EIA.


At the bottom end is a 7/8 EIA flange.    We would like to pressurize the antenna.


Current connectors at the top and bottom are L45R that aren’t pressurizable.


Are there pressurizable 7/8 inch EIA connectors available for LDF5-50?


I was told we can pressurize this coax and antenna by sending the nitrogen up the hollow center conductor.




Bill Hurne

Chief Engineer

The Pilgrim Radio Network


Follow-Ups: Re: Pressurize LDF5-50?
(Kevin Kidd <kkbroadcastengineering@gmail.com>, 14 Jul 2017 21:57:39 -0000)
References: Pressurize LDF5-50?
("Bill Hurne" <billhurne@pilgrimradio.com>, 14 Jul 2017 18:01:56 -0000)
Re: Pressurize LDF5-50?
(Kevin Kidd <kkbroadcastengineering@gmail.com>, 14 Jul 2017 18:59:46 -0000)
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