Hi All, N connectors seem to get a bad rap for some reason.
I have used them in my eme systems on 2m and 70cm for over 20 years and
find them to be very reliable. There have been quite a few contests run for
hours at a time at the 1500 watt level even using the JT65 digital mode that
is full carrier key down for 50 seconds and key up for 70 seconds.
I have had a couple of failures in flex loops where the shield worked loose
and the insides of the connector overheated and turned into charcoal. Even
that problem has disappeared since learning to reinforce the connector
with a length of heat shrink tubing. Have never seen a center pin failure.
For Heliax, the connector choice is limited. As far as I know, there have
never been any C connectors offered. Maybe LC but not too sure about that.
As Roger, K8RI mentioned, there are plenty of 7-16 DIN male and female
connectors available for excellent prices. They are the ultimate for
robustness
and easy to install.
73,
Gerald K5GW
In a message dated 12/24/2011 2:21:24 P.M. Central Standard Time,
balmemo@sympatico.ca writes:
N-connectors are not much better than BNC and they don't stand up to much
power! ;-) A better choice is C-connectors but they are a rare breed.
Merry Christmas and a Happy New Year to all!
Bert, VE3NR
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of K8RI
Sent: Saturday, December 24, 2011 1:55 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Used Heliax ?
On 12/24/2011 12:06 PM, Jim Brown wrote:
> On 12/24/2011 8:44 AM, F5vjc wrote:
>> I'm thinking to buy some used Heliax locally. I have a couple of
>> offers, one is LDF4-50 which I am familiar with, the other is LDF1-50
>> which I am not. I have of course looked these up on the net and can
>> find and compare the specs of both.
>>
>> This is for an HF only installation (up to 50 MHz) 150 feet in length
>> so losses are not my major concern.
> Then why do you want Heliax? The primary advantage is lower loss.
> The only other one I can think of is robustness against rodents. I use
> LDF4-50 and LDF5-50 for 100m runs to my tower.
>
>> However in general is there anything to watch out for when buying
>> used Heliax of any type? I believe it is Andrews. The LDF 4-50 will
>> come with N type connectors so that is a plus,
> LDF4-50 is very nice cable, connectors are widely available at
> moderate cost, and the loss is significantly lower than the best RG8-size
coax.
> I'm using LDF4 to go up the tower and LDF5 for the longer run on the
> ground.
I do not like the 1/2" heliax. I've found it too easy to kink and gave
away
most of what I had.
I have one brand new N connector for the 1/2"left, but unfortunately some
where in the last 20 years the center pin seems to have walked off.
I like the 7/8" stuff for VHF, UHF, and 160 meters. Running the legal limit
on 160 with the resulting very high SWR at the band edges the voltage is
high enough to take out type N connectors. Also the 7/8" has better
current
capability. Currently I'm using LMR-600 and modified UHF connectors for
160. No problem there other than UHF connectors for larger coax can be
kinda
pricey and difficult to find. I don't run enough power on 144 and 440 for
it to be a problem, but there I like the low loss.
Unfortunately even with a remote tuner I have to run feed line from the
tower to the slopers. It can be window line, or true open wire, but I'm
not
a fan of either. I guess the window line would be the most convenient.
It's roughly a 228 foot furn from the rig to the top of the tower.
I hear of those "free" deals, but I always seem to be a day late <sigh> Two
years ago at the local swap there was some 7/8" at a good price, but
unfortunately the lengths were too short, so for the time being I have
multiple runs of LMR-600 up the tower. That and the 600 is a whale of a lot
easier to pull through 4" conduit. If I find enough 7/8" I'll have to dig
up
the 4", or add additional conduit runs ...which might be easier.
73
Roger (K8RI)
>
> 73, Jim K9YC
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