----- Original Message -----
From: "Michael Hatzakis, Jr MD" <mail@hatzakis.net>
To: "'K8RI on TowerTalk'" <K8RI-on-TowerTalk@tm.net>;
<towertalk@contesting.com>
Sent: Sunday, November 26, 2006 9:47 PM
Subject: RE: [TowerTalk] LMR600
> Hi Jim,
>
> I've been following some of this thread, but I am curious why you are
> considering using LMR600 for a Steppir with 6m.
>
> I mean, seems to me that for a 300 foot run, at 50mhz, LMR600 has 1.4db
> loss
> and LMR400 superflex has a total loss of 2.1db. LMR600 is exactly twice
> the
At 50 MHz:
Using the times wire page I get 1.2 db for 300' of LMR-600, 2.7 db for
LMR-400 and 3.3 db for LMR-400UF
Minimum *repeated* bending radius is LMR-600 = 6", LMR-400 = 4", 400UF =
4"
You would not want to be bending it to these radiuses on a regular basis as
with a rotator loop. You'd want at *least* 3 to 5 times as much radius for a
rotator loop. I use a 3 turn, 18" diameter loop, or (3 * 9 = 27" effective
radius)
Weight in pounds per foot: LMR-600 0.131, LMR-400 = 0.068 and LMR-400UF =
0.09
> weight with the same temperature range and are both made with copper clad
> aluminum. I believe LMR600 is multiple times the cost. LMR400 is much
> easier to use, has almost half the bend radius.
Cost is (depending on where you go) LMR-400 = $0.64/ft and LMR-600 =
$1.60/ft list. Prices vary widely from bulk to retail.
Don't forget that crimp on connectors for LMR-600 may be close to twice the
price of those used on LMR-400. Clamp type are more.
>
> I have a Steppir and three VHF/UHF antennas on top of a 70ft tower and run
> LMR400 to all four of them using 100' vertical run and a 150' underground
> run. I bought a spool of LMR400 and got a good quantity discount locally.
> They slide well with lube. Been in a buried tube for 5 years now and work
My runs of LMR-400 are about the same and have been in for about the same
time.
I'm going with the 600 for 144 and 440 MHz.
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com
> well with the same run loss measured with an antenna analyzer since the
> day
> they were put in. I am sure lots of people on this list are doing the
> same.
>
> Michael K3MH
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of K8RI on TowerTalk
> Sent: Sunday, November 26, 2006 6:27 PM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] LMR600
>
>
> ----- Original Message -----
> From: "Jim McDonald" <jim@n7us.net>
> To: <towertalk@contesting.com>
> Sent: Sunday, November 26, 2006 9:02 PM
> Subject: [TowerTalk] LMR600
>
>
>> Is LMR600 or the equivalent too stiff to pass through three 45-degree
>> sweeps
>> in a 4" PVC?
>
> I'm running it through three 45s and one sweep 90. I use a messenger
> cable,
>
> tape the ends to a point, and use *LOTS* of cable pulling soap. It is
> stiff.
>
>> How about with an 89' crank-up tower? I am trying to decide
>
> I've not tried it, but IF you have room you *might* be able to get away
> with
>
> letting the coax coil around the tower, but that would probably take up a
> lot of space. I seriously doubt if it'd work well, but maybe someone on
> there has tried it. I am using three turn coils of LMR-600 at the top of
> the tower in place of rotator loops.
>
>> whether to reuse my Davis RF Bury-Flex or replace it. This antenna, a 4L
>> SteppIR, will have 6M on it, and I've never had to be concerned with
>> attenuation for that band before.
>
> As a personal opinion I'd reuse the Bury-flex if it's in good shape and
> the
> run is not long.
> What's the loss calculate out for the length of your run?
> I'm putting in two runs of LMR 600 and one run of 5/8" Heliax, but it's
> 228
> feet to the antennas.
>
>
>>
>>
>>
>> Jim N7US
>>
>>
>>
>> _______________________________________________
>>
>>
>>
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>
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