> 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
> 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.
I'll be putting up my new SteppIR soon and had to make the same choice for
my 250' coax run. Using the coax loss calculator at:
www.ocarc.ca/coax.htm
I get the following at 50 MHz for a 300' run of coax:
LMR400 2.6dB loss
LMR600 1.6dB loss
LDF4-50A 1.4dB loss
LDF5-50A 0.8dB loss
For me it was a no-brainer. LDF5-50A (7/8" Heliax) has 1.8 dB less loss
than LMR400 for a 300' run at 50MHz. People spend a lot of money on bigger
antennas (not to mention bigger rotators and heavier duty towers) to gain
1.8 dB. The cost of 300' of surplus 7/8 Heliax is a pretty cheap way to
gain 1.8 dB. On 20M LDF5-50A has about 1 dB less loss than LMR400, which is
still a worthwhile improvement when trying to pull that weak signal out of
the noise.
73,
Clay W7CE
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