[SixClub] 6m alive earlier tonight in EL 29

[Roger (K8RI)]

Mike Andrews W5EGO wrote:
> On Fri, Aug 08, 2008 at 04:50:22AM -0700, Michael McFatridge wrote:
>   
>> I had better luck here in el29. I woked a bunch of
>> stations on Arizona and Colorado. I had to play with
>> my new Kenwood TS-2000. I'll be glad when I get out of
>> this wheelchair.Going back to Dr. today to see if more
>> surgery is required on my foot. . Mike N5TYW
>>     
>
> Just before 2000 local last night (0300Z Friday Zulu) I heard and 
> worked a gent in DM02 from EM15. That tells me that my feedline's not
> the problem; I had thought that it was attenuating the weak sigs too
> much[1], but if it had been, then neither of us would have heaard the
> other last night. Gotta build that Cebik interrupted current loop for 
> 6m; friends are having the most marvelous results with it. 
>
> [1]  Though not as much as the National Weather Service's feedline in 
>      their new building here in Norman. The idiot architect put the 
>      radio room in the *center* of the building, 40 feet under the 
>      roof and about 200 feet back from the exterior wall where the 
>      antennas are mounted. The cable raceway length from the radio 
>      room to the antenna mounting structure is just under 400 feet.
>      Even with LMR-600, they get something like 96% attenuation at 
>      70 cm., and about 85-90% at 2 meters. 
>   
I'm not sure where those figures came from, but based on  Times Wire's 
own calculator at: http://www.timesmicrowave.com/cgi-bin/calculate.pl 
there's a bit of a difference.
Though not good it's not quite as bad it's still not good.  400 feet of 
LMR-600 on 440 is 6.8db loss or 20.9% efficient. That's 79.1% 
attenuation, not 96%. On 2-meters that's 2.5db loss for 56.3 % 
efficiency or 43.7% attenuation, not 85 to 90%. 
OTOH it's probably on par with typical ham installations using much 
smaller cables. I know of several locals using RG-8X on 144 and 440. 
They may be short runs, but still...  Oh, and one uses about bury flex 
to his ground mounted HF vertical while using the 8X on VHF and UHF.

Roger (K8RI - ARRL Life Member)
www.rogerhalstead.com
N833R (World's oldest Debonair)