I have been watching this discussion with a lot of interest. The interest
being, what is the power loss at 30 MHz for a 100' run of 1/2" vs 1 5/8"
hardline? Turns out it is ~82 W.
This is for LDFX-50A
1 5/8" loss @ 30 MHz/100' = 0.109 dB
1/2" loss @ 30 MHz/100' = 0.375 dB
http://www.rfparts.com/coax/heliaxcoax.html?cat=469
That will not break any pile-up on any band. Period!
Everything from hereon in is based on a 100' run of coax. You can do the math
for any run shorter or longer.
Now, what is the cost of shipping 100' of 1 5/8" coax from the east coast to
CO? Ain't gonna be cheap.
How much do the connectors cost? Ain't gonna be cheap.
Need any adapters? Not cheap.
How manageable is the big stiff stuff? It's big, stiff and heavy.
What about the 1/2" stuff. Easy. The ultraflex is even easier to manage.
Gotta put flexible jumpers twixt the run and rotated antenna as well as in the
shack in both cases.
1/2" hardline costs ~$3.00/ft vs ~$14.00/ft for the 1 5/8" stuff.
Geez, unless you are running more than 6 kW @ 30 MHz (1/2" hardline) with a
100% duty cycle, I can see no reason for the use of 1 5/8" hardline. The last
time I checked the legal limit for us, USA hams, was 1.5 kW PEP.
Unless you NEED bragging rights. Then, by all means go for it.
IMHO, sell the 1 5/8" where it resides and buy new 1/2" at your new new QTH.
BTW, all my shack jumpers used to be LMR-400 but I got tired of the lack of
flexibility so I went with to LMR-250UF.
Of course your mileage may, and will vary.
---
Ciao baby, catch you on the flip side.
GEO
http://www.w3ab.org
3 thoughts:
Recall that the gain from a lot of aluminum high in the sky works both ways.
QRO works one way only.
If you are unable to hear them, you will NOT work them.
I'd rather put 12 dB of gain @ 60' rather than get 12 dB of gain from the 220
VAC outlet.
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