Date: Thu, 30 May 2013 21:22:25 -0700 (PDT)
From: GEO Badger <w3ab@yahoo.com>
To: "towertalk@contesting.com" <towertalk@contesting.com>
Subject: Re: [TowerTalk] 1-5/8 inch Andrew Hardline stored outside in
New England for 5 years - still good?
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.??????
## perhaps the fellow intends to use 200 to 300 feet of it on VHF + UHF at
some time in the future. Who cares what it costs per foot....he already owns
it.
Type N for this size cable is a waste of $$. But 7-16 dins would not be
cheap... but hardly any more than type N. Using a coffee mug size connector
with a tiny
BNC size pin is fubar. Even the telco’s and cell companies have switched
from type N to 7-16 DIN.
## How do you propose to get 12 dbd of gain @ 60 feet... on
160-80-40-30-20-17-15m ?? Can’t be done.
## You can’t work em...if they can’t hear you ! 12 db of gain from the 240
vac outlet works on all bands. Your 20m yagi only works on 20m...and only has
5-7 dbd of gain.
## I use LMR-600 T-comm ultra flex for jumpers in the shack + shop. 27
strands in the center conductor. Way more flexible than 213-U. ...like
spagetti.
## 1/2 inch and 7/8 inch heliax is plenty for most applications for HF. 1/2
inch heliax handles 12 kw pep easily..even on 15 M...and more on the lower
bands.
Jim VE7RF
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