Re: [TenTec] Coax For Low Power HF

[Ken Brown <ken.d.brown@verizon.net>]

Currently, I am using a 450 ohm bed antenna.

Is that a bed spring antenna, or is "bed" and acronym for something?

Can I get by ok with the regular old RG 58 coax on my less than 100 ft runs?

Absolutely! I have a SGC SG-235 autotuner, rated at 500 watts, and it 
has a RG-58 pigtail for the 50 ohm port. Assuming the tuner is doing 
it's job and the SWR is low, the RG-58 will work fine with 500 watts. 
RG-58 is much lighter than RG-8 (or RG-213 or similar) and will make 
your dipoles sag in the middle a lot less, given the same tension on the 
dipole.

I am used to ladder wire and having an amp;

On the other hand if you use bigger coax, you will still be able to run 
higher power, if you decide to later.  Bigger stuff generally has lower 
loss, but for less than 100 foot runs below 30 MHz, you'll probabaly 
never notice that difference. You may wish you had the bigger stuff if 
you want to operate with some more power on a band where the system has 
a higher SWR.

There are so many varieties of coax out there.

Yes, and many different qualities are labled as RG-58 or RG-8 or RG-213, 
etc, etc. Before you buy anything, look at what is available. Remove the 
outer sheath and see how dense or sparse the braid is. Many of the 
suppliers will give a specification for that, and most will probably 
send you some sample pieces so you can see for yourself. Also you need 
to consider the connectors. If you intend to use "regular" solder on 
PL-259  connectors, make sure the coax can be soldered. There are many 
versions of coax that have really fantasitic specifications, but require 
special connectors that may require you to buy a fairly expensive 
crimping tool to install. You can buy already connectorized cable too, 
but then do you really want to be unable to fix it if the connector 
comes off?

There are some "RG-8X" styles that may be good ( and no doubt some that 
are junk ) that are about the size and weight of RG-59, but are 50 ohm 
and are almost as good (loss and power handling capability) as full 
sized RG-8.

Good luck, have fun.

DE N6KB





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