With the exception of open wire feeders, and not ladder line, the cheaper
you go with transmission line, the less power you will have at your antenna,
period! If your SGC SG-235 tuner is located at your radio end and not right
at the interface between your dipole wires and your coax, you have done
absolutely nothing to improve the SWR at your antenna, thus if the SWR at
your antenna is high, the losses due to the high SWR WILL be realized in 100
foot of RG-58, etc., BUT your radio will see a sweet SWR! This is not
folk-lore nor 'my antenna is better than your antenna'-ism, it's simple
arithmetic.
Why would anyone pay $1000 to $2000 for a radio that puts out 100 watts and
not pay the price for good transmission line that will at least let you
realize more than 70 watts going into your dipole?
Tom - W4BQF
----- Original Message -----
From: "Ken Brown" <ken.d.brown@verizon.net>
To: <larrylg1@roamer.net>; <tentec@contesting.com>
Sent: Thursday, September 16, 2004 12:52 AM
Subject: Re: [TenTec] Coax For Low Power HF
> 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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