For an 80M 4-sq how much loss difference is there between RG179 and RG302
per choke? I wouldn't think you could tell the difference, correct? I
already have the RG-179.
N2TK, Tony
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Jim Brown
Sent: Tuesday, February 19, 2019 2:26 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] RG179 Chokes For TX 4-Squares
That's a judgement call that I wouldn't argue with. Choke guidelines for
RG400 would apply.
73, Jim K9YC
On 2/19/2019 8:48 AM, john@kk9a.com wrote:
> I think RG-302/U would be a better 75 ohm PTFE coax choice.
>
> John KK9A
>
>
> Jim Brown K9YC wrote:
>
> After some discussion on one of the reflectors about chokes that could
> be used in 75 ohm phasing lines, Grant, KZ1W, sent me some. I wound a
> bunch of chokes using the same methods, and on the same cores, used to
> produce the new Cookbook, and added winding guidelines for these chokes.
> They have been added to the latest version of
> k9yc.com/2018Cookbook.pdf Refresh your browser to make sure that
> you've got the latest version. If you have the latest, you'll a a
> photo of a choke wound with white miniature Teflon coax on page 3.
>
> Note that RG179 has much more loss than RG400, so they have a lot more
> differential mode dissipation for the same power level. They MUST be
> exposed to air so that they don't overheat. If used in this manner,
> they are probably sufficient for use in a 4-square in which power is
> equally divided between the four antennas, running at legal limit.
>
> What looks like new old stock RG179 is plentiful and cheap ($0.35 -
> $0.50/ft) on the big auction site from vendors with 100% ratings.
>
> 73, Jim K9YC
>
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