Maybe in your part of the world but there is often some RTTY or digital bozo
warbling away in the CW "DX Window" until he gets chased off.
Then there is the CQ QRP weenie right on top of a DX station. I also work
QRP but I also have several Beverages and dont call CQ down there.
Carl
KM1H
----- Original Message -----
From: "Jim W7RY" <w7ry@centurytel.net>
To: <amps@contesting.com>
Sent: Sunday, October 06, 2013 6:53 PM
Subject: Re: [Amps] 160M PI network Toroidal Coil
There is little to no RTTY activity on 160 meters.
73
Jim W7RY
On 10/6/2013 6:28 AM, Carl wrote:
----- Original Message ----- From: "Bill Turner" <dezrat1242@yahoo.com>
To: "Amps" <amps@contesting.com>
Sent: Saturday, October 05, 2013 11:43 PM
Subject: Re: [Amps] 160M PI network Toroidal Coil
ORIGINAL MESSAGE: (may be snipped)
On Sun, 06 Oct 2013 00:25:36 +0000, Manfred wrote:
You are wrong regarding the loss. The loss isn't "essentially zero",
unfortunately. Such a coil will likely end up having a Q between 300
and
350, perhaps lower if other metal objects are too close to it, or if it
uses some lossy support. Now if the loaded Q of the tank circuit is 12,
as is often done by design, then the coil will loose about 4% of the RF
power. At 1500W output that would be 60 watts, which is enough to make
that coil very hot, unless there is a strong stream of air cooling it.
REPLY:
I stand by what I said. I have such a coil in my homebrew 8877 amp using
#4
wire and it runs barely warm with the key down. I call that "essentially
zero" in the sense you'll never notice it.
73, Bill W6WRT
However the thread is about a SB-220 which may make 1300W PEP on a good
day and will never be used for RTTY at more than half that due to the
wimpy PS.
A pair of T200-2 toroids works fine for that as well as the thousands of
Alphas and other amps that have used them at up to twice the power.
Carl
KM1H
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