Yes, D-104 lip zaps were so much joy. 3rd floor attic shack, Viking
Valiant 200w AM transmitter, random length end fed long wire. Ground?
We got no stinking ground! A death grip was needed on the D-104 PTT
lever. Long before ANY digital stuff in the house, otherwise all of it
would have been lit up. However, the blue arc haze around the Heathkit
air core balun was a fun to observe when the SWR really got nasty.
Grant KZ1W
On 9/23/2017 11:03 AM, Patrick Greenlee wrote:
Decades ago I had an Atlas 350XL aboard my sailboat. I used the
insulated backstay for a random length vertical with a Drake tuner. My
operating position was the nav station which put my metal hand mike
about 9 ft from the bottom of the insulated backstay. Of course the
antenna started at the output of the coax fed tuner less than 4 ft
from the mike. The 350XL was a 200 watt rig. If I turned it up much
past 100 or so watts out on some bands/freqs I would get RF sparks
jumping from the metal mike to my lips.
In defense of the setup... On some bands/freqs I could go full power
without getting zapped. I had a decent ground, the engine, shaft,
prop, and a ton of steel in the water (fin keel.)
Patrick NJ5G
On 9/22/2017 8:06 AM, john@kk9a.com wrote:
I remember the biting mic/radio days. I had that happen on an
expedition to
Antigua in the early 80's using a very low beam with no balun. It is
obviously a good practice to put a choke at the antenna. I have one
on every
antenna. Is there benefit to also putting a choke near the station
entrance?
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 40M rotary dipole and CM current
From: "Joe Subich, W4TV" <lists@subich.com>
Date: Thu, 21 Sep 2017 21:07:45 -0400
List-post: <mailto:towertalk@contesting.com>
By suppressing common mode current in TX you prevent the "random radial"
phenomenon. In doing so, you mitigate the "pin 1" problem by reducing
the RF voltage on equipment cases/connecting cables and avoid issues
of a "biting mic" (if you're old enough to remember RF burns to the lips
from the case of a D-104).
73,
... Joe, W4TV
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