Exerpted from 200 METERS AND DOWN... copyright ARRL 1936
ELECTRICIAN & MECHANIC published the following table in 1907 showing the
relative performances of different types of transmitting and receiving
equipment of the day.
SPARK COIL ANTENNA HEIGHT COHERER LIQUID DETECTER
SIZE
OR
BARRETTER
1/2 INCH 35 FEET 1/8 MILE 1/4 TO
1/2 MILE
1 INCH 40 - 45 FEET 1/4 MILE 1/4 TO 3/4
MILE
2 INCH 50 FEET 2 1/2 TO 3 1/2 5 TO 10
MILES
4 INCH* 75 FEET 10 MILES 10 TO 20
MILES
6 INCH* 100 FEET 15 MILES 15 TO 30
MILES
10 INCH* 150 FEET 50 MILES 50 TO 75
MILES
15 INCH* 180 FEET 60 TO 75 75 TO 100
MILES
* = TUNED
An alternative to the 15 inch spark coil was an oil immersed 1/4 kilowatt
transformer and a battery of Leyden jars; with this combination 100 miles
was guaranteed.
Denny k8do@aol.com
>From dnorris@k7no.com (Dean Norris) Tue Jun 25 23:08:09 1996
From: dnorris@k7no.com (Dean Norris) (Dean Norris)
Subject: Steve Mendelsohn's letter
Message-ID: <2.2.32.19960625220809.0069408c@mail.syspac.com>
At 18:30 6/25/96 PDT, you wrote:
>Aren't we missing the point here? ARRLs flat membership ( based on their QST
>circulation data which includes other than members ) represents about 20%
of the
>US ham population.
What? That would be 50,000,000, 50 million. No way! I think you added a
few 0000's to the copy? Or...if I am wrong, god help us. Where did you see
those figures. I have been a member for 40 years and a life member for 20+.
If you could tell which issue quotes those figures I would like to see them..
73/DX
cdn
C. Dean Norris
Amateur Radio Station K7NO
e-mail to dnorris@k7no.com
http://www.syspac.com/~dnorris/
>From dave@egh.com (David Clemons) Tue Jun 25 22:44:15 1996
From: dave@egh.com (David Clemons) (David Clemons)
Subject: Denny K8DO's ARRL Handbook excerpt
Message-ID: <Pine.3.89.9606251756.A4817-0100000@newman.egh.com>
re: An alternative to the 15 inch spark coil was an oil immersed 1/4 kilowatt
transformer and a battery of Leyden jars; with this combination 100 miles
was guaranteed.
Talk about the good old days! I bet nobody had any trouble holding their
frequency (...or actually frequencies...) with that little contraption!
73,
Dave Clemons K1VUT
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