Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1922-12-08
RODY CAPACITY is
CAUSE OF ANNOYANCE
Methods by Which Its Effects
MAY Be Avoided - Possible
Reasons for Fading Signals.

inc an apparent phenomenon i'll tun-
mo The phenomenon III the case is
Mo+ inst as the operator tuned in his
.,otion and removed his hands from
no knob. the signals faded out; or it
nov have been the other way around
md If the operator touches his set
rbne listening to Il concert, the sig
,als will fade out.
This may be caused by body ca
oocity, and while some stations run
into it quite frequently, others are not
,botbered at all. Those living close to
broadcasting station will never be
,othered with it as it only occurs with
, very close tuning. 1t is explained
nv the fact that the capacity of the
body coming III contact with the set,
which is very finely tuned, is thrown
ant of adjustment by the outside in
duCtance.
There are several ways to guard
AGAINST it. and one Of the best Is to
line the inside of the panel with tin
foil or aluminium foil and ground it.
IN pasting the tin foil on the back
Of the panel, 1t is cut away from all
binding posts. switch points or rods to
ueyent short cirCuitng the set. There
il one exception to this, and that is the
ground binding post. If the tin foil Is
pasted over this, it is, of course, auto
matlcaly grounded.
Shellac will do to make the foil ad-
here to the panel, which will not have
TO be diSmantled to be lined, as the
foil can he placed on in small strips.
Another method Of remedying the
effects of body capacity is by using
metal dals on the variocoupler and
mrlometers; and In sets where the
arOmeters are very close to one an
other, moving them away will help.
Or In case 1t Is not desired to change
The set placing a nonmagnetic ma
teria between the variometers which
are close TO each other and grounding
4 Il will remedy the Ill effects. For this
case, a piece Of glass such as photog-
mphers use, covered with tinfoil ON
one side, is effective.
Fading signals have long been en-
COuntered by amateurs when receiving
Ong.dlstance stations. In this case,
The signals from IA gOOdly distance
away may be coming in loud and
clear and then without warning fade
away. In few seconds they may
return with all their force, and then
when the amateur is cOngratulating
himself, again the voices or music die
out Or fading may take the form
Of varying intensity Of signals, one
minute the operator being forced to
strain his ears to catch the sound
While the next voices may be loud
and clear.
There have been many theories adj
Vanced for this phenomenon, and we
IRE giving today two Of the latest.
The radio division Of the Department
Commerce is reported to he under
NE impression that fading occurs
Elan cloud passes between the
tanSmltting station and the receiving
st This theory has been one of the
most popular among the experts. and
recent tests have been made to obtain
more complete data. II the passing
uOOd theory Is a good explanation
o. fading there will be some new
fsOlo Development very shortly. The
saects Of various types Of clouds upon
ue signals is being studied, and the
results of this study will be of inter
vi to everyone interested in radio.
G"ernment officials are interested In
aminating fading, or overcoming 1t
much as possible, largely from the
"andpoint Of the amateur, as the com
ueFclal stations, having much greater
""er than amateur sets, are able to
"Hcome the atmospheric effects to a
Feat extent.
Inc other theory, which has close
,'iauon to the cloud theory, is that
auing occurs when the signals pass
trough an area where rain is falling
'ais theory, the idea Is brought out
Inherent manner 1t Is stated
erect that clouds are q benefit to
NC signals, but that the rain will
wi, them. The theory Is that the
.Onuehsation of the particles Of mois-
Suie IN the air which form the clouds
% r' Inc property of making this me-
auin highly conductive to radio sig
~" Just before u storm when there
uore Condensation in the clouds, the
T euals should be at their strongest.
a"eh the storm breaks, and the air
,, J,V'nes saturated, the condition is
,s u 10 change and the falling rain
suy grounds the signals. This
,sa sen change in atmosphere is stated
\ n ~e reason for the varying intensity
approximate method of measur-
~ "e antenna resistance is by means
dr., condenser and calibrated o.
ass assistance unit connected In Sc
\ ~ Ihis so-called phantom antenna
ana 'n connected with the antenna
dnh,e SOUND circuit to q double pole,
q ~ throw switch, so that the output
pec,as transmitting set can be con-
gors either to the antenna and
nl, Vt 10 the phantom antenna cir