The evening herald. [volume] (Albuquerque, New Mexico) 1914-1922, 1922-03-26

Tho PRINCIPLES and fundamental
OF the Radiotrola are not new to
aiuatvurs The Radiotroia is not
the ultimate receiving set, yet. II II
the first Of It's kind to be built ~
as TO operate on an indoor loop
with no ground and receive for any
apprccinhie distance or distiuctncHs
As conceived hy the author. this
set o. as easy TO operate and ns
ornamental a. the latest type %
talking machine.
More than eight weeks OF expert
research work wore required to
bring this set to completion rms,
including cost 81 material, broush.
It's cost az to about $500. The
following Instructions give tho
reader the heucf. of the author n
experience and make IL possible Ia
build the set FOR about Slao.uu ANA
| probably a great deal less. II de-
ponds upon how good a shopper
| ihc builder be-.
The Cabinet
Tho ease. as shown la the dia-
gram, b. the lower pact ct "a pnOnO-
| srtitu Via was formerly used as a
record cabinet. a. wac bought 1T
"a cun hand suup for 4I1.UN.
| While "a much larger cabinet could
have been used, % was tuuuEht best
mot TO do 90 a- thc loop wuuld
maze extended Co au announcement
| height which would have made the
instrument appear cumbcraume.
Aithousn somewhat Crampcd IN
the small space OF the cabinet. TIA.
apparatus o. very business like m
Appearance and does It's work
nicely.
me main switch hpa been placed
right utu the battery circuit 80
,nnt when closed u lights up all of
the nlameats and connects the
muguuyoX simultaneously This
MAKES I! possible TO adjust once
and not make adjustment again.
except Tor very sliEht variations
i'ur Instance. II was found that
with the maEuuyuN music came IN
very we'll and that with tho same
adjustment spoken words were D., -
c,tted loud but not clear. Ly de
tuning fhu last circuit IN, words
came distinctly but not so
load.
The Range
The Itndiotroia mas O. range with
its indoor loop and loud tuIkCr ni
about 20 miles. This can be great
~ increased where local conditions
are favorable. For longer ranges
another state OF radio frequency
ampliflcntion can be added. hut
this Is not used In the original in
firument Head receivers may hc
connected in that Will increase the
range to about 10 miles. The
range may Dee further iucrsaSd
with an outside aerial The iaticr
De- vol recommended a. Il dcprc-
ciat's the novelty and appearance
Of the set. II Is not essential that
"a mngnHyoN be used nny standard
loud talkor will be efficient.
The Amplificr
In conjunction with the loop
Aerial which acts as the tuner. =
combination radio and audlu-fre-
quoncy nmplifier il used. The cir
cult. fg. 1. shows In detail the con-
n,ctious between tho various cic-
mcnts which nre numbered for rof-
oroncc. In this circuit No. I a. tht
loop aerial, consisting OF n woodci
frame 20x1S inches and 81
inches Wide. wound with 10 turn'
Of LAtz wire. or small cable fin,
copper wire spaced one-half inch
upart.
No. . Is tho .GO1 inf tuning con
denScr with a small fixed capacity
Of Ou0b mr. ~ parallel which ms,
be connected by means OF a small
switch. with this capacity ths
range Of wave lengths which cns
be- tuned " from 2GO to coo meters
No. 3 Or o. potentioineter used ~
vary thu grid potential Of the tw,