New-York tribune., 1922-04-09
Wave Length of Aerial.

ouestion--is there any way In wb,oh T
NJ uvtIeirdfs the natural wave length Of
incr1d;na us ioo feet long altogether
'H''uu'hS 1ne nat top.--A r
Answer-This can be done accuratslv
ohiy by means of wave meter. which
also celebrates the total aerial circuit
including the aerial inductance and ca.
pac'ty, 1t is possible, however. 70
iouehIy calculate the natural wave
Iehgth OF your aerial with sufficient ac-
.uf@cy 10 answer most requirements
assume that your aerial, from thr
ground connection to the free end ~
me aerial, is 100 feet. Multiply il bv
.he factor LA, and this will give YOU
me approximate wave length--in other
words, LA meters. Of course. as vou
VIII see, this does not take into consid.
eIa.ioh the tuning coil and condenser
; ;m". may De IN use in the circuit 1t is
Just simply q rough method az da+or
mining the aerial wave length. and aa
you undoubtedly know the maximum
wave length of your aerial tuner. YOU
Sah calculate roughly the total wave
lefgtn OF the aerial circuit by addinU
the two together.
on Using Radio Frequency
question. Can use a loon aerial with
one stage OF radio frequency and tvn
Tyases wats .; OF audio frequency: 2. win tho act
IL not what change must | maka so 90
TO use either aerial at wiIlp car 10
c9gSse con's coi's ons wave ienth by using honey
r. c. WIN 'he &erial'-
Answer-l. The application Of radio
frequency amplification to the reception
u nroadcasted music has not vet been
really developed. 1t depends at the
present time upon the development Of
speGia'iy tuned transformers to be
SEQ oet"een the vacuum tubes. When
1uiiy constructed. it will be quite nos
Slhie to use such a set with a loon
aerial, but in that case the usual re-,
eeneratlve circuit will not be NECESSARY
anu ,, cannot be employed. 9. The set
VIII work, OF course, with an outdoor
aer'al Just as we'll as with a loon
aerial. 3. You can change from one
aerial to the other by utilizing a sim
PIE change-over switch that YOU can
oeSign yourself. 4. If you are usinr
Iaolo frequency amplifcation | would
NO. aovlse the use of honeycomb
Io'lS. on can increase the wave
length or the ordinary regenerative
se' oy the use of honeycomb coils, in
sertlng the coils specially designed for
the wave length you desire to listen
to-, 3. If you insert the honevcomh
COZ IN series with the aerial it acts as
loading coil, but of course you can
not vary the inductance in that coil.
Combined Long and Short Wave Set
estion-i. Can 7 construct short
and longwave rcgenerative sci hv ns,nr
q Nariocoupler and two variometera ro-
NE short-wave and honeycomh coils for
t'i' iohs wave, with multiple change
over S"ltch from one set to the other ?
:. What is the correct size for a vario-
coupler tthat ls, what is the number Of
turns II should have)? 4 What sic
honeycomb coils should use for "I, H. sise az
'ereht wave lengths above 1000 meters :?
Answer. Yes, provided that YOUR
s"itch IS so arranged that it throws
out the variocoupler and variometers
and inserts the honeycomb coils into
thelr proper places in the circuit. 2.
FOR short-wave purposes the vario-
coupler should be wound with No, "a
double silk covered wire of sixty turns.
the first ten turns should be tapped
individually, and after that take tap
every fifth turn. These taps should be
connected to suitable switches, so that
you can obtain any number of turns
IN the primary circuit. The secondary
should be wound with fifty turns Of
No. rs DISC. The primary tube should
be about 3ia inches in diameter and
the secondary tube inches. 8. The
correct honeycomb coils to use for
long-Wave purposes are the following:
Wave Length Primary Secondary Tickicr
'nh Vail