The Challis messenger. (Challis, Idaho) 1912-current, 1925-11-18

Of resistance coupled application. Be
fore going. let It be said that the
resistance-coupled application en-
ployed should not be confused with
similar systems described in the past
because 1t is now possible to maintain
tone quality, for which this type OF
amplifier Is famous, together with
great volume, due to the foresighted-
ness of some of the tube manufacture
ers who are now marketing what are
known as high-Mu tubes. These tubes
are specially designed for resistance
coupled amplification and the ampl-
fication per stage which Is obtainable
with them is far greater than has
heretofore been generally possible
"As was mentioned above, tuning Is
accomplished by q single dial. This
dial Is used to control a Hanscom
single-control unit and Is the main
tuning control 1t is unique arrange
ment Of two Remler condensers, geared
together In q manner which makes
tuning Of the antenna and radio-fre-
quency circuits simultaneous. Tho
panel Is by Is inches and there ID
plenty Of room on 1t for all the equip
ment necessary, when a sub-base Ii
employed.
"The tuning inductances and the
variable condenser assembly, antenna
switch and battery switch are mounted
on the main panel, while all the re-
.fx,fr INN AnA 10 al on
top or bottom of 2h by 1711-inch
subpanel, which Is suspended from the
main panel by means Of Benjamin No.
900 brackets. On the upper side of
the subpanel are mounted the five tube
sockets, three resisto-couplers, the grid
condenser and leak mounting, and the
variable neutralizing condenser. 1t Is
also possible to find room for all the
binding posts, including those for the
three connections for the G battery, If
they ere thought to be desirable. On
the under side of the subpanel there
are five mountings which are used for
the f1lament ballast resistors. All these
points are clarified by the illustrations
of the original article in Radio Broad
cast Magazine.
Lists Of Parts.
The list Of parts used Is as follows:
One by IS panel.
One 21s by liz subpanel.
One Hanscom 8. G. condenser unit
One set Eastern knockout coils
One Carter filament switch.
Two Apex knobs.
Five Benjamin sockets.
Three Daven resisto-coupIers with
three L megohm resistors and one
each 1 meg, 8 meg. and % meg. re-
sisters.
One Hammarlund neutralizing con-
denser.
Two .004 Sangamo fixed condensers.
One Dubilier IS microfarad bypass
condenser.
Six Daven No. so mountings.
One Daven leakandenser Ga new
unit which combines the grid con-
ienser and leak).
Five Daven ballast resistors (the
of these resistors depends on
he type Of the tubes used).
One Belden standard color, five wire |
,able.
Two Benjamin No. 600 brackets.
Two to six Eby binding posts.
Two dozen 6 or 8-32 round head |
,rass machine screws, X inch long.
About six 2-foot lengths of bus bar |
1.-The five ballast resistors are shown
n the diagram as R1-2-3-4-5. The Sc
ection Of these will depend entirely
IN the types Of tubes employed. The
deal combination of tubes consists In
he use of two ordinary six-volt stor-
zee battery tubes for the radio-fre-
uency amplifier and the detector, two
igh-Mu tubes for the first two stages
( audio, with a semipower tube in the
irst stage. Some tubes will work
without any resistance In
he filament circuit when used as am
liflers."