illrrrrrrW

esults. The transmitter adj ustme nts may
affect the qua lity of th e modu lation, so
listen to the signal on a receiver to make sure
everything is to your satisfa ct ion. Now
connect t he flasher circuit. The Beeper
sho uld sta rt to beep off an d on . If it doesn't ,
check the flasher output with a voltmeter ; if
it is okay. chances are that the osc illator is
not breaki ng into oscillat ion. Readjust CIO
if this is the case.
When the Beepe r is connecte d to a 12V
volt power source, there should be enough rf
present to light the 4 7 pilot lamp to half
brilliance. My Beeper will opera te with less
than a volt. Don't be tempted to increase the
voltage to gain more ou tp ut. Th e unit draws
20 rnA when it is no t transmitt ing and about
ISO rnA whi le trans mitting.
Never operat e the Beeper wit hout some
form of load, an d try to provide as good a
mat ch as possible . Th e mo du lation qualit y
seems to be directly relat ed to th e qua lity of
the ante nna used , and a good antenna is also
cheap tra nsist or insur ance. Generally, the
transmitter will not have to be ret uned afte r
th e initial settings are mad e, and th e final
tun ing is quite broa d. A quarter wavelength
of wire will radiate a signal over several miles
of o pen te rrain. I was able to receive th e
signal two miles away fro m t he Beepe r with
a Lafay ette IIA-650 portable transceiver
using the whip antenna supplied with the
HA-650. With the same setup an d using the
Scrncter on th e HA--650 , I was ab le to locat e
the Beeper within a few fee t of where it was
hidden by a friend.
Th e Beeper can be put together in a
few evenings. Most of the par ts used are no t
criti cal, and it should be easy to find subst i­
tutes for most of them. Th e UTC transform
er which I specified for use in the
modulator may be difficult to find. If on e is
not available, almos t any high impedance
int erstage tr ansfor mer will work sati sfactorily
. If yo u desire, t he flasher circuit
and/or the modulator can be elimina ted
from th e Beeper.
The Beeper does its job well, and it can
pro vide its ow ner with many hours of fun .
Why no t build on e and then get t he local six
meter group toget her for an old fashioned
tran smit ter hunt? Happy Beeping!
... K lZJH
FEBRUAR Y 19 71
~ I
Mobile Antenna System
VSWR
GUARANTEE
of 1.5/1or better
Celebrati ng Our 25t h Year !
Mos ley Electronic s, Inc. takes
pri de in i nt roduc ing an Anniversary
- Spec ial ..• The new " Rode­
Master", featuring a GUARANTEE
of an adj ustable VSWR of 1.5/1
or better at any gi ven fr equency
on each band.
Desi gned for the economy - Minded
Ham. the new " Rode- Master"
offers a choice of 6, 10, 15, 20,
40, 75 &/ 0' 80 meters. The upper
tel escopin g Whip secti on doubl es
as a & meter ante nna complete ly
adjustable for t he entire band.
You select fro m f ive new prec i­
si on wound 400 Watt Coi ls for
10, 15, 20, 40 and 75/80 meter
operation.
Other Speci al Features:
Bumper or trunk mounting option
. . . Guyi ng dev ice for frequency
stabi lity at highway speeds . . .
Break - over (h inge) to lower antenna
. , . Rotate antenna 360 0
in
the break-over posi t ion. A conve
nience for easy co i I in ser ti on,
whip adj ust ments etc. . . . OX
Matching Network: Small, simple
to install and operate. The real
reason why Mosley can Guarantee
an adj ustable VSWR of 1.5/ 1 or
bett er.
Free QSO Index with the purchase
of a complete " Rode - Master" a n­
tenna sy st em, Get all the fact s,
See your Mos ley dealer or write
Dept. 206.
, J#I.,.le'l ~~
46'0 N. L t N OB ERG '"4 B L V O . BR I D G E T ON M O 630 44
59