How
would
you
like
to have a
knock-out
punch
on
our
low
est frequency band? You
have the makings in
Adding
The
your
shack.
160
Heath
may
already
Meters
58·220
To
Linear
BY ROBE
RT
Amplifier
G. EV
ANS'
, K6QAY
W hile wanting to put more power
than 60 to 70
meters
was decided
band
With
decided to go
periencing many problems such as
parasitic oscillations, failure
final to
ment supply, burning
diode and meier lights, I decided to
write this article so other interested
hams could take advantage of the
with
to
my Heath 220.
no information available 1
dip
watts
out a large expenditure, it
to
attempt to add the
it
on my
, r.f. getting
available on 160
low
own
oul
. After ex-
of
into
of
the fila-
the zener
the
through the 80 meter input. The pi network
resonant frequency. This eliminated the
need to change the band switches and
the addition
It was felt that
hole
160
tradetn value should you decide
upgrade at a later date.
You should add the chan ges
schematic on page 87 of your manual
and poss ibly add a copy of t
If
will
in the panel was
meter
you use your finear on 160 after
pass frequencies below its
of
a 160 meter input
the
feature can
drilling
justified
only
add to
his
coil
of one
, as
ar
to
tic
the
the
the
le.
.
to
1. Reducing
2.
Re
ducing
separating t
feeding the PAl
transformer fr
PAl
a variac voltage
Approximately 60 volts
primary
200 watt input range. I
voltage control is i
article. However, it is not necessary to
the 160 m conversio n. It may be plugged
intothe
of
will
the
wall
the
Mic gain,
plate transformer from
place you
or
exciter drive and
or
as I do by
he
om
filament supply
of
the wall plug the
control.
nc
a variac.
the filament
into
into
nf
luded in this
the 150 to
ormation on
the
countless
frustration I have been through .
Since the 220 has a pi network
it
was
'10509 Co
91344
dec
hours
ided
llett
Ave., Granada
of
10
work and avoid
drive
the
160 signal
Hills
the
input
CA
sundown you must remember to
reduce
the
reduce
limitations
power
the
input power
in order to stay within
for your area. You can
by
:
I hope you
joyable hours
had
ti
about
go to K6ZHJ, W6JUT, W6FVW and
W6FPV f
was testing this rig.
ons
with
mine. If you
the conversion should take
two
hours
or
pu
will
with
or
tti
ng
have as many en-
your linear as I have
follow
less. Thanks must
up
wit
the
h me while 1
direc -
Instructions
1. Remove r.t.
replace with a National
equivalent.
choke
part #45·fi1
R175
or
Left: The pane l
48 •
CO
_ _ _ _ I
posit
• February, 1979
ion
of
the added
the " 160" decal.
togg
le
switch
. Right:
Note
the
addition
of
2. Remove
replace w
your own as I did from page 155
the
book.'
' ThiS
(rom
St., N.
choke
KT-33'7)J
30-37·7)
choke
Amidon
Hollywood
kit
may
bifilar
ith
1978 Radio Amateurs Hand·
may be ob
Associat
[30 A., 1.8MH
or
the
be
ferr
obta
choke
B&W FC30A
tained
es, 12033
CA 91607. The
z (part
ite
ined
rod
separately.
part
in
number
(part
#45-78
or
make
kit
form
Ostego
filament
FL-
number
of
,
homem ade angle brackets. Bolt to
left hand perforated panel.
Installation of the "801160" toggle
switch.
6. Install one each
2,500 volt capacitor with a heavy
lead to the RH
variable C55 at fro
7. Inst all one each
2,500 volt capac
lead
variable
8. I
nstalla 4 pole doub le
gle
hole
top
the
switch
to
the LH
CS7
switch
to
clear
of
panel and 2-
pla
te
part #406N Newark
ti
tie
at fron t panel.
on front panel. Drill
switc
me
ter
.OOO15j.lFmica
e bolt of the
nt
panel.
.OOO75j.l
itor
bolt of the 840j.lF
wit
h 1"
to
.
Alco
F mica
h a heavy
throw
dow
the lett
250j.ol
n from
togg
stock
F
tog-
of
le
The
add
ed
160
~
meter
indu
ctor
.
3. Install one each.
capacitor a
C23 at filament choke.
4. Cut wires fr
go
ing to
capacitor C57.
5. Install 160 m
minidu
turns per inch, 24 turns needed. Install above C
cto
cross
om
output
r #3907·1 2"
S5
and
15j.olF
each
80 m
line and variable
indu
CS7
600 volt
of
C22 and
inductor
ctor
. B&W
dia
secure
L7
. ten
to
#61F878.
9. Connect the .
and the
with
ween term. #5 and
ground at left hand side
panel.
Note
heavy wire. Install
: You
.OOO75f,.Ftoterm. #10 both
the
cap
it was done purposely
sho
acito
rten the leads and pre-
OOO
might
gound
rs is a
15
j.lFto
term.
jumper
#6 run #5
think
mistake
breaking
of
bet-
of
side
these
but
#9
to
to
up position
the two capacitors and
shorts
the 80 m
positi
14. Install the 160decal to the right
the
panel. In
right of the toggle down position .
Install the 160 decal above the ex-
toggle
sta
out
on
.
up posi tion
ll the 80 decal
. It disconne
the 160 m coilin
toggle
of
down
front
to
cts
01
the
>PL
Fig. 1 -
the filame
Adding
nt
Added
a
and bias tran
cord
BlAC"/GR~~"
li
ne
cor
(
T2).
d and fus
sf
orme
ing
,
10
c
To
ord
T1
Fig.
3 · Wiri
,
regulated
1I
0e
•
Variac 120,140v, a.c.
r
60 cvcle.
Fig. 2 · Wiring the Variac.
20a
E~;5t
,og
C22
New
r
":'
ng
choke
1111
cn
r
1"
":'
the new cho ke.
•
left hand perforated side panel.
Slide one piece of 1/8
ptextqlass or any other insulat ing
material into the coil. Cement to
s
the coil
wit
h
tw
tiffe
o each 1- X 1- X
ners. Fasten coil
"X
17
/8X3
11
8"
vent a bad reaction prob·
-
10.
11
Connect a heavy wire fr
#4 to the input end of the n
il
co
term. #8 to the output end of the
oi
l.
c
. Bend one piece of buss or heavy
wire (must
stall fr
from chassis bo
th
wi
panel,
lem enc
m band.
, connect a heavy wire fr
be
om
in 2- of the left hand side
output of 80 m coil L7 1-
th
en bend upward and
ount
self suppo rting). tn-
ered on the 80
om
tto
m then to
term.
ew
160
om
15. 160 m will
16. When you wish the 160 band set
isting 80 m decal at the left side of
the resonating capacitor dial.
di
p fr
the high end of the 160 m band
ith
w
panel.
the band
The toggle to .160, tun e as you do
in the 80 m markings on the
sw
itc
om
h to 80 m position.
the l
ow
end to
toward the front panel to fit input
of
end
12. Bend 1 piece of
bet ween ou
disconnected outpu t wire and the
disconnect ed
capacitor.
13. Note: The new t
new coil.
tput
840j.ol
int
rodu ces the 160 coil and
the two capacitors in
circ uit in the 160 m toggle
heavy wire. insta
of
160
F C57 variable
og
gle switch
coilto
to
the
now
the
ll
, ,
0 0 0
,
,;,
Fig . 4 - Wi
,
To To
.00015 .00075
February
T09'Ile 5wi
e
"
ring
, 1979 • CO • 47
tch
,
,
0
..
the
:.-
J
•
"0 0
to
gg
~
le
swit
,,~
ch.
l
o
A
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