W4NFR AMPLIFIER PROJECT
Pair of 3-500Z Tubes
"Stone Creek Special"



Finished Amplifier and Power Supply







                                                                                                                                                            
                                                                                                               Top View











                                                                         Bottom View Showing Tube Sockets and Filament Choke








                                                                                                Side View of HV Power Supply









                                                                                              Front View of HV Power Supply







                                                                                                                                                  Power Output





See the write up  after the Schematics and Photos
:


                                                                                                                                                                                                                                                                                                                                 


                                                       AMPLIFIER RF DECK




                                                                                       AMPLIFIER RF DECK







                                                HIGH VOLTAGE POWER SUPPLY





                                                                                  HIGH VOLTAGE POWER SUPPLY







WRITE UP  & DESCRIPTION


STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


The following describes a 160-10 meter linear amplifier that uses a pair of 3-500Z triode

power tubes. It was designed and constructed by William Moneysmith, W4NFR. The

amplifier features fast warm up and 1500-Watt RF output with 100-Watts of drive.

The 3-500Z is a relatively inexpensive tube and has been around for a long time.  Each

tube has an anode dissipation of 500 watts, 20-Watt grid dissipation and plate voltage up

to 4000 volt.  Each tube has a 5 Volt/20 Amp filament requirement.  With plate

dissipation of 1000 Watts they are not as rugged as some more expensive tubes.

However, in SSB service, they are rugged dependable workhorses and much less

expensive to replace this day and age. The amplifier can be easily duplicated and

provides full output. There have been many amplifiers built around the popular lineup of

a pair of 3-500Z tubes.  This amplifier incorporates improvements and has a different

look. A matching 3200 VDC adjustable HD power supply is included.

The amplifier uses a conventional grounded grid design. The input tuning uses a

commercial computer-controlled input tuner, model LDG-Z11Pro, from LDG

Electronics. (www.ldgelectronics.com)  and really simplifies the design and eliminates

the need to manually tune the input.








Page 2

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


The output is a pi-network using two air wound coils for 10 through 80 meters and a

toroid coil for 160-meter operation.  The tune and load capacitors are air variables.  There

is a heavy-duty auxiliary ceramic switch (S2) to add 100 pF of fixed capacitance for 160

and 80 when needed.

Cooling is accomplished using a 4” muffin fan, which provides 120 CFM around the

tubes. The ambient noise is minimal.

Chassis and cabinet can be made or purchased.  My amplifier has a small physical

appearance, using a gutted out Heathkit SB-220 chassis and cabinet obtained from Ebay.

The cabinet is well ventilated and rugged.  Using the old chassis saved many hours of

metal work.  The amplifier package is very compact, but did yield some challenges

during construction.  A new front panel was made from an old aluminum rack panel and

custom fitted to the old Heathkit chassis.

The RF deck required a new front panel to accommodate the mounting of the tune, load

capacitors, auxiliary switch, meters, and band switch layouts.  Fortunately, the original

chassis provided shielding for the meters. A Greenlee chassis punch was used for cutting

the meter holes.








Page 3

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


The amplifier project was constructed in my garage using basic tools.  The  tools include

a band saw, jig saw, drill press and common hand tools.  One can build your own cabinet

and chassis, but I purchased the old Heathkit cabinet and chassis on Ebay for a very

reasonable price.  New commercial cabinets are expensive, so I would recommend

buying used at a Hamfest to save money.  A fresh coat of paint will do wonders for an old

cabinet!

It is wise to collect all the parts needed before construction.  This will help you determine

how to layout the amplifier.  I started the project by mounting the tube sockets; filament

choke and transformer, barrier strips, switches, meters, relays, cooling fan, control cable

chassis connector, and HV flanged connector.

Once the components are in place you can start wiring the amplifier. On the amplifier

deck is a 12 Volt DC regulated power supply to provide power to the LDG input tuner

and the two 12 VDC relays for PTT operation.

The meters have custom scales made using a great piece of software called METER,

available by downloading from James Tonne, at  (www.tonnesoftware.com).  The amplifier

deck uses two 1 ma meters.  I made one scale for the grid and one for the plate current.

The scales were printed on inkjet printer using photo paper. You can add your call sign

and customize the scales and colors.  Also, used this program to make the tune, load and

band switch labels.






Page 4

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


The tube filaments are powered by the T2 Transformer, which provides 5 VDC @ 30

Amp. of current to the RFC-4.  When S4, the Filament on/off switch, is activated, the B1

Fan, the T2 Filament XMFR and the Low Voltage 12 VDC power supply is activated.

The filament voltage is adjustable using a small VARIAC TRANSFORMER (T3).  Using

a very accurate meter, measure the XMFR (T2) T.P. for 5 VAC.  A 5 VAC filament will

last a long time.

The 12 VDC PS powers the input/output and bias relays.  The RF in and out relay is

energized first and then the bias relay is energized last.  The 10K (R1) biases the tubes to

cut off in standby receive mode. A 7.5 @ 50 Watt Zener diode is mounted on a heatsink

and used for bias and limits the idle current.

I used the LDG-ProII to automatically tune the input to the pair of 3-500Z tubes.  I

bought and removed the original cabinet.  Then I constructed my own custom box made

from G-10 PC board, to provide a shielded compartment for the tuner and move the

operating controls to the top.  BNC female chassis connectors were added for easy

connection of the in and out cables.  A connector for the 12 VDC was added and a pair of

wires brought out for remote manual start from the amplifier front panel.  With the

thousands of memories, I never have to retune. The tuner works great and simplifies the

input-network design, construction and operation.





Page 5

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


SPECIAL DETAILS

RFC-1 Plate Choke is a ferrite loaded RF Plate choke using a value of 275 uh and used

To eliminate any resonance in the Ham bands. This lessons the chance of parasitic

oscillation.  The ferrite RF choke is wound on Teflon or Delrin with ferrite embedded

inside the Teflon making a very compact choke.

The control cable between the amplifier and the power supply is accomplished using

“Daniel Woodhead” MOLEX cable and panel mount receptacle.  A female panel mount

receptacle, (Part # 1R5004A20A120), is mounted on the rear of the amplifier deck.  A 6

ft. cable with matching male connector, (Part # 105002A01F060 male 6’), run from the

high voltage power supply and connects to the amplifier deck. This is very high quality

cable and panel mount. Lesser quality can be used and not critical, but good quality 16

AWG wire and connectors is recommended for dependability.


AMPLIFIER CIRCUITRY

The two 3-500Z tubes are connected in parallel. Each of the three grid pins of the tube

sockets is grounded to the chassis. The drive signal goes to the filament circuit of the

tubes, which is isolated from ground by a bifilar RF choke (RFC-4).  Mica capacitors

(C1, C2) are used to distribute the driving signal to the filaments of the tubes.

 



Page 6

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net



In the plate circuit, plate high voltage is applied to the tubes through a heavy-duty RF

ferrite loaded choke (RFC-1) and resistor (RFC-2). Two 1000 pF @ 12 kV ceramic

doorknob capacitors is used for the high voltage plate blocking capacitor. The PC-1

and PC-2 are made using two 5” # 10 copper wires, bent in a U shape.  They

are  2” x 1” x 2” and  a 56 ohm, 2 Watt resistor is soldered across the input of the U

shaped wire.

The pi-network coil is divided into three parts for highest efficiency and ease of

assembly.  The first portion covers 10, 15, 20 meters, and a second coil is added to the

first to cover 40 and 80 meters.  A third toroid coil is added to cover 160-meter band in a

compact manner.

The band switch  (S1) was obtained from Ameritron Parts (MFJ).  Use a switch with

heave duty contacts or one with dual contacts to handle the voltage and current.  For this

amplifier, I use a 6-position switch for covering 10 through 160.  It has auxiliary contacts,

so extra capacitance can be added for 80 and 160 band loading.

Tuning capacitor (TC-1) is 15-56 pF, so for 80 and 160 an auxiliary (S2) heavy duty

switch will add 100 pF to the tune range.

Loading capacitor (TC-2) is 25-840 pF, so for 80 and 160 an additional 100 pF is added

to the range. RFC-3 is for safety and provides a path to ground if a component fails.





Page 7

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net




My desired plate load resistance is a 4700 ohms for each tube.

            Ep                      3200
RL=  ______    =   ____________   = 4700 ohm Plate Load   
           1.7 x Ip            1.7 x  .400




TABLE 1 shows thc coil and tap data.  This is course setting data and optimum results

can be obtained using the method described below.

Pi-Network coil taps are easy to perform.  I suggest the use of an MFJ-269 HF/VHF/UHF

SWR ANALYZER to find the best coil tap for each band.  A 4700-ohm resistor is

secured from the finned anode of each tube to ground.  The MFJ-269 is connected to the

output coaxial SO-239 connector. Manually activate the in/out RF changeover relay (K2-

A, K2-B) to the send position.  Set or adjust the TC-1 and TC-2 capacitors and tune the

MFJ-269 frequency adjust to obtain the best SWR.  The frequency of best SWR indicated

is the tap resonance and you can tap and readjust until optimum tap is achieved.  This

method works great.  When finished, remove the two 4700 ohm resistors from the two

anodes.









Page 8

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net



HIGH VOLTAGE POWER SUPPLY

The High Voltage power supply was built from scratch, using a 1-ft x 2-ft x 3/8”

Aluminum base. This PS is heavy when loaded with the Variac, Transformer, Capacitors

etc., so four heavy-duty castors are mounted on the bottom for support and mobility. All

the heavy components are mounted on the base plate.

The PS is built in a separate cabinet using the castor base and is connected to the RF deck

using a 5-conductor control cable, with a separate high voltage (HV) cable.

The power transformer has multiple primary taps (220/230/240 VAC) one secondary. 

The output voltage is adjustable from 0-4500 VDC using a large Variac (T4).  I use 3200  

VDC to power the pair of 3-500Z-tube amplifier.  A step-start circuit is included to

protect against current surge at turn on that can damage the diode bank.

The high voltage power supply provides 3200 VDC underload. It uses a fullwave bridge

rectifier and is filtered using a total of 52 uF @4 kV oil filled capacitors.  Whenever the

HV supply is plugged into the 240-volt line, it will not operate until activated by the RF

deck.  120 VAC originating from the S4 Plate on/off switch will turn on the K-1PS relay.

The step-start relay will then activate and the HV light on the amplifier deck will light on

the S4 switch in about 2 seconds.





Page 9

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


HV B+  is monitored using metering.  Two resistors and a pot for calibration is used to

feed a 0-5 kV meter (0-1-mA movement). The movement is 1000/volt, so I used two 2.2

Meg @ 2 Watt resistors, plus a 1 Meg @ 2 Watt adjustable  pot in series to feed the

meter.  All the PS meters were obtained at Hamfests and are off-the-shelf meters. These

include 0-300 VAC Primary voltage, 0-5 kV High Voltage and the Hours On meter. The

HV cable between the RF deck and the power supply is made from a 6-ft length of HV

insulated wire obtained from R.F. Parts.  The connectors are MILLEN HV female on

the panels of the RF deck and the PS.  The HV cable uses male MILLEN HV connectors

on the insulated wire.


AMPLIFIER TUNING

I prefer to use a device called a “Pecker” to tune all my amps safely.  These pulse devices

will get you in the ballpark without stressing the tubes.   The Pecker is used to tune your

amplifier in the SSB Mode without a CW or AM RF carrier. The Pecker is a single

pulsed tone that works with a 70% off & 30% on duty cycle with your transmitter in the

SSB Mode. This short duty cycle allows you to take your time on tune-ups (or testing of

your amplifier, antenna, or other equipment), with very little chance of tube damage,

power supply stress, and arc-over with your amplifier, or tube transmitter, like you have

using a CW carrier. The Pecker allows you to tune your amplifier to full Peak Output

Power quick and easy.





Page 10

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


You will never go back to the old "Peak & Dip" tune-ups with a CW carrier for drive

once you have used a "3898 Pecker". Ask those who use a Pecker and they'll tell you that

for speed and ease of tune-ups, you just can't beat the Pecker. 

Read some of the reviews they posted at http://www.eham.net/reviews/detail/5121 .

The 3898 Pecker uses a single pulsed tone through the radio's SSB MIC audio circuit,

thus tuning your amplifier in SSB MODE for SSB OPERATION. You must use a PEP

Watt meter when using the 3898 Pecker because the short duty cycle won't let the

average reading meters show the full out-put of the amplifier. Thus making it harder to

see when the RF hits its peak out-put. The website for Mr. Pecker is:  

http://www.3898pecker.com

The Operate/Standby switch (S5) must be switched to the Operate position.  Once you

have performed your initial tune-ups, make a “Tune” preset chart-showing settings for

each band. This will save time in the future operation.

I would suggest not driving more than 200 ma Grid current and no more than 700 ma

Plate current.  A 100-Watt transmitter will drive this amplifier nicely without

overdriving.


Thanks to LDG Electronics, Varian for tube data, Ebay, Molex (Daniel Woodhead), RF

Parts, Ameritron MFJ, Henry Radio, ARRL and Mr. Pecker Electronics for parts

information and references.





Page 11

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net



TABLE 1

COIL DETAIL:

L1 = 2.125” ID. ¼” copper tubing, 9 T, 4” long.

L2 = 2” ID. 21 T # 14 wire, 6 TPI, 3.5” long.

L3 = 27 T # 12 Teflon wire, (3) 2” Ferrite Cores. Use Fiberglas tape to wrap cores.


Tune Capacitor End:__
                                        )
                                        )
                                        )---------2.5 T     (10M)    1.8 uh
                         L1          )
                                        )---------4.4 T     (15M)    2.3 uh
                                        )
                                        )---------7.4 T    (20M)     3.2 uh
                                        )
                                   -- I
                                        )
                                        )
                                        )
                         L2          )--------18.0 T    (40 M)   7.4 uh
                                        )
                                        )
                                        )
                                        )
                                        )----------28.0 T (80M)   12.6 uh
                                   -- I
                         L3          )    (27 T Toroid (3) 2” Ferrite Cores)
                                        )
 Load Capacitor End__)------------------(160 M)  36.0 uh
 


                                      

Page 12

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net



POWER SUPPLY CABINET

The Power Supply is built on a 1ft x 2ft x 3/8” Aluminum base with 4 HD casters

mounted on the bottom.  The cabinet is made by using ½” angle Aluminum to frame in

the 1 ft x 1 ft x 2 ft cabinet.  The frame is covered with perferated Aluminum sheeting on

the two 1 ft x 2 ft sides.  Solid Aluminum sheeting is used for the 1 ft x 1 ft end and rear,

also the 1 ft x 2 ft  top.  A fan and EMI filter screen is mounted on the side of the PS to

ventilate the interior.


List of Materials:

Quantity:                    Description:

 (1)        1 ft x 4 ft  Perferated Aluminum  0.062” thick sheet.

(1)       1 ft x 4 ft  Solid Aluminum 0.062” thick sheet.

 (1)       12 ft Long Aluminum ½” Angle Stock.

 (1)       1 ft x 2 ft x 3/8” Aluminum Base.

 (4)       2” Heavy Duty Casters.









Page 13

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


Amplifier Parts List:

V1, V2    =     3-500Z  Triode Vacuum Tubes,  RF Parts.

C1, C2    =    .01 Mica Capacitor, Micamold. CM45B103K

J1, J2      =     SO-239  Chassis Mount.

J3            =     Phono Jack, Panel Mount. (PTT) input.

C3-C7     =     .01 Ceramic Disk, 600 VDC.

C8, C9     =     .01 Ceramic Disk, 1.6 kV.

TC1         =      TUNE CAPACITOR, AIR VARIABLE, 15-56 pF, RF Parts.

TC2         =      LOAD CAPACITOR, AIR VARIABLE, 25-840 pF, RF Parts.

C10, C11 =      .001 mF @ 12 kV, Door Knob.

C12          =      .02 @ 5 kV, HV Plastic Capacitor.

C13          =       .001 @ 5 kV, Door Knob, HEC.

C14          =       680 pF @ 6 kV Feed-Through  Capacitor.

C15          =       100 pF @ 15 kVDC N750, Door Knob, HEC HT57

C16          =       100 pF @ 5 kV, Door Knob, HEC

C17          =        50 uF @ 50 VDC. Electrolytic Capacitor.

C18, C19 =        .01, 600 VDC, Ceramic Capacitor.

C20          =        0.1 @ 50 VDC Disc Capacitor.

C21          =        20 uF @ 50 VDC. Electrolytic Capacitor.






Page 14

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


Amplifier Parts List:

C22      =               1000 uF @ 50 VDC, Electrolytic Capacitor.

FT-1 thru 5  =      .047 uF @ 10 Amp, Filtron Feed Thru (5 Items)

PC-1, PC2    =      Parasitic Choke, (2) 56 ohm, 2 W. Resistor (Non-Inductive).

                             Two pieces of  5” Long, # 10 Wire, Bent U Shape, 1” x2”

Tube Sockets  =  Two Ceramic,  3-500Z, Johnson Flat, Ebay or RF Parts.

T1A                  =  Low Voltage Transformer, 120 VAC Pri, 14 VAC Sec @ 1 Amp.
                      
                             RF Parts.

T2                      =  Filament Transformer, 5 VCT, 30 Amp. RF Parts, 167x5

                               Hammond Mfg.

T3                      =  Small Variac, 120 VAC. Ebay.

HR-6                 = Two  HR-6 Tall, Transmitting Tube Plate Cap Radiator.

RFC-1                = PLATE RF CHOKE, 275 uh, Ferrite Loaded. Ebay.

                              Contact: Ron  Brown,  Ron@rgb52.com

RFC-2                 =  10 OHM, 20 WATT RESISTOR.

RFC-3                 =  2.5 mh, 500 ma, multilayer choke, Miller, National, Hammond.

RFC-4                  =  BIFILAR 30 AMP FILAMENT CHOKE, Ebay, RF Parts.

S1                         =  Bandswitch, 6 position and three Aux contacts, Ameritron
        
                                  (Dual HD Contacts)





Page 15

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


Amplifier Parts List:

S2              =      HD CERAMIC, SPDT HV RF SWITCH. HAMFEST, EBAY

                           MUST HAVE WIDE SPACING ON THE CONTACTS TO
     
                           PREVENT ARCING.

S3              =      Pushbutton Switch, N.O. Momentary On.

S4              =      Pushbutton Switch Assy. Consisting of two switches and one light.

                           Molex Mfg. 125 VAC @ 8.5 Amp switches and 125 VAC Lamp.

S5               =      SPST Toggle switch. 125 VAC @ 5 Amp.

K-1A           =     Bias Switching, DPDT, 12 VDC Coil, Potter Brumfield AMF

                            KT11D. 

K-2A & B   =     RF Changeover Relay, AMF, Potter Brumfield Div, KT11D,

                            12 VDC coil. Small HD, DPDT, 10 Amp Contacts.  Or Equil.

D1 – D5       =     1N2007 Diode, 1000 piv, 1 amp, RF Parts or equil.

D6                =     Diode Bridge or 1 amp diodes for a full wave, MDA3500, RF Parts.

ZD-1            =      Zener Diode, 7.5 Volt @ 50 Watt, 1N2805A. RF Parts.

HS                =     Aluminum Heatsink,  2” x 4” x 1”

B1, B2          =     Fan, 4” , 120 CFM, 120 VAC, “Sunon”, 4.7” x 4.7” x 1.5”, RF  

                             Parts.  W/AC cord and plug, finger guard and EMI filter screen.





Page 16

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net

Amplifier Parts List:

IC-1            =     7812,  12 Volt Regulator, 3 terminal.

F1               =      1.5 amp Fuse and Holder.

Terminal Blocks  =  Three 12 terminal barrier strips or equil.

CB-1, CB-2   =    10 AMP CIRCUIT BREAKERS, 120 VAC.

AC1             = PLUG & CORD. 120 VAC, 15 AMP. USE GOOD QUALITY # 12

                         WIRE AND INSULATION, 6 FT LONG.

LDG TUNER =  Modified LDG Model Z-11Pro Autotuner, 

                             http://www.ldgelectronics.com

RG-142B      =  4 ft long, Beldon 83242, 50 ohm Teflon.

BNC              =  Two Male connectors to fit RG-142B cable.

FB-43            =  5 Ferrite Beads (FB-43).

M1, M2         =  1 Amp Meter Movement. 2” Face.

TP                  =   Two Meter Test Points.

R1                  =   10 k@ 25 Watt Resistor.

R2, R4           =   50 ohm @ 20 Watt.

R3                  =   27 ohm @ 1 Watt.

HV Cable      =  Two Millen Female Chassis Red Part #  37001D (RFParts).
                           Two  Millen Male Plug HV Connector Red Part # 37001C

HV Wire        =  20 ft of  HV-30, 60 kV Breakdown, 20 AWG, (RF PARTS).






 Page 17

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net

Amplifier Parts List:


Control Cable 
And Panel Mount
Receptacle                  =    6 ft long, “Daniel Woodhead” MOLEX Cable, 5 wires.
                                           Part # 105002A01F060 (Male)
                                           Panel Mount Part # 1R5004A20A120 (Female)

L1, L2, L3      =  SEE TABLE 1 FOR DETAILS.


HIGH VOLTAGE POWER SUPPLY PARTS LIST:

P-1      =     240 VAC MALE PLUG AND 6 FT CORD, # 10 WIRE.
                   (2 WIRE + GROUND) NEMA.

F1, F2    =   15 AMP, 120 V FUSE.

F3           =  ½ AMP, 120 V FUSE.

DF          =  DELTA FILTER, RF PARTS # 20DCGS4 20 AMP EMI.

K1PS, K2PS = 120 VAC RELAY, RF PARTS # W99AX5, MAGNICRAFT, DPDT
                    25 AMP CONTACTS  OR CONTACTOR RELAY.
                    PB PRD-11AYO-120.

T4           =   Large VARIAC, 0-240 VAC, 8.5 AMP. (WESCHLER INSTR)  OR
                     Equil.  Ebay.

T1           =   High Voltage Transformer, 220 VAC INPUT, 3057 VAC OUTPUT @ 1
                     AMP. ( HARBACH ELECTRONICS, info@harbachelectronics.com

M3          =  0-300 VAC, WESTON 476 METER.

M4           =  TIME ON HOUR METER (Hamfest).

M5           =  0-1  mA Meter, 1000 ohms/ volt, 0-5 kV. (Hamfest).

D1-4         =  High Voltage Diodes, VIRO 60, 10,000 VOLT@ 1 AMP.






Page 18

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


HIGH VOLTAGE POWER SUPPLY

PARTS LIST:

C201, C202   =   10 uF @ 4 kV, OIL FILLED HD.

C203, C204   =    16uF @ 4.5 kV, OIL FILLED HD.

R201 – R204  = FOUR  50K @100 WATT WITH MOUNTING CLIPS.
                            DALE, RF Parts, HL100-06Z-50K,  6.5” X 7/8”

R205               =  50 OHM @ 30 WATT, MEMCO, DALE, RF Parts.

R206               =  1 MEG @ 2 WATT POT.

R207, R208    =  2.2 MEG @2 WATT. DALE

R209                = 47 OHM @ 55 WATT, DALE, Hamfest.

FB-77               = FERRITE BEAD # 77, AMIDON or equil.

C205                 =  .001 @ 7.5 kV CERAMIC CAPACITOR.

R210, R211      =  25 OHM @ 25 WATT, DALE, HLW12A1Z2S, RF Parts.

PL1, PL2          =  120 VAC, PILOT LIGHT.



WARNING !  Always use caution when working on an Amplifier or Power Supply.
High Voltages are present and can kill.
Use extreme caution and common sense when using this type of equipment.







Page 19

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


BIO:


W.G. Moneysmith, W4NFR, has been enjoying HAM radio as an Extra class licensee since 1961.  Bill enjoys all facets of radio, especially AM, CW, PSK-31, RTTY, Packet, DSSTV, QRP and chasing DX.   He is an avid electronics and Ham radio enthusiast, with a particular interest in antennas.  He has written many technical articles and is a retired Electronics Engineer. Current activities include RV camping/traveling,  gardening,  wood carving,
gold panning,  and metal detecting with my wife Lydia.







FIGURE  CAPTIONS:

TABLE 1  -  Pi-Network Coil Detail.










Page 20

STONE CREEK SPECIAL
(2) 3-500Z HF AMPLIFIER
By
William G. Moneysmith, W4NFR ; w4nfr@earthlink.net


REFERENCES:

RADIO HANDBOOK
22 nd Edition by William I Orr, W6SAI
Page 22.19 to 22.27

ARRL Handbook, 2006
Page 18.29 – 18.37
3CX1500D7 RF LINEAR AMPLIFIER
BY Jerry Pittenger, K8RA

Molex “Daniel Woodhead”
Catalog – Panel Mount Receptacles
Cables with Connectors
http://www.woodhead.com/eCatalog/Product

Henry Radio 2kd-5 Amplifier
11240 W. Olympic Blvd.
Los Angeles, Calif 90064

RF Parts Co.
435 S. Pacific St.
San Marcos, CA 92078

SAMS Radio Handbook
23rd Edition By William I, Orr, W6SAI
Page 17-8 to  17-14

ARRL Handbook, 1999
Page 13.1 thru 13.47

ARRL
Handbook, 1981
Pg. 23-11

Amplifier Tune-Up Safely
Mr. Pecker Electronics
http://www.3898pecker.com





The End