DEMI 3-3PACK User guide

/Kits/3-3pack.doc 1 Rev. D 11/24/2008

DEM Part Number 3-3 P A C K

3 Watts, 10 GHz Linear Amplifier Complete Kit

Specifications

Frequency range:

10.0 - 10.5 GHz

Power Out (at 1 dB compression):

3 Watts nominal

Power Out (saturated):

>3.5 Watts

Power Input for rated power out:

<20 mw for linear operation. <30mW

Return Loss:

>10dB @10.368 GHz

DC requirements:

13.8 volts DC @ 2 amps. for nominal output
15 volts DC absolute maximum

Connectors:

SMA(F) only

Size:

3” L x 2” W x 2.5” H

Active devices:

FMM5061VF (Eudyna)

Keying Option:

PTT High or Low

Kit builders Checklist and Requirements

This kit is a simple 3 CM power amplifier but it requires some basic knowledge of FET
operation and microwave principles. This amplifier will generate a minimum of 3 watts of power in
the 10 GHz region. This amount of power could be harmful if not used correctly. Correct safety
procedures must be maintained while aligning and using this power amplifier. This amplifier
should never be operated into a open or un-terminated load. Quality coax and coaxial devices are
required to test and align this kit. If you do not have any microwave construction experience, it is
suggested that you return this kit and purchase a assembled version. Proper alignment of this kit
requires a quality RF power meter that is specified to be used in the 10 GHz region, a accurate
volt/ohm meter, a 50 Ohm load capable of dissipating 5 watts at 10 GHz, a 12-15 volt, 3 amp
power supply, and a 10 mw driving source between 10 and 10.5 GHz. Any thing less than this will
not ensure proper alignment and operation of this power amplifier kit. Improper assembly or
alignment may cause premature failure of the active devices used and improper use of this
product may cause harmful injury.

IMPORTANT!

The FET supplied with this kit is tested and the data is supplied with the packaging. We
have had a 100% success rate with the FMM5061VF and do not foresee any problems in the
future. Therefore, because it is in a kit, we can not replace this FET if it fails for you. If it fails, we
assume it is because of improper assembly or testing. If you find this statement uncomfortable,
return the kit for full credit towards an assembled version. The FET is approximately 60% of the
price of this complete kit. You may purchase a replacement or spare at anytime but we feel it
should never

be required!

Pre-Assembly

This kits is supplied as a complete kit only. Any deviation of assembly or misuse of
components will void any technical assistance provided by Down East Microwave Inc. Read all
assembly instruction before starting assembly. If you have a question about a procedure
(assembly or test) please call for technical assistance before starting the assembly. Be sure about
what you are doing first!! Check all components with the parts list and begin when ready!

/Kits/3-3pack.doc 2 Rev. D 11/24/2008

Assembly

1. Prepare the PC board by installing copper foil on the ground plane side beneath the RF input
and output connectors. This foil improves the ground connection of the PCB to the enclosure
and RF connectors. See Figure 1 for proper assembly. Make solder connections as smooth
as possible. File smooth if necessary.

2. Install the PCB on the pallet using the three mounting holes located by IC2’s mounting position
with 3-48 x 3/16” screws. Do not tighten. Now install 4-40 x 3/16 screws in the corner holes of
the PCB. Be sure the copper foil will cover the connector mounting holes on the ends of the
pallet and the machined pocket in the heat sink is aligned with the FET hole in the circuit
board. Bend the copper foil down over the pallet sides and verify that it is flush with the
surface. If the circuit board has a bump in it or the foil will not fit smoothly to the pallet, you
may need to file or compress the solder by gently taping with a small hammer. Be careful!!!
NOTE: We use the hammer in the factory! Solder compresses easily.

3. Using the component placement guide and the parts list, install all components on PCB except
for R7, IC2, and D3. Keep the PCB as flat as possible during assembly. Flexing the PCB
during or after assembly may fracture and destroy surface mounted components. See Figures
2,3, and 4 for proper pin prepping of K1, IC1, and R2. All components are surface mounted.
Do not place any ground connection leads through any via holes! Be sure of the polarity of C4.
Solder them on the top surface only. After assembly is complete, inspect the sides of the PCB
for solder that may have “puddled” on the edge of the board. Remove the excess.

4. Prep the RF connectors by removing the Teflon extension and trim the pins to approximately
3/16” long. Install the SMA connectors on the outside of the housing l using 3-48 x 3/16”
screws in the threaded holes. Just snug the screws do not tighten. Now install the RCA
connectors on the sidewall without the washer or nut.

5. Place the housing on top of the heat sink assembly with the RCA connectors on the IC1 side of
the circuit board. Align the housing with the circuit board by centering the connector pins with
the input and output connections on the circuit board. If the copper foil is correct, the housing
will fall into place and the bottom connector holes will line up with the mounting holes in the
pallet behind the copper. Use a sharp object and puncture the foil through the connector holes
and then insert the four 3-48 x 3/8” screws. Now this may be difficult because of alignment of
the pallet screws. You may need to place the assembly in a clamping device such as a vice
and “Squeeze” the housing down onto the pallet compressing the PCB on it’s edge. Now install
all of the connector screws and tighten being carful of the SMA pin alignment.

6. Inspect the IC2 pocket in the pallet and remove any debris that may have become trapped. It
is extremely important that this surface is clean and flat before installing the MMIC. Apply the
smallest amount of Thermal compound (heat sink grease) as possible to the bottom of the
power FET. It should be a transparent layer. Wipe any excess off with a cotton tip applicator
or the excess will migrate up to the circuit board after assembly of the MMIC on the pallet.
Install the MMIC in the heat sink pocket aligning the leads as shown on the component
placement. The leads should line up close to the center of the microstrip on the PCB. Install
two 3-48 x 3/16” screws. Do not tighten.

7. Use Teflon wire to make connection from RCA connectors to the indicated points on the PCB.
A large gauge and a small gauge wire is connected to the +13.8VDC input jack. The small
gauge connects to the E6 pad on the PCB. The large gauge connects to the E11 pad. You
should at this time decide if you want a PTT to ground (E5) or a PTT high (E4) and wire it
appropriately to the second RCA jack. Use the lighter gauge for the PTT (push-to-talk). Also

/Kits/3-3pack.doc 3 Rev. D 11/24/2008

wire the +5VDC jumper. (E10 to E9) with the light gauge. Then using two 1- ½” piece of heavy
gauge wire, connect one end to the E7 and E8 pad.

8. Solder the RF connectors. Be sure of their connections. Verify the pins of IC2 are still aligned
and the flange screws are tight, and then solder all pins. With a very short piece of solid wire
from a leaded component,( One of the diodes) connect both pin 4 and pin 6 of IC2. Do this by
making a short loop over the RF line as close to the IC as possible. Inspect for shorts. Install
R7 on the output connector wall using two 4-40x ¼” screws(remove the 4-40’s mounting the
PCB to the pallet). The resistor is treaded. Then install D3 as shown.

Testing

1. At this time, the only missing component in the amplifier is the wire jumper from R7 to E8. With
a Ohm meter, verify that IC2 is correctly installed and not shorted during installation. The gate
(or Pin 1) is high impedance and if R2 was not installed it will not measure in the Mega-ohm
region. The drain (or Pins 4 and 6) should measure only a ohm or two. It is difficult to verify if
it is shorted so measure a few times to be sure. If the ohm meter test are OK go to step 2.

2. The amplifier requires a single 13.8 volts DC supply with a minimum 3 amp rating for the next
test. Connect the power supply to the 13.8VDC connector. If you have a current limiting power
supply limit it to 500 mA. All measurements are referenced to ground. Measure all +13.8VDC
connections. If your power supply is less or more than 13.8VDC, all of the +13.8VDC voltages
points will be your power supply voltage. Do not exceed 15.0 VDC or attempt to operate with
less than 11 VDC. Now measure VR1 and confirm it is operating at 5 volts (± 0.3VDC). Then
check IC1. Measure the circuit for negative 5 VDC (± 0.5 VDC) at the junction of C4 to ground
and positive 5 VDC at the junction of C12 to ground. Then measure the voltage on the gate
lead (Pin 1 of IC2) directly and adjust R2 for maximum negative voltage. (-5VDC ± 0.5 VDC). If
OK, key the PTT-L or -H and measure the voltage on R7 to verify that there is +13.8 VDC (or
the power supply voltage!) Un-key the PTT and the voltage should slowly bleed out. You may
short the output of R7 to ground to be sure it bleeds off. This slow bleeding will not happen
after R7 is connected to E8.

3. Remove the DC power supply connection and install the large gauge wire from R7 to E8. Now
terminate the input and output connections with a 50-ohm load of some type. The output
requires a load capable of 5 watts. The input may be connected to the drive source but be
sure the RF source is off.

4. Connect the power supply to the amp. Remembers to un-limit the current or readjust it to 2.5
amps. The next step needs to be understood before attempting. The idle current of the
amplifier needs is controlled by the negative gate voltage. Be sure it is set for the maximum
possible. If it is too low, IC2 will over dissipate and damage it. An adjustment of R2 may not be
required but is available. To adjust it correctly you need a accurate current meter on the power
supply or measure the voltage drop across R7. If you need to measure the voltage across R7,
use good clip leads connected to your voltmeter. Key the PTT line and quickly verify that the
current drain is not more than 2.5 amps. That would be a 7.5-volt drop across the 3 ohm
resistor. If more release the PTT line immediately and check the gate circuit voltage or a short
on the drain circuit. Most likely it will be less than 6 VDC drop. With the amplifier keyed,
decrease the gate voltage (less negative) by adjusting R2 until minimum of 6 VDC drop is
obtained. This should not take much adjusting at all.

5. After the idle current is set, remove the DC power before removing the clip leads that may be
attached. Connect a RF power meter that is rated for 10 GHz and capable of measuring 5
watts. Then connect your drive source if not connected already. Reconnect the DC power

/Kits/3-3pack.doc 4 Rev. D 11/24/2008

source. Key the PTT circuit. The amplifier will be drawing current. Now slowly apply RF drive
and notice the output power on your power meter. It is sometimes possible to obtain as much
as 3 watts with only 10 mw of drive. The current drain at the maximum power output level will
be less than 2.5 amps. Do not exceed a drive level of 30 mw or whatever drive level saturates
the power amplifier. If power output is low or non-existent, check all series RF components
first, then re-check voltages without the RF drive applied. R7 will get hot to the touch! Remove
to other two 4-40 x ¼” screws holding the PCB to the pallet and install the Cover on the
amplifier using the long 4-40 screws and #4 washers through the cover. The PCB is held in
place by the enclosure.

Instructions for Use

1. To achieve maximum performance the amplifier should be mounted in a well ventilated area
with heat sink fins in the vertical position for optimum cooling. A cooling fan is required for
100% duty cycle operation.

2. It is advisable but not necessary to use circulators and band pass filters when available. This
will prevent stray oscillations and needless waste of power by amplifying local oscillator
frequencies or generating high power out of band spurious signals.

3-3PA Component List

All resistors and capacitors are chip components unless specified.

C1 1.0ρF

C12 2.2µF can

VR1 78M05

C2 1000ρF

C13 0.1µF

Q2 2N2222

C3 0.1µF

C14 10.0µF Tant

D1 1N4000

C4 2.2µF can

C15 10.0µF Tant

D2 1N914 or 1N4148

C5 2.2µF can

C16 1000ρF

D3 CZ5348B

C6 100µF can

C17 10.0µF Tant

K1 G5V-5

C7 0.1µF

R2 200 POT

IC1 NMA0505S

C8 0.1µF

R3 5.1K Ω

IC2 FMM5061VF

C9 0.1µF

R4 5.1K Ω

PCB board

C10 1000ρF

R6 51Ω

C11 1.0ρF

R7 3Ω 10 watt

Hardware Parts

1

Pallet

4

3-48 x 3/8” screws

1

Enclosure and lid

7

3-48 x 3/16” screws

2

SMA connectors

4

4-40 x 1 1/4” screws

4

Screw type Rubber Feet

4

4-40 x ¼” screws

2

RCA Connectors

1

Thermal compound

1

2” x 1” Copper Foil

4

#4 washers

/Kits/3-3pack.doc 5 Rev. D 11/24/2008

Figure 1

Figure 2

Figure 3

Figure 4

3

2

1

6

5

4

Pin Out:

1

V G G

2

RF in

3:

N.C.

4:

VDD

5:

RF Output

6:

VDD

/Kits/3-3pack.doc 2 Rev. D 11/24/2008

/Kits/3-3pack.doc 3 Rev. D 11/24/2008

+

+

+

+

+

+

+

E7

E8

E10

E5

E9

E4

E11

E1

E6

D3

JUMPER