Figure 1:
Top:  Typical installation of an outdoor unit.  A feedhorn is attached and the unit is mounted in a carrier that permits rotational adjustment of polarity.  (Yes, those are 10-meter dishes in the background...)
Bottom:  Examples of two of the outdoor units from which the amplifier modules were obtained.  The feedhorn and "OMT" (Ortho-Mode Transducer) have been removed on these units as they may have been re-used.  The upper unit had been deployed near the ocean and was mechanically damaged:  Its amplifier module was the source of the one in the pictures below.
Click on a picture for a larger version.

• Added diagram for amplifier bias control circuit and 8 volt switching power supply (8/19/2011) - See below.
  

Working on the Satcom industry, I noticed a growing pile dead of Hughes "Tigris" ODU (OutDoor Unit) modules in the bone yard.  Made from the late 1990's into the early 2000's, these were various returns from the field and were, for various reasons, declared dead or not economically unrepairable.  Since it will often cost about as much to repair a unit as to replace it, "dead" units are often put in bone yard and used as a source for mechanical parts to repair other units.

The typical failure modes of these units may be grouped into two general categories:

• Environmental.  Being outside, they are expected to weather the elements over time, but inevitably mother nature takes its toll.  In this category there are two types of failure:
• Moisture ingress.  Typically, moisture gets in through one of the unit's RF connectors (typically F-type) due to either improper/inadequate weatherproofing at the time of installation, or the gradual breakdown of the weatherproofing material and as you might expect, if water gets into a connector and combines with voltage, corrosion ensues.  Sometimes it is possible to replace just the connector, but occasionally, it gets farther than that and damage to the electronics occurs.
• Mechanical damage due to corrosion.  Being cast aluminum, these units are more subject to degradation when installed in an environment that contains salt - such as near the coast.  Inevitably, this attacks the aluminum and weather seals get compromised and/or parts of the casting corrode and/or are broken when one attempts to remove screws.  At that point, the unit is mechanically considered beyond repair although the electronics inside may still be perfectly serviceable.
  

• Electrical.
• Lightning/surge.  Although they are well-protected against transients, etc. Lightning or other sources of transients (due to ground loops, open shields, etc.) will occasionally blow up the circuitry associated with the input terminal (IF amps, regulators, etc.) of these units.
  

• There are 2 watt - and maybe some 0.5 watt - units, but the majority of the units of this style are likely to be the 1-watt units described.

• The prototype amplifier that was tested and described below used components from the badly-corroded unit shown in Figure 1.
  

• The signals from the indoor unit are conveyed via either 50 or 75 ohm coax (it was designed to accept either).  Typically, the older versions had "N"-type connectors while the newer units used "F" connectors.

• The unit is powered by 19 volts DC (nominal) sent up the coax.  A portion of this is sent to the LNB while other voltages are produced inside the unit to operate the various subsystems.

• For receive, an external LNB converts the 11.7-12.2 GHz signals from the satellite to the standard  950-1450 MHz L-band using a 10.75 GHz local oscillator.  These signals are diplexed inside the unit onto the coaxial cable to be sent back to the indoor unit.

• A VCO running at 1/2 the transmit frequency (7.0-7.25 GHz) - locked to a 109.375-113.28125 MHz signal at 1/64^th of that frequency coming up the coax from the indoor unit.

• The output of the VCO is frequency-doubled and amplified to the 14.0-14.5 GHz transmit frequency.
  

• This transmitter is modulated using OQPSK - a version of QPSK that does not require any sort of amplitude component to be present and can be modulated solely via a special sort of frequency modulation (e.g. FSK).  This modulation is imposed on the "reference" frequency (at 1/128^th of the ultimate transmit frequency) and the PLL, tracking this modulation, conveys it to the output frequency.  (Yes, the index of the modulation in the 109-113 MHz range is very low!)
  

• A 1 MHz signal is modulated with a 1 kHz square wave that has a varying duty cycle that is used to control the transmit power.  The duty cycle of the 1 kHz component varies from 0% (e.g. complete absence of this signal) representing full power to approximately 66%, representing "minimal" (but not "zero") power.

• A 10 MHz on/off signal is used to enable/disable (e.g. "key") the transmitter.   (10 MHz = transmit.)

• As a bare minimum, the 10 MHz and 109-113 MHz signal must be present to enable transmit.

• The TBQ-3018 GaAsFET MMIC, described below.

• A low-level MMIC driver stage.  This was part of the original circuitry, but since it is located very close to the power module itself, it is easy to retain and make use of it.  Marked simply with "C8", this device is an RF2048 made by RF Micro Devices.  While the '2048 is characterized only to 8 GHz, like many other MMICs it has useful power and gain well above its nominal operating frequency range.  This device is typically biased to 40mA resulting in 3.6 volts or so across the device. (The lead with the diagonal cut is the input.  A data sheet for this MMIC may be found at alldatasheet.com)
  

Figure 2:
Top:  The entire circuit board from the outdoor unit.  The section containing the TBQ-3018 power amplifier is in the lower-left corner of this picture, having already been cut from the main board.
Bottom:  The small foil shim that was under the power module.  This piece should be carefully saved as it is used both for thermal conductivity and RF grounding.  The "tab" on the side opposite the mounting holes goes under the portion of the board with the output RF connector.
Click on a picture for a larger version.

• Set up your work in a static-controlled area.  At the very least, use a large cookie-sheet or large, shallow baking pan to contain the parts connected to ground.  Before picking up any part or setting a part back down, touch the sheet or other grounded object to discharge any accumulated static - particularly if you have walked across a room or haven't touched the sheet for a while.
  

• Disassemble the unit.
• There are some hex-head screws that hold the cover in place and these should be removed.  It is not too uncommon for these to snap off, particularly if the unit had been used in a coastal area and the threads have galled.  After undoing the screws, the cover will lift off, although a bit of prying may be necessary.
• Using a T-10 "Torx" (tm) bit, remove the die-cast aluminum shield that covers a portion of the circuit board and save it.  Carefully note if any RF absorbing foam sticks to the circuit board or its components and put it back in the shield cover.
  
• Remove the two screws holding the RF power module into place.  These are usually two small "Philips" head screws.
  
• Remove the rest of the screws holding the circuit board in place.  These are also T-10 screws.  Note that there are also screws on the voltage regulators as well.
  
• Unsolder the RF connector from the end of the board opposite the waveguide flange.  This could be either a type-N or an "F" connector.  Often, the connector is "stuck" and cannot be removed, so the long center pin will have to be either clipped off or bent out of the way.
• Note that there are two "F" connectors on case on the backside of the circuit board.  The center pins of these connectors are soldered to the circuit board.
• Lift the board out while applying heat to to the center pins of the two "F" connectors, one-at-a-time.  It is usually easier to lift up the edge of the board opposite the "F" connectors and then heat one of the pins, and then the other.
• Once the board is out, remove the waveguide probe pin near the power module.  Clear solder from the hole so that the center pin of the SMA connector may be inserted.
  
• Note that there is a small piece of metal foil that was mounted underneath the power module:  Save this as it is useful for heat transfer as well as assuring a solid RF ground between the flange of the RF power module and the bottom of the circuit board itself.

• Cut away all but the portion of the circuit board containing the output power module.
• The first step was to extricate the module and this was done by cutting away the section of circuit board containing the power amplifier away from the rest of the board using a hacksaw.  When doing this, take care to minimize the likelihood of static buildup.  Make sure that you leave about 1/8"-1/4" (3-6mm) from the gold-plated portion.
• Keep in mind the amplifier module itself is mounted on rather fragile leads and that care should be taken to avoid flexing them.
• As noted above, I'd first removed the output waveguide probe and cleaned the hole of solder.
  

• Clean up the circuit board section:  The edges of the board were then "cleaned up" using a fine-tooth file to remove the "raggedness" from the sawing.
  

• Cut away a portion of the shield:  The next step was to saw off a portion of the cast aluminum shield covering the unit - see the top picture in Figure 3.  Fortunately, this is fairly easy as the needed portion of the shield can be easily separated at a narrow section. 
  
• The shield is very important:  In testing on the bench, the unit was operated without a shield, but it was extremely unstable and tended to break into self-oscillation.  The use of the shield and its contained RF absorbing material allowed the unit to be unconditionally stable!

• A suitable enclosure was chosen.  I chose a small die-cast aluminum box as it would also serve as a heat sink.  With its backside being flat instead of finned, this facilitated the installation of flush-mount SMA connectors.  If you have access to a metal-working tools, it may be possible to cut and mill portions of the original case in which the amplifier was mounted or to cut out areas among the fins of a standard heat sink to clear the screws and RF connectors.
  

• Mark the holes in your amplifier box.  Very carefully, I laid the extricated piece of circuit board in the box and marked where the mounting holes needed to be drilled.  The former position of the waveguide mounting hole was noted as was marked the position where the input connector would be placed.
  

• Drill holes in the box.  Holes were drilled in the die-cast box in the marked positions to accommodate - including the holes where the input connector would be.
  

• Select and mount the RF connectors.  For RF input and output connections, I used "3-hole" SMA connectors:  These are the types with a 2-hole mounting flange and the 3rd hole being the center conductor itself.  The case was marked and drilled to accommodate mounting of these connectors as well.  These connectors may be seen in Figure 3.
• "Single-hole" chassis-mount connectors may not be suitable for this project and "5-hole" units - if usable - would have to be carefully mounted as to have their screws avoid interference with the shield cover and the circuit board traces - or just two of the four mounting screws used. If larger holes are used in the mounting box it may be possible to solder the connector directly to the bottom (ground plane) of the circuit board, but note that the foil on these boards is quite fragile and connectors mounted in this way could easily be torn off when tightening the SMA fitting!
  

• Check and drill holes in the board for the antenna RF connectors.  The board was then "dry-fitted" and the holes for the input SMA connectors were marked on the bottom of the circuit board.  Corresponding holes were then drilled in the bottom of the board to accommodate the connectors' mounting screws.

• Re-check the fit and drill more holes.  Without the fragile circuit board in place, the die-cast shield was installed and held in place with the already-drilled mounting screws and holes.
• At this point additional holes were drilled where the two SMA connectors would be mounted, through the cast shield cover.
• As necessary, filing was done with a set of "needle files" to make sure that the screws fit well and were aligned properly - the idea being that it should be possible to insert and tighten the hardware without needing to shift the board around.
• Note that one of the mounting screws does not go through the shield cover and is used to hold the board down before attaching that cover.
• Near the output connector, it may be necessary to file off a ridge on the top of the die-cast shield to provide a flat space for the nut for the screw that holds the output SMA connector in place.
  

• Check the mounting of the RF connectors.  Make sure that the SMA connectors will mount to the die-cast box without the center pin shorting to the bottom foil of the circuit board or putting mechanical stress on it.
  

• Add holes in the shield for power/bias connections.  Small holes were drilled in the shield cover to permit the connection of the MMIC's bias and drain supplies.

• Add a groove to allow connection for the MMIC's power.  A groove was filed into the shield cover near the driver MMIC to allow a piece of wire to be passed between it and the circuit board for powering the MMIC.

• Disconnect the power supply traces from the bottom side of the circuit board.  On the bottom side of the circuit board the traces connecting to the drain and bias leads for the power amplifier module were identified.  Also identified was the power supply trace to the input MMIC amplifier.  (Pictures to be added.)
• Using a small drill bit from the bottom side of the board, the circuit board "via" leading to the top side was drilled out.  It's not necessary to drill completely through the board to do this.
• The idea here is to disconnect this via from the trace on the bottom side of the board as the board itself will be bolted to the die-cast box which would otherwise short out those connections.  Usually, it is also easy to pull up the trace and remove it as well although this won't disconnect the via, either.  (It may be possible to pull up the trace to the via and then drill a countersink into the die-cast box to prevent shorting of the via.)

Figure 3:
Top:  The lower casting is the unmodified RF shield cover while the upper shows which portion was removed.  Be sure to save any pieces of RF absorbing material in the shield castings..
Center:  A modified, extracted amplifier board section with the "input" being at the bottom-left.  Extra holes have been drilled to accommodate the 3-hole SMA connectors.  Also note the cut in the trace on the left side in preparation for a DC blocking capacitor to be added for the input predriver MMIC.  The above picture shows an early test unit on which I'd broken some of the leads of the TBQ-3018 power module and resoldered - a reminder that the leads are VERY fragile!
Bottom:  Annotated picture showing the various connection points.
Click on a picture for a larger version.

• Clean up the board.  Clean up and de-burr the holes drilled into the circuit board as necessary.

• Install the input blocking capacitor.  Somewhere along the trace between the cut-off portion of the board where the input connector will be mounted and the input predriver MMIC, cut a slot in the trace about 1/8" (or 3-4mm) wide.  Remove the chip capacitor that is still on the remaining main board that had been on the input of this same MMIC and place it over the slot in the trace.  This is done to provide DC blocking for the predriver MMIC.  This cut may be seen along the left side of the bottom images of Figure 3.
  

• Connect the power/bias wires.  On the top of the board, small pieces (about 4" or 10cm) of wire are soldered to the supply points of the output module and the input MMIC as noted in the bottom image of Figure 3.  I used #30 wire-wrap wire for this.  These make the bias and drain connections for the output amplifier and the bias supply for the predriver MMIC.  The drain supply for the power module connects to a small bypass capacitor while the bias supply connects at a 350 ohms chip resistor.  The supply for the predriver MMIC connects at the junction of the chip resistor and its bypass capacitor.
  

• Clean the inside of the shield cover.  Inside the cast shield cover are small pieces of RF-absorbing foam that are very important to the stability of the amplifier.  When drilling and filing, these pieces of foam and the adhesive holding them into place tends to cause small flakes of metal to accumulate:  Very carefully remove these small pieces of metal without removing/losing the pieces of RF absorbing material.
  

• Bolt the power module and foil shim into place.  Locate the small piece of foil that had been placed under the RF power module (see the bottom picture of Figure 2) and put it into place where the power module will go in the die-cast box.  The "tab" on this piece of foil sits under output terminal of the amplifier module where the RF output probe used to be.  Using #2 or #3 hardware (very small screws) loosely attach the output power module and board to the die-cast box with the piece of foil underneath it.

• Re-check hardware/hole alignment!  Check the alignment of the mounting holes and adjust as necessary.  Be prepared to remove the board again and file the die-cast box (and drilled holes) as necessary to assure a somewhat loose fit of the hardware.
• It is important that one prevents the board from shifting once the power module is bolted down and putting stress on the leads.  As can be seen from Figure 3, I managed to break the leads of the device by moving it around too much while trying to mount the board!
  

• Start installing screws and re-check alignment.  With the mounting holes in alignment, install the one screw that does not go through the shield casting and tighten it:  This is the screw that goes into the hole closest (and just to the left) of the input driver MMIC as seen in the bottom picture of Figure 3.  Once the alignment holes have been re-checked and it is verified that stress won't be placed on its leads, tighten the two screws holding the output module down.

• Install/solder the RF connectors.  Temporarily install the screws holding the two SMA connectors and solder the center pins into place on the circuit board.  Once this is done, remove the screws holding the SMA connectors.

• Install the shield cover.  Install the die-cast shield cover, carefully threading the wires connected to the bias and drain of the power module through the holes drilled into the shield.  For the pre-driver MMIC, make sure that the wire is routed in the groove that was filed into the casting and not pinched.
  

• Fit the shield cover into place.  Loosely install screws into the original mounting holes in the casting - but do not install the screws for the SMA connectors just yet.  After verifying that everything is in alignment and that no wires are pinched, tighten the screws that are used to hold the shield in place.
  

• Tighten down the screws for the RF connector.  Now, install the screws that hold the SMA connectors in place.
• It is important that this be the last step as these "non-original" holes may be slightly out of alignment with those originally in the shield casting.  Because these holes need to follow the contour of the original casting, the drill bit may have followed something other than the intended course and knocked them out of alignment.  It may be necessary to drill larger holes and/or do some filing to get these screws to fit nicely.
• Note:  Tightening the screws holding the RF connectors into place while the other screws are still loose could shift the board and break the wires connecting the output power module.
  

• Install bypass capacitors on the power/bias leads.  On the various power leads, electrolytic capacitors were installed to provide low-frequency stability.  For the drain lead, a 100uF unit was used while a 10uF capacitors was used for the predriver MMIC's supply and a 0.1uF was used for bypassing of the bias lead.  The values aren't critical, but I wouldn't recommend less than 4.7uF or more than 100uF for the power leads.  It is recommended that low-ESR capacitors rated for 105C (high temperature) be used.  A 100 ohm, 1/4 watt resistor is used to drop the 8 volt drain supply to the proper voltage/current for the MMIC input stage (e.g. approx. 40mA with a MMIC terminal voltage of approx. 3.6 volts.)
  

• Do an ohmmeter check.
• It should be noted that when referenced to ground, an ohmmeter test on the gate bias lead will show the presence of the 350 ohm chip resistor.
• The drain lead will show a resistance of an ohm or so with zero gate bias, so it is difficult to rely on this reading to indicate a shorted device or connecting wire unless you have an ohmmeter that will resolve very low resistance and you take into account the resistance of the connecting wire itself.
  

• The output power amplifier MUST have a source of negative bias voltage - around 1 volt - in order to function properly, and the data sheet warns against applying drain voltage without the proper amount of negative bias!  For initial power-up, this bias voltage needs to be set to about 1.5 volts to guarantee complete cut-off the drain current.  In testing, this unit showed around -0.5 volts for a drain current of 600 mA, but note that this will vary with temperature and from unit-to-unit.
  

• Also, the drain voltage - nominally 8 volts - MUST be current-limited for initial testing.  For this, an LM317 current source can be constructed to limit the maximum current to 0.6-0.8 amps, or if you have one, a current-limited power supply may be used.  Once proper operation has been verified, the drain current may be increased as necessary.

• As noted above, the input MMIC is operated from the 8 volt drain supply:  A 100 ohm 1/4 watt resistor is used to drop the voltage.
  

• Do NOT use a power supply that will deliver more than 600-800 mA for initial testing!  YOU HAVE BEEN WARNED!

• Allowing the drain current to exceed 1 amp - particularly if the bias voltage is too low - can instantly destroy the amplifier module!
  

Figure 3:
Top:  The repackaged TBQ-3018 VSAT amplifier under test on the workbench.
Center:  The amplifier installed in the die-cast box with the shield covers in place.  Notice the wires for the drain and gate bias emerging from holes in the shield casting.
Bottom:  The "other" side of the amplifier, showing the "3-hole" SMA connectors and the screws holding the board, connectors and shield covers in place.  Since these pictures were taken, feedthrough capacitors have been added and holes drilled and tapped to allow mounting of the amplifier to a heat-spreading plate.
Click on a picture for a larger version.

• Connect a load suitable for 10 GHz to the output.  Typically, one would use an attenuator between the output amplifier and the microwave power meter, but remember that there may be more than 1 watt of RF present, so pick a load/attenuator that can handle the power.
  

• Apply the negative bias voltage first!  Start with -1.5 volts as this will pinch off the drain current.  Take care not to exceed -1.5 volts.  Note that on the circuit board is a 350 ohm resistor that loads the DC bias line.
  

• Next, apply 8 volts of current-limited drain voltage.  It is recommended that one monitors both the drain voltage and drain current simultaneously.
• If you are using a voltage regulator, it is best to apply voltage to the INPUT side of that supply (or regulator) first.  The reason for this is that such a supply will likely have a filter capacitor on its output and if, for some reason, the bias is gate bias is too low, that output capacitor may discharge across the power module, exceed its ratings and destroy it instantly!  Applying the voltage to the input of the drain supply/regulator will help assure a "soft start" and avoid such momentary high-current pulses.  The 100uF capacitor on the drain line noted above will help protect the device, but be careful, anyway!
  

• Slowly decrease the bias supply while noting the drain current.  Rather suddenly, the drain current will start to rise:  This typically occurs at approximately -1.0 volt.
  

• Adjust the bias voltage for about 0.6 amps of drain current for initial testing.  Note that with a current-limited power supply, further decrease in bias voltage or even additional increases in drive will cause the amplifier to attempt to draw more current, pulling down the drain voltage.

• Now, connect the predriver MMIC's power lead to a voltage source.  For testing,  one may use a 300 ohm resistor in series and a +12 volt supply for the MMIC to limit the current to the 30-40mA range, or one may put a 100 ohm resistor in series with the 8-volt supply.  The actual voltage on the MMIC is unimportant - just select it (and a series resistor) for approx. 40mA of current.  If you do use the current-limited 8-volt supply to power the MMIC stage, keep in mind that if current-limiting occurs, the MMIC's supply current will also decrease along with the RF drive to the module - but this is probably not a bad thing!
  

• The data sheet is a bit vague and contradictory on the device's maximum ratings.  For example:
• It shows the maximum input power as being +1dBm, yet one of the graphs implies test data to +10dBm.
• The maximum drain current isn't specified, but "typical" values of 650mA under test conditions are given while the various curves show currents as high as just over 1 amp.

• Remember that when the board is "hacked" as described, a "pre-driver" MMIC is present on the chunk of circuit board, next the the output module.  Again, this MMIC has yet to be positively identified so it is unknown how much gain this device has, but at 6-8dB minimum gain would be a reasonable assumption.
  

• The gain of the TBQ-3018 amplifier module alone is stated as being in the area of 30dB at the nominal 14 GHz frequency.  Down at 10.368 GHz, however, its gain is likely to be much lower.  The "guesstimate" that it is around 20dB in the 3cm ham band.
  

• The measured gain of the combination of the input predriver MMIC and the TBQ-3018 was measured as being approximately 34dB at the 1dB compression point at 10.368 GHz.
  

• When run at or below the 1dB compression point, about -5 dBm is required to drive the combination of the predriver MMIC and output amplifier.  At 8 volts and 600mA, this power level correlates to a bit over +27dBm (500mW) at 10.368 GHz.

• The amplifier was also tested at 1 amp of drain current at a maximum of 8 volts.  At full saturation and with careful adjustment of input bias, over +32dBm (about 1.6 watts) was achieved at 10.368 GHz.  This power level was maintained for only about 10 minutes as the small die-cast box and the 20dB attenuator being used between the amplifier and the power meter were getting very warm!  There was no apparent harm observed.  (This test was done just prior to the 18-hour "burn-in" at +30dBm.)\

• The unit was run with the drain current limited to 800 mA at and output power of  +30dBm (1 watt)  for about 18 hours with the die-cast box partially covered to increase temperature and further-stress the amplifier.  The power remained stable to within a few 10^ths of a dB during the entire test period.  The required input power level was approximately -2dBm at 10.368 GHz.

• As noted below, the unit picture in Figure 3 has been installed in the K7RJ 10 GHz beacon.  It has operated for several weeks, continuous duty, will running at an output power of 1 watts which, when final installation and integration with the bias/drain current controller circuit, correlated with a drain current of roughly 750 mA at 8 volts.
  

• When driven into saturation, the bias voltage may be "tweaked" to achieve maximum power output, but it is unknown how stable this sort of adjustment might be over wide temperature excursions.  Again, with a current-limited supply, maximum saturated power may occur with the drain voltage being "folded back" to less than 8 volts.

• While I would not recommend trying it, the unit has been proven to be quite forgiving of poor output termination (e.g. no load) and has shown no signs of instability or damage.
  

Figure 4:
Top:  The schematic of the 8 volt switching regulator.
Bottom:  The schematic of the bias control and current limiter.
Click on a picture for a larger version.

• More testing!  So far it looks as though this amplifier should be easily capable of just under 1 watt PEP output on 10.360 GHz with reasonable linearity or just over a watt on CW with the drain current set to about 1 amp.  For full-time key-down beacon operation (e.g. FSCW) a power level of 1 watt would appear to be "safe" given adequate heat-sinking - but that shouldn't be too difficult since only about 6-8 watts of heat need to be dissipated!

Update:  This amplifier is currently undergoing testing for long-term use in the K7RJ 10 GHz propagation beacon at an output power level of 1 watt.  Thus far, the results look promising!

• Build a permanent power supply.  For actual in-field use, a bias voltage generator and drain current/voltage regulator is required and when this circuit is completed, details will be posted here. .  This circuit should also properly sequence the drain voltage, applying it only after the bias voltage has come up to its proper value, reversing the process when the amplifier is "un-keyed."  The design that I have in mind will regulate the bias voltage by "looking" at the current-limited drain supply voltage, but we'll see...

Update:  I've built and tested a regulating power supply for this amplifier in preparation for its use in the K7RJ 10 GHz propagation beacon.  This supply uses a switching regulator to provide the 8 volt drain supply, it has both overcurrent and bias-fail protection and it uses servo techniques to dynamically set the bias voltage - see above!

• Improved heat-sinking.  The small die-cast box seen in the pictures is adequate for intermittent (e.g. SSB or CW) use where the duty-cycle is limited and the amplifier's power supply is keyed with the radio's PTT, but its heat dissipation capability should be increased if continuous duty/beacon use is anticipated.
  

Update:  When this amplifier was installed for use on the K7RJ 10 GHz propagation beacon, its die-cast box was bolted to an aluminum plate to provide additional heat-sinking.  Testing has shown that this degree of heat dissipation is entirely adequate.

• Improve this web page!  I plan to put another one or two of these units together and when I do, I'll take better pictures and improve the documentation.  As the opportunity and time permits, I'll add to this page - possibly adding information about other types of similar units.
  

• At the moment I have information only about the older-style Hughes "Tigris" outdoor units - specifically the 1-watt varieties that may include part numbers in the "1025901-xxx" series.  There is a 2-watt version of this unit (possibly, with a part number of "1028350-xxxx") and there are a number of newer modules out there as well, but I have not had the opportunity to investigate the usability of parts in these other units!  Unfortunately, it is not always easy to tell the 1-watt units from the 2-watt units from the outside unless one compares part numbers with a magic list... which, apart from the information above, I don't have at the moment...
  

• There are a number of other manufacturers of similar units - often referred to as "BUCs" (e.g. Block UpConverters) that take L-band and convert it to the transmit frequency.  I know nothing about these other brands!

• Before you ask me any questions about whether or not the unit(s) that you have onhand can be used at 10 GHz, please re-read the above two statements!
  

Go to the KA7OEI microwave page, or go to the KA7OEI main page.

 
If you have additional questions, you may send email using the link at this page.

This page updated on 20160720