USING THE TOSHIBA LINEAR ON 3456
USING THE TOSHIBA LINEAR ON 3456
Many of us have purchased these amplifiers from Joe Ruggieri on the eBay auction site. You can order a 40 watt amplifier directly from Joe, courtesy of the NR6CA web site for $150.00 plus a small shipping charge. Contact Joe by E-mail or call him at 1-407-767-5119. Send an E-mail to Joe HERE. The amplifiers are very high quality amplifiers that were made by Toshiba for Lucent Technologies. There application was to have been wireless communication systems but as we all know, the market for that business has fallen apart. Joe had a large quantity of these at one time and may or may not still have some available, at least as of December 2002 as I write this.
The amplifiers came in a couple different configurations with some minor differences. They were sold as 20 watt and 40 watt units. Some had a right angle SMA connector on the output and some had a right angle SMA output connector. There seems to be some differences internally between these two different connectorized versions. Below is a complete compilation of all the information I have on these. Additional information is welcome and would be added to this web site.
These amplifiers are pretty much bullet proof. They have an input return loss of 40 dB, which is a near perfect match! There is ample protection but it them to offer proper protection from output mismatches and such. But of course you still want to get the output the amplifier sees as close to 50 ohms as possible. They are designed to work into a maximum load VSWR of 2:1 according to Toshiba. Operating temperature is specified as 85 C and they shut down at 90 C and issue an alarm signal on one of the pins.
The output FET is rated at 9 dB of gain, 60 watts output at 1 dB compression. The basic design on the amplifier has the output stage under driven by a wide margin. The same solid state lineup is used in both the 20 watt and 40 watt versions. They have sufficient gain to only require 0 dBm (1 mW) input for full rated output.
As a point of reference for these amplifiers, at the price Joe sold them, they are truly a bargain. In 1000 piece quantities, if you were to purchase only the solid state microwave devices you would spend over $1100.00 and still not have an amplifier! And these are very close to plug and play units. You can simply connect +12.6 VDC to the proper terminals, connect ground on transmit to appropriate terminals, and of course a DC ground, add drive and be on the air. Getting the maximum available performance requires a little (but not much) work.
The 20 watt amplifier will draw something on the order of 11 amps @ 12.6 VDC, or approximately 140 watts. With 20 watts output that means the heatsink that must be added needs to be capable of adequately dissipating around 120 watts. The 40 watt unit will consume around 16 amps or so. For that one you need an even larger heat sink capable of around 160 watts.
Below is a pin out listing for the 40 watt version, which may be the same as the 20 watt version.
Check first to be certain.
The connector is a SUB-D 15 pin unit.
|
PIN
|
APPLICATION
|
| 1 | 12.6 VDC |
| 2 | 12.6 VDC |
| 3 | Ground |
| 4 | High output alarm |
| 5 | SWR alarm |
| 6 | Unused |
| 7 | Ground |
| 8 | Low output alarm |
| 9 | Ground on transmit |
| 10 | Ground |
| 11 | Ground |
| 12 | 12.6 VDC |
| 13 | 12.6 VDC |
| 14 | Unused |
| 15 | LED through 7-800 ohm, 4-5 mA |
Here is some additional information that is based on the 20 watt units. The is from Steve at DEM.
"... simple to soup up! Depending on which model you have. The difference is the output connector. So far I have had the best results with the Swept right angle connector version. This one is the easiest! Near the output circulator there is a 6 pin jumper wire. Just unplug it!! Power should come up to about 30-35 watts. This part of the circuit is the power output limiter. Voltage gets feed back into a comparator circuit from the power detectors and adjusts the output power to the 15-20 watt level. Then if you want to go for all of the gusto, drive the amp to your desired drive level and tweak the 4 pots nearest the input side of the circuit. These are not bias adjustments!! 2 control a variable attenuator and the other 2 are range controls for the power limiter. This should net 40+ watts. The bias in the amp for all 4 stages is an active bias circuit. No adjustments can be made and are not needed! I have done some additional tuning of the RF circuits and got 55 watts out of one unit."
"Now if you have a 90 degree output connector, its a little more complicated. You can remove the same 6 pin connector to yield 30 watts and call it a day. Now the adjustment on the circuit board are not the same. The two output FET do not have active biasing. You can adjust the first 3 pots because they are for a attenuator and a range control. The pots in the middle of the board control the negative bias for the 60 watt FET and the 2 pass transistors that limit the drain voltage to the 8 watt driver and the 60 watter. So!!!! I don't think you can blow anything up, but I wouldn't recommend screwing with them with out using a voltmeter to see what is happening! I have tweaked the shit out one of these for 45 watts out. Over all, I don't think you can blow any of them up. They will draw 12-14 amps at 12 VDC. Be sure that the voltage doesn't sag below 12 VDC when tuning. The DC power FETs start working funny. The more current they draw, the lower the voltage and the RF power doesn't go up!!!"
Some additional notes for the 40 watt version:
1) The amp has 4 pots that need adjustment, R217, R210 & R138 are the first three pots counting from the left and R150 is located directly to the right of the regulator. R217 and R220 can be turned full clockwise to disable the leveling attenuator.
2) If you have trouble getting a 40 watt amp to full power (which should be 15 amps) measure the voltage on the right pins of P3. It should be 10.3 VDC. If it is low, adjust R150 to set it to 10.3 VDC.
3) R138 can be used to adjust the amp for 15 amps with 0 dBm input power.
4) You can set R138 to a higher level then step 3 but output power will not increase. All you do is make more heat that you need to get rid of.
So there you have what I have available. Any additional information for inclusion on this page is most welcome. Send it to me by E-mail and I'll include it. If you want credit listed for the information you supply, just let me know. E-mail it to "nr6ca @ nr6ca.org." Sorry about not making this a clickable link but I am trying to keep the spammer software from harvesting the E-mail address.
Good luck and I'll see you on 3456.
73, Randy, NR6CA