Typical 2-tone test plots at 1kW pep are shown below - click on the image for a larger pdf version. The difficulty of matching the low impedances involved here to a 50Ω resistive load over a wide frequency range has dictated a broadband, base-driven or gate-driven architecture, using ferrite-cored input and output matching transformers. He does not subtract drive power, from the radio, in his formula. Operating Manuals, Remote Software and Firmware updates are available from. Will post more pics and info when i do these.
Now the tube will have to be able to dissipate 1500 watts of power that is turned into heat. This amplifier weighed only 47 pounds. They not only are more difficult to cool, if one transistor fails they all have to be replaced. It was very nice, put I'll never be able to afford one of my own. Anyone have experience with this little amp- possibly own or previously owned one? The reason behind this is simple…people can more easily understand and operate in watts but our equipment operates in Decibels Db. If you are using a 15-amp breaker, it will not trip as soon as you draw 15.
The shunt has not yet been mounted in the picture that shows the Power Supply open. It has now been running for a week with no problems. Pi-L uses an extra inductor or the addition of a 4:1 unun in the tank coil assembly. Their plate voltage is too low and the tube is not cooled properly. The amplifier is built in a very robust all aluminium case. The first real level of protection amplifier manufactures incorporated in amplifiers was grid protection. The toroids were wound with two parallel 1.
Four of these tubes will generally produce 1200 watts of output power. The lead time is typically two weeks. I purchased the copper spreader from. Here is a real-life example: you are transmitting at the 100 watts output power level. All my tests so far has been with one module running. His boards are much higher quality and he is an engineer innovating in this space. There are only necessary push buttons in the front panel.
The capacitor bank is capable of sourcing a lot of current at startup, so I use a relay to hold back the initial current. That would equate to a 100% duty cycle. Just thought of something else. If your amplifier is the only item that is on your 120 volt line that goes from the breaker box to your shack, you should not have any problems running your amplifier at a 750 watt output level. With drilling solved or so I thought , I moved on to tapping, again using lubricant. They call it the Model 99 and its just a bit larger than the copper spreader. Understanding that 1500 watts of output power is the legal limit, that is as close as you are going to get to an S7 meter reading.
The thermistor is in physical but not electrical contact with the copper spreader. It also allows me to select band switching from the amplifier or from an external source. With grid trip protection, if the grid current went past a predetermined value, the grid protection relay would drop out and the amp went into a standby mode. That means you have to dissipate 1000 watts of heat. The amplifier seems to perform as expected. The copper was drilled and tapped using 6-32 screws ready for the mounting of the ldmos. The presence of valid in-band signals is detected and will initiate switching automatically to that band.
Nicos was on the Island of Crete, in the Capital City. Even the time of day and the season of the year can come into play. You can gauge the capacity of a transformer by its weight. There is also another useful Doug DeMaw article in the. If you touch the high voltage line in an amplifier, you will get a charge of 2000 or more volts plus, over 100 amps of surge current. Your voice peaks can easily draw 16 amps, for a very short period off a 15 amp breaker and not trip the breaker. The reason is, they do not have to be tuned which makes for fast band changing.
I built the small circuit below to switch it on once the temperature of the copper spreader is above above 30C. I used to design the Low Pass Filters. The code was uploaded to the pic and it fired up with no issues. Watch how the manufactures advertise their power supply ratings; it is all in the wording. If your amplifier is only 50% efficient, that means you will need 3000 watts of input power to produce 1500 watts of output power. I thought about moving the holes again, but with three pieces of debris stuck in the copper I ordered another piece. The only difficult component to obtain for the power supply is the transformer.
They did not like to be run at anywhere close to 50v even though they are rated at this voltage. I did not design anything fancy, just 7 pole filters with a small amount of pass band ripple. After some initial issues with some rf getting into the controller circuitry. In a 500W-class amplifier, a 3-port hybrid-transformer power-splitter divides the drive power equally between two 250W modules. Here is another photo of the heatsink drilled and tapped using M4 bolts. Then the added cost of have a 75-80 amp power supply , again I would always like some head-room in running gear.
A working Q of 12 ensures adequate harmonic suppression. For this reason, two to four push-pull modules 2 devices per module with a hybrid splitter and combiner are the preferred topology. Loading into a really high-Z mismatch could cause loading cap arching, but it's never occurred with mine. Do not ignore the loss in your transmission line. Then we would have exchanged signal reports and moved on. This rating means the amplifier can put its rated power out, nonstop, 24 hours a day 7 days a week. The only value the fuses offered were to give some protection after a catastrophic failure like a shorted power transformer.