[Amps] test frequency TSPA

[Will Matney]

The way I read that, it was for linear amplification at 750 watts as it was designed to work between 2 to 40 MHz. Even though it can be used as part of a plasma generator, etc., they had other amateur frequencies listed under the same spec. I was wondering why, even that the 27.1 MHz frequency is used for plasma generators, they didn't show a circuit for the 13.56 MHz one in place of that, or a higher one up to 40 MHz. Most every other manufacturer I've seen does that. The way they have that one, it's ready to go almost for anyone who want's to use it for other purposes. However, I did notice that the schematic didn't follow the part layout as it shows an extra capacitor and coil on the input before the stripline. Those weren't listed in the BOM either.

One thing about a power supply for this, the transformers would be cheaper as one could use a 240 Vac isolation transformer for the power. After the voltage drop, you would see about +300 Vdc on the circuit. 240 Vac X 1.414 = 339 Vdc / 1.13 = 300 Vdc. 1.13 (13%) about always matches the drop on most power supplies I've seen or built.

Best,

Will

*********** REPLY SEPARATOR  ***********

On 5/20/05 at 12:32 PM John T. M. Lyles wrote:

>The 700 watt RF output is measured in a nonlinear power amplifer, 
>used for industrial RF power at 27.12 MHz. This is an FCC-authorized 
>frequency for ISM equipment which allows some radiation, not much. As 
>Vic alluded to below. Part 18 of the Rules and Regs cover this sort 
>of work.
>
>In a linear amplifier, or an amplifier requiring some sort of 
>envelope modulation, one would have to derate the power quite a bit. 
>However, in a class E (EER) amplifier, you might be able to pull full 
>power from it as stated. The new SGC amplifer apperars to do just 
>that, although not sure whose devices they are using.
>
>73
>John
>K5PRO
>
>>Has anyone tried the ARF1505 FET in any solid state amps yet? The 
>>characteristics look very good and it is a HV FET running at 300 Vdc 
>>with a 700 watt output. It is for operation primarily from 2 to 30 
>>Mhz. Below is a link to the page it's at and where the spec sheet 
>>can be downloaded. Also notice the test frequency given on the spec 
>>sheet, wonder why they used and or published that?
>
>
>>Because it's one of the standard frequencies (the other is 13.56 MHz) for
>ISM
>>devices like plasma generators.  Not what you're thinking!
>>
>>--
>>73,
>>Vic, K2VCO
>>Fresno CA
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