The entire RCA BTA-250L consumes 1825 watts @ 100% mod of its 250W carrier.
Its transformer has 7 terminals, that one has 8 and has different numbers.
Maybe that one is for a 500W transmitter considering the 2.16KVA rating for the plate alone - 2KW if the 90% efficiency rule of thumb is applied.
Even so a 500W transmitter's plates might consume 600W DC for the RF stage and 600W DC for the modulator. -1200W DC. not including large bleeders and voltage dividers used for supplying screen grids and/or other stages as was common.
A 1KW TX would use more like 1200W DC plus the same for a modulator, but these guesses above are based on 80% RF efficiency and 50% modulator efficiency, so 2KVA might just be enough.
90% RF eff. plus 65% AF eff.
90% = 1000W RF
65% = 500W AF
100% = 770W DC
1870W DC for an efficient 1KW TX. Does this make sense? Is it wrong?
Back to the other disucssion we had on another thread.
The transformer KVA rating is based on total current drawn from the AC line.
You can't count on a power factor of 1.0, so if a 250W transformer draws 1850 watts, the KVA might be considerably above 1850 when power factor is considered.
Does anyone know the power factor of a typical broadcast transmitter?