03-08-2012, 09:29 AM
I've done a temporary install of the capacitive dropper and it's looking good. All my voltages seem just a little on the low side; heater volts = 65V and B+ = 90V. Heater chain current is about 270mA. I've set the supply voltage at 120v on the variac. The diagram says B1 is 105V. The set seems to work OK - picking up Hilversum (or at least it's all in Dutch) on shortwave, etc. Since it seems to work I'm not sure how concerned I should be about the volts being a bit low.
One thing I noticed is the surge limit resistor does get quite hot so I will make sure it is fixed to the case of the can to make sure the heat gets dissipated. I used a 5watt resistor (formula indicates 3watt - hopefully 5watt gives sufficient headroom). I may need to drill some discrete holes in the can to allow for air circulation but hopefully I can do that such that it is not too obvious.
Today is the last day of my summer hols so with any luck I'll get the can all finished and installed by the weekend. Back to work on Monday - ho hum!
Cheers, John
One thing I noticed is the surge limit resistor does get quite hot so I will make sure it is fixed to the case of the can to make sure the heat gets dissipated. I used a 5watt resistor (formula indicates 3watt - hopefully 5watt gives sufficient headroom). I may need to drill some discrete holes in the can to allow for air circulation but hopefully I can do that such that it is not too obvious.
Today is the last day of my summer hols so with any luck I'll get the can all finished and installed by the weekend. Back to work on Monday - ho hum!
Cheers, John
Time flies like an arrow, fruitflies like a banana!
