>
>Hello All,
>
>I am rebuilding an SB-230 amplifier. I need some carbon comp resistors for
>the swamping network on the input. I need 15-20 1500 ohm 2 watt CC
>resistors. Anyone have any or know of a source besides Surplus Sales?
>
? [chortle] Panasonic/Matsushita makes a 3w-rated resistor that will
easily dissipate 10w continuously in free air. My guess is that with a
100w driver, you need a capability of dissipating around 70 w pep.
Digikey carries these resistors. They cost around %0.50 each. // One
of the disadvantages of a SB-230 is no tuned input. Thus, virtually no
loading on the transceiver exists when the cathode is driven on the
positive half-cycle. This problem can largely be corrected by putting a
ultrafast-recovery 1A diode in series with the shunt load so that the
load conducts only when the tube is cutoff. In my opinion, there would
be an advantage in adding a resistor in series with the cathode. With a
27w drive requirement, you have power to burn, literally. I would use 20
to 40 ohms plus enough shunt R to make the input look like 50 ohms.
- cheers, Jeff
- Rich..., 805.386.3734, www.vcnet.com/measures.
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|