Recent content by DannyAbear

I use the jb150 for local talking, only a matter of time before i forget to turn it off, hence the reason for wanting to pad the input of dx300

AAAha, so the resistor would have to be inserted into the input line feeding the tube, huh|?

I am building/modifiying a SB200, into a 4cx400 grid drive using a dx300 schmatic; I know they also marketed the DX300 as a KW-1, by using resistors in the input circuit, but can't find that schmatic

If I wanted to drive one of these amps with a JB150, could I use a 't' connector on the input, with a 50 ohm 25 watt dummy load on one end and the other end connected to the jb150?

Leaning more to the Swetlana 4cx400, I have enough power supply for it; would the input circuit be the same as for a 250b and would something change?

Anyone tried the Russian 4cx-400? Is it a worthwhile upgrade from a 250b?

Thanks for the info; I am building/converting a Heathkit SB200 to run a 4cx250 or 350, haven;t bought tube yet, I remember trying a 350fj in my pride 25-30 years ago, with very little improvement; I have all of the major components, just built a Harbarch HV board for it.. The hardest part is...

1 Will those little blue chinese caps hold up if used to ground the cathode tube sockets, or do I need silver micas? 2 Have located a 500v CT transformer, 40 ma, good enough for 1 tube? 3 How do you determine what value doorknob cap to use? 4 What valvue for plate choke? One from an SB200 ok? 5...

I would like directions/instructions on how to make the 9 to 1 input torid