Thanks for suggesitons. and Thanks BAMA! It sure helps to have a schematic. SB200 has grids at RF ground and cuts tubes off with a neg bias to grids. I'm going to nip the wire, lock the relays down a
Phil I've been looking at GS35B as well. HF vapor cooled with homebrew boiler. Who wants to listen to 500lpm fan noise :-) Could you share some references to the guys running at 4 to 4.5kV. I was thi
A good choke is hard to find. Anyone measured microwave oven tranny secondary for R and L ??? -bob -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative re
Dan I knew about the weld and had read that to use these as tranny for HV power supply that one should grind off the weld and bang the gap closed with a hammer and block of wood. I used to see dead m
This may be common knowledge but I just discovered how telling an electronic trip to Peter Dahl can be. Look at the specifications of the power transformers of some of these amps. -bob -- FAQ on WWW:
Harris RF-110A. Looking for block diagram and schema. Pretty neat. Shows a tad over 4k hours on heaters of 2 x 4cx1500A. Claims autotune but I'm not sure what 'auto' means. Has a passel 'O' couplings
Looking at transformers I see things like 2750V 800mA ICAS and 2250V 2A CCS Just what is ICAS rating when compared to CCS. Is there an agreed upon standard? -bob -- FAQ on WWW: http://www.contesting.
Bert Thanks. So, if I'm comparing Dahl transformers it's 1.5 I take it this means there is no standard conversion factor. That's what I wanted to know. -bob -- FAQ on WWW: http://www.contesting.com/F
Recent surgery and being stuck at home led to a touch of ebay madness. What was I thinking???? mombo bandswitch. that's a 4-400 for scale. http://216.91.87.4/~bob/yos-1/switch/MOMBOSW.JPG should clea
Tom Thanks for writing. Perhaps you could give me a little more info. When you say to the transformer maker "ICAS 50% duty cycle with maximum load period 5 minutes" how does he translate this to core
Anyone running 200W or better up here (2350-2400Mc)? -bob -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Probl
Time for a 'mombo' homebrew induction heater. Something to do with one of those marginal 10KW broadcast tubes and that polepeeg that are gathering dust under the back steps :-) -bob -- FAQ on WWW: ht
Say I have my tube all wired up and wonder if I've got any unwanted positive feedback. With the amp all assembled I stick some white noise on the input. Just a little, say from one of those Palomar a
Picked up this pretty Jennings UCS-500-10S at Shelby hamfest. I've never used a VVC before and wonder about stops when adjusting. How does one know the physical range limits? Also, any tricks for con
PhilNostalgia, eh? Run 'em class C! There's nothing like a pair of Big Jugs on CW. -bob -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amp
I'm curious. How do I figure out how much current I can squeeze through a tube. Lets use the 4cx250FG for example. 4cx250FG It's heater draws 14 watts. The max plate voltage is 2KV and it's rated as
Forgive me if this has been beat to death already... I have been resurrecting a number of 30's vintage radio receivers lately. Hallicrafters SX-18, National NC-44 and NC-46, etc. I notice that they a