Tetrode Progress slow.
I had to stop today after a test lead/clip came off and sparked blowing 2 glass Resistors on the AC input of my HVPS board. Nomad, if you're reading this, what are the values for replacements? Glass I think. The remnants are unreadable. I re-wired buck-boost for more voltage as I made some tuning progress. Resistors did their job, just like a fuse.
EDIT: Found it: 5W 5ohm ww (http://www.nomadradio.com/HDHV/HDHVassembly/index.html).
I finished revising the RF Input section --I think. Mistakenly had a DC ground for the 6:1 input unun (300 ohm resistive) but replaced w/bypass caps & raised it above ground with another 300 ohm NI R. Input SWR's good with a tit midway on toroid inductor for switching between 80/10-40.
I'm Still using old tubes of unknown quality saving new tubes after I work out issues. Tried SSB drive first time today. Surprised at swing relative to AM carrier I've been using. (IOW: I graduated from my junkiest AM CB drive signal to a proper 10M rig. Amp has a fixed Pi network coil so my drive is more consistent with Tank coil.
ALC signal working & adjustable. Screen current protection circuit still problematic. I get no ability to set the mA-limit. Reset circuit works fine when tripped though. Operating voltages, standing current and Control Grid are sorted-out but at the cost of buying more 50W resistors than a consumer should ever need . Tetrode Boards working for the most part and the Screen/Control Grid mA meters show appropriate values when tuning/troubleshooting.
Neil, nyc
I had to stop today after a test lead/clip came off and sparked blowing 2 glass Resistors on the AC input of my HVPS board. Nomad, if you're reading this, what are the values for replacements? Glass I think. The remnants are unreadable. I re-wired buck-boost for more voltage as I made some tuning progress. Resistors did their job, just like a fuse.
EDIT: Found it: 5W 5ohm ww (http://www.nomadradio.com/HDHV/HDHVassembly/index.html).
I finished revising the RF Input section --I think. Mistakenly had a DC ground for the 6:1 input unun (300 ohm resistive) but replaced w/bypass caps & raised it above ground with another 300 ohm NI R. Input SWR's good with a tit midway on toroid inductor for switching between 80/10-40.
I'm Still using old tubes of unknown quality saving new tubes after I work out issues. Tried SSB drive first time today. Surprised at swing relative to AM carrier I've been using. (IOW: I graduated from my junkiest AM CB drive signal to a proper 10M rig. Amp has a fixed Pi network coil so my drive is more consistent with Tank coil.
ALC signal working & adjustable. Screen current protection circuit still problematic. I get no ability to set the mA-limit. Reset circuit works fine when tripped though. Operating voltages, standing current and Control Grid are sorted-out but at the cost of buying more 50W resistors than a consumer should ever need . Tetrode Boards working for the most part and the Screen/Control Grid mA meters show appropriate values when tuning/troubleshooting.
Neil, nyc
Last edited: