E.F.Johnson Capacitor 500B90

[WB2G]

Has any body got an idea what the ratings are for a Johnson 500B90 capacitor .It's big 15long ,7wide,4.5high.Plate spacing is .25 meshed,19 rotor ,18 stator .Thanks Joe.WB2FQD

[K9TR]

If I recall my Johnson nomenclature correctly, it's 500 pf at 9kv peak.  I have a split-stator version of the same, which is even longer (about 24 inches) awaiting some big breadslicer project.

73! Mark K9TR

[WB2G]

Thanks Mark,I had an idea the voltage was about 10KV  but I wasn't sure what the 500B meant.I plan to use it in an antenna tuner and toast bread when I get on 160M.Thanks.Joe WB2FQD 

[WA1GFZ]

Yup .25 inch is around 10 kV. that will make a great cap for a 160M antenna tuner.
I use a pair of 300 pf 10 kv Cardwells in parallel in my balanced balanced tuner.

[WB2G]

Thanks,I've got two 22uH roller inductors to go with it.Hopefully it'll match the coax to the 600 ohm ladder line.I have to run the last 15 foot of the dipole ends straight down to about 20 foot above ground,the center will only be 60 foot up.Does this sound feasible or is it a waste of time .Joe.WB2FQD

[Steve - WB3HUZ]

Should work fine. Hope to hear you on 160 meters soon.

Thanks,I've got two 22uH roller inductors to go with it.Hopefully it'll match the coax to the 600 ohm ladder line.I have to run the last 15 foot of the dipole ends straight down to about 20 foot above ground,the center will only be 60 foot up.Does this sound feasible or is it a waste of time .Joe.WB2FQD

[WA1GFZ]

I use a pair of 22 uh 5 KW roller inductors in my tuner. At 1855 I run about 400 pf and 22 uh. My input balun is 30 feet of RG393 wound on 4 inch PVC pipe. The feet is #10 spaced 4 inches with Johnson spreaders.
It sounds like you have the parts to do a nice tuner. 

[WB2G]

Gentlemen,Thanks for the feedback,I'll be starting the antenna this week,THE SNOW IS FINALLY MELTING  OFF THE ROOF,now I can get up there without going sking.The tuner and antenna should be done in two weeks,see you on 160 than.Thanks Joe.WB2FQD