>Hi Jon,
>I appreciate the response from the reflector.
>The SB221/220 had the Harbach nichrome suppressor kit installed some
>years ago, which got rid of arcing I had at that time (although
>I don't remember where it arced at that time).
>The TUNE C arcing happens on at least the 10m, 15m and 20m bands.
>Inspecting the Tune C shows a little black on some of the fins
>where the arcing has occured.
I would clean this out good. That might not be the cause but it
certainly doesn't help.
>From original condition, I did the nichrome suppressor kit, added
>10m (purchased bandswitch and caps/coils input circuit from KM1H),
>also did the Harbach softstart kit. Recently did the Rich Measures
>input circuit mods to bring down the input VSWR.
>I thought the Tune C looked clean but someone mentioned I should
>clean as thoroughly as possible of any dust; yet to be done.
>Does this reply get thru to the reflector?
No, it didn't, but I posted my reply through the reflector as well.
As others have eloquently pointed out, it is possible to make the SB-220
arc just by mistuning it. It is possible that this happened and that now
it arcs all the time becuase of damage to the cap. Without seeing it, I
have no idea.
I have suggested measuring the values of the supressor resistors. Wether
or not they are bad, it is good engineering practice to just do a sanity
check on all the components. It hurts no one to see if everything is
where it should. If the values are good, then that's great, if bad, then
you gotta replace them.
Anyhow, the resistors may or may not be your problem. Mis-tuning may be
your problem instead. Follow correct tuning procedure if you aren't
already. If you follow correct tuning and are confident that you are
doing it correctly, then examine all your components.
Check the input circuits for proper construction as well.
73,
Jon
KE9NA
--------------------------------------------------------------------------
Jon Ogden
jono@enteract.com
www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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