On Mon, 12 Oct 98 08:42:38 -0000 Jon Ogden <jono@enteract.com> writes:
>
>>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).
Make sure those suppressor resistors have not burned out. They can be
open with no external signs of damage.
>>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),
I must "assume" that the switch alignments are correct ??
>>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.
There are 3 versions of the SB-220 and early 221 Tune cap. One is the EF
Johnson 154-9 which does not have removable plates so you have to use a
less than ideal method to clean them.
There are 2 versions with removable plates, one is the same length as the
Johnson ( Heath # 26-131) and the other is wider spaced ( Heath #
26-164). I have replacement plates for those as well as complete caps of
all three types.
73 Carl KM1H
>
>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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>
>
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