>>Tom Rauch has given me some good possible suggestions for the
>>suppressors. Perhaps I just need more inductance and a heftier R or
>>something. Anyone else care to chip in an idea?
>
>
>
>Been away on a long weekend so hope I'm not duplicating here.
>
>I seem to recollect suggesting the new 5W metal oxide resistors from
>Mouser more than once Jon.
Yes, I know. I've been considering ordering some. Are metal oxide and
metal film resistors different? I haven't used any carbons for some time.
I've been considering looking into getting some fairly non-inductive
resistors made by a company called Caddock Engineering. I used some of
their devices in commercial designs in the past and their stuff is
excellent. The make some resistors in TO-220 packages. Real good for
heatsinking. But those aren't applicable here. Anyhow, their resistor
design has very low inductance and I figured that they might be a good
way to go.
>
>BTW, something is really screwed up in your amp for the Load cap to act
>that way. And yes it is possible to blow that B&W switch, happened to
>many and B&W used to sell replacement contacts.
Wow! Those are big contacts. Yes, I am beginning to believe that I have
a definite layout problem. Tom's suggestion of running RF *THRU* the
multisection cap also makes a lot of sense as that at VHF, I am sure a
multisection cap looks a lot different from an equivalent cap of a single
value.
>I would suggest removing all RF components and then carefully clean all
>connections, particularly grounds. Do not rely on a panel to be the
>primary ground return to the chassis either.
>Be careful about dissimilar metals and NEVER use braid at RF.
Not a bad idea. I've done some cleaning, but I'll clean some more. And
I probably need to clean the plates on the Load C. I might even just buy
a new load C as I have no idea what the range is of the one that I have.
Good suggestions. And I didn't think about the braid the original
designer put in there, but you and Tom make a good point about it. It's
gone!
73,
Jon
KE9NA
--------------------------------------------------------------------------
Jon Ogden
jono@webspun.com
www.qsl.net/ke9na
"A life lived in fear is a life half lived."
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|