[AMPS] More amplifier experiments

[Jon Ogden]

>>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."


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