[Heathkit] sb200/220 fan

Sat, 30 Nov 2002 18:04:10 -0500

----- Original Message -----
From: "Jim Shorney" <[email protected]>
To: "Carl Huether" <[email protected]>; <[email protected]>
Sent: Saturday, November 30, 2002 11:34 AM
Subject: Re: [Heathkit] sb200/220 fan

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> On Sat, 30 Nov 2002 11:10:56 -0500, Carl Huether wrote:
>
> >Rich and I have a serious disagreement with what causes some events.
> >I, for one, do not believe in ghosts nor magic parasitics that manifest
> >themselves particularly when the tubes are in full cut-off.
>
>
> Not to get into a debate here, but much of what Rich says sounds
> logical and reasoned.

He does sound good with his spiel!
So did P.T. Barnum

>
> >See your NCL-2000 schematic for the proper way to mitigate that effect.
>
>
> Could you be a little more specific?  I'm not an engineer.

Neither is Rich.
The trick is to quench the off resonance HV; see that little 10pf cap
between the 40-20M contacts?
Ive gone up to 15 pf on the 220 without problems. It does add to the Tune C
but not enough to affect 10-15M.
Trick is as old as the hills, just rarely used.

>
>
> >C. You will find VHF resonances in any amp.
>
>
> And this is a reason not to try to minimize thier effect?  Not really
> trying to be argumentative here, I really would like to know.  Rich's
> surpressors do seem to work as advertised, at least according to
> anecdotal evidence.  Just because something is there doesn't mean it is
> right or proper, IMHO.

If they dont cause a problem why look for one or even create another with
half thought out ideas?
Do you use all the various automotive additives just because someone said it
works?
Or are you even aware of the Slick 50 and other lawsuits over the last
several years?
Oh, hot rods and performance engine building is my "other" hobby.

>
>
> >The internal tube structure is
> >the biggest one and the parasitic suppressor is designed for that
purpose.
>
>
> Technology in almost every other area of radio electronics has improved
> greatly over the last 50 years.  You're saying parasitic surpressor
> technology hasn't, or can't improve?

Yep.

  Please explain.

Dont really need to, its good enough for the tube designers, its good enough
for you and me.
If there were a reason to change it would be an addendum to spec sheets, a
tech bulletin or even a blurb in a magazine.
Anything that would cut down on warranty failures would certainly not be
suppressed (pun intended).

I personally discussed the issue with Eimac engineers when the QST article
first appeared. Since I work on amps on a regular basis I was concerned.
Their comments are better left unsaid here, this is a family forum.

>
> >Funny looking magic parasitic cure-alls do nothing except generate
revenue.;
> >they address the symptom and not the cause.
>
> Ah, much like the war on drugs.  I can see your point.  OTOH, I always
> thought the 'standard' parasitic surpressor was funny looking too.
> IMO.  There is some merit to treating symptoms as well as causes; It
> also seems to me that improved surpressors DO indeed treat the cause,
> if you read Rich's theorys.

Rich got into a firestorm with the ARRL some years ago over his junk science
theories.
It continued on the Internet. Lets just suffice to say that several well
respected amp and tube engineers had a jolly old time.
Rich wouldnt back down an inch and got quite abusive. He is pretty much
ignored by them these days.

If you like his stuff then by all means use it. I remove them from every amp
that comes in for repair, then fix the causes.

>
>
> >Carl
> >National Radio 1963-69
> >Part of NCL2000 Design Team
>
>
> Pleased to meet you.  The NCL2000 has always been my favorite amp.
> Works nice, and it's 'pretty'.

The NCX5 and NCL won commercial design awards, a first for a ham product.

> >I currently offer repair and modification services to any amp, HF thru
> >Microwave
>
>
> What sort of mods are kicking around for the NCL2000?  I've never seen
> any (aside from Rich's), so I always assumed that it was 'done right'
> from the start.  Perhaps we should take NCL discussions off-list, since
> it is OT.

Very little for mods, mostly adapting newer replacement parts for items no
longer available

>
> Again, I'm not trying to be argumentative.  I'm just reading everything
> I can find and trying to suss this all out.  I've had the NCL for many
> years,

I have 3 of them, all started as engr prototypes.  One I converted to 6M in
1965, its still in use; another covers 160-10 inc WARC; the other is a parts
queen.

 the L4B is a recent acquisition (and my first 3-500z amp).

A nice amp. Unfortunately it appears to have been designed by a committee.
The RF and PS people never talked it seems.

My day to day amp is a LK-500ZC. Its survived me since new as well as about
6 years of very serious contest use by a guest op.
Still has the original 3-500Z's.

Carl

>
> 73
>
> Jim
>
> - --
> Jim Shorney      -->.<--Put complaints in this box
> [email protected]
> [email protected]
> Ham Radio NU0C
> Lincoln, NE, USA
> EN10PT
> http://incolor.inetnebr.com/jshorney/
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