The discussion is about the 3-500 and the SB-220 in particular. Why add
other tubes that are inherently stable or do you just want to water down the
discussion?
Just about anybody can build a stable amp given enough time. A one-off is a
no brainer. A monobander is a no brainer also.
The problem is to build thousands of them in kit form that are constructed
by persons of a wide range of skill levels.
The problem is to keep factory built amps from destructive behavior as is
known with the AL-82, AL-80 series, SB-1000, various Henry's, TL-922A, and a
few others.
That requires tackling the source of the problem, not the symptom with
makeshift cures and other hack procedures.
OTOH, there are a few fully GG 3-500 factory amps that appear 100% stable.
My 1988 one owner, beat to death, set contest records for many years,
original tubes, LK-500ZC has never even popped a breaker. And it still puts
out 1200W even on 10M with the original parasitic suppressors.
Carl
KM1H
----- Original Message -----
From: "David H Craig" <davidhcraig@verizon.net>
To: "Carl" <km1h@jeremy.mv.com>; <dezrat1242@yahoo.com>;
<amps@contesting.com>
Sent: Sunday, August 23, 2009 11:53 PM
Subject: Re: [Amps] parasitic oscillation techniques
> Maybe the "moderator" won't block this one. I am tired of this old
> saw- you got rid of the parasitic, so to speak, and I personally agree the
> nicrome idea is a bad one. That said, I guess a hobbiest (not a
> "professional" with at best a MS, as seems to be the case here) with an
> AA, BA & JD with ideas & emperical evidence doesn't matter on this List
> with a bunch of old grumpy "EEs" on it. If this is in fact not a
> "Romper-Room" for EEs with big heads, I'll try one last time to tactfully
> mention that with 5 homebrew monoband amps under my belt so far, with
> DIRECTLY-GROUNDED GRIDS, 0 issues with parasitics or whatever. I don't
> even use suppressors on my GS35bs, just a LPF. This list with
> directly-grounded grids also includes an SB220 conversion (yup, chokes &
> caps into the junkbox & replaced with solid strap to ground)...
> My EE friends (WITH VSAs for the anal-retentive), who don't share the
> same compunctions of some on this list, agree. Raytrack, which as you
> know is a FB performer in demand on the used market, also used
> directly-grounded grids on it's 6 meter 2 x 3-500Z amp- you fail to metion
> that little fact. My HB 6 meter amps work, 3-500Zs, GS35bs, 3CPX800A7s.
> When I get my 8877s done, I'll let you know if directly-grounded grids
> work there, if the "moderator" doesn't censor that post like my last. Oh,
> and to the "moderator": If you censor this one, kindly remove me from the
> list like I asked (as per instructions with "Remove" in the Subject Line)
> 2 months ago when you censored my last reponse to this "floating grid"
> discussion, which had NOTHING improper in it except that I assume you
> dislike the fact my amps work. N3DB
>
>
> ----- Original Message -----
> From: "Carl" <km1h@jeremy.mv.com>
> To: <dezrat1242@yahoo.com>; <amps@contesting.com>
> Sent: Sunday, August 23, 2009 11:04 PM
> Subject: Re: [Amps] parasitic oscillation techniques
>
>
>> Im glad you agree..........
>>
>> My conversation was about 22 years ago. Thats how long the voodo science
>> parasitic farce has been going on.
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message -----
>> From: "Bill, W6WRT" <dezrat1242@yahoo.com>
>> To: <amps@contesting.com>
>> Sent: Sunday, August 23, 2009 10:47 PM
>> Subject: Re: [Amps] parasitic oscillation techniques
>>
>>
>>> ORIGINAL MESSAGE:
>>>
>>> On Sun, 23 Aug 2009 21:20:02 -0400, "Carl" <km1h@jeremy.mv.com> wrote:
>>>
>>>>Call Eimac yourself and stop blubbering.
>>>
>>> REPLY:
>>>
>>> Just what I thought.
>>>
>>> 73, Bill W6WRT
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>
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