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[AMPS] 4-1000A plans

To: <amps@contesting.com>
Subject: [AMPS] 4-1000A plans
From: measures@vcnet.com (measures)
Date: Fri, 17 Sep 1999 12:55:02 -0700
>
>measures wrote:
>
>>  Most hams are so terrified of a tetrode with 10,000w of dissipation,  
>>they will sell cheap.  My guess is that an 8171 can be found at a 
>>reasonable price on rec.radio.swap. 
>>
>Yeah, but Rich, unless they trip over one at an estate sale, MOST hams 
>wouldn't even come into possession of one in the first place.
> 
I know a ham who has a 8170, 8171, 8281 and 8349  (including socket) for 
sale. 

>>>Also who says you have to 
>>>drive a pair of 4-1Ks with 350 Watts?  That would assume that a single 
>>>4-1K would need to be driven with 175 Watts.  
>>
>>At 3500v, 175w of drive is about right.
>
>WHO drives a 4-1K with 3500 volts?  That would be majorly silly.
> 
That is what it takes for 1500w out.  
>>
>>>I drive my single 4-1K with 
>>>about 80 to 100 and get full legal limit.  And I ALWAYS get great signal 
>>>and audio reports.
>>>
>>zzzzzzzz  zzz
>
>So I guess this means you aren't interested or applaud others in their 
>success?
>>
Crowing is ok for roosters.  For humans, it's not.  .  

>>>Plus there's a romance in seeing the glow of those old firebottles!
>>>
>>In a 4-1000 there is so much screen L, it's like being in parasitic hell. 
>
>Hmmm...Gee, once I came up with a good layout, I didn't have any 
>parasitic problems.  

Tom Rauch talked plenty about "good layout" being the magic elixer to 
cure parasites, but he never explained the real-special secret stuff to 
us.  . 

>In fact, I don't run nichrome in the anode OR 
>supressor resistors for that matter.  Haven't been able to find 
>instability yet 

Humans do not find parasites.  They find you.  .  

>and I run 50 wpm dits with the PA all the time when 
>tuning.  Oh yeah, and with my layout, I have NO anode resonance I can 
>find in typical 4-1K resonant area.

[chortle].  If you say there is no measurable dip with a dipper at the dc 
blocking cap, a large pizza with 5 toppings and salad bar says there is. 
>
>But then I guess I've done the impossible since every amp should have 
>nichrome?
>
The first tetrode with handles amp that I built did not use a 
resistance-wire suppressor.  The second one did.  The first one was an 
education.  The second one was boring.  //  Using a nichrome suppressor 
is no big deal.  It reduces VHF gain and Rp a bit over 40%.  

>I left parasitic hell a long time ago and my amp came with me.
>
... when will they ever learn ...?
>
later, Jon


-  Rich..., 805.386.3734, www.vcnet.com/measures.  


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