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[Amps] Mailing list for parasitic osciallations.

To: <amps@contesting.com>
Subject: [Amps] Mailing list for parasitic osciallations.
From: garyschafer at attbi.com (Gary Schafer)
Date: Sun Mar 16 16:48:29 2003

rlm wrote:
> 
>>rlm wrote:
>>
>>
>>>How about a separate mailing list for power supplies where only amplifier
>>>power supply discussions are allowed -- and all other topics are verboten?
>>
>>If *very detailed* discussion of power supply design, was repeatedly
>>discussed by a *small group* of individuals and formed such a *huge*
>>part of the mailing list, there would definitely be an excellent
>>argument for a 'hv-power-supply' mailing list. But at this moment it is
>>an issue that:
>>
>>a) Affects a lot of people - i.e. is of general interest.
> 
> 
> **  Oscillation is an issue that effects all amplifier builders -- except 
> those who use 813s.
> 
> 
>>b) A large number of different people contribute to PSU design
>>discussions. I have myself on a couple of occasions.
>>c) The technical arguments are not that difficult to follow by the
>>average person. 
> 
> 
> Good point.  Non-switching PS design is old hat.  
> 
> 
>>d) The same arguments don't keep being put forward. 
> 
> 
> There are still those who believe that a FWB is superior to a FWD.  
> 
> 
>>e) It is not like religion, where you are unlikely to convince a person
>>believing in X that X is rubbish and they should accept Y. 
>>
> 
> Those who do not accept AC circuit-analysis are in the same category.
> 
> 
>>I'm not suggesting an 'hv-power-supply' mailing list should not be
>>considered - it is perhaps not such a bad idea. It is perhaps the most
>>obvious split, as 'amps' is a large mailing list which I do feel needs
>>splitting up. 
> 
> 
> I do not.  
> 
>>The reasons for my suggestion of a parasitic-osciallations mailing list
>>is:
>>
>>a) The number of people contributing to the discussion seems quite
>>small. Although I have not collected any statistics on it, I would guess
>>95% of the posts are contributed by less a dozen individuals. 
> 
> 
> It seems to be more than a dozen.  
> 
> 
>>b) The first point (a) implies it is not of a wide interest.
>>c) The discussions gets so detailed that few can follow them. 
> 
> 
> **   The most complex part of understanding the mechanism for reducing 
> VHF gain in MF/HF amplifiers is seemingly the 
> series-to-parallel-equivalent Z-transformation.  This was explained in  
> "Calculating Power Dissipation in Parasitic-Suppressor Resistors", March, 
> 1989 QST, page 7, 'Finding Impedance by Solving for Admittance'. .? The 
> American Radio Relay League, Inc.  (available at Figure 18 on my Web 
> site).  To someone who does not understand how impedance can be found by 
> solving for admittance, the process may seem like voodoo. 
> 
> 
>>d) There are a large number of posts on the subject. 
> 
> 
> **  Perhaps disinteresting posts should be avoided?
> 
> 
>>e) It is like religion. A person believing in X is most unlikely to be
>>persuaded to believe in Y. 
>>
>>Clearly if e-mail would have been available when the first amateur radio
>>experiments were performed, there would have only been one mailing list
>>- 'amateur-radio'. However, that would be a bit of a disaster now, with
>>all the wide interests.  
> 
> 
> Good point.
> 
>>I have several Sun w....... 
>>
>>Parasitic oscillations has I feel reached the point where the
>>discusssions are so detailed, that the detailed arguments should be
>>taken to a separate mailing list. There is nothing stopping people
>>subscribing to both 'parasitic-osciallations' and 'amps'. There is
>>nothing stopping a limited amount of cross-posting to the two mailing
>>lists. But detailed discussions should be moved to the
>>'parasitic-osciallations' mailing list. 
>>
> 
> **  Perhaps you need to take this up with the person who is forcing you 
> to read posts that you find boring ?
> 
> cheers, Dave
> 
> -  R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, 
> www.vcnet.com/measures.  
> end
> 

I skip reading lots of posts that I am not interested in. Parasitics is 
not one that I skip.

73
Gary  K4FMX


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