[Hallicrafters] Re: [Boatanchors] Replacing recttubeswithdiodesquestion

[jeremy-ca]

Bill, it took me quite awhile to quit laughing, you should do well in a 
stand up comedy club!

Engineering tradeoffs, phase noise, IP3 and AC/DC all in the same breath! On 
a 60-70 year old entry level radio no less which was the start of this 
thread! I could see it if the SX-115 was being discussed but a S-40B? Wow, 
what a stretch!

If you wish to discuss those engineering performance subjects and my 
involvement with Ulrich Rhode, Kenwood and Yaesu I will be glad to discuss 
it on the proper forum. The Hallicrafters or Boatanchors forum is not the 
place for it.

Carl
KM1H




----- Original Message ----- 
From: "Bill" <kirklandb at sympatico.ca>
To: "'jeremy-ca'" <km1h at jeremy.mv.com>; <wq9e at dtnspeed.net>; 
<erastber at tampabay.rr.com>
Cc: <boatanchors at mailman.qth.net>; <hallicrafters at mailman.qth.net>
Sent: Wednesday, February 13, 2008 6:52 PM
Subject: RE: [Hallicrafters] Re: [Boatanchors] Replacing 
recttubeswithdiodesquestion


> Unfortunately Carl I don't seem to have a copy of an earlier email from
> you
> discussing any exceptions or voltage reduction.  I only saw the email I
> responsed to
> which made quite blunt general statements.  What I've found lacking in
> your responses
> Carl is a lack of discussion of the engineering trade offs or a good
> solid analytical
> analysis. Please pass it along.
>
> e.g. Just because something is done, in one receiver, e.g. AC/DC radios
> where
> B+ is applied, doesn't mean it was the best thing to do. They may well
> have made an engineering trade off, cost, performance, simplicity of
> design for the
> sake of some tube life. Who knows, maybe it was intentional, keeps the
> customer buying
> tubes.
>
> As for National giving the ok, great but since I don't have access to
> the engineering
> report I have no idea what the trade offs are.
>
> As for receiver sensitivity, good to hear that it didn't change but what
> other parameters
> have to measured, e.g. IP3, oscillator phase noise?
>
> Instead of indicating such and such is a myth because "it worked for
> me/others", I would
> rather see a good solid engineering/analytical discussion.
>
> It's good to have a great RF lab, unfortunately you didn't quote any
> measured results.
> Maybe in a previous email thread? If not, posting them and maybe some
> enterprising
> individual could put it up in an html page. Reminds me, guess I should
> do a google.
>
> I merely pointed out the obvious differences between the tube rectifier
> and the solid
> state rectifier.  If you have some good analytical data, I would love to
> see it and then
> perhaps a good html page could be set up.
>
> I guess in summary there are 4 groups, "best practices", "acceptable
> practices", "bad practices"
> and anything else.  It seems some of those that methods that might be
> considered "best (better)practices"
> get relegated to myth status.
>
>