Enhanced Apache TX-1 Audio

[Robert & Linda McGraw K4TAX]

Lin & Company:

I couldn't agree more in terms of keeping it original.  You did take notice 
that I did not actually remove any components or drill any holes. I only 
added components to what was already there while leaving all others intact 
and original.

As to the design for communications and channeling the voice energy into a 
narrower passband, yes I agree,  if it was done correctly.  However, due to 
the bias structure on the last stage of the 12AU7 and the choice of cathode 
bypass filter for the triode connected 12BH7 the modulated THD is 10% or 
greater.  This is simply poor engineering in anybody's book unless one is 
intent on developing a guitar fuzz tone box.  {And that's already been done 
by an engineer that I worked with in a Nashville recording studio.}  Yes, 
channeling into a narrow bandwidth is good but it must be very low 
distortion to be highly intelligible.  Sorry but Heath missed it on this one 
point.

And if I want to run AM BC quality, I light the AM BC transmitter and all of 
it expensive mikes and exotic processing.

73
Bob, K4TAX


----- Original Message ----- 
From: <digital-conjurers at ADELPHIA.NET>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Wednesday, January 04, 2006 10:53 PM
Subject: Re: Enhanced Apache TX-1 Audio


Ray,

That kinda hits the same note here, though in a different way.  Now, I know 
that Hams love "modding" their equipment, but if you're into the 
preservation ethic, wellll...if I started modifying my Apache to the point 
that it had great audio, it would no longer be what was originally, as the 
kit came from the factory...a "Scratchy Apache".  The way I look at at, 
that's what makes it what it is.  It's not a design defect, (some might 
disagree) it's the way it was designed (or so I am told), to put all the 
energy into a narrower passband for better communications intelligibility in 
difficult conditions. Collins, Johnson, maybe even Hallicrafters, all 
probably have "better audio".

Car collectors are finding the same problem...it's hard to find original 
classic cars that haven't been hot-rodded, modded, chopped, etc.  A friend 
of mine wails in despair every time he sees a early 50's Lincoln Hot Rod, as 
he wants to buy one that remained "Just Stock".  But he's not a Hot Rodder. 
:)

OTOH, if you're really into AM BC quality audio, gosh, there are lots of 
vintage AM transmitters out there that'll make that trip better, I 
imagine...but, if that's your thing, and you only have an Apache, well, go 
for it, I guess.   "à chacun, leurs propres." (To each, their own.)

-Lin/KJ6EF
========================================================



>FOLKS ... this is HAM RADIO ... this is COMMUNICATIONS ...  this is NOT 
>broadcasting.   We are not broadcasting the New York Philharmonic 
>Orchestra.  We are having a conversation.   WHY do you want to have studio 
>quality audio during a communications procedure?  Personally, as long as I 
>can understand what  youre saying, I dont particularly care or notice 
>whether youre tonsils are
>giving forth with that beautiful bass tonal quality or you have the 
>falsetto voice of a pubescent teenager...    HI HI.
>And, if it's a DX or other contest, we've only said three words to each 
>other before we are history and a mere log entry to each other.
>
>Again ... just my own idle curiousity...  not a complaint or criticism.
>Ray  WA7ITZ
>__________ NOD32 1.1349 (20060102) Information __________
>
>This message was checked by NOD32 antivirus system.
>http://www.eset.com
>

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