[AMRadio] : Apache audio Real good - Use of 6146's


Larry Knapp kc8jx at yahoo.com
Mon Apr 15 15:14:47 EDT 2002


Gary - Thanks...As I said, it's up to you as to whether you wish to use them or
not.  Who told me that the 6146B's where designed primarily for SSB service? 
Mainly Collins, Heath and the actual tube design sheets.

73, Larry KC8JX

--- Gary Schafer <garyschafer at attbi.com> wrote:
> 
> 
> Larry Knapp wrote:
> 
> > Gary - It's totally up to you whether you wish to use 6146B's in place of
> > 6146A's.  I refer you to G Zook's recent article in Electric Radio.  It's
> > possible they do work in some early transmitters, but in others, using
> 6146B's
> > in place of the original design for 6146 or 6146A's will cause severe
> > parasitics and improper neutralization.
> 
> I have used the B's in lots of transmitters with no problem. I remember one
> or two
> collins transmitters that I did have to change the neutralization components
> on to
> get it to neutralize properly though. Any time you change tubes you should
> check
> the neutralization. I have also seen several transmitters with 6146A's in
> them that
> were not properly neutralized also.
> 
> The DX-100 was never manufactured with any neutralization in it that I know
> of.
> There was a mod that a lot of people did to neutralize them. Very simple to
> do.
> When properly neutralized you will find that you may be a little short on
> grid
> drive on 10 meters. I have never seen any more parasitic problems with the
> B's than
> with the A's when properly neutralized.
> 
> The VHF and UHF radios the Glen spoke of are more of a problem because of the
> frequencies that they operate at. In those radios inter electrode capacitance
> plays
> a bigger roll in fixed circuit component values than it does at HF.
> 
> > The 6146B's were designed primarily
> > for SSB operation, not AM.
> 
> Who told you that?
> 
> 
> > It's up to you.  I prefer the 6146 and 6146A's in
> > my DX-100B, Valiant and Heathkit Marauder; all before 1963.
> >
> > 73, Larry KC8JX
> 
> I wouldn't think twice about using 6146B's or W's rather than A's or plain
> 6146's.
> If I were buying tubes I would pick the B before I would the plain or A
> version.
> More plate dissipation in the B.
> 
> 73
> Gary  K4FMX
> 
> 
> >
> >
> > --- Gary Schafer <garyschafer at attbi.com> wrote:
> > > Yes you are right Larry. I can never remember that the DX-100 was
> advertised
> > > 100 watts output and the Apache was advertised 150 watts INPUT. You end
> up
> > with the same output on both. I first see the 6146B advertised in QST
> around
> > 1963 or 64. I think the Apache appeared in 1959?
> > >
> > > As far as using 6146B's in place of the A's though there is really no
> problem
> > > doing
> > > so.
> > >
> > > 73
> > > Gary  K4FMX
> >
> > =====
> > May your days be full of sunshine and good thoughts fill your head.
> > From: Larry Knapp, KC8JX, St. Joseph, Mi  49085
> >   Best 73's
> >
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=====
May your days be full of sunshine and good thoughts fill your head.
From: Larry Knapp, KC8JX, St. Joseph, Mi  49085
  Best 73's

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