[Boatanchors] 1930's era cw transmitter

[Bry Carling]

I guess then a Pi Network just ha sa whole lot of "inherent easiness" (grin!)

Yes, for those desiring period authenticity I think it would be a blast to build something link 
coupled, designed only for a specific band, and antenna, etc., or use it with an external 
tuner, which expands the number of componnets in the transmitter setup and 
complicates things. Plenty of guys made good contacts using link coupling, but who 
knows how much power some of them were actually  feeding to their antenna. 

YMMV

Bry

On 3 Jun 2013 at 14:04, mac wrote:

From:           	mac <w7qho at aol.com>
To:             	Rob Atkinson <ranchorobbo at gmail.com>
Date sent:      	Mon, 3 Jun 2013 14:04:22 -0700
Copies to:      	"boatanchors at mailman.qth.net List" 
<boatanchors at mailman.qth.net>
Subject:        	Re: [Boatanchors] 1930's era cw transmitter

> No inherent difficulty with feeding coax from a link but the
> tank/link  
> coil arrangement has to be designed with just the right turns ratio
> if  
> fixed or, alternately, with a variable arrangement (swinging or  
> rotating link, series cap, etc.) configured to provide a match over
> a  
> range of load impedance values.
> 
> Dennis D.  W7QHO
> Glendale, CA
> 
> **************
> On Jun 3, 2013, at 4:53 AM, Rob Atkinson wrote:
> 
> > On Sun, Jun 2, 2013 at 8:47 AM, Bry Carling <bcarling at cfl.rr.com> 
> > wrote:
> >> Another popular (but tricky) circuit from the 1930s was the LINK 
> >> COUPLED RF final.
> >>
> >>
> >
> > It was "popular" because the feedlines of the day were balanced
> > parallel wire.  What you are probably really referring to is the
> swing
> > link output.  Since just about everyone (not exactly sure when
> > unbalanced line became common but I think it was after WW2) used
> open
> > wire line, a balanced link coupled output was pretty much a
> standard
> > arrangement.   The Meissner 150B from WW2 used a pi network
> because it
> > was originally made to work into a random length wire (unbalanced)
> in
> > the field.  That's about the earliest rig I know of using a pi
> network
> > output (but my knowledge is far from complete).
> >
> > you don't say what feedline you were using.  If you were trying to
> get
> > the link coupled to work directly into 50 ohm coax then of
> course
> > you'd have difficulty.  It was designed to work with twisted pair
> or
> > parallel line to either a balanced dipole or a floating link input
> to
> > a balanced tuner like a EFJ matchbox (but with its link connected
> to
> > the twisted pair).
> >
> > 73
> > Rob
> > K5UJ
> 
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