[Boatanchors] 1930's era cw transmitter

[Bry Carling]

Another popular (but tricky) circuit from the 1930s was the LINK COUPLED RF final.

I had trouble with link coupling a few of times... Not everyone does. Your mileage will vary.  
However, I had an ELDICO TV75-TVI model transmitter (or something similar) - and it was  
great fun but would  only make a few watts out from the 807 P.A. until I converted the plate 
circuit  from link coupling to a PI NETWORK (the easiest) and after that it greatly increased 
the  ability to match antennas and produced 25 or 30 watts as best as I remember.  

73 - Bry AF4K

On 2 Jun 2013 at 0:04, Richard Knoppow wrote:


>      Have a look at the ARRL Radio Amateur's Handbooks for 
> the period. They had many low power transmitters.  Another 
> source is the _Radio Handbook_ published on the West coast 
> by Radio magazine, the predecessor to CQ. While it covers 
> similar material to the ARRL handbook the approach is 
> different and one can find many interesting projects in it. 
> I think at least some ARRL handbooks may be available on the 
> web.  I would look at somewhat later ones too, at least to 
> the early 1950s because the tubes and other components may 
> be easier to find.
>      It was quite common to have separate amplifiers and 
> modulators as a matter of economy; that is a lot of hams 
> could not afford to build a complete transmitter at once so 
> built the amplifier for CW and later added a modulator.
>      There are many tubes capable of 50 watts either singly 
> or by using two in parallel or push-pull.  Despite what has 
> been said in other posts to this thread there are many plans 
> for push-pull amplifiers shown.
>      The RCA Transmitting Tube Handbook, published in many 
> editions over the years also has circuits for both 
> amplifiers and modulators but does not give the mechanical 
> plans as the handbooks do.  The RCA books have a very good 
> tutorial on tubes and design and are worth reading.  At 
> least a couple of the TT manuals are on the web.
>      I think this is an interesting project and should be 
> fun.  The HRO is a good receiver and even the old ones 
> perform quite well.
> 
>      See http://www.tubebooks.org for a wonderful collection 
> of scanned books on tube electronics.  Also, if you are an 
> ARRL member you can get copies of articles from all issued 
> of QST ever published except for some of the most recent 
> ones from the ARRL web site.
>      Good luck with this.
> 
> 
> --
> Richard Knoppow
> Los Angeles
> WB6KBL
> dickburk at ix.netcom.com
> 
> ----- Original Message ----- 
> From: "w5sum" <w5sum at comcast.net>
> To: <boatanchors at mailman.qth.net>
> Sent: Saturday, June 01, 2013 12:54 PM
> Subject: [Boatanchors] 1930's era cw transmitter
> 
> 
> > howdy y'all
> > I'm awaiting the arrival of my HRO Senior.  I want to 
> > build up a 1930's era CW transmitter.  This could be a 
> > cool thread.
> >
> > How many of you have built one and what did you use? What 
> > tubes would you suggest?  I would like to have 50 watts 
> > minimum output, but higher power is great.
> >
> > Yes, eventually I will modulate it.
> >
> > Suggestions?
> >
> > Ronnie W5SUM
> 
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