[Hallicrafters] S-40

[k6uuz at juno.com]

Hi Burt;

If I were you, I would get that 5Z3 out of there immediately. It draws 3
amps of filament current, where the 80 draws only 2 amps. You may be
shortening the life of the power transformer by overloading it. It is bad
enough to run a radio designed for  110/115 volts on today's 122 VAC,
without making substitutions that increase the power draw. If you can't
find/afford a 80, a 5Y3 is identical except for the base. You can make an
adapter or change the socket. Under separate cover I am sending you some
info on why so many power transformers fail. Good luck.

Ed Richards

On Fri, 01 Feb 2002 10:27:22 -0600 Burton Pratt K4PRF <pratt at zebra.net>
writes:
> I have just finished restoring what I believe to be a very early S-40 
> as
> it has an electrodynamic speaker as was used in the S-20R.  I think 
> that
> most of the S-40s used a regular pm speaker.  The dials are green.  
> The
> chassis is stamped for an 80 rectifier although there is a 5Z3 in
> place.  I was unable to find a circuit diagram showing the setup for 
> the
> electrodynamic speaker with the field coil being used as a power 
> choke
> so I used the S-20R diagram.  Everything seemed to match up OK.  The
> serial number of this unit is 51207.
> 
> Thanks for the suggestions on getting more zip out of the HT-40 on 
> ten
> meters.  Listen for me on 29.05 Mc. or 29.025 in the next week or 
> so.
> 
> Having suffered through the restoration of two SX-28As in the last 
> two
> years I am beginning work on a straight 28.  It is in retched 
> condition
> so will be a challenge.  At least there are no extra holes in the 
> panel
> and the receiver has never been modified although there are many 
> things
> hanging loose.  The S-meter is damaged so will be trying to locate 
> one.
> I have a parts rig but the meter is missing.  When I finish this one 
> I
> will have a few parts left for those who are willing to tackle one 
> of
> these beauties.
> 
> 73,
> 
> Burt Pratt, K4PRF
> pratt at zebra.net
> 
> 
> 
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