Group,
This discussion re the power supply filter has got me thinking.
This stuff has been done both ways.
I have built a power supply for my TBW using the swinging / smoothing
choke arrangements.
However, I also have in operation a 115 vac power supply for the ART-13.
It was made by the R.L. Drake Company - yup, the same one that is (was) in
Miamisburg.
Oddly enough, it is not that heavy. Perhaps 40 lbs.
When I got the unit the filament supply transformer was dead.
I replaced the (4) 866jr with silicon, all the electrolytics have been
replaced and I reworked the filament supply.
I removed the giant selenium rectifier in lieu of a full bridge rectifier
that was now mounted to the chassis.
I placed some large computer grade 35 volt cap across the output.
The filament transformer was replaced by a 19 volt 30 or so amp transformer
( 19 X 1.41 = 26.79 volts - close enough. )
The filter for both the hv supplies is a choke input followed by the
electrolytic. Presumably, it is pure smoothing.
The only thing I did to the ART-13 was remove autotune functionality by
desoldering a field winding.
Apparently, the fields are energized the entire time filament was supplied
making for a warm front panel and unnecessary load on the power supply.
By the way, I understand there is a mod to get around this "continuous field
on" situation besides my approach of desoldering the field connection.
If anyone has the dope on that pleas let me know.
de KA4JVY
Mark
--- Rick Brashear <[EMAIL PROTECTED]> wrote:
> Jim,
> I appreciate your take on the power supply and agree for the most
> part. Even though this particular ART-13 will see little if any CW
> operation I would like the supply to be as stable and clean as
> reasonably possible. You are absolutely correct about the difference of
> availability of capacitors and chokes in today's world versus the days
> of W.W.II. I considered using more modern components and at one time
> even thought about an all solid state power supply. It would be much
> easier and cheaper to construct and less expensive to operate with less
> heat. However, the lure of the olden days kept calling me back to
> glowing tubes and swinging chokes. So, even though I agree that with
> modern technology applied I could have a cleaner, lighter and less
> expensive supply, I will likely stay with the old school thinking on
> this one. That is IF I can get the ripple to a low enough level so as
> not to cause problems on the transmitted signal.
> Thanks again for your advice and explanation, you make a very valid
> point and one which would serve my project well.
> 73,
> Rick/K5IZ
>
>
>
> Jim candela wrote:
>
> >Rick,
> >
> > Sorry but I am going to throw a wrench into this discussion. Those
> >swinging choke power supplies, although useful, have been out of favor for
> >years...
> >
> >
> >
>
>
> ______________________________________________________________
> AMRadio mailing list
> Home: http://mailman.qth.net/mailman/listinfo/amradio
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:AMRadio@mailman.qth.net
> AMfone Website: http://www.amfone.net
> AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
