Power Supply for a ART-13

[Joe Moore]

 I am looking to build a power supply for a ART-13.
Any info would be appreicated ie. Plans, Parts or
anyone looking to sale one.
Thanks..   Joe KF0XV

[KB2WIG]

Joe,
Try a search of Electric Radio. There was a supply along with some info on how the auto tune works. You'll need the December 03 along with the January 04 issue of ER. I'm moving so i don't have the copy at hand; there is a mistake on the December schematic so you also shud get da jan issue.......

 Alos, dont switch the HV supply with the LV supply, you'll let the smoke out...  klc

[KE6DF]

I'm in the process of collecting parts for the same project.

Here is a simple schematic for an ART-13 power supply.

http://www.kf9cm.com/schematics/image001.jpg

Notice that the schematic has an error and shorts out the high voltage B+.

That would provide more excitement than I am looking for.

The old Surplus Conversion Manuals have two different designs for ART-13 power supplies. See volumes 2 and 3.

http://www.mines.uidaho.edu/~glowbugs/SurpConv.html

These are older designs using MV tube rectifiers.

I had an ART-13 on the air when I was in high school in the 1960's. I got the power supply off another kid, but had to modify it to get it working. For the 28 volt 10 amp supply I used one of the old selenium recitifiers about the size of a loaf of bread. That TX is long sence gone.

I have a couple ART-13's now. One complete and untouched. Another where someone removed the band switch and output circuits. I also have a parts unit with a lot of stuff missing, but it does have the band switch. I'm hoping to get at least one and perhaps two of them back on the air.

I have scrounged a UTC-303W transformer (3000v ct) which I plan to use for the HV B+.

I'm thinking of using tube rectifiers like I did back in the 1960's. Probably 836s as I never had a bit of trouble with them and still have some.

Of course there is no good engineering reason not to use silicon diodes. But then, I like tubes, and this is a hobby not a paid engineering design project.

No more selenium rectifiers however as 50amp diode bridges cost about $3.

[KF9CM]

The schematic has been fixed. I built the power supply 7 years ago and is been working ever since. 165 watts on 3.885 MHz.


de Gary, KF9CM

[fg5fc]

Hi KF9CM!
i wonder if you have a good filtering( no hum) in the power supply you used without choke filters?

 73'S JOHN

[KF9CM]

The ART-13 draws 150ma @ 1300 volts in CW.  The voltage drop after the peak will be I/C * delta T, where delta T is 1/2 cycle time (8.6 mSec for 60 Hz)

For .15 Amp, and 75 uF of capacitance.  .15a / (75E-6) * 8.6E-3 = 2000 * 8.6E-3 = 17.2 Volts. Thats about 1.3% ripple.

I was trying to get away from having a power supply so heavy it has to be mounted on wheels.

73 Gary, KF9CM

[KE6DF]

In the good old days, when chokes were used, a 1500 volt 200ma power supply would typically use capactors in the 4 or 8 mfd range. Can you imagine how expensive it would have been to put a 75 mfd capacitor bank together in 1950 - and how big it would have been using the oil capacitors of that era. Chokes were needed to get acceptible ripple back then.

Another reason is that rectifier tubes don't have nearly the peak current capabilities of modern silicon rectifiers and a capactor filter like the one in Gary's supply would probably have exceeded the peak current ratings of any tube you might use.

But times have changed with large electrolytics and diodes.

I happen to have several chokes, so I'll probably use them -- along with modern capacitors. Overkill, maybe, but the lower the ripple the better.

I also want to play around with a resonant choke filter so I might use the power supply for an SSB (oops I said a bad word) linear.

[TedN]

Joe;
I am using Gary’s design and in AM with the audio input shorted there is no detectible hum.
To hear the audio I’m using the RF sample box described elsewhere on this site. I came up with the 28V supply by rewinding the secondary of a 250W transformer. Because the secondary was only 28V I decided to rewind without disassembly of the core. It was only 30 feet of wire. I couldn’t come up with the iron for the two HV supplies so I purchased new toroidals from AnTek (sp)? Low cost.
Nice transmitter, hope to hear it one the air.

73’s

Ted KC9LKE   

[fg5fc]

Many thanks Gary for the reply also wb6iyh for the comments, i have both chokes and hight value capacitors...Better way with light iron!

JOHN

[WU2D]

Joe,

I built mine up in 1992 and it has been a solid dependable beast. The simple time delay allows the fillaments to light before applying B+.

Mike WU2D