Jack Roland KEØVH@q.com
Greetings all, I hope you had a great beginning to the New Year, and now that we are in the swing of writing 2012 in our checkbooks, time for some new projects.
For a long time I have been fascinated by converting old computer power supplies into something useful for the work bench or powering a radio. Never hurts to have an extra power supply on hand too, for whatever the reason. There are many articles on how to convert a computer PS into a bench supply to provide 12 volts for whatever use you might need. A few years ago I converted one that I have used for many applications such as powering a business band 2-way radio, and then after that was done I used the same PS to power an APRS beacon that I ran on Lookout Mountain for a year or two. I won’t bother with listing all the ways to do this as there is plenty of information on the internet, but I will show one of my conversions here. The main thing is to bring the regulation up by providing a resistance across the 5 volt lines, and many supplies are either adjustable or can be modified to do so. The easiest way is to provide a 1 ohm 10 watt resistor across one of the 5 volt lines to ground to do this. Again, all the technical explanation is easily found on the internet.
Interior of the Power Supply
In the picture above the leftmost blue adjustment pot allowed me to set the PS to about 12.9 or so volts. You can experiment with this or other ways of raising the voltage to the proper level depending on the supply. The resistor to bring up the 5 volt regulation is shown below. It is mounted on one of the heat sinks where there is room with heat sink compound on it to the metal sink.
The front of the supply The 1 ohm 10 watt “regulating” resistor
I installed an LED on the “Power Good” line for on indication and a toggle switch to turn the PS on and off from the front panel using the pair of wires indicated for power on and off. The circuit board in this case was labeled where the wires were attached, but again this information is available on the internet easy enough. I installed an Anderson Power pole thru holes drilled in the front and another pair on another 12 volt/ground wire pair out the back of the PS. The PS is being used right now as a bench supply or backup where needed. This one delivers 12.9 volts at 15 amps, and I will experiment in the future with different uses and see how it holds up.
Another great project that I have a real interest in is what my friend Kenny, K4KR in Chickamauga, Georgia near Chattanooga, Tennessee has been up to lately. He obtained an amplifier module from Bruce, WA2ZST, who is an engineer with CBS-TV in New York City, which originally helped to power the Harris transmitter for WCBS-TV. Kenny has built a 50 volt 50 amp power supply to run the amplifier, and will soon be putting a kilowatt out on 6 meters with this! What an historical and cool piece of gear this is! Several of these were obtained by ham operators around the country and are being converted for ham use. Once Kenny gets this all racked up and mounted in his shack, he will be feeding a big 7 element with a 28 foot boom 6 meter yagi with it and will truly be a “big gun” on 6 meters. More on this story as it develops!
K4KR 50 volt 50 amp power supply and former WCBS-TV Harris VHF amplifier.
April is not too far away, and with it will come the 100th anniversary of the sinking of the H.M.S. Titanic in 1912. If you are familiar with the story you will know that Jack Bride and Harold Phillips, the wireless operators aboard Titanic of course are remembered for sending out the CQD’s in morse code (then the equivalent of SOS) that made the Titanic’s plight known to the world. There will be Ham Radio special event stations commemorating the event in honor of these radio operators, the passengers and crew lost, and the event that still captivates so many My friends in England will be operating the GM100MGY (MGY being Titanic’s radio call sign) again as they did back in 1990, under the call sign GM90MGY. From their official News Release:
To commemorate his heroism on the centenary of the disaster, a Surrey radio club – Wey Valley Amateur Radio Group – will set up a special radio station in April, 2012, located at Charterhouse School, on the outskirts of Godalming. Transmissions in morse code on the amateur radio bands will begin on Tuesday, 10 April (the day, 100 years ago, when Titanic sailed from Southampton). They will pause at 05.46 GMT on Sunday 15 April, the exact time at which transmissions from Titanic ceased and the vessel sank. Titanic’s radio call sign MGY will be remembered by the station’s special UK call sign: GB100MGY.
A very special commemorative QSL card will be offered! I will be in the hunt for that one for sure! More information on the activities of the special station and sponsorship opportunities can be found by contacting Mike, G3IAF or Mike GØEFO via GB100MGY@gmail.com
The QSL from the 1990 event
WØS will also be operating out of Branson Missouri at the Titanic Museum April 14th and 15th 2012 and offer a really cool QSL card too from stateside.
Jim, KCØRPS made a “hut trip” to one of the cabins way up in the Rocky Mountains of Colorado to do some back country skiing and relaxing miles from any civilization. The 10th mountain division huts, interspersed in the back country of the Colorado mountains and are accessible by hiking or skiing in offers solitude (unless you take a lot of friends, which is great fun), back country skiing, and the spectacular views of earth and sky that testify for sure to the handiwork of the Lord! One of his companions on this trip took video and pictures to chronicle the weekend getaway! It also is a great way to do some ham radio operating from great remote locations too. Jim and I have talked via the Colorado Connection repeaters at various times, and he is working on a QRP 40 meter CW rig that he plans on taking with him soon. Check the spectacular video of this trip at http://www.youtube.com/watch?v=yzql4b2H224&feature=youtu.be
Bob Heil, K9EID, and Gordon West, WB6NOA recently visited the set of ABC’s “Last Man Standing” starring Tim Allen, who plays a married father of three tries to maintain his manliness in a world increasingly dominated by women, and, is a ham radio operator! Mike, KA0XTT, Allen’s character, operates a ham station on the show and on this facebook page there are pictures of Bob, Gordon, Bob’s lovely wife Sarah, and Tim Allen.
https://www.facebook.com/media/set/?set=a.285406404850423.74590.269589906432073&type=1
Full a full write up about the show and Tim’s character, see this ARRL Article at:
AND, Tim Allen isn’t the first ham in a sitcom. Check this out for a “monster” great ham station: http://www.youtube.com/watch?v=Kqx2ZCwHKa8&feature=related.
And, finally, have you seen the latest radio entry from China into the US market? I and several others I know own the Wouxun (pronounce “OH-cheng” like “ocean” with a g at the end) dual band HT and are really happy with how well it works and sounds, not to mention the under $100 price. Now, there is a $48.00 or so dual bander! The handheld BAOFENG UV-3R (Mark II)136-174/400-470Mhz Dual Freq Display HT. (See it at http://www.409shop.com/409shop_product.php?id=106279). Wayne, WA2KEC, Jim, KCØRPS and several other hams we know are really happy with it. And at this price how can you miss? I look forward to seeing how this is received by the US ham community. See reviews of this radio at http://www.eham.net/reviews/detail/9749 .
The radio also comes in many available colors, see the Rigpix pictures at: http://www.rigpix.com/mischam/baofeng_uv3rmk2.htm.
Don’t forget the SBE IRLP/ECHOLINK Hamnet, the 1st Saturday of the month and the 3rd Tuesdays now. Details on how to join us are at http://www.qsl.net/ke0vh/sbehamnet.
73’
KEØVH
www.qsl.net/ke0vh