Wednesday, February 24, 2010

Alpha 78 Rehab




The ARRL Contest Update for April 28, 2010


There is one less Voo-Dude contester following the untimely passing of Vince Thompson K5VT. Diagnosed very recently with leukemia, Vince was unable to tolerate the resulting therapy. As a member of the Voo-Dude contest team, Vince was instrumental in putting West African multipliers in all of our logs. In addition, he was a friendly face at hamfests and conventions, never lacking for a humorous remark. He is already missed by us all. (Thanks, Roger G3SXW and Tony N7BG)

Vince sold me this Alpha 78 after it had made several trips to Africa with him.


Back on the Air today!  Seems to be solid again and the clean blower is really Blowing NOW!



Last week the Alpha was put on the operating desk and a 45 min contact on SSB worked fine so we hooked it up for QSK CW and got ready for the CW Contest.  It worked perfect for 125 or so contacts running QSK with the MK-V we turned it off to sleep and when we woke up the amp did not come back on line! We are now working on it some more.

The manual says to check;
  Input Cable
  T/R input relay
  Input circuit

All of this seemed to be ok be we did find a lot of dirt in the blower so we tried to get it apart to check everything.

Right now my guess is the Filiments are not coming on!

The 'black pin' on the Molex connector is the Filament winding from the transformer.

The Blower come away from the motor with two screews on the inside of the blower fan.  Washed it in the wifes kitchen sink.  The gunk was 1/8" to 1/4" all inside so the airflow should be improved.

Sunday, February 21, 2010

ARRL DX CW Contest

ARRL DX CW Feb 2010 Summary

 Band    QSOs    Pts  Cty
   3.5      43     129   33
     7     124     372   57
    14     202     606   63
    21     146     438   59
    28      28      84   13
 Total     543    1629  225
Score: 366,525

Rig Yaesu FT-1000MP Mk-V
Ant Cushcraft R7 (24 ft vert) and 1/4 wire out the 3rd fl window for 80/160
Amp Started with Alpha78 but coax grnd opened after 150 Q's so switched back to Clipperton
Software N1MM
Keyer WinKeyer USB www.k1el.com

Read the great book Zen and the Art of Radiotelegraphy by Carlo Consoli, IK0YGJ and thought a lot about my 'career' as a cw op.  Every CW op should take a look at it.  It is available for free download at http://www.qsl.net/ik0ygj/enu/index.html.


This contest was my personal best in any CW contest, partly because of the improved conditions and partly because of my attitude towards the higher speeds.  Some ops are much better than I am and turning the speed up past 30 wpm seemed to be more comfortable to many and hey you just get used to it after a while!  


Putting the full QSK Alpha 78 on the air for the 1st time was only a partial success because after a rest period it did not come back online, no drive at all.  I put the Clipperton back online and will get to troubleshooting the problem later.  I did find a coax that seemed to be causing lack of drive on the other amp and it showed an intermittent ground with the ohm meter.  


The best moment in the contest was breaking a moderate pileup on TX4T (French Polynesia),  by turning the speed up to 33 wpm!  The op was very good and running the simplex pileup and most were 25 wpm more or less and I could tell the op was ready for more speed.  After way too many calls I cranked the speed up and he came back to me after ONE more call!  It was over my comfort zone but not his!  He picked it right out of the noise and I know I was not the strongest signal.  For the rest of the contest I often changed speed up and got many very easy exchanges by going faster.  Relax and let the code come.  Become  one with the CW.  


Thanks for the great Read on CW Carlo!



Monday, February 15, 2010

CQ WPX RTTY 10

        Band    QSOs    Pts  WPX
         3.5      10      26    4
           7      64     258   44
          14     148     279   92
          21      47     103   41
          28       4      12    3
       Total     273     678  184

  Score : 124,752

Skipped Friday night totally.
 Rig Yaesu  MP mk V and the Clipperton to the R7 Vertical.
 Software    N1MM

The RTTY events have really gotten popular in the last few years!

If you are interested in RTTY there is a good webinar on http://www.nccc.cc/webinars.html




Saturday, February 6, 2010

Big Snow #2


Did not make it too far today.  Out to the street and out to the woodpile was about it....

Monday, February 1, 2010

Olive Oil and the FT-1000!




CQ160M Port at Bryce Mt.




Last week I had to trade my last FT-990 for a FT-1000. I left it in the car so I could try it out portable at Bryce this year. The Bryce family reunion often falls on the weekend of the Jan VHF contest (ARRL VHF??) but this year we came during the weekend of the CQ WW 160M CW test so it would probably be a good test, the probelem would be to get an antenna up that would actually be heard out of the valley where the condo is located. After reading some of the collected articles on the web I chose what I hoped would be a workable and easy portable anteanna I could put up for one time use. The antenna was origanilly described by G3YCC and I found it in a nice collection of articles at http://www.iw5edi.com/ham-radio/?a-practical-antenna-for-160-metres,32  A few weeks ago I had picked up a set of fiberglass poles and they were about the same diameter as mentioned. I also had a nice roll end of 22ga. teflon wire that I thought would have enough wire on it. I measured out 140 feet of wire in the driveway and put a paint mark at 70 ft and 140 ft. Later it turned out I could not find the paint marks in the low light, tape may have been better or a differnt color of paint. The idea was to put 70ft of wire on an 1.5" fiber pole with 1/2 inch pitch. I ran out of pole before I got to my paint mark but I thought I would be close. I left about 15ft of wire at the 'lower end' to attach to the feedpoint as I thought there might be a 2nd story balcony and I would operate from the ground floor. For feedline I used an old piece of coax from my R7 Vertical that had seen several years of use before being run over by the lawn mower and replaced. After cutting off the 'bad' sections there was enough for a feedline from the operating position to the base of the antenna maybe 25 ft or so with a 'PL" still on one end and bare ends on the other. This was some sort of 'MiniX' type cable and it would work fine. I left the spool end of the #22 teflon wire connected to the top of the pole and then I could deploy the top hat part of the antenna quickly. I had about 8 mast pieces but only took the one with the coil and three others for a height of 12 ft or so plus the piece with the coil on it. We arrived at the condo with about 45 min of daylight left so the first task after unloading was to errect the mast and get the antenna hooked up. The 4 mast sections were assembled on the balcony and the lashed to the corner 4x4 with a yoga strap. This was very easy so far! The lead in wire was throw over the balcony and the wire spool was dropped on the ground behind the condo. Downstairs the wire spool was unrolled but I never did see my red paint mark so I guessed at the distance. I hooked up the center of the coax to the radio and heard good strong signals so that was a good sign I thought. My original plan was to cut the spool and use another piece of the wire for a counterpoise but then I remembered I had a 10M dipole that I had put 'extensions' on using some of the same wire so I used these two 50ft or so pieces as the counterpoise. The auto tuner would not tune it right away. and I could not really get a good reading anywhere. After shortening the antenna a few times the SWR went to below 2:1 and the tuner seemed to deal with it OK, as it was now snowing hard we accepted this setting for the remainder of the weekend. This is where more time spent improving the match might have improved the effiecney. I never really did find a resonance point but it did take power on every band 160 through 10 M so the antenna can at least be used to some degree on other bands with a tuner.



Disaster strikes in the form of a 'major equipment failure' during the wee hours of the 1st night of operation. About 1:30 AM local time the Main VFO knob started to become difficult to turn after only a few more revolutions it 'locked almost solid' the knob was now slipping on the main shaft and I could feel and hear the set screw tearing into the shaft. It was so tight that I was able to turn it back and forth and force the knob loose with out loosening the set screw which I did not have an allen wrench for. Looking up the service manual I did not see anything that could have come loose inside the optical encoder so I grabbed the shaft with a pair of pliers and was able to turn the shaft a bit but it was starting to turn the whole encoder it was so tight! I was in a panic as I could not get the radio to turn....I wondered what might happen if I put a drop of oil on it? I remembered that the condo next door there was an open bottle of Olive Oil so I applied a drop with the tip of a small screwdriver and turned it slightly with the pliers again, it was barely moving but after a few seconds it felt like it was getting easier to turn with the pliers. Another drop and it was even better after the 3rd drop it was starting to be a bit easier but I could still not turn the encoder with my fingers. The knob was replaced by hitting it with my hand and forcing it it back on as the set screw had not moved. Turning it it with the knob a few turns and suddenly it starting spinning freely! I could not believe that 3 drops of Olive Oil had totally fixed the bearing on the encoder. It worked fine for the rest of the weekend.



The Antenna was working and contacts were made untill about 1AM local time. Both nights I slept between about 1 or 2 AM loacal time and set the alarm for about 4:30AM to catch the morning greyline. I heard some signal enhancement but it was not as noticable as last year's event but I was portable and my contact count was up over a hundred by Sat. evening. The second night was a bit slow going tried some CQing but only a very few calls so went back to S&P looking for some new stations.



CQ160CW Score Summary Sheet







Band QSOs Pts Sta Cty

1.8 136 311 31 0

Total 136 311 31 0





Score : 9,641





Not bad for what is probably about as effiecent as a 'rubber duck' on the 160M band. Good number of Q's up to a range of 1000 miles or so in a valley with the only open horizon window only a few degees wide to the south. It will be interesting to try this antenna again with a bit more tuning and in a 'better' location. It did seem to work about the same as my 'Alpha Delta Twin Sloper' thrown out the 3rd floor window.

Tuesday, January 19, 2010

Alpha 78 Arrives from AZ



Alpha 78 arrived yesterday from AZ. 1st inspection looks like it survived the UPS trip ok. According to K5VT this amp has made several trips to Africa with the Voodudes "That amp did some time in VP5 before I got it and then we had it in XT2 for 2 contests and TZ got two contests. I love it when the gear has a bit of a 'story to it'  http://www.voodoocontestgroup.com/.  It looks a bit rough but if it runs ok it will be a useful addition to the station here.

This thing is a bit of a monster.  The transformer came in a seperate box.  The red item next to it is an auto tire gauge for size.

Wednesday, January 13, 2010

Drake T4Xb On the Air Again




The T4Xb is on the air again.  The radio was purchased along wtih a R4B, MS4 and AC4 about 2 years ago.  The R4 was working when received but failed after a few months.  Last week I found a loose rivet on the RF Gain Pot that was keeping it 3/4 muted.  After repairing the loose connection it was working well again and I deceided to unpack the T4 and give it a try.  The rig fired up and seemed to be working for about 15 min. and then the +250 V filter Cap in the AC4 'smoked'.  I replaced the twist lock dual cap with two computer electrolytics under the chassis and tested it again.  Now working sort of but only at low power levels and the plate meter was pegging at very low output like 5-7 watts.  The tubes were putting out 80 watts with the bias control cranked all the way and the meter was 'hard pegged'.  One of the guru's on the Drake list suggested looking at the meter shunt resistor which is located on the vertical board behind the three power resistors.  This resistor was found to be open and the 2.2 ohm resistor was replaced and this brought the power up to 110 watts with a more normal meter reading. The meter was still reading a good bit low though so back to the Drake Forum and it was suggested to put a 5 ohme resistor in the B- line and measure the voltage drop to set the idle current.  I had a 6 ohm and calculated that .075 A should give about .45V (Note the AC-3 had a test point here with a 5 ohm res but it was deleated in the AC4).  Then I removed R39 (on the slide switch) and replaced it with a small 0-200 ohm pot.  Adj the pot until the meter reads .075A then measure the pot and replace with closest value resistor.  Mine changed from 122 ohms to 24 ohms, not sure why but now the meter is reading correctly at the idle current point at least.  Another try on a Cantenna and by increasing the loading a bit more managed 120W output.  Still a bit low but the plate meter is correct at least and the output is in the ballpark at least.  Alignement or new driver or PA tubes is probably the next step but for now 120W is fine for my purpose.   Lots of fun to get these old things on the air again!

2/07/10
After working FB for a couple of weeks I did buy some used tubes on eBay for the Finals and they were weaker than what I had.  I left them in for a few days and one AM when I turned it one it started smoking after a min or two and I am still troubleshooting it again.  Should have left it alone.  The Filament fuse opened and so did R3 the 100 ohm 5W resistor in the AC4 250V B+ line.  I looked for where the smoke was coming from but just cant see it so I think it is a wire somewhere.  I hooked up the filaments and replaced the resistor with a 'test' one and the 250V line is still nearly shorted somewhere.

2/12/10

With much help from the 'Drake List' folks the following problems were solved.  One of the Finals was shorted and took out a screen grid resistor R30 68 ohms.  This is where the smoke 'came out'.  With the original finals back in the radio was not switching VFO's properly with the R4B and it was drawing idle current all the time.  Tube V2 was also found to be shorted Cathode to grid and was pulling down the 'transmit control' line.  After replacing V2 the rig started performing correctly.  Lots of work trying to get a few more watts out of the rig was a bigger 'learning' experience than I expected but it was a good way to spend the 'Blizzard of 2010' here in Maryland.

Thanks again to all who helped me troubleshoot this!