Wednesday, March 7, 2012

Weinermobile





We saw this Weinermobile in Annapolis.  This is the 75th Anniversary of the Weinermobile.  Currently there are six in the fleet.

Saturday, February 25, 2012

Swan 350

Swan 350 circa 1966
This is a radio I have never used before.  The Swan 350 was a popular rig in the 60's and 70's.  I repaired this one for my friend John W3JOI and enjoyed using this rig.  The radio is an interesting design using a single crystal filter in the IF.  The radio is powerful and has a good sensitive RX.  I also got to use a D-104 mic for the first time.  This radio will pin my 200 Watt meter quite hard and gets good audio reports.  It only took a couple of tubes to get it going again.

I checked into the Swan Tech Net today and was told the S/N of this radio (C 618852) was manufactured in 1966 and that the radio was produced from 1964 to 1967.  This one was late enough to have the one piece xtal filter instead of sockets for the individual crystals that the early ones had.  During testing I measured the B+ ripple at about 3v.  Stu K4BOV said that the it should probably be less than 1v so the filters are a bit weak.  Stu suggested to use 80-220 mfd caps rated at, at least 350.

The Swan Tech Net is on Sat PM at 2:30-3:30 or so on 7235.  Check it out sometime if you are interested in these oldies.

Fictional Character eligeble for Elser-Mathes Cup for Mars QSO!


Just finished reading this book.  It has some radio in it and even a Character that would be eligible for the Elser-Mathes Cup  http://www.eham.net/articles/222 for the 1st contact with Mars.  Not quite ham radio but a pretty good story.  If you are a science nerd you will enjoy the story.  I am a bit surprised that it is not a Young-Adult book.  Some good suspense and science.







For more about about Fred Elser seehttp://www.para.org.ph/membersarticles/PI-3AA/KA3AA.htm

New to me TR-4C

New to me TR-4c






New TR-4C is on the air.  This was an eBay purchase that checked out and seems to work fine.  Several of the tubes did not light at first but they all checked good on the B&K 707 tube tester.  The previous owner had swapped out the 3/16" mic jack for a 1/4 one with 'non-std' mic and ptt wiring so I changed it to match the Tip=PTT and Ring=Mic that Drake uses on the stock 3/16" connector.  I found an old Turner 454 SSB that had a 1/4 plug on it and it seems to work.  The pig tail on the AC-4 is not picking up the Spkr Audio but the headphone jack sounds great.  Will rag it off some and maybe put a drop of oil on the PTO bearings and I think it will be pretty good.

Sunday, February 19, 2012

ARRL International DX CW














 Band    QSOs    Pts  Cty
   3.5      23      69   18
     7     132     396   59
    14     165     495   77
    21     148     444   73
    28      57     171   30
 Total     525    1575  257
Score: 404,775

This included a couple of new countries.  One was Antarctica on 20M,  DP1POL who confirmed it on LOTW.

Set-up for the contest:
FT-1000mp Mk V
Alpha 78
Cushcraft R-7 (end fed half-wave vertical)
N1MM logging software
Digimaster 780 for 'help' with copying
Koss Headphones
Vibroplex Code Warrior Jr.




Before getting on the contest both the QSK amps were 'down' and This crimp on the filament wire in the P1/J1 connector had failed.  The 'hot' spot has been there for the last few years but cleaning it and tighting the pin up 2 years ago seemed to 'fix' it.  This time the crimp NOT the conection at the pin itself gave up.  I cut the pin off.  Cut off a bit of the red wire and installed a short 'by-pass' jumper of 1" of #16 wire which fit the crimp better.  The red wire was maybe #12 or #10 and was really too large to be properly crimped.  I carefully opened up the crimp and re-attached the new smaller wire then made a loop and soldered ti to the original large wire.  Some tape and it seems to be holding.  For now anyway.

Tuesday, January 10, 2012

Classic Universal Sound Card Interface

This interface by Skip Teller was put to use this past weekend with the FT-817 and a laptop running N1MM and using an end fed half wave wire down the 2nd floor hallway during recent trip to Lovettsville, VA.

The interface is described in the Jul 2010 QST
The Classic Universal Interface has two isolation transformers and an opto isolator to run the PTT line from the computer serial port.  I used a Radio Shack Gigaware USB to Serial Converter and this works well once you figure out the port the converter is using.  It helps to look at the Device Manager on the computer.  Then you have to tell the program you are using to use the correct pin on the serial port.  An earlier and later ver of KH6TY Skip Teller interface using an audio derived VOX signal to trigger the PTT line which will also work.

All of the interface boards seem to be sold out on Skip Teller's site but FAR Circuits lists the VOX board from the June '09 QST Sound Card Interface for FM Transceivers.
http://www.farcircuits.net/modem1.htm

New DigiVox Interface Mar '11
There is also a newer ver of the VOX interface from Mar 2011 QST article.