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.

Happy New Year 2012

J38 on Straight Key Night

Happy New Year
When I was a boy starting out in radio I bought one of these keys from a TV repair shop in Madison NJ for One dollar.  It was brand new in a Lionel box and I used it for many years.  Eventully I sold it at a hamfest but bought another years later to use for ARRL's straight key night.  I try to get on and make a contact or three on New Years Eve or New Years Day.  This year only made one contact with KA2PJO 'Tony' in NY on 40M CW.

FT-1000MP Mk V CAT Port Failure

MAX232 chip in MP

I found out that the 'CAT' port chip a MAX232CWE  is not very robust.  When testing the End Fed antenna at hi power the computer connection dropped out and this chip is a common failure.  The CAT cord has home made and not well shielded for one thing.  The chip is pretty direct to the cable on the computer side and they tend to fail in hi RF situations in other types of gear as well.  The good thing is that they are inexpensive and I ordered two from DigiKey for about $3.70 each.  Some experience with replacing SMD parts is suggested.  You will need a jewelers hood and a bright light as well as a small pair of flush cutters, and a small enough iron to complete the job.  The chip is accessible with removal of the covers only.  No other dis-assembly is required.  Unfortunately I did manage to pull some traces off the board due to not being gentle enough in removal.  I was able to repair on trace with a single strand of copper from a CAT V wire and I wired two pieces of enamel wire direct to the connector pins.  Not pretty but it works.  I did not follow the advice of another repairer who suggested using a cutter to remove the chip.  I cut one side off but I heated the other side with the desolder gun. Usually I have had good luck removing SMD parts this way but NOT this time! Using a cutter and then removing the pieces carefully is the way to go.  The desoldering gun or braid can be used to assist removal of the pieces of leads that are still on the board. When the board is clean and smooth place the chip over the pads and solder it back on using the smallest iron you can get.  Pins 8 and 9 pads lifted off the board too but there is no connection to these two pins so that is 'OK'  Use the schematic and make sure that all the connections to the new chip are good. Here are some notes I used at the bench for my ohmmeter checks.

Pin 1  and Pin 3 C5011
Pin 2 and  Pin 16 C5012
Pin 4 and Pin 5 C5018
Pin 6 C5018
Pin 7 RS162
Pin 8 N/C
Pin 9 N/C
Pin 10 Busy Pin 15 on Q5035
Pin 11 C90 CAT TX 8pinchip
Pin 12 C81 CAT RX 3pin
Pin  13 TX pin 3 RS-232 connector
Pin 14 RX pin 2  "             "
Pin 15 GND
Pin 16 C5012

Check all these with ohmmeter to make sure the chip is soldered in correctly and that all the traces are good and it should work.  I used no real static protection.
In addition to replacing the chip I also purchased a fully shielded RS-232 Cable with RFI hoods on the connectors and put some 'Beads' on each end of the cable.  Not sure this will help but changing the chip is not  going to be any easier the next time.

Thanks to Hal for these directions
Dear Paul, Unfortunately for me, I did the same thing on my MarkV,and had to
change the chip. There are web sites that have good explanations on howto
perform the surgery. The chip is a huge SMD with what looks like a billionwires.
The idea is to buy more than one replacement so you feelcomfortable if you screw
up. The good procedure is to clear a table top, put down layers ofterry cloth
towels, get some good high-intensity halogenlighting up above your head and
aimed from two differentdirections, plus a smaller halogen goose neck to getreal
close to the board. The next good idea is to fabricate a chassis ground gromthe
radio frame to the a.c. electrical ground. Then, obtain a static wrist strap and
secure it to thegrounded radio frame. Now you are ready to yank off the covers
to the radio. Start with all the top stuff, flip the radio over andremove t
bottom covers. Have the rear apron close to you and look down intothe radio near
the left edge as appearing upside down. The '232 chip is close to the rear
apron. Tie off as much of the cabling as you can to exposethe chip. Make sure
you identify what direction the chipnumber one lead faces! Use a flush-cut
dikes, ( a good pair, not junk) and cutall the wires off the '232 chip. The pull
the chip body away. Using a needle-point soldering iron like a Weller W60P andan
electronic tweezers, heat and pull up the remainderwires from all the pads. When
done, clean pads with 10 % MEK / 90% Alcohol mixture,and a toothbrush / rag. Use
a magnifying glass to absolutelyconfirm all the debris is gone. This clean up
process may takehours. Go slowly, don't overheat the board. The chip lands need
to bebright and shiny when you're done and the tiny spaces between the landsneed
to be clear of debris. A #11 scalpel lightly applied with blade upis a good way
to shovel this debris, followed by the toothbrush and rag. Tin the iron well.
Tin the lands, one by one with a tiny addition ofsolder to each one. Get yer new
chip, face it correctly and use 1 tiny drop of Barge cementunder it and lay it
down so all the lands and wires line up exactly. Holduntil you feel the chip is
settling into the cement. Wait 1 day. Recover your nerves. Back to it: Tin the
iron's tip well, and do this every lead. Heat every lead so it melts the solder
under it. Be quick about it, which is why the iron is important to beclean.
Inspect carefully. Use the toothbrush, scalpel, magnifier. Removedebris. Yer
done. Button up and continue hamming. HalW4HBM

8:1 Transformer and Air Variable Cap as EFHW Matcher

8:1 and Air Variable Cap

Today I made a 8:1 Transformer out of a piece of 18 ga. house wire.  24 turns as Secondary and 3 turns as primary.  Using the Air Variable that I recently purchased on eBay that has about 3/8" plate spacing the half wave 40M wire tunes to 1.2:1 with the plates of the cap meshed about 2/3 of the way.  The wire is probably still a bit long as I cut it to 468/F + .05% and then added about a foot to be sure it would not be too short.

Although it tuned well using a tuner and the 4:1 Unun on 80-10M the SWR and RF in the shack was too much for the CAT port on a FT-1000MP Mk V.  The MAX232CWE chip failed.  These are available from Digikey for less than $4 and I ordered two but installing them will be a challange for later.  In the meantime I have pulled the MK V off the op bench and replaced it with the back up FT-1000(almost a 'D').  Several contacts were made on 40M with the 8:1/cap matcher today with good results.  I did not notice any RFI and the SWR was low but this was with only 200W. Later I switched back to the 4:1 Unun and internal tuner for the 10M contest and made another 20 or so contacts some on QRP and some on CW.  Comparing the 8:1/Cap combo and the 4:1 and internal tuner on 10M it looked as though the 4:1 had a one 'S' unit or so advantage.

On the right is the 4:1 Unun (Rybakov style) in a radio shack box.

CQ WW DX CW 2011

 Band    QSOs    Pts  Cty   ZN
   3.5      22      54   18   10
     7     183     513   76   19
    14     102     280   63   17
    21     127     354   68   22
    28     163     453   89   26
 Total     597    1654  314   94

Score: 674,832

Had a great time working the CW contest this year.  This was an personal best for me at this station.  Running the Cushcraft R7 vertical on a pole in the backyard.  

Working conditions 

N1MM logging software

DM780 running in background to 'help' with decoding

K1EL USB Winkeyer

FT-1000Mk V (with all the filters)

Alpha 78

Cuschcraft R7

Dentro MT-3000A tuner Used to load the R7 on 80M (works ok with 130 ft feedline)

W3LPL or K1TT  for Telnet 

Go PVRC!

After reading Zen and the Art of Radiotelegraphy I really came to understand that many of the operators are so much better at CW than I am it seems to help them to go a bit faster.  Going faster than the pile up seems to help.  After 49 years of hamming my CW is still improving (but is still not very good). I found this year that I made many QSO's with the keyer set at 29-33 WPM with only a few slower and a few faster.  One by accident I set the key at 42 and the op came right back --no problem!  

Rybakov 4:1 Unun

Started working on another End Fed Half Wave matcher that will take a bit more power.  I have been using the PAR 40 Meter at 10-15 ft and it works well for the ECARS regional net on 40M.

Coil ready to go int box t200-2

Here is a T200-2 core with 14 turns of Zip Cord sitting in a radio shack project box getting ready to be mounted.  (Still under construction)

Here are some interesting links for end fed half wave antennas or other hi impedance wires.

Rybakov antenna the start of the 4:1 Unun idea for me

http://www.iv3sbe.webfundis.net/html/Rybakov806.htm

Steve Yates excellent article on End Fed Half Wave Antennas
http://aa5tb.com/efha.html

Amateur Radio (G3TXQ) - UnUn experiments

http://www.karinya.net/g3txq/unun/

Good write up on the Cushcraft R5/R7 matcher

http://www.iol.ie/~bravo/r7_vertical.htm

Good write up on Inv-L multiband 

http://www.hamuniverse.com/slopinginvl.html

UV3R

UV3R with broken Display