Greg Buchwald - K9QI
Reprinted by Permission
Timely Technical Topics: Dayton, 2001 Wrap-Up
One-Touch Tune from W4RT Electronics and Other Products Observed
Greg Buchwald, K9QI firstname.lastname@example.org
with contributions from Craig Behrens, NM4T
The annual pilgrimage to Dayton, 2001 is now history. Despite the weather on Friday, our group from the Motorola Amateur Radio Club (MARC) had the usual good time. I also was able to take a new ham, Roy KB9ZPN, along with us for his first Dayton experience. I can take partial credit for pushing him towards his amateur radio ticket. Roy enjoys building crystal radio sets and receivers of 1 and 2 tube regenerative design, including some beautiful replicas of radios that would fool the experts. In addition, he grew interested in tuned oscillator and crystal controlled 1 and 2 tube transmitters; all low power stuff, of course. I suggested that he go after his license so that he could actually try the rigs out on the air. On the day we left for Dayton, I checked the FCC database and found that his license had actually issued he had studied for a few months and then took a one day class at the local community college a week or so earlier. I fixed him up with a 70 cm handheld and he was "one of the boys" while at the fest Figure 1.
Figure 1: KB9ZPN, K9QI, N9EAO, and WB8HMD with the Dayton-mobile.
I had a personal first at Dayton as well: I finally made it to some of the FDIM activities. I had been urged to do so a few years back by Bob Dyer KD6VIO, but always seemed to have a full schedule, and never made it. This year, at the urging of Craig Behrens NM4T, I finally made it to the Ramada for the Thursday night FDIM activities. I am glad that I did. While there, I saw some products that really caught my eye. The first of these was the small, ice cube-sized add-on One-Touch Tune for the FT-817, manufactured by W4RT Electronics. Also quite interesting were the replacement battery pack / cover plate for the FT-817 which allows smart charging of NiMH batteries without removing them from the radio, a neat little paddle that slides into itself for protection during transport, and several QRP portable antennas.
Sometimes Its Clear, and Then There is Dayton&ldots;
This years trip didnt start off too well: We drove from Chicago to Ft. Wayne in heavy fog Wednesday night, getting to our room about 1:30AM. We continued Thursday morning to Lima, OH where we stopped and visited Fair Radio Sales&ldots;and the rains started. Continuing on to Dayton, we dropped our small trailer at our flea market spot and grabbed chow before retiring. Thursday morning started early 5AM wake-up call and off to the fest to set up. It was foggy, but it wasnt raining&ldots;..yet. At 10AM, we had light rain. Then it cleared, but that didnt last - just a sucker hole in the sky. By noon, the heavens opened up. NOAA weather broadcasts indicated a severe thunderstorm warning with heavy rain in Butler County only a mile or so from us. Sure enough, the down pour started. Signage from flea market vendors washed past us in the river of water that was once the flea market area. I think we had an inch of rain in 20 minutes. Figure 2 is a photo of Roy and me keeping (mostly) dry and having a great time despite the weather. Friday was an outdoor washout, but we still had the Ramada FDIM exhibits to look forward to later that night. Saturday proved to be entirely different. No rain, and sunshine peaking through by 11AM. When the clocked ticked past noon, the skies were clear and a great hamfest was underway indoors and out.
Fig 2 Yes, it was pouring rain, but Dayton was STILL Fun!
One-Touch Tune from W4RT Electronics
Now that I have owned the FT-817 for about 8 months, dragged it around the world, and still thoroughly enjoy the rig, I am on the lookout for accessories and add-ons that make the rig even more functional. One item that I saw at FDIM and at the Dayton Hamfest was the One-Touch Tune module from W4RT Electronics. It was at FDIM that I met Barry Johnson W4WB, who was showing the product in his exhibit space. I use my 817 with a LDG Z-11 tuner with great results. The one hitch to using the system is the need to key the radio, and, at the same time, reach over and hit the "tune" button on the Z-11. I prefer to use the semi-automatic (initiate tube command via front panel pushbutton on the Z-11) mode vs. the automatic tuning mode. When operating SSB, the job is even more difficult as you must change modes to AM, FM, packet, or CW before keying the radio, and then change the mode back to SSB before beginning the call or QSO. The One-Touch Tune device makes the job much easier.
Figure 3 One-Touch Tune module attached to the FT-817 and Z-11
The unit is about the size of a small ice cube. It is attached to the back of the 817 with two mating Velcro strips. A small cable with a male DIN termination is plugged into the radio "ACC" port, and a second cable with a female DIN connector is provided to act as a new "ACC" port for connection to a computer for CAT commands or any other purpose. A third cable is terminated with an 1/8-inch female stereo phone plug. Provided with the module is a 1 foot long cable with an 1/8-inch male stereo phone plug on one end and a small pushbutton switch on the other end. When the pushbutton is depressed, the module sends a CAT command to switch the radio to the "packet" mode, on the frequency that you have tuned and at the power level you have selected. Further, a PTT command is generated as long as you hold the pushbutton in the depressed position. The result is the generation of an un-modulated carrier at the power level and carrier frequency you have selected. Figure 3 shows the unit attached to the back side of the 817.
Figure 4 Figure 5
Front and back sides of the One-Touch Tune PC boards.
Internally, the module has a small microprocessor, which generates the proper CAT commands. These commands enable the radio operation as listed above. A PTT command is also issued. Furthermore, the microprocessor and a series of logical gates buffer the new "ACC" port. When the module is activated, by depressing the pushbutton, the replacement "ACC" port floats and becomes inactive as far as the radio is concerned. The board construction is quite good a high quality glass epoxy board material is used and surface mount construction is utilized. Figures 4 and 5 show the parts placement on the top and bottom of the board, respectively, and the high quality of construction.
When the One-Touch Tune module is connected the 817, no internal modifications are required of the radio. The only connection to the 817 is via the "ACC" port. To establish proper communications with the 817, you must set the CAT data rate (Menu 14 on the 817) to 9600 BPS. When the module is active (which is only when the pushbutton is activated), the current consumption is about 20 mA. As soon as the pushbutton is released, the current drops to less than 25 m A. In the standby / idle mode, the module generates no spurious radiation. I carefully checked to be certain that no spurs could be detected and none were in fact found.
The One-Touch Unit makes tuning and spotting an easy task, but the really cool advantages are not witnessed until the 817, with the One-Touch module, are mated to a LDG Z-11 tuner. With the addition of a single cable to the Z-11 tuner, the pushbutton cable assembly is replaced by a control signal from the tuner itself. When this modification is made to the Z-11, a simple push of the "Tune" button will cause the radio to key, the Z-11 to find the proper match, and the radio to de-key, leaving the radio ready for use. The entire process generally takes about 1 2 seconds. This feature is really great, especially when using a random wire antenna and operating in SSB or the DIGLSB or DIGUSB (example: PSK-31) modes. There is no fumbling with the radio to generate a carrier, and re-tuning on QSY is a breeze. Even in the CW mode, the advantages of a single tune control are easily recognized, especially during band changes.
The interface to the Z-11 is easy, as is making longer pushbutton control cables. I mentioned earlier that the input to the One-Touch Unit is made via a 1/8-inch stereo phone jack. The sleeve of the connector is ground, while the tip is active low. Therefore, if a longer control cable is desired, the connections to the switch should be made between tip and sleeve and the ring should be left unconnected. I, in fact, did make a longer cable by using RG 188A 0.100-inch diameter Teflon coax and a sub-miniature pushbutton switch from Radio Shack. Of course, you can use the more common RG174 thin coax as well. I would recommend using coax for the control signal cable as the inputs seem to be high impedance; they might be susceptible to RF if non-shielded cable were utilized. The cables supplied with the One-Touch Tune module are also shielded, coaxial type assemblies.
In addition to the installation of the control cable to the tuner, most Z-11s in use today will require replacement of the microprocessor. The new micro and cable are sold as an accessory by W4RT and are priced very reasonably; the cost of the chip basically covers the cable cost and the shipping of the chip to your address. You simply install the new chip and return the old chip to W4RT. Barry then recycles the chips through LDG where they are reprogrammed for the latest revision of code, including the modifications for the One-Touch Tune mode. Essentially, the only code change is to allow a 60 ms wait period while the CAT commands are issued and received by the -817. The Z-11, in its original state, is about 10 ms to fast for the CAT buss, and you neednt worry, you wont notice the additional delay. New factory Z-11 kits and assembled units that contain the compatibility software for One-Touch Tune will available from LDG Electronics in the near future. W4RT Electronics sells Z-11 units that are fully modified for use with the One-Touch Tune. The collaboration between W4RT Electronics and LDG Electronics resulted in their units working together flawlessly.
The cable is also easy to install. If you look at the back of a Z-11 tuner, you will see a small hole about the center of the unit. The supplied cable is inserted through this hole and routed to the front of the unit. The center conductor is connected to the top of the "Tune" LED, which goes to 5 volts when the tuning circuit is activated and ground during standby mode. The ground / shield can be connected to any convenient point; I found an easy place to be the main PC board near the screw that mounts the board to the cabinet. I simply scraped the solder mask from the board and soldered the ground / braid to the board at that point.
After testing the unit, I decided that I wanted to clean the installation up a bit. I went to Radio Shack and picked up a 2-pack (1 required) of three conductor, 1/8-inch phone jacks (RS part number 274-249) as well as a 2-pack of 1/8-inch, three conductor phone plugs (RS part number 274-284C). The hole in the back of the Z-11 is enlarged slightly to accept the phone jack. A short piece of 0.100 inch coax, RG-174 or, in my case, RG188A, cable is connected to the LED and ground as indicated above. The other end is connected to the phone jack. This is where the stereo phone plug and jack become important. The tip of the phone jack is active "low", but the ring of the phone jack is active "high". Therefore, the phone jack must be connected to make contact with the ground to the sleeve and the center conductor, from the top lead of the "Tune" LED, to the ring (not tip) connection. Even more interesting was the fact that the Radio Shack jack labels the ground pin (the one closest to the front of the connector) as Pin 1, the ring as Pin 2, and the tip as Pin 3. Pin 3 is in-line with the ground pin, Pin 1, while Pin 2 is on the opposite side. When I wired it in that fashion, I found that the unit did not work. After checking the jack, I found that the instructions where, in fact, incorrect, and that Pin 2 and 3 were reversed. The ring connection was actually the pin directly in line with the ground pin on the jack. Once that was sorted out, a jumper cable was made with the two 3-conductor phone plugs. Once again, the ring of one plug is connected to the ring of the other plug using the center conductor of the thin coax and the shield of the coax is connected to the sleeve of each plug. The tip connection of each plug is left unused. Just for grins, I made two such cables and secured the second one inside the Z-11 box. That way, if I forget to bring it, a spare is close at hand! The finished interface is real clean, and the package is fully connectorized, eliminating the fear of ripping the cord off through some sort of mishap. Once the cables were tested and known good, I filled them with a small amount of RTV / silicone before securing the screw-on end caps. The silicone rubber acts as a strain relief for the cable.
After using the One-Touch Tune interface with my Z-11 tuner, I must wax ecstatic about it. Im not quite sure how I survived without it! The modification is simple to make, and the module is easy to attach to the 817. In fact, the only thing you can screw up is to forget to change the data rate for the CAT link in the 817 menu (dont ask!). I was very impressed with the fast response I received from Barry I bought the unit at FDIM right there on the floor and the new Z-11 chip arrived a few days later. The modification was easy to make to the Z-11, and the operation of the Z-11 appears completely unchanged. Furthermore, since Barry had not yet typed an instruction sheet for the chip replacement / Z-11 modifications, he was very helpful, both by email on over the telephone. The instruction sheets have now been completed and are very straightforward and easy to understand. About the only suggestion that I had for Barry, was that he might consider moving the control cable entry point on the module from the upper left side to the lower left side so that would be displaced a bit more from the power connector on the radio. But that would only be icing on the cake as far as I am concerned.
Barry is also working on a second product which should be shipping by the time you are reading this a replacement battery pack for the 817 that includes the cover panel for the radio. It also includes a power connector that can be used to charge the batteries internal to the radio without using the "dumb" charger that is built into the radio. It is also much easier to change batteries. I was able to see the unit at Dayton, and observe it in operation, but shipping is planned for early June too late to try it and review it here. If it is anything like the One-Touch Tune module, I dont mind waiting for a quality product!
For more information on the W4RT products, you can check out their web site www.w4rt.com or contact Barry at email@example.com.
Dinner and a Rigblaster&ldots;.
After a very successful Dayton trip, a few of the guys from the Motorola Amateur Radio Club and I decided to grab a last dinner for the road trip over at a local establishment. While there, the party seated at the table next to us happened to be the sales and engineering team from West Mountain Radio makers of the RIGblaster audio card interface products. Since both groups finished eating about the same time, they asked if we had seen their latest product. Now, having "Dinner and a RIGblaster" might not be quite up to speed with having Dinner and a Movie (the Friday night movie program on TBS) with Annabelle Gurwitch (sorry, guys), but the RIGblaster team was really great. Ned from West Mountain Radio offered to go out to his vehicle and bring in some samples of their products for us to have a look at. After two long days on the show floor in the Hara Arena, I was somewhat surprised by the offer, but had to take him up on it. I had used the standard interface unit before, but this would be my first look at the NOMIC interface. I have used my 817 for PSK-31; the817 is a perfect radio for that mode. Five watts is more than ample to communicate world-wide especially now that we are at the peak of cycle 23.
I was pleased to see the size of the NOMIC unit. At 1.5x2.25x3.25 inches and weighing 4 oz., it is a good mate to the 817 as well as other QRP radios such as the K2. A pre-made cable is also available for most radios making it truly plug and play. A 9-pin RS-232 serial connector is provided for interface to the computer along with audio input and output. It should be noted that, while other RIGblaster products are relay isolated (which allows their use with most all types of radios) and are powered from a "wall wart" supply, the NOMIC model was optimized for very little power consumption, small size, and use with solid state rigs: It utilizes an opto-isolator for PTT functions and requires no external supply. Although it does not provide mike switching, the plus side is that the unit draws what little power it requires from the serial port of the computer, basically to operate the opto-isolator. The audio levels are fully adjustable, and the unit is small enough and quite lightweight; it makes an ideal companion for travel. Figure 6 is a photo of our after dinner tutorial on the line of RIGblaster products. The insert in the lower left is a photo of the NOMIC unit from the West Mountain Radio website. The fine folks at West Mountain Radio can be contacted via their website: www.westmountainradio.com or at 203-853-8080. Provided with all RIGBlaster products is a CD-R of software which supports the use of many of the popular operating modes. The PACK-IT reference guide from VE3AYR, seen in the photo, is also a must have for the 817, and is available from W4RT Electronics.
Figure 6 From left to right: WB8SFY, K9QI, Ned (from RIGblaster) KA1CVV, and KB9ZPN
A Few Other Cool Products As Well
Craig was mesmerized by Walter SpiethDK9SQs demonstrations of how his amazing Fiberglass Telescopic Tower can be used. A simple vertical antenna can be erected in 1 or 2 minutes by twisting the mast as you raise each section. The Super Quick 8-Band (Folded) Vertical covers 80m10m. The VerticalLoop Antenna covers 40m10m. Horizontal support elements are included in the carrying bag when you buy these along with the Fiberglass Telescopic Tower. Additional components are shipped in small bags. These are great systems for portable operation that can easily be set-up by a single person. Craig has already packed them into his RV for field use. (See our Kanga ad to order/get info or Kanga@bright.net). I have to add that I, too, was impressed at the masts for their portability, size, and weight and had to purchase 2 masts for use with dipoles while traveling. Sure beats trying to take the 32 foot military masts we at MARC use for field day!
This being Craig NM4Ts first Dayton experience, I asked him what his goals were. His response, probably not unlike other hamfests has attended over the years was: "The first day there, I bought what I planned to buy--several little bags of anti-corrosive antenna grease. The second day there I succumbed to temptation and bought some neat QRP goodies. These included 2 DK9SQ masts with antennas, the "Introduction to Surface Mount Construction" kit from George DobbsG3RJV, and a "Mini-Paddle" by Hannes HillerDL9SCO. " In later telephone conversations with Craig, it was obvious that he had a really great time and looks forward to coming back again. He was especially impressed with the overflow crowd for the QRPARCI banquet.
Speaking of that little CW paddle, Craig had this to report: Hannes HillerDL9SCOs new Mini Paddle is a CW operators delight. The paddle slides into the little housing so that it can simply be carried in your pocket. Or, the key can snap in and out of the Quick Mount foot that is included. This could be attached to your favorite rig or 2 small magnets can be snapped into the Quick Mount to provide a magnetic mounting capability. (You will probably want to buy a couple extra Quick Mounts for use with other rigs.) A small keyer cable and anti-skid rubber surfaces on the bottom of the key are also included. Hannes has gained notoriety for his attention to detail and the elegance of his products. (See product announcement in the April 2001 QQ or try http//www.ulmnetz.de/HANNES/Keyer.html for more info.)
Craig also commented on his attendance to the session on chip component construction techniques by George DobbsG3RJV. George presented an "Introduction to Surface Mount Construction" at the FDIM Proceedings. George shared with us that, traditionally, electronic construction projects have looked like works of artNow&ldots;they look like robot vomit! None-the-less, he challenged us to keep up with evolving technology. To help us out, he created an ideal 4-kit packet so "SMD Newbies" can gain construction experience on while building useful QRP builder items. His packet includes kits for a Peak-Reading Diode Probe (2 versions), an Audio Amplifier (LM386), a Direct Conversion Receiver Mainframe, and an SMD ONER transmitter. George facilitates construction by including a special velum page in the accompanying booklet with the component overlay drawings. Needless to say, this is a first class way to give SMD construction a try. (See our Kanga ad to order/get info or Kanga@bright.net).
Another product that I had seen for the first time while touring the exhibits at the Ramada, but that is probably known by most QRPers, is the PW-1 portable antenna from Vern Wright W6MMA. Crafted with meticulous precision, the antenna, with ground plane packs into a very small case for transport. The adjustable coil reminiscent of a mobile screwdriver antenna is usable from 80 M on up with the addition of one extra coil and from 40M with the adjustable element. Although the assembled length of the driven element is just about 7 feet, thus making it a bit inefficient on the lower bands, it also includes a counterpoise which stabilizes the antenna feed-point impedance and as well as improves it radiation efficiency to some extent. Finally, brackets are available for purchase which allow the antenna to be attached to a railing or balcony for use in an apartment, condo, or hotel setting. The antenna construction is so impressive looking that I would be tempted just to set it up on my desk to initiate comments from others! Besides, look at all the antennas that are used for mobile applications on 80, 75, and 40M many of them arent much longer in terms of percentage of wavelength they work, dont they? I think that item will be on my wish list for future purchase! I hope to review this antenna in an upcoming issue of QQ. For more information about the antenna and ordering the unit and accessories, visit the Super Antennas by W6MMA website at : www.superantennas.com
One more interesting product was observed in the flea market area. As I look through my junk pile at home, I find that I have a number of old CRTs that are just laying around looking for use. Everything from one-inch diameter 1CP1s and 1EP1s, 2-inch varieties such as the 902, 2AP1, and nice 3 inch tubes with oddball phosphors such as 3JP12, 3FP7, 3WP2, as well as the common 3BP1. I have always found CRTs interesting. I have built modulation monitors, small oscilloscopes, and even magnetic fields demonstration devices (yes, electrons really can be deflected with a magnet) from some of these tubes. But I had not seen anything quite a interesting and as much of a conversation piece as the CRT-based Clock Kit from David Forbes at Cathode Corner in Tucson, AZ. David has developed a CRT-based clock that uses old, surplus CRTs to display the time. But the display is not digital: He creates the numbers by generating a series of arcs, lines and circles. A PIC microprocessor keeps track of the time and feeds a D/A of sorts which then uses a sine and cosine generator to generate the display no raster scanning in this unit! Think of it as a rectangular to polar conversion computer. The power supply is a small switcher and uses a voltage multiplier configuration to generate up to 1500V to run the CRT. The clock, in the custom case that he can provide at additional cost, is shown in Figure 7. The insert shows the time as it is displayed.
Fig. 7 CRT Clock from Cathode Corner
In addition to the standard 12 hour version, a 24 hours version is said to also be available making this an ideal UTC clock for the shack. Since the seconds display is sometimes desirable, but other times distracting, it can be turned on and off as desired. Furthermore, since the CRT might become burned by constant bombardment of the screen by electrons, the display is slowly moved dithered around the face by a small amount by a random number generator over the course of time. You will not notice it when the clock is running, but as you set the time, you will see the display move a fair amount! Kits are available for the clocks in various forms including just the boards and parts without CRT or socket (so you can use your own tube) right up through a complete kit with a spectacular clear case. Total power consumption for the clock is about 10 watts.
Personally, I think the best tube to use is a 3FP7, which uses a cascaded phosphor. These are old radar tubes, which, when excited by the focused electron beam display the numbers in a bright blue color or very short persistence. When excitation is removed, a yellow image is retained for several seconds. You can literally watch time melt away! (Many hams may remember this phosphor as the one used in very early B/W SSTV displays in the 1970s.) If a classic CRT display is more to your liking, simply use a 3BP1 with medium persistence green phosphor. If you build the kit, but make your own case, nearly any 2 5 inch CRT can be driven provided it is of the electrostatic variety and uses a 6.3 volt filament. Information about this product, as well as contact information for David, can be found: www.cathodecorner.com
Odds and Ends
Finally, we always see products that just dont quite fit the hamfest atmosphere. This year I saw people selling air conditioners, beanie babies, and other things that, shall we say, dont require a ham ticket to operate. Most are pretty benign, but one item that was pretty disgusting was a certain BBQ pork sandwich, Figure 8 that was for sale in the flea market area marked down in price to boot! It was there all day, and didnt seem to get any takers. Good thing!
Fig 8 A really stale pork sandwich as seen in the flea market area.
Nearing completion on another great Dayton road trip, we still had to make our annual stop at the Waffle House Restaurant for a great breakfast and Tee shirts (un-official hamfest clothing) for next year. A small group of our MARC party stopped there Sunday morning and had a great breakfast. Our bubbly and attentive waitress Lindsey Lou made sure that we were well fed and fixed us up with the shirts (Figure 8). Waffle House breakfasts and Dayton just go hand in hand!
Figure 9 From left to right, K9QI, WB8HMD, Lindsey Lou the waitress, KB9ZPN, and, mostly hidden, N9EAO, all in appropriate Waffle House garb.
Well, Dayton 2001 is now history, but despite the rain, it was a great time. The only thing left to do is start planning for next year! In addition to getting together with fellow hams, seeing all the product offerings new and old, and spending more time at FDIM, I also look forward to the goat (of goat-cam fame Figure 10) and his buddies Fleabite the Welsh Corgi, and the three ferrets in the flea market again! Most of all, I look forward to all the fest has to offer.
Fig 10 The goat and I in the flea market.
Until next time, 72 de K9QI