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Zenith Transoceanic H-500 Restore

This is my first radio/electronics restoration project, a Zenith Transoceanic H500 short wave receiver, circa 1951. As I have read, the radio is based on an AA5, a 5 tube superheterodyne using 2 1U4s, a 1U5, a 3V4 and a 1L6. I am fortunate that this particular rig has an almost religious following on the Internet, so troubleshooting an restoration tips are very easy to find. The radio was in a barn for the better part of a few decades and had several generations of insects and rodents making a home in it. The speaker cone was completely destroyed, and a nice layer of corrosion covered the chassis. The tubes are still in good condition though, although one of the 1L6's (there was a spare set of tubes) is shot. The selenium rectifier and main power supply filter cap still test good, so those will stay for now until I need to replace them. The bumblebee caps should eventually be replaced, but all in good time. The current status is that after about 10 hours of work, it fires up an receives audio on some of the bands, others are quiet, but lacking a frequency generator, I can't easily verify alignment. Guess I'll be looking for one of those at the upcoming hamfests.

Working in IT, I am reminded daily of the importance of a good backup strategy. Given the diversity of computer platforms I run at home, I wanted to revisit the methods I use for backup. Previously, USB attached storage drives would be the traditional route, using tools like rsync and rsnapshot to grab data on the linux side, and whatever free tool of the month I wanted to try on the windows side. While the USB attached backup system works fairly well, I found I got lazy about running backups since the computer the drive is attached does not run 24x7, so backing up meant booting that system or disconnecting the USB drive and hauling it over to whatever system I wanted to backup. I certainly could just leave a system up all the time, but I am also trying to be conscious about power consumption and heat produced. What finally made me rethink my strategy was the USB disk was starting to produce filesystem errors and tell-tale bearing noises. Replacing the disk would be easy enough, but why not kill two birds with one stone and look at network attached storage. I did not need RAID since the storage would only server as a backup to the primary storage on the individual systems. I figured anything that would handle SMB/CIFS and FTP would be suitable for my needs, so that left a fairly wide field of low cost NAS devices. I decided on the Western Digital MyLive Book 1TB unit. The cost was only a little more then a standalone 1TB drive with enclosure and came with a 3 year warranty. The plus side was that the system runs a Debian variant and can be enabled for SSH access from the web management interface. A whole host of utilities already shipped with the O/S, and there was a wealth of application repos, as well as other hacks and mods, available for it.

N8HB StepIR Antenna

An old fashioned antenna raising! One of our radio club members took a direct lightning hit this summer, destroying a vertical VHF antenna and damaging the control elements on his StepIR. After a few months of acquiring replacement components, we started putting the system back together. New enhancements to the StepIR included a 40 meter element, replacing the main feed point, and a heavy duty pivot plate that keeps the beam elements horizontal to the ground while the tilt tower is raised and lowered. We got the beam balanced and positioned before a strong thunderstorm moved in and stopped work for the afternoon.

PSKMeter Build

One of the aspects of Amateur Radio that holds my interest is the interfacing of computer and networking technology with high frequency radio transmissions. I have been a long time computer geek, it's my primary hobby and my livelihood. After getting my license, I quickly became involved with using a computer to transmit digital signals to other receiving parties, mostly in the form of PSK31, a rapidly growing protocol among Ham radio operators. So, I built my own interface, mostly consisting of simple discrete components like resistors to divide the voltage coming from the computer sound card. I have tuned and adjusted this specifically to what my Icom 706 is expecting on the accessory port (around 100 mVolts max). Not thinking twice, I decided to try the interface out on our club rig which was only expecting around 10 mVolts. Needless to say, my signal was severely over modulated causing my transmission to take up 5 to 6 times the bandwidth it should. This is very annoying for other operators and kind of makes you look like a total n00b. After that fiasco, I tore down my digital interface and expanded the capabilities with a selectable jumper. WHile this looked all good and well on the multi-meter and the oscilloscope. I really wanted to see what my IMD (Inter-Modulation Distortion) values were, but it's not terribly practical to drag a large oscilloscope everywhere I might take my laptop and rig. I came across the PSKMeter from KF6VSG which turns your PC into a mini oscilloscope for PSK, showing IMD values among other points of interest (ok, that's not completely accurate description of what it does, but close enough for this purpose). The kit shipped amazingly fast. I built my own rs-232 splitter cable and supplied my own 12v power supply. The rest of the components where easy to assemble with basic soldering skills, and their construction guide was incredibly well documents.

A Man, A Plan, A Workbench? Delta?

My shop...My single car garage that has never actually housed a vehicle...I am glad to have it and at the same time, a little embarrassed by it. I had some people see the woodworking items I have created and they want to know about my setup, or worse, want to stop by to see it or get lessons on the lathe or scroll saw. My shop is usually in a state of disarray as I scramble to find adequate power and/or space to work on a project. So I set off last winter on planing a new workbench specifically to hold the major power tools like the miter saw, the lathe, the drill press, etc. Construction would be relatively simple, using dimensional lumber, for the framing and OSB topped with 3/4in MDF as the surface. I took into account the space I had to work with, and the space the tools would need to operate safely. The miter saw was the most demanding, since it is a sliding-compound system, it requires 30in of depth. Combined with the other tools I wanted to have on the surface, it is overall 132 inches long and 30 inches deep. The whole bench was probably overbuilt, but the end result is that there is almost no give on the work surface which will certainly help when running the lathe.

I-Com Bracket for my Kia Forte

Here are some snapshots of a home fabricated aluminum bracket for my I-Com 2200H 2 meter rig. My I-Com 229 was having PA deck issues, so I pulled that rig and wanted to put the 2200H in. The problem was space. There are not a whole lot of places to mount a radio, and I'm against putting any holes in the interior while the car is only 6 months old. I found the ideal location on the side of the center console, but getting it to stick was a challenge. I originally tried a lot of hook and loop tape, but when the car would sit in the sun with the windows up, the glue would give way and the radio would fall to the floor. Not wanting to put holes in the console, I decided to try fabricating a bracket. I obtained a good chunk of aluminum plating from a fellow HAM and used a hack saw to cut the pattern. Lacking a brake system for bending sheet metal, I used clamps and dowels to bend the edges to form. I rather liked the warning labels on the aluminum, so I cut the bracket to feature those.

Ice Tube Clock Kit

This is a Vacuum Florescent Display clock kit using a 9 digit surplus Russian tube with blue display and a pre-programmed micro-controller for maintaining time and date The kit has about 2 dozen different discrete components, along with two PCBs and the acrylic display case. The soldering requirements are intermediate, no surface mount stuff, but tight component placement on the PCB. The delicate VFD also requires a bit of care in handling to get it threaded into the interface PCB. Total build time was about 4 hours and I now have a nice clock on our entertainment center. You can buy the clock kit from MakerShed with great step-by-step directions located here.

Hueston Woods 2010

Our trip to Hueston Woods State Park in Southwest Ohio for Thanksgiving 2010. My family used to vacation at this state park in the 70's, usually a couple of times a year. We usually camped, but on one occasion we stayed at the Lodge. I told myself that one day I would stay there when I was older since it was such fun as a kid. Fast forward 25 years or so and I finally returned with my wife for a few days. The park and Lodge almost seemed to be frozen in time, much of what I remembered had not changed. While some might say this is a lack of progress, I found it quite enjoyable as a door way to some of the happiest memories of my childhood. The Lodge was warm and comfortable. The staff was extremely friendly and helpful, and the food in the main dining room was fantastic. I think I may have to make this a new annual tradition.

The Fulton County Amateur Radio Club is holding a Fox hunt on July 31st. A fox hunt, for the non-HAM friends, is an exercise in radio direction finding (RDF). The premise is that one club member (the fox) will venture out into the county to an undisclosed location and transmit at routine intervals in a predetermined frequency. The hunters then use directional antennas and transceivers to triangulate the signal and find the fox. I have most of the equipment I need minus a good directional, portable antenna. I wanted one that would work for the 2 meter band and could be constructed easily. I found a few prefabricated antennas (arrow antenna's is a good source), but really wanted to try making one. I found many pages on-line describing a portable 3 element yagi using PVC pipe and a steel tape measure. The benefit is that it is small and light weight, has very deep null on the backside (for searching when close to the transmitter), and is very inexpensive to build. I think I have $11 in parts on this one. The director and reflector are solid lengths while the driven element is connected with a hairpin match. There is also an 8 wrap balun to choke out stray RF. There are much better sites on-line describing he construction and operation, just google "tape measure yagi".

These are some loading coils I wound this afternoon to create a shortened 80m dipole antenna. The primary portion of the leg is 406" which should work well on 40m and 15m. The coil is constructed of 20 AWG enameled "magnet" wire on a 1.5" I.D. PVC pipe with the following specs:
Inductance = 101.236 uH
Form Diameter = 1-7/8" (48.26 mm)
Coil Diameter = 1-15/16" (49.199 mm)
Coil Length = 2-1/16" (53.076 mm)
Wire Type = Enameled
Wire Diameter = 0-1/32" (00.939 mm)
Number of Turns = 56.534
Turns Per Inch = 27.1
Turns Spacing = 0-1/32" (00.939 mm)
L/D Ratio = 1.08:1
I should have some time on Sunday to cut the 12 AWG lines for the various bands, but probably will not get it hoisted to test until next weekend, unless I get some nice weather this week when I can test it after work.

Edit:

This is a really good site for calculating loading coils http://www.k7mem.150m.com/Electronic_Notebook/antennas/shortant.html

This weekend I spent some time building a digital mode interface rig based on the designs of Clint Hurd, KK7UQ listed here and Ernie Mills, WM2U at DX Zone. I ordered my parts from Mouser.com earlier in the week and dusted off the soldering iron this morning. It is 4 separate circuits within the enclosure, audio out from the radio passes through to the laptop microphone/line in connector, audio out from the laptop passes through to the radio mic connector, RTS from the laptop serial port is sent to the PTT control on the radio, and last, DTR is used to toggle the keyer on the radio for Software CW. Optical Isolators are used from the laptop RS-232 for both RTS and DTR signals, and 1:1 audio transformers are used, along with 1K variable resistors for audio signals in either direction.

As before, the map to the right links to photos we took during the drive. As an added bonus, here is a panoramic view of the town of Leenane framed by the mountains in Connemara (It's too wide to import into the main photo album). We woke up in Galway on Thanksgiving day and had a wonderfully decadent Irish breakfast at the Marriott Hotel. Todays excursion was a driving loop around the Connemara region (County Galway and County Mayo). Connemara is the name given to the western portion of County Galway, which lies between Lough Corrib and the Atlantic, highlighting the rugged beauty of The West of Ireland. We picked up the R336 outside of Galway and had a scenic drive along Galway bay with beautiful views of the Aran islands. The weather was a mixed bag, with a little sun and a little rain, sometimes at once. Before 11:30 AM we were treated to no less then seven intense rainbows along our drive. We stuck to the coastal route, switching to the R340 and R341 before eventually reaching Clifden. Right in town you will see roadsigns for "Sky Road", a short driving loop that climbs high along the rocky terrain, offering stunning views of the Atlantic and surrounding land. There is a great car park near the highest point, and is definitely worth the short detour. We rounded the lower road and headed back to Clifden for a quick lunch before moving on.

For the impatient, click the image to the right to proceed to a photo tour of Day Four of driving tour. We woke up in Killarney on day four, packed our gear, had breakfast and hit the road for another scenic drive. This days destination was ultimately Galway, with a quick diversion to the Dingle Peninsula. In many ways, this is probably one my favorite spots in Ireland. The terrain combines sandy beaches and rocky coastlines with amazing mountains and lush green fields. There are loads of ruins to explore and quaint towns to visit. It's very manageable in a half day visit, but on a future visit, I think I would prefer to spend a day or two there. Leaving Killarney, we picked up the R561 to the Dingle Peninsula. Along the way, we stopped at Inch Beach (probably not proper any longer since Ireland is on the metric system). It was a bit blustery, but it was a nice stop to stretch our legs and stare out at the Atlantic for a bit. We continued on towards Dingle Town (not sure if they call it that, but it seems to have a nice ring to it) where we picked up the Slea Head driving loop (the R569). The Slea Head loop hugs the southwest coastline with fantastic views of the Great Blasket Island and the Atlantic. We took advantage of a break in the rain and enjoyed the view before moving on to the ruins of Kilmalkedar Church. The last time we saw the ruins, it was the pretty well covered in scaffolding for renovation. All of that had been removed, and a nice sunny afternoon allowed us to get some great pictures. We touched our thumbs in the ogham stone (thus renewing our marriage vows) and looped back to Dingle Town for some lunch and light shopping. Leaving Dingle, we headed north up Spa Road to Connor Pass. The pass goes just east of Mt. Brandon, and has spectacular views looking north and south.

The heavy rains from the low pressure system over Ireland were with us once again on Tuesday. We awoke to overcast skies and blustery winds with the occasional rain pelting the window. Not the greatest day for a drive, but still better then a day in the office. We had breakfast at our new hotel (they had a wonderful selection of Irish cheese as well) before packing up the vehicle and hitting the road. For the benefit of those who have not had the thrill of driving the N71 between Killarney and Kenmare, try to avoid it in the rain. The road is narrow and winding, with a ridiculously fast speed limit which the Irish are sometimes intent on achieving. All that aside, the views are spectacular near Lady's View and Moll's Gap before crossing over on the downward drive to Kenmare. I've often wondered on how tour buses can manage to navigate the curves in the road on this stretch, I had a difficult enough time with our little Kia Sportage. We arrived in Kenmare and continued on to Glengariff at the southeast end of the Beara Peninsula. We did not have the time to explore the Beara the last time we were in Ireland, and I only wish the weather would have been more cooperative this time around. There are many quaint villages on the drive around the rocky coastline, and it can easily be done in a few hours. We eventually looped back to Kenmare and stopped for a very tasty lunch at a local B&B/restaurant.

After a night of much needed sleep, we had a wonderful Irish breakfast at the hotel before getting a cab to the rental care depot. The car rental was a bit too far of a walk, and it was not even an option since it was raining that morning. The cab driver was a pleasant enough person who seemed to enjoy talking about current events in Ireland. Specifically, he (and the rest of the country) were up in arms over a recent soccer match between Ireland and France, which had a bad call causing Ireland to lose. He stated that they had done everything short of declaring war on France. My comment to him was "they (france) probably would have surrendered if you did that". That made him laugh for quite a bit, so points for making an Irish caby laugh. We were also updated on the recent flooding issues in areas we were intending on visiting. As I understand it, the floods in the Shannon river valley, Galway, and Cork had never happened before in recorded history. There was an option on our route for a trip the the Blarney castle in County Cork, but being unsure of the road conditions, I opted to stick to Cashel and Killarney. After getting the rental, I found it actually quite easy to slip back in the mode of driving on the left side of the road, it was not nearly as bad as our first time Ireland.