Well, the HV power supply seems to be humming along nicely. The meter on the control head displays 2500 VDC which is probably about right considering my line voltage in the shack (248 VAC). As promised, I measured all the resistors that were removed from the supply and noted their values. I also noted their specified range based on the five percent tolerance value. As expected, not a one was in spec. I’m not sure that this really makes much difference as the power supply isn’t exactly a calibrated circuit, but it would be silly not to replace them while refurbing the supply. They’re inexpensive and easy to replace. I substituted metal film resistors of the same value and power rating rather than the original carbon composition.
I haven’t had a single issue at all with breakers tripping on the amp or sub panel since making the repairs. I’ll conclude that it was definitely a faulty filter cap (or maybe several). It uses six 240 uF 450V computer grade electrolytics in series for a total of 40 uF DC filtering goodness. I don’t have a way to test them at this time to determine their values. Actually, I don’t even have them anymore. The neighbor kid (Jacob KC9ZYV) wanted them (and also the caps from the Amp Supply LK-500 NT power supply I refurbed last year). He mentioned something about a rail gun…future mad scientist at work!
I recorded the values for everyone on a pad of genuine Purdue green engineering graph paper. I still have nearly a full pad of this stuff after nearly 20 years. I wasn’t an engineering student! I hope you all find the info interesting. The next order of business for the amp is to synch the DC drive system with the Tune and Load air variable caps in the RF deck. Then I can calibrate them all for roughly every 100 KHz of each band and let the amp auto tune itself!
Check out how far some of the resistor values have changed.
I got an enjoyable surprise in my email last weekend. Gerald PA3GEG from the Netherlands sent me an mp3 file of our recent DX contact. Conditions have been pretty favorable for 10 and 12m lately and I’ve been trying to take advantage. I actually worked Gerald about a week before on 12m USB. It was neat to hear my own audio from so far away. I’ve since added a couple TX profiles for my Flex-5000 (one for DX and another for rag chew) so hopefully I’ll sound even better now. He sent me a couple links so I went ahead and signed his guest book and checked out his page on QRZ.com. There’s some good stuff there worth taking a look. You can see his page here. It was an enjoyable contact for both of us. Thanks Gerald!
It’s been a long and busy summer and my blog has suffered. I’ve neglected amateur radio quite a bit due to a heavy work schedule. With the onset of Indiana winter and the first snow on the ground I may be able to carve out a little more shack time now. I’ll try to do a quick recap of the last five month and hit any ham radio highlights.
We were sorely in need of some better antennas and feedline at the WD9BSA shack. We were able to trade off some excess equipment for a 500 foot spool of LMR-400 feedline. This allowed us to make brand new runs out to the antennas. We now have two multi-band antennas in the air and ready to go whenever the Scout radio station is activated and on the air.
Unfortunately, I missed Field Day this year because of work. I was able to operated portable Field Day style at Ransburg Scout Reservation. After a more than twenty year absence from Boy Scout camp, I returned with my oldest son, Jared, for a week in July. I had a portable station setup in the STEM area and managed several contacts. The station included a Buddipole antenna and an older Kenwood TS-450SAT with matching power supply. Some contacts of interest were: W100AW ARRL Centennial station, W9ZL special event station at EAA Airventure, and DX station CO6LC in Cuba. Our troop’s Senior Patrol Leader earned his ham license so we were able to communicate throughout camp with HT’s.
I have numerous old boatanchor radios in the shop. They’re in various stages of disrepair, unfortunately. I was, however, able to get two of them fired up using a variac. The two I’ve been working on are a Hallicrafters S-53A and Hammarlund HQ 100A. They both exhibit some audio hum and could use some refurbishing, but so far they receive pretty well on a wire antenna. The S-53A now rests on the mantle in my family room and is occasionally fired up for a little AM listening enjoyment.
My most recent project is getting the shack cleaned up for winter operation. I’ve moved around a bunch of gear to improve the overall layout. Some items have been packed away for a later date and new projects are on the bench. I built a new shack computer to operate the Flex-5000 and all the software that goes along with modern radio operation. In the last couple days it’s been getting a workout on 10m due to some decent propagation to Europe. I have more ham blog goodness on the way…but that’s a teaser to keep you coming back. 73 for now.
The zero pressure balloon preparing for launch.
April 19 I was able to attend my second high altitude balloon chase event. As part of a nationwide competition the Purdue AMET club launched two balloons. The Purdue Physics Society also launched a balloon. This required a concerted effort to chase three balloons launched at different times from two different locations. I was able to get in on the balloon projects since I’m a member of the Purdue Amateur Radio Club. We’ve partnered with the other clubs to assist in tracking and comms support. In the process, we’ve been able to encourage many of the club member to get licensed. We even started our own PARC VE team.
In addition to the various club members out tracking I also had my son, Jared, riding shotgun; and friends Nick N9SJA and Tabb W9TTW in their mobiles. We were able to track and recover two of three balloons. AMET balloon #2 is MIA and hopefully will be recovered by someone and returned to the club. AMET balloon #1 was a special zero pressure balloon that was actually totally constructed by the club members. It’s designed for an experimental payload. What it lacked in speed and altitude it made up for in endurance. We followed it all the way to the end of a dirt road outside a small town in rural southern Ohio. We were actually able to see the balloon and follow it as it floated along at 40,000 feet altitude. I wouldn’t have believed that possible. The Physics balloon ended up in a tree in a golf course community in Fishers, Indiana.
Liftoff for the zero pressure balloon.
It was nice to really make use of the APRS features of the Kenwood TM-D710 in my mobile. We were able to copy the balloon’s beacons direct from our mobiles. It was also helpful to be able to tether my tablet to my cell phone and view the balloon in real time on maps. This also helped us plot our route as we followed along. At one point the balloon went right over my house and used my digipeater. That was really neat for me. It definitely took us into some unfamiliar territory. We knew it was a good sign as it went past Dayton, OH. Being that near to Hamvention land was some good mojo. Can’t wait to get back there in a few weeks.
I’ve included a pic that shows the flight path of AMET #1. You can see the red line is the path it traveled. The blue line is from the pickup point back home to West Lafayette. They must have turned off the beacon and then turned it back on again later. It was neat to follow it along and see it hanging in the sky, especially after it got below 10,000 feet. As it got cool in the evening the altitude really started to drop. I wish I could’ve gotten a picture of it lit up by the sun and floating along about 5000 feet thorugh some rolling fields out in the country.
We’re looking forward to some more balloon projects this summer as many of the members will be sticking around campus. We also have plans for using the kite antenna again. Maybe this time we can send up a small, low power repeater.
AMET balloon path from aprs.fi.
My home digi in operation.
For a long time I thought that APRS was pretty much a solution to a nonexistent problem. It provides position tracking, but how many times can you follow your buddies around on a map before that gets boring? It uses a 1200 baud packet radio protocol, but most packet has been dead for years. The only exceptions are a few DX cluster nodes and some emcomm stuff. And even at that, 1200 baud is slow when most any gear can run 9600 now. So, what’s the attraction?
My thoughts changed after tracking a high altitude balloon. APRS really proved itself invaluable in this endeavor. We were able to not only copy direct packets from the balloon, but also see the beacon packets on aprs.fi using a smart phone when we were out of range. This made recovering the payload much easier–of critical importance when there’s the potential for a high altitude to travel outside of state lines and beyond.
At some point the location beacons stop getting reported to the APRS-IS network if it gets out of range of a digipeater. The last two times it was when the balloon was still 2-3000 feet up. This prompted me to examine how many digipeaters were in my local area. I live directly between two fairly large cities. Indianapolis and Lafayette both have wide area digipeaters but there aren’t any local digi’s in my area. Just one I-gate in Lebanon. I thought it might be nice to set one up. This should help provide coverage for local passing motorists and may be of help to the local ARES team in the future. Just last fall we had a destructive tornado come through my county only 10 miles away!
I’ve done a lot of reading on different ways to setup digi’s and I decided to purchase an older Kenwood TM-D700. This dual band data radio will operate APRS on one VFO and also VHF or UHF FM phone on the other VFO simultaneously. This is different than many dual banders that will operate phone on both bands, but not data and phone at the same time. The added benefit is that I now have a handy radio in the house for repeater/simplex operation. It was easy to setup the APRS features and get the packets beaconing. Then I enabled it to digipeat local WIDE1-1 packets and saved this config to one of the Programmable Memories. Phase two involved taking the digi to the next level. I downloaded
The guts of the system are housed in this box under the table.
aprsisce/32 on my spare laptop. I had to make a couple changes to the xml file and then it would operate as a digi. Then I changed the 700 to run as a KISS TNC and connected it to the laptop. This proved simple once I found correct straight through F/F serial cable. The 700 still has an old school DB9 male serial port so I didn’t have to construct a special serial cable with a mini DIN connector like the newer TM-D710 requires. After making all these changes I saved the config to another Programmable Memory channel. Now my digi can operate stand alone or with the laptop. Using the laptop is nice since it shows all the activity in the area and also handles APRS messaging.
I have a feeling this is going to be a long blog post. But hey, sometimes I have a lot to say. Occasionally, it’s even interesting. If you like older Kenwoods or just playing around with different rigs, then this will be for you. It’s not really a product review, just some general observations.
Over the weekend I hooked up a nice, old Kenwood TS-450SAT. This is one of the radios I got from Mark Quebe N9EKG over the summer. Some readers of this blog will remember my previous post on this adventure. Sure was glad to have Dad and my sidekick Nick N9SJA there for the long day of work. Initially, I’d hooked the radio up just to try it out and didn’t have spectacular results. I could hardly make it work at all. With disappointment I’d packed it away for another day. Having nothing better to do, I hooked it all back up again. I think the cabin fever is setting in. What I found out is that it seems to receive quite well, but has very little AF output. This is likely something easily fixed. Even better, it was now showing full power output into the dummy load. I don’t remember it working at all last time so maybe it’s had some group therapy sessions in the shack with the other gear I’ve banished to the shelves. Either that or reading the operator’s manual has paid off. I don’t know which?
I attached an MC-60 mic and hooked it up to the hexbeam for some real testing. This proved to be successful as I made several contacts on 17m, including DX. For a smaller radio it has a good, solid feel to it. Kenwood built some quality into these back in the day. In spite or converting to a Flex-5000A as my main shack radio, I still love to spin the dial and push buttons. But what to do about rig control? I’ve gotten used to having all my gear interfaced to the computer with the Flex. I had to keep reminding myself to manually input band, freq, mode, etc into the HRD logbook. Then I remembered this USB rig interface kit I built years ago for an original Icom IC-756. It was designed by N0XAS HamGadgets. Sadly, it’s no longer produced, but it worked quite well on the 756 and also a Yaesu Ft-736R. After I dug it out I found that it even had the correct 6-pin DIN plug on it for the TS-450, and it was wired correctly! When you’re hot, you’re hot. After a little bit if research I found that Kenwood used inverted TTL for their serial rig control. I can’t even guess why they would do that other than to be different. This normally requires buying their interface box or a homebrew lashup with opto-isolators and such to deal with the inverted logic. Fortunately, the rig interface had a utility program on the software disk called MProg. It allows you to change the settings and configuration for the FTDI chip and then flash them to it. It worked quite well and I’m pleased to report that the radio is now communicating happily with the HRD suite.
Other than having to run the AF gain all the way up I’m pretty pleased with this radio’s performance. The antenna tuner seems to be jammed up so I don’t use it. Maybe when I dig into the low audio issue I can check out the tuner, too. As I’ve researched it on the web there are very few known issues requiring mods. That says a lot about the radio’s design. It’s not fair to compare it with the Flex but it does perform solid. I could improve it a little by adding better filters and maybe a Heil mic. International Radio has an excellent assortment of them available. Unfortunately, I could spend more than the radio’s worth on filters! It’s still going to be an early ’90s compact HF transceiver, though. I don’t want to try and make it more than what it is. I think I’ll just enjoy it for now…and then on the the next project!
Sunday afternoon I finally had a chance to get on the air. After the annual Cub Scout Blue & Gold Banquet with Amber and the boys, I found myself with a few hours of non-designated free time. This is a rare treat for me so I chose to check out the bands rather than do the work I really should be taking care of.
2014 is a big year for the ARRL. We’re celebrating 100 years of the League advocating for our amateur radio hobby. They’re planning many activities to celebrate this occasion. One of them is called the ARRL Centennial QSO Party. The League is using the special callsign W100AW from headquarters in Newington, CT. In addition, they’re using volunteers in all fifty states to operate portable. The idea is to allow hams to earn Worked all States by the end of the year working only W1AW/P stations. Here’s the schedule for the year long operating event. In addition, there’s a quasi contest for those who are so inclined. Stations and operators are worth varying points that will be tallied at the end of the year.
I heard W1AW/6 on 17m this afternoon and had to give them a call. That was kinda cool so I continued to tune around the bands looking for some action. I managed to work Belize on the first try. Love a little DX. Tuning around some more turned up W1AW/6 on 15m. The bands seemed to be in great shape I even heard stations operating on 12 and 10M. While tuning around 10m I hear yet another W1AW/6 station. This one was definetely the hardest. I could hear the YL op easy 59 but she couldn’t hear me at all. It took an hour of frustration and tuning around different band, but I finally worked her. Now I’m motivated to try to pick my missing WAS states by using these W1AW/P stations.
New year, new projects. Trying to kick off 2014 in grand style. I’ve been so busy working on ham radio projects I’ve hardly even gotten on the air. My online logbook looks pittiful! Projects are really enjoyable for me…and often are very good learning experiences. But I do miss making radio contacts. One of my recent projects involves setting up an APRS digipeater. Not a wide area one like in big cities, but something local that will help get packets from mobile or low power stations out to the bigger stations and onto the world wide networks. This interest all started back in November when my buddy Nick N9SJA and I went chasing a high altitude balloon that had APRS tracking. You can read about that adventure in my previous post.
I’m happy to say that the project is successful and fully operational. However it’s potential is not yet fully realized. I feel like I’ve just begun and have so much to learn about best practices and proper setups for a local digipeater station. My choice of radio is a Kenwood TM-D700. This radio is no longer in production, having been replaced by the TM-D710, but it’s still a good radio and available at a discount used. It’s mounted in my family room and connected to a dual band J-pole antenna in the attic. The antenna is one of those homebrew arrangements constructed from a piece of 450 ohm ladderline. The nice thing about the Kenwood is that it has built in APRS capabilities that can operate on one band of the radio while letting the other band function for normal voice duty on 2m/70cm, simultaneously. Right now this is a very simple arrangement.
The D700 has a serial port on the front of the radio that will allow it to interface with a computer. This will allow you to get a visual on what the radio is hearing. One of the programs I’ve used for this is called APRSISCE/32. It can operate as a monitor only or can actually control the radio. After getting a passcode, it’ll allow you to beacon packets from the radio and also directly to the APRSIS network if connected to the internet. With some modification to the XML file it will also act as a digipeater. So now I have multiple options on how I wish to operate the station. An added bonus is now I can monitor local simplex and repeaters without having to go out to the shack.
So where do I go from here? I think I’ll mount it all in a box and do a little cable management so it looks better in the main room of the house. I also think it would benefit from having a backup power supply in case of power outages. This happened just last fall when a tornado ripped through my part of the county. It’s my hope that the local ARES/Skywarn volunteers might be able to make use of my digipeater when needed. When the weather gets up somewhere above freezing I plan to construct a new and improved antenna and locate it outside for better coverage. This attic antenna is deaf compared to the Diamond X500 I have connected to the dual bander in the shack. Crossband repeat might also be handy as I have a couple dual band HTs that could be pressed into service. A final option is to setup different operating modes using the Kenwood Programmable Memory function for each scenario. This allows for five completely different setups that can be programmed into preset buttons on the radio control head. I’ve rambled on long enough. Stay tuned for another upcoming project blog coming soon. After that I may get around to making some contacts!
The weekend of November 16-17 was the annual Ft. Wayne Hamfest and Computer Expo. It’s also the annual ARRL Indiana Section Convention. For my friends and I it signifies the end of the yearly hamfest circuit until the “Big One” in Dayton. I try to attend when I can. It’s held at the Allen Co. War Memorial Coliseum and is all indoors. A real bonus this time of year in Indiana. My travelling buddy, Nick N9SJA accompanied me to the event. We didn’t go to any of the convocation lectures that were held, but did enjoy looking at all the wares on display. There was quite a variety of new and used radio gear and accessories for sale. I somehow managed to spend a couple hundred dollars on random goodies. Nick had more self control than me and only came away with a neat book on cold war missiles.
In addition to the commercial vendors and swap meet sale tables, there were several displays. I enjoyed the FlexRadio display since I’m a proud owner. That new 6000 series SDR is really something. One display that really caught my eye was an APRS demo. I think their main emphasis was targeting the EMCOMM community but it’s applications are far reaching. As we were watching the display we saw the Purdue University AMET high altitude balloon beacon come across. The students are doing upper atmosphere and near space research. The W9YB Purdue Amateur Radio Club was partnering with them to provide tracking and comms. As members of the Purdue ARC, Nick and I were quite interested. The members had texted us earlier to let us know when it launched. It was really neat to actually see the W9YB balloon beacon on the screen as it floated through the area.
The Purdue chase team already had two van loads of students on the way to track the balloon to the landing point. Since The Nickster has a Yaesu FTM-350 mobile in the mighty F-150 we would be able to directly intercept the APRS packets. We decided to join in the hunt. Off came the shorty dual band antenna and on went the big 5/8 wave for better signal reception. It also turned out to be of assistance in comms with the other chase team since they only had HT’s. We were able to access good maps using our smartphones and aprs.fi.
After a hearty dinner we headed out on our adventure. The last beacon was heard just south-west of Kalida, Ohio. It was just under 3000 feet in altitude and travelling about 40 MPH. We estimated where it might go down based on it’s direction of travel and approximate rate of descent. You can’t believe our surprise when we saw the first directly-received packet come across the display on the Yaesu! We were only a half mile away. Soon after that we got a call on the radio and the AMET/PARC students had recovered it in a field. They had thought ahead and covered the payload with blue LED’s in addition to multi-colored flagging to make it easier to visually locate. An excellent idea as it was fully dark by this time. They saw a glowing blue light in the field that led them right to it.
If you’ve read this far you might be interested in some further information. Here’s a nice article and video from the local station WLFI TV18. The AMET crew has loaded several videos from the on-board GoPro camera on their Youtube channel. A lot of this was boring as there wasn’t much to see besides clouds. I skipped a lot of them but really enjoyed the take-off and landing. Warning! the camera spins around a lot and can actually make you dizzy just sitting on the couch. Still, pretty neat to actually see the curvature of the earth from so high up. Finally, there are some nice pics on the TechPurdue flickr page. They show some really great detail. This was probably the most enjoyable ham radio activity in which I’ve participated in a long time. Nick and I definitely want to do this again. Now I guess I’m going to have to start building an APRS station for the “Zed Sled.”
One of the radios I received from Mark Quebe N9EKG was an old Hallicrafters S-40B. I was hanging out with my buddy Nick N9SJA and we decided we should fire it up. Seemed like a good idea since he was there with me when I got the radio. I used my trusty method of bringing up the power slowly by inserting various wattage light bulbs in series with the hot lead in order to drop the voltage. This is a crude method but it works. I’m pleased to say that Nick and I both now have proper 20A variacs for this chore in the future. I haven’t done anything with the radio but wipe it down with some Armor All and blow out the dust. It isn’t perfect but it plays pretty well on the AM broadcast band. The caps definitely need replaced and the pots need sprayed with some DeoxIT but you have to love it when a radio from the early ’50s is still working with no catastrophic failures. It’s fun to listen to some old AM on the boatanchor radio.