N1GY- The Simple Approach to Ham Radio

About my "Blog" (see below): As I think of some subject that I want to make a short comment about, whether it be something new on the site, or something of import elsewhere, I will make an "UPDATE" to this home page. The latest "UPDATE" will appear at the top of the "LATEST UPDATES" text below. As older "Updates" become dated or no longer of importance, I will remove them from the site.

LATEST UPDATES FROM N1GY'S RADIO ROOM

UPDATED 06/02/12

Our local ARES group just completed our participation in a section-wide SET (Simulated Emergency Test) designed to test the performance of Winlink 2K as a means of transmitting and receiving messages to and from simulated shelters to the local EOC (Emergency Operations Center). While several of the participants had no trouble getting Winlink to work either via RF or Internet, the same cannot be said for operations at N1GY. The Winlink system steadfastly refused to accept messages sent from my computer although other stations were having no problems at all. In addition, the programs I was using to generate the messages appeared to have some difficulty in saving the messages in the proper folder that I had created to store all of them. Some were saved there, others were not.

I must admit that I am not the most computer literate operator and I have no doubt that the problems are probably a matter of user error, however, any program that is designed to assist in the speedy transmission of emergency communications in less than ideal conditions should be able to handle the occasional operator error and redirect the user into the proper path to follow in sending such methods. In the case of Winlink 2000 and the other message creation programs this is certainly not the case, at least for this operator.

I certainly will admit to being a bit of a luddite, particularly when it comes to computer technology, but I have managed to build and update my website on a regular basis without any significant help using a program that my ISP provider offers at no cost. If I can do that, I should be able to operate a simple forms generator program. In discussing these problems with our local EC, he noted that several other participants had similar and occasionally different problems with their own computers interfacing with the programs. Further training will be needed and it may take some modification of the settings on each users computer to make everything work smoothly together when using these programs.

In my own experience today, it would have been far easier and faster to simply pass the traffic as voice using standard ICS-213 or ARRL message forms. I have no doubt that many of the problems I encountered were due to my own lack of familiarity with these programs and Winlink, but in a real emergency, some of the operators pressed into service will probably not have had any training at all on the sophisticated applications that were used in the SET today. I think the powers-that-be may want to take a hard look at the training required to operate complex messaging systems for the average operator and whether or not a step back to simpler messaging techniques might be actually faster, easier and more accurate in real world situations. Just my opinion

UPDATED 05/30/12

Yesterday, I took a ride up to Chuck, W4CLL's place to meet with him and Don, KI4EFL with a plan to attack the RFI which continues to negate any attempt to operate HF with the engine running. We used one of Chuck's fancy scopes and various probes to try to find the source of the RFI. We were more successful at determining what was Not causing the interference than identifying the exact culprit. It is not the ignition system. It appears that one of the many sensors attached to the engine is causing a random pulse of sizeable current about 200 times a second. It varies with throttle position, which is why we thought it was ignition noise in the beginning. Unfortunately, we did not have enough information about the engine, a 4.3 liter Vortec V-6, to be able to isolate the specific sensor. There is also the possibility that there is more than one source. Don is mailing me some schematics he found later that should add some light on finding the offending sensor(s).

I must say that this is the most taxing and irritating problem I have ever seen in a mobile installation. It is probably a forerunner of things to come , as cars get ever more complicated. My previous vehicles have all had very simple engine electrical systems and the V-6 in this Blazer is full of all kinds of sensors that apparently can (and do) cause all sorts of RFI. Curing the problem continues to be a long and agravating slog. By writing about it here, hopefully it may help the next ham who finds a similar problem with his or her car.

On another note, while all this RFI is going on, the HM-118NT DTMF mic in the Blazer decided to go all wonky with scratchy and decreased audio. I switched back to the stock HM-103 mic and tore the DTMF mic apart to see what went wrong. Amazingly, the pin 6 and pin 7 positions on the RJ-45 plug seemed to be shorted. Since pin 6 on this mic is mic+ and pin 7 is chassis ground this is not good. The HM-118NT uses RJ-45 plugs at both ends of the mic cord with the one inside the mic plugging into a PCB mounted jack. The difficulty was to choose which plug to change. Either one could be the culprit. I chose to replace the one that plugs into the radio first since it had more straight cord behind it and got lucky. As soon as the RJ-45 plug was swapped out, the mic functioned perfectly. It turns out that the RFI I am suffering through on HF had not migrated to the VHF spectrum after all. This was a case of two separate problems at the same time. Whew! at least one problem had an easy solution.

UPDATED 05/18/12

Well, today my son in law and I changed out the alternator and the battery. Unfortunately, this had very little effect on the RFI I am experiencing on the HF bands. We did find that disconnecting the antenna did not completely eliminate the RFI. It did cut it down but not completely. Thus it would appear that the RFI is both radiated and conducted. With all the repairs, replacements and modifications we have made to the feed to the radio and the HF antenna, I am at a standstill. I plan on obtaining more expert assistance in tracing down and eliminating the cause of the RFI but it will take some time. On a brighter note, it appears that the RFI which showed up on the VHF frequencies has disappeared. Little comfort when the HF RFI is still there, but at least the FM side of things appears to be better for the moment. I am very frustrated at the seeming insolvablity of this RFI. I have never had any problem that resisted attempts to cure it with so much tenacity. However, I can be just as tenacious and we will get this problem solved.

UPDATED 05/10/12

The noise I have on HF in my mobile setup has advanced into the VHF spectrum. We have pretty much narrowed the culprit(s) down to the alternator. While it has tested to still be charging properly we were unable to confirm that the diode pack is 100% OK. As much as I hate to do it for cost reasons, it looks like I will have to replace the alternator again. The cost I was quoted for repairing the present unit was almost twice the cost of a rebuilt alternator from the local auto parts store. Unbelievable! This makes the second alternator for this car in the six years I have owned it. I just hope that the replacement fixes the RFI problem because I am running out of ideas.

UPDATED 04/28/12

With the hum at the home station banished for the time being it was time to return to the RFI on my mobile HF antenna. Today I bonded the exhaust pipe to the frame and double checked the braided strap that bonds the engine block to the chassis. No improvement! In total, I have bonded every door, the hood, the tailgate, the exhaust pipe and the engine to the car. I have replaced the spark plugs, the spark plug wires, the rotor and the distributor cap. I have added a "brute force" filter to the power feed to the radio and re-run the power cables to a larger gauge. I am stumped! I think it is probably time to seek out some expert help to try to track down the problem. For right now I think HF mobile opereations will have to wait for a solution to this very vexing dilemma.

UPDATED 04/26/12

I hope that the hum problem I mentioned yesterday has been sent packing. Today I tore the operating position apart and rebuilt it one unit at a time. I think the problem was that the AC power cable to the flat screen display was loose and thus the AC hum was getting into the radio system. It sounds a little iffy but other than cleaning up the cable runs behind the desk, I really could not find anything else. After much testing by myself and my amazing wife KJ4YMX using a handheld to listen to the signal from the 706 on a simplex frequency we seem to have killed the hum. I did discover that swapping the headsets for the 706 and the FT-7800 also helped but left the 7800 with a different noise. I plan on rebuilding the headset for the 7800 but one problem is enough for one day. We will see if the problem is truly gone tonight on the Tech Net at 9:00 PM local time.

UPDATED 04/25/12

Once again the 60 cycle hum has reared its ugly head. I found a loose PL-259 (same one as before) so I added a little assistance from a Channelock tool to make sure it was tight. Not very much, you understand, but just about a sixteenth of a turn. Unfortunately, that did not solve the problem. Next, I removed the LDG Z-100 tuner from the IC-706 and connected the HF antenna directly to the radio. The noise was attenuated slightly but not removed completely. I have a feeling that to get rid of it entirely I am going to have to disassemble the station completely and start from scratch. One of the areas I am looking at is separating the various computer peripheral cables (flat screen display, keyboard, speakers, etc) as far away as possible from the Radio RF and power cables. This sounds easy but it will require completely disassembling the operating position to be able to get at said cables and wires. For a few days at least I may be doing all my operating as a mobile while the rebuild is accomplished.

Nothing like having a "fun project" to do!!

UPDATED 04/20/12

The other night I got a report that distressed me considerably. A fellow operator told me there was a 60 cycle hum on my transmitted signal. As soon as possible I investigated the cause of this RFI and much to my chagrin discovered two problems. First, the wire connecting the case of my IC-706MkIIG had become disconnected from the ground bus at the back of my operating position and second one of the PL-259s on the back of the 706 was loose. With both problems fixed the hum immediately disappeared. While this was embarassing personally, it also brings up a good point. One should routinely check the various wires and cables that connect our transceivers to the outside world. I cannot imagine how the coax connector got loose, but it did. The ground connection might have been the result of my tugging on some computer peripheral cables a few days before. I am not sure about either but I am sure that I will be checking the back of my operating desk more often and particularly after I do any other work around those components.

UPDATED 04/14/12

On Thursday evening, on the Tech Net, I posed my RFI problem to the amateur operators in attendance. I got several good suggestions on how to track down the offending device in the car and I will be following up on those ideas very soon. The Tech Net, Thursday evening at 9:00 PM local time on the NI4CE repeater system is an excellent venue to bring questions or problems with your amateur radio operations. Usually there are from three to five Technical Specialists on hand and many of the hams who check in have had and solved those same issues before. The sum total of the experience and expertise on the Tech Net is amazing to me. I say that not because I am the Technical Coordinator for the Section but because I am truly awed by the experience level of the net's participants. Several are professional electronics engineers, others have worked in the communications field for many years. We even get a broadcast engineer or two. When the Echolink components are operational, which unfortunately they are not at the moment, the Tech Net can field inquiries from all over. I hope that the Echolink issues on the system can be solved soon for that reason.

UPDATED 04/11/12

Today, our son, bless his heart, replaced the plugs, plug wires, rotor and distributor cap on my SUV. We had high hopes that that would cure the RFI mentioned in a previous post because the RFI noise appears to be RPM dependent. After about two hours of work (changing the plugs and wires on a Blazer is not easy) we fired up the engine only to be greeted by the same RFI. No change at all. I must admit, I am at a loss for a next step. It would probably entail work I am not capable of doing and expense I cannot afford. If anyone has a suggestion, by all means email me. The RFI appears to be radiated rather than conducted, but by what? For now, HF will have to be done in short spurts while the car is turned off and parked.

UPDATED 04/10/12

I attempted to use my new HF Mobile antenna the other day and discovered yet another glitch in the proceedings. The antenna loaded up fine but with the engine running in the car I get what appears to be ignition noise on the receive audio. That fact begot a series of attempts to cure the RFI, so far without any measurable success. So far I have bonded all four doors, the hood, and the tailgate using braided and tinned lines. I have added a "brute force filter" to the power lines running to the radio. The RFI only affects the HF or SSB side of things, there is no RFI on FM 2 meters or 70 centimeters. I even powered the radio from a separate and isolated battery and determined that the RFI is being radiated not conducted through the power feed to the radio, so the filter I added was probably redundant. It was a fun project to make however, so not entirely time wasted. The next move will be to replace the spark plugs, wires, distributor cap and rotor on the engine. The car is now 12 years old and I would bet that the wires, cap and rotor are probably original. Time to put some new stuff on and see if that cures the problem.

I am also considering the addition of a second battery to power the radio and other ham related devices in the car. The second battery would be connected to the main battery but would not draw on it to power the electronics. The main battery would be isolated from the draw of the electronics so that it is always able to start the car. There are several ways to do this and I am still researching the best option at present. I may also add a small generator to the equipment list if funding can be found. The amateur radio world keeps spinning along.

UPDATED 04/01/12

Yesterday, I had the privilege to staff a display at the First Annual Mini-Maker Faire in Tampa. Along with several other hams including Dee Turner, N4GD, the Section Manager we presented amateur radio and several DIY projects such as antennas and microphones. For those who may not be familiar with the "Maker" concept, it is an increasingly vibrant effort on the part of many people to return to the idea of "do it yourself" this can apply to electronics, robotics, electric cars, almost any sphere of endeavor where the public has become used to "just buy it" These "makers" are not just young people. I saw presenters there from 10 years old to my age and beyond. Lets just say I am retired and leave it at that. Some of the designs I saw at the Faire were very impressive. Believe me, "homebrewing" is alive and well. Follow their example, build something today. If you have no experience at DIY radio, that is OK. Just start small with a simple project and build your skills and your experience as you proceed. Before you know it you will be tackling projects that would have given you the shakes a few months before.

UPDATED 03/28/12

I borrowed an MFJ analyzer from Ed, NI4MX yesterday and today I did the analysis of the HF mobile antenna. With the damaged feed line replaced and the ball mount no longer grounded to the car body, testing went very well. The antenna might even be resonant on 160 meters with a longer whip but for now I am quite happy with coverage of 75, 40, 20, 17 and 15 meters. The promised page has been added to the web site and you can see photos of the finished antenna there along with a full description of how it was constructed.

UPDATED 03/27/12

Today I did what I said I was going to wait a few days to do. Yes, I know I am an impatient so and so. Testing revealed that the coax to the back of the ball mount was indeed shorted. After some heavy disassembly of the right rear of the interior I was shocked to discover that at some time in the past I had managed to drive a screw right through the coax to the ball mount. After slapping myself silly several times I cut off the damaged coax only to find that the ball mount itself was shorted to the car body. It was OK when I first mounted it several years ago but I guess I did not leave enough clearance around it. Thus the next step was to remove the ball mount and clearance the hole around the feed point another 1/4" in diameter. Before re-mounting the ball, I added some insulation around the feed point so the problem will not recur.

Then we built a new coax run to connect the ball mount to the system. All new coax and connectors. At each stage we tested for shorts and when the feed for the mount was installed we checked again. Finally we can get to analyzing the antenna for bands covered and the effect of the matching coil on SWR. Hopefully that will happen tonight before the ARES meeting. If not, then probably tomorrow. What a monumental mess. It just goes to show that Murphy is still around and very active.

UPDATED 03/26/12

First, the good news. We put an analyzer on the new antenna today and could not get a reading at all. After much mental cogitation we determined that there must be a problem in the coax feed that connects to the back of the ball mount. Electrically, the antenna is fine, but until we get the feed to the ball mount resolved we cannot even test the antenna. Now for the bad news. To get to the back side of the ball mount, I will have to disassemble most of the right side interior of the back of the car. This is not a job that I look forward to at all. The radio and tuner panel has to come out, followed by most of the interior trim on that side of the rear compartment. To get that out I will probably have to remove a lot more. The only other option would be to start all over again on the left side of the car, but that would mean similarly dismantling the left side of the car as well. I think I will take a few days to gather my endurance up before tackling that task. So the addition of a page on the new antenna will have to be delayed a while until I fix the problem with the ball mount.

UPDATED 03/25/12

A bit of miscommunication has delayed the analysis of the new HF mobile antenna. The antenna analyzer that was to be at the "foxhunt" got left at home, so no testing got done. On the other hand, Audrey, KJ4YMX was first to find the "fox" at the event yesterday and the picnic afterwards was enjoyed by all so all in all a good day. I will borrow an analyzer later in the week and get the tap points marked on the coil in due time. Those who examined the new antenna on Saturday were most complimentary so although disappointed by the delay, I am encouraged that the antenna will do a good job once the tap points are found.

UPDATED 03/23/12

While the RF testing of the HF mobile antenna project will not take place until tomorrow, the mechanical testing of the project has been going on for several days. So far, the antenna appears to be holding up very well to the stresses of driving around at up to 70 MPH. The PVC brace is holding firmly to the luggage rack and I have found no evidence that vibration is loosening the various mechanical connections. The fly lead alligator clips are holding well to the coils as well. I did do a little touching up to the paint job on the antenna itself but those small defects were caused during assembly, not by any effect of being in motion. Tomorrow, the RF testing will be accomplished and then we can start actually using the antenna in an attempt to gauge the actual performance. All mobile antennas are, to one degree or another, compromise antennas. The best one can hope for with any mobile HF antenna is to increase the efficiency as much as possible. The work continues.

UPDATED 03/20/12

The HF mobile antenna that I mentioned in my last update has been completed. The 3" x 10" coil arrived today from MFJ and after a quick modification to the coil mounts, the antenna has been mounted on the car. Testing will have to wait for this coming Saturday when Jim, KE4INM will be able to connect his analyzer and we can determine what bands the antenna is capable of covering. The design is similar to the one designed by Frank King, KM4IE back in the April 2000 QST. I have changed the sizes of the coils and the mechanical construction details to use what I had on hand. The basic electrical/RF plan is the same but I hope to have access to a few more bands because of the larger coils. Testing will provide the answers to those and other questions about the antenna. Once the testing numbers are in, I plan to add a page about the antenna and the construction methods I used to the web site. It may be a few days though, because the upcoming couple of weeks are going to be very busy. We will have family visiting from up North and there are also many ham radio related events to cover before the family gets here. One of these is a Mini Maker Faire in Tampa. The ARRL will have a booth at this event and I have been asked to display a few of my "homebrewed" projects. It sounds like a lot of fun and I am eagerly looking forward to it.

I also managed to rewire the Radio-In-A-Box II today. It turns out that one of the two 7AH gel cell batteries had gone belly-up. However, in changing out that battery, I discovered several less than optimum connections in the wiring harness, so a complete rewire was done. The batteries charge up well now and all of the wiring connections are secure.

UPDATED 03/15/12

The HF mobile antenna that I mentioned in my last update is well underway. There have however been a few changes in the construction process. After much consideration, I decided to use the remains of an old "Hamstick" that I had laying around. By stripping most of the wire off of the core, I wound up with a central "spine" that is much stronger than if I had assembled it from PVC. The two coils, matching and loading were to be wound on 2" PVC but after the difficulty I had winding the matching coil I decided to order the loading coil from MFJ. I plan on using the end caps from the original plan to secure the MFJ coil to the "mast" of the antenna. The support brace that will attach to the luggage rack is built as in the original article and should work well. I still have no idea what range of bands this antenna will cover. I will be borrowing an antenna analyzer to determine the range of bands it can cover. As mentioned in the original article from 2000, the band coverage is detirmined by the dimensions of the antenna and my project differs in almost every way from the original. Experimentation is one of the aspects of amateur radio that attracted me to the hobby in the first place, so my comfort level is fine with this unknown. Keep on building and experimenting- This is amateur radio.

UPDATED 03/07/12

With the DTMF project complete, I have been casting around to find a new project to work on. I have decided to built a multi-band mobile HF antennna for my SUV. An article in QST from several years ago entitled "A $20 HF Mobile Antenna" by Frank W. King, KM4IE, caught my eye and I have discovered that I have a few scraps of 2" PVC Sched 40 laying around. While these scraps are a little larger than the 1.5" used in the article, Frank wrote in the article that very few of the dimensions in the antenna are critical. This antenna is kind of like a "Texas Bugcatcher" on a diet. With a slight shortening of the lower mast and a little fattening of the coils, I think it will work out just fine. I will post the results on these pages as the construction progresses. Build something! this is ham radio.

UPDATED 02/15/12

The rewiring project I mentioned in my last update has been accomplished. There are just a few minor details to finish tomorrow like securing and neatening up the visible wiring. Apart from a small glitch due to a Power Pole contact that wasn't all the way in, the project actually went about as expected. The only major change from the original plan was to eliminate the 140 watt Inverter. With a 330 watt unit just behind the passenger seat, the smaller unit was redundant. I still keep it in the car just in case I need it, but it is not permanently wired into the system.

This time I used 30 amp relays for the two major draws, the IC-706MkIIG and the auxiliary power feed. The Inverter has an on/off switch and fuse built into it so it was wired directly to the distribution box. The GPS power is the only feed that goes through a switch directly. The other two switches operate the relays to turn on the radio and auxiliary power.

All fuses are now easily accessible and if something like a switch malfunctions, it can be replaced without having to tear the interior of the car apart.

The only problem I had in completing the project was finding suitable splices for 8 gauge wire. The local stereo shop had 8 gauge butt splices but I did not have a crimper tool that was up to the task. I found suitable connectors at a home improvement store that used screw-down clamps to secure the wires. They were a little expensive, but they did the job well and I was able to insulate them with some large diameter heat shrink tubing that I had on hand. The total time actually working on the project was around 16 hours over two days. Added to that would be the time spent planning the task out and assembling the necessary parts.

I have a feeling my next project will be to clean up all the detrius left behind by the wire prep and the like.

UPDATED 02/14/12

My project for the day, apart from celebrating Valentines Day with my wife, has been to start the major project of completely re-vamping the wiring inside my SUV for ham radio. I installed an IC-706 MkIIG in my 2000 Chevy Blazer when I first got the car almost 5 years ago. In the meantime, what with additional devices, all requiring DC power, added from time to time, the wiring has turned into a "rats nest" of red and black wires. About a month ago I decided the time had come for a complete re-do of the DC system.

After a good deal of planning as to how much power was needed by the various devices, I came up with a schematic that I think will satisfy the now and future needs in the Blazer. The cornerstone of the system is a power distribution box that will be mounted behind the front passenger seat on an enclosure that surrounds the masting and other gear for ARES deployments. The box will be accessible without having to disassemble any part of the vehicle. All connections out to the devices and the switches that control them is by Power-Pole connectors. I am using 8 gauge wire from the battery through the firewall and also back to the 2 main heavy power users, my 706 and a 330 watt Inverter. 10 gauge wire is used to connect the distribution box to the 140 watt inverter and the auxiliary power center. 16 gauge wire is used to power my GPS unit and also to connect the relays that actually switch the radio and the auxiliary power center to the control switches installed on the center console. Both inverters have their own internal fusing and switches which makes adding these items to the distribution box redundant. Power is also supplied to the wireless PTT switch receiver through a 3 amp fuse. The PTT receiver turns on automatically when the 706 is activated.

The end result will probably not be noticable to a casual observer, but the increased reliability of the system will be noticed by me for years to come. Access to fuses and relays will be immediate and the increased current carrying capacity of the 8 gauge wire will ensure that big current draws will not be risky. Certainly the fact that all splices and junction points will be in one secure position will lessen the need to disassemble the interior when something goes amiss. All connections outside the box will be via Power Pole connectors. Tomorrow I plan to install the distribution box and complete the wiring runs to each device. As they say in the homebuilt aircraft fraternity " I am 95% done, only 50% to go".

UPDATED 02/05/12

Last night I added a paragraph and a circuit diagram to the cellular headset adapter page. With the cellular industry seemingly awash in BlueTooth headsets, the wired type are getting harder to find. On the brighter side, PC type headsets are now coming out in the same over the ear styles as the wired cellular headsets used to use. I therefore added a circuit that demonstrates how to wire the circuit with two 3.5 mm stereo jacks to suit the PC style headset. I have been able to find these "earsets" for as little as $1 each in one of the "Dollar Stores" around town. The audio is just as good on these as with the cellular units. The only real change is two jacks instead of one.