ARRL Gets A New Website

The American Radio Relay League, ARRL, is launching their new website today! I heard the site was changing at the ARRL's section meeting at the past Columbus Hamfest. I will be curious as to what it looks like.

As per the bulliten on the current site, they will be down for a few hours starting around 10:00AM EDT (1400UTC).

Blogger FTP Publishing To End May 1

I have been using Google Blogger all this time to get my content up on my site. I just publish over to a different server, which is accessed through my .com address. This is why my blog doesn't have a ".blogspot.com" address.

Well, Google is stopping the support of FTP publishing May 1. This is what allows users like myself to have their own address.

I am not sure what will happen between now and May 1, but hopefully I can get something in the works that will allow me to manage my blog on my .com address. I sure don't want to loose all of my content.

Tarheel Model 200 Screwdriver Antenna - Fixed

I have been having some SWR problems with my Model 200 Screwdriver antenna, made by Tarheel Antennas. It is an older one, I believe I got mine in 2002. For the most part it has been a great antenna. I have used it for portable, mobile, as well as base use at some point in time or another. The versatility of a Screwdriver antenna makes them hard to beat in a lot of situations.

I suspected the SWR fluctuations were due to a bad connection some where. The first place I checked was the safety spring on the whip. I like to use the 3/8"x24 spring shock absorbers on all of my antennas with that style mount for some safety from impacts. As part of the design there is a wire that runs up the center of the springs (it doesn't matter what size, large or small, they all have it) so that when the whip bends over the stretching of the spring doesn't act like an inductor changing the resonance of the antenna - the wire shorts it out to maintain resonance. After having a spring fail in the past I checked this first. Sure enough, the wire strands inside were corroded and all but one strand was broken.

So I pulled the spring off and directly screwed the whip in to the top of the antenna. No luck. The SWR still went all over the place going down the road. Since we had a pretty good winter this year with lots of snow I figured all the subsequent road salt might be playing part of the problem by getting up into the coil. So I figured I had a bit bigger problem on my hands than replacing (or just removing) the spring.

I decided to take the antenna apart to check it out. I have had this one apart several times in the past so I knew how to do it, it really is a pretty simply constructed mechanism.



The first step is to raise the antenna all the way up to expose the whole coil. Then disconnect the shield from the top of the coil and slide it down. This exposes the coil. To access the entire coil you need to pull off the machined top of the base by loosening three set screws. This part has copper finger stock inside and is what makes the electrical connection between the coil and the base.



If you look above my fingers inside the part you can see the edges of the copper finger stock strip inside. This needs to be cleaned as well as the coil itself.

I didn't really have to do this as it turned out, but I pulled the guts out of the antenna. I was trying to get the mounting stud off the top so I could pull the PVC cap off to get the machined contact off the coil to clean it. The stud is ON THERE FOR GOOD. I don't know how they got it on that tight, but I would have ruined the antenna if I tried any harder to unscrew it. So I just left it in place and improvised.



For cleaning I used strips of a thin cardboard box. I wanted something I could rub the parts with that was mildly abrasive but also stiff and strong enough to not tear. Paper is a good contact cleaner - I learned that trick from some old CW operators for cleaning key contacts. I figured paper would work just as well here, but the cardboard is one better as it is thick and won't tear like paper.



Here you can see one of the strips I used. Note the black stuff on the cardboard. That is just from the finger stock surfaces!!! That isn't the strip I used for the rest of the coil.

After scrubbing down the coil and the contact I put it all back together. Surprisingly, the SWR still was fluctuating! I thought I had tried everything. The coax is sealed real well (with my favorite PlastiDip weather proofing treatment) so I didn't think that would be an issue. Though, I would probably have sliced it open just to inspect it. A can of PlastiDip is only $6 so even if I got one use out of it (which, if you seal up the cap REAL well with tape after you open it the can will last a while) it is pretty inexpensive stuff (as opposed to CoaxSeal).

After pondering what to do I got one more idea:



The screwdriver antennas are so big that the base alone is not strong enough to support it. There is a second support up off the base for two points of attachment (the ring support on the antenna for the mount is shown here). Originally, the base had a plastic strip around this secondary support hole on the mount. After a few months it wore through so I wrapped this part of the antenna that contacts the mount with electrical tape, as seen here.

Well, I figured the electrical tape was worn through. I couldn't really tell too easily so I figured it wouldn't hurt to add more to it anyway. Then the antenna started working! Only, I had put too much tape on and I couldn't tighten the antenna down all the way - the tape made it too tight in the hole. So after driving around this morning I removed some of the tape and got the antenna all the way down in the mount and it worked all the way home! I talked with Ernie VA6EJR in Alberta on 17 meters for a good while - with a solid SWR less than 1.1:1 the whole way!

If I had just gone to the ring and checked the tape the first time I probably would have had this antenna back up and running in no time. However, I am glad I pulled the whole antenna apart and took some time to inspect and clean the contact and coil. This antenna is in daily use on my truck, and quite frankly I am surprised it has held up this well for so long! Tarheel Antennas really are good antennas, just as with anything else they do need a little maintenance.

Mobile Antenna Experiment - Whip and LDG Z-11Pro

This is something I have been wanting to do for a while and I just got around to doing it!



My screwdriver antenna, a Tarheel model 200 (the older model, mine is 8 years old - the new ones are made even better) is having some tuning problems. I need to take it apart and clean the coil as well as the finger stock on the top of the base which contacts the coil. My SWR fluctuates all over the place going down the road. That's not to talk bad about it - the antenna has LOTS of miles on it and we just came out of a pretty bad Ohio winter with lots of road salt.

Since the screwdriver is off the truck I figured I would use that as an excuse to work on my whip and tuner experiment. The first task was making the antenna mount. I did this just like I did on the other side for my CB antenna - I cut a 2x4 down to fit inside the stake hole and screwed a metal plate on top which is what the antenna mount attaches to, off to the side of the truck. The CB antenna has worked flawlessly for years.


The new antenna mount. Note the next paragraph.


This is the old CB antenna mount. This one has MANY miles on it, as does the screwdriver. They are on the truck nearly 100% of the time. Note the thick base under the spring - I machined that from stainless steel.

I had a broken tri-mag mount, one of the old MFJ's with the 5" magnets and 1/4" aluminum frame. Since it was toast already I took it apart and stole the top bar - the one that had the original 3/8"x24 mount bolted to it. The hole was already there - all I had to do was drill through the end to screw it to my wood block. The thick bar makes it hard to get the cap to latch shut. I will probably change it at some point.

After that - it was on to hooking up the wires. I decided to connect the ground to my screwdriver antenna mount. It was already grounded very well and it was easy to attach my tuner ground wire to one of the mounting bolts. The wire between the tuner and the antenna just plugs in to the center pin of the SO-239. I tinned the wire and left a blob of solder on the end just big enough to press fit in the center pin (not too tight). For my random wire antenna at the house I use an old PL-259 I melted off of a bad cable. I soldered 14g solid wire to the center pin, filled the body with epoxy to lock the wire in, and put a spade connector on the other side. This makes it a bit easier to work with, but I didn't have another junk PL-259 to use this time.


Note the tuner and the battery (black box hiding under the corner of the rug). I didn't feel like running the power cable for this experiment as well so I just threw an SLA back there.


The whip I am currently using is a 10m hamstick with a couple of Buddipole arms on the bottom for some extra length (see the first picture - the blue poles on the bottom are the Buddipole arms). The good thing with a non-resonant whip antenna is you can toss what ever you want in the air and get the tuner to do the rest. Generally the longer it is the more efficient it is on lower frequencies. For stationary use I have a 9' or so telescoping whip to put on top of the hamstick base (in place of the stinger). I have done that for more efficient operation on 40 meters on the screwdriver sitting in the driveway and it worked pretty good! I had about 15' of whip above the coil, but hey I got out.

So how does the antenna perform? Well, I had a nice conversation with Jeff G4SOF in England all the way home from work this evening on 17 meters. I was running 50 watts. I guess that's not too bad.

Now the real scoop -

The antenna loads up on 40-6 meters with the tuner. However, if I run a carrier at anything over 10 watts the SWR starts jumping around all over the place (key down CW). If I am running SSB I can get up to 100. I was hesitant to run much more than 50 watts at the time I spoke with Jeff because when I tuned up I did so on CW and the SWR went haywire with much power. However, after we signed I played around with the power and called CQ a few times at 100 watts SSB and never saw the SWR jump.

Running the tuner in this configuration places high voltage between the tuner and the base of the antenna. The wire I am using to connect to the two is not high voltage so I am probably getting some arcing. SSB has such a low percentage of power compared to CW that only on voice peaks do I hit whatever I set my output power to. CW is full power with every tap of the key, which means a much higher chance of arcing.

At some point in the future I will play around with a few different things - tuner placement (perhaps outside of the bed) as well as swapping the wire out for some high voltage stuff. My goal is to be able to run 40m CW. The thick bar for the mount also makes it hard to get the cap to latch shut. I will probably change it at some point to some thinner gauge steel, like the CB antenna mount is.

Here are some more pictures of the install.


Ahh. My favorite weather proofing - PlastiDip!!


I wrapped the wire here with electrical tape trying to up the breakdown voltage. I don't know how well it worked. If I key up on high power I still get the SWR going wild. What irritates me is when the tuner knows it is at a good match then when I kick the power up it goes out of whack. The tuner re-initiates a full tune cycle and the match it just had is gone. RF can be screwy sometimes.

IC-756ProIII and LDG Z-11pro

The April edition of QST has some neat articles in it. One is adding a 5kc roofing filter to the IC-756proIII. The filter is produced by International Radio, the same company that makes the filters I put in my FT-857D last year - good stuff.

One fact of life with the middle of the road and down HF radios is they generally use a 15kc+ front end. My TS-2000 is no different. Even though the specific radio might be a DSP rig, the IC-756ProIII and TS-2000 included, there is only so much digital filtering can do to help the performance of the radio. Having a mechanical filter to narrow the passband up front is most definitely the best route to go. That way your DSP has less crap to work with = better performance.

This may be something I should look in to for my TS-2000. I have a blown RF choke on the CW keying circuit right now so I need to get my hands in the case anyway. Speaking of that, I ordered the part (3 to have extras) about two months ago. They were out of stock when I placed the order so I figured as soon as they become available again they will ship. Maybe I should follow up and see what the deal is...

In any event, adding a narrower roofing filter would surely add to the usability of the TS-2000. Having all those bands in one box is amazing. However, you can't get all that in one package without some sacrifices. Receiver performance, unfortunately, is one of them.

There is also a nice article on the LDG Z-11Pro autotuner in QST. I would like to see a review of the tuner. The article isn't a regular review. Maybe they can toss in some other tuners in the same range. I know MFJ makes one and the SGC tuners may fall in a similar category also.

RF Systems Engineering, of sorts

My big work project right now involves setting up localized differential GPS base stations. I work for a John Deere dealer and we are trying to get some coverage for our area of responsibility on what is called "RTK", Real Time Kinematic correction. Basically, the idea is to put a localized differential GPS station up (like WAAS if you have a hand held GPS) - the units have a 1" accuracy at the GPS receiver out to a 12 mile radius (theoretically, based on propagation). You can read more of the systems and learn a lot more than I can put in a post here on John Deere's site.

My project has been piecing together the systems. The main components are coming from John Deere, so those are taken care of. However, power supply, back up power supply, RF routing, power levels, and ultimately building the the systems will be mostly my task.

This past week I have spent a lot of my time thinking about the systems and what should go in to them to get them on the air. We got the information filled out for the FCC license (coordinates, elevation, etc) so once we get out frequency and power allocation I can finish the EIRP calculations. Just for the mean time I plugged in some known component values - antenna gain and coax loss (the BRAND new 7/8" AVA5-50A from Andrew/Comescope/Heliax [replaced the LDF series, even lower loss] - the GOOD stuff!!). The rest of it we should be able to control from our radios. The power level will be adjustable between .2 and 2 watts with an amplifier of a max PEP of 50 watts.

Some challenges left to tackle - enclosing the components to where they are protected (in most cases from the weather - outside mounting) while allowing adequate cooling of the power supply. The amplifiers are not quite out yet, but they are supposed to be weatherproof for direct outside mounting negating the need for cooling (the whole case is a heat sink). The power supply is another ball game. I ordered some Astron RM-50M's for easy rack mounting. They will be the most versatile in our application since they can either be rack mounted or desk mounted. If we put it in a case it will go in a rack, however one location is inside a building on a desk more or less.

For stand-by power I am using two ~110Ah batteries in parallel and a PWRGate from West Mountain Radio. The PWRGate allows constant battery system maintenance with instant switching of the load from the power supply to the backup batteries. It actually is not powered itself, it takes power off of the power supply and passes that on to the batteries - however much it needs (you can set it for up to 10 amps of charge current). Once the voltage of the batteries comes up the charging current drops off until it gets to 13.8v. At that point the PWRGate switches to a float charge mode.

One aspect of this project that adds to the challenge is the fact that once these are on the air they will run 100% of the time at 100% load, except if the power goes out. We will have around 7 to 8 hours of reserve back up power. This is why the ventilation/cooling of the power supply is critical. I ordered one size larger power supply than I really needed (based on constant amperage) so they are running at a lower percentage load. This should help out on the reliability. However, if they get too hot, which can happen even at 60% or so load, they are going to fail.

All in all I have my hands full right now! This is a really neat project, though. I am very glad I can apply some of my ham radio know-how to getting these systems up and running. I don't necessarily know all the answers but I have a lot of resources to tap and know which ones to use - people, companies, books, websites, you name it. On top of this RTK project I still have to juggle piecing together the GPS systems that our customers run on their farm equipment (tractors, combines, sprayers, etc)...

AT Hikers Story: Three Hundred Zeroes

I am not one to read books. I have books from my last quarter of college that I bought new because they were the only ones left and I needed at least something to flip through, which I never ended up reading.

However, I read the recent article in QST magazine about Dennis Blanchard, K1YPP, and his hike of the AT (Appalachian Trail). I discovered through e-mail correspondence about his book - Three Hundred Zeroes. So as soon as it was available I ordered it!

Those that have read several posts of mine probably have figured out that I like backpacking. I won't spoil the book any, but that is the main topic. The Appalachian Trail is what is typically thought of as the crown jewel of backpacking - over 2000 miles from Georgia to Maine along the Appalachian mountains.

Though there isn't much talk of Ham radio in the book, if you have any interest in backpacking, with or without Ham radio, I would recommend the book. I have a hard time putting it down. I have finished the first half of the book in three days (thats really saying something!). I don't know that I could ever devote my life to such a journey, but Blanchard does give me some inspiration for more treks, albeit shorter!

VUAC Taking Votes on EME Contest Categories

For anyone that is interested in EME (Earth-Moon-Earth, or moonbounce, communications) I think you should read this and take a stance. This past Fall the VUAC changed the rules for EME contests, effectively chopping out the Assisted category.

The problem with this move is that EME is perhaps the most difficult, technically challenging mode of communication possible and requires either well-equipped stations or a little bit of planning to have a shot at making a contact at all. The smaller, lesser equipped stations have no chance of making many contacts (except with the big-gun stations like W5UN, KB8RQ). Without setting up scheduled contacts the chances of the smaller stations to compete is non-existent. Even if a schedule is set that doesn't mean that the two stations will be able to make it through, but without a schedule there would be no chance at all.

Here is a message from Army, AE5P with an offer to vote on the issue. Please read thoroughly. Note that any correspondence to be considered must be in by February 17th:

______________________________________________________
ARRL’s VUAC is considering revising the current rules for the ARRL International EME Contest, and we would like your input.

Effective with the 2009 contest, assistance is not allowed per rule 6.3 as follows:

6.3 During the contest periods, no contest entrant, in any category --single-operator or multi-operator-- may use non-EME means for the purpose of self-spotting, solicitation or coordination of QSOs or attempts to make contact; nor may any entrant use assistance or provide assistance in the form of frequency spotting or use any form of DX spotting, Packet Cluster, Ping Jockey, email, telephone, etc. Exception: liaison to coordinate band-by-band activity is explicitly permitted for the bands2.3 GHz and higher.

VUAC members have received numerous messages from many of you folks regarding this change; some in favor; some opposed. We are considering making further changes to the rules to address your concerns, and we would like to hear from the EME community on this.

Several proposals have been put forth, such as:

1. Reinstate the rules regarding assistance as they existed in 2008.


2. Establish a new class of operation called “Coordinated”. Entrants in this class would be allowed to post ONLY their call-sign and calling frequency via the internet or other methods for other entrants to see. Any station posting or viewing this information would be considered to be in the “Coordinated” class.

3. Let the current rules (non-assistance only) apply to one of the two weekends for 50-1296, and let assistance be used on the other 50-1296 weekend.

4. Run a separate EME contest for 50-1296 using assistance on the weekend reserved for 2304 and up.

5. Don’t make any further changes. Let the rules remain as they are now.

The VUAC would very much appreciate hearing from you concerning these proposals. Where do you stand on this matter? Which proposal do you prefer, and why? Feel free to modify any or all of this as you deem best.


Please respond to this survey to your VUAC representative AND to Army Curtis, AE5P (ae5p@arrl.net) . A list of VUAC members can be found at http://www.arrl.org/contests/vuac.html . Comments must be received no later than February 17, 2010 to be considered by the VUAC. If you do not have a VUAC representative, please respond to Jon Platt, W0ZQ (w0zq@aol.com ) AND to AE5P (ae5p@arrl.net ).

When you respond, please indicate what bands you have made EME contacts on, and if you have ever participated in an EME contest.
Please let us hear from you.
73,
Army - AE5P

49 States Covered With Snow?

Yeah, that's what I just heard today on The Weather Channel! With the last snow storm that hit the south from Texas all the way through the pan handle of Florida, on to the Carolinas, all but ONE state, Hawaii, has some snow cover on the ground! Incredible.

We are again looking at some snow for Monday where I am. They are calling for up to 6" as of now, but I am sure that will change a bit. With the last two storms we got a foot the first time and 6-8" the second.

What happened to Global Warming??? I like the snow, though. Lets keep it around as long as we can!

Good Deal - Fluorescent Shop Lights, Grow Lighting

Last year I set up a fluorescent shop light as a grow light for starting my garden plants. I got a 2 foot long single T-12 light. This got the plants growing OK but became problematic once I brought the plants outside. The plants were used to the very limited amount of light and got burned real easy in the sun.

So I figured I would get some bigger lights so I can get my plants used to more intense light!

Lowes has a really good deal on two bulb T-12 4' shop lights - $10! That's what I paid for my 2' single bulb T-12 last year.

I picked up two of them. Each bulb is 40 watts, so I will have 160 watts x 4' of lighting (as opposed to my 20w x 2' last year). That should help with getting my plants used to more intense light. I will still have about the same amount of plants.

Last year I used an outdoor timer for Christmas lights as my light timer. This worked OK. However, I found a digital in-wall timer today that I am going to try this year. It should make for a cleaner set up.

The next task is to get a shelf set up that I can mount everything to. I really rigged up my light last year and it worked, but I would rather have a nicer set up than what I did in the past. The timer will be in a box on one of the legs and the lights will be mounted so the plants get hit on both sides.