Monday, July 30, 2007

Cayman update #2a

I just wanted to post a quick couple of pictures from the trip. First, here's a view of how close the antenna was mounted to the roof. That roof is metal, as is (obviously) the railing that the antenna is attached to, and most of the windows are metal as well. The counterpoise wire is angling off to the left in this shot, but it's just about impossible to see. Also, it's a little hard to tell from this angle, but the antenna was mounted on the 2nd floor.

Aside from the difficulties with the antenna, the actual physical operating conditions were hardly difficult. That's me during the IOTA contest operating from our bedroom at the house. You can see the laptop and radio in the picture, the power supply was a few feet away on a chair (mostly because it has a fan that is pretty noisy and runs constantly. In the background, looking out the window in the foreground you can see the Buddistick antenna, and past that, across the water, is the Blue Tip Golf Course. Yeah, we did have a pretty amazing view out the window.

Admittedly, this was not a "roughing-it" trip by any stretch of the imagination. In fact, short of actually living there full-time this was about as easy as it gets. Scott, NE1RD commented in his blog that his idea of roughing it was staying in a hotel that didn't have room service. Well technically, we didn't have room service here (it was essentially a private house) but since we did have maid service I guess that doesn't count. About the toughest thing that I had to do was to open the slider to adjust the antenna, which let some of the heat into the room. Gee, I guess I'd better not complain to the BS7H folks.

Sunday, July 29, 2007

Cayman Update #2

I wrote the following post while offline in the Grand Cayman airport, and had forgotten that I've covered a fair amount of the same material. I'm now sitting in the Charlotte airport, with the storms in Newark having delayed our return flight home, and I decided that rather than edit what I wrote, I'll just post it as written. Please forgive the duplication.

Sorry for the lack of updates from during the trip. This update is being written as I sit in the airport waiting for the first leg of my return flights home. Although my original intent was to provide a few updates during the trip, other matters, such as sitting by the pool, jet-skiing, eating, eating, eating, and the occasional (!) "adult beverage" seemed to take up a lot more time than I'd expected.

The Antenna Issues

As I mentioned in my first posting, I did have some trouble getting the Buddistick tuned. Over the course of the week, I discovered a few things that almost certainly causes the issues. First, as you'll see from some pictures (I'm not sure if they'll be in this blog or elsewhere, as I'm currently writing this offline) the antenna was mounted on a railing on the second floor of the house. We were quite close to water, but unfortunately the roof of the house was metal, which did cause problems. (I considered mounting the antenna on the grass in the backyard or on a patio table, but decided not to do that as I would have had to either operate outside or run the feedline over the backyard. Neither of those options seemed desirable.)

However, I think the bigger issue was that I was probably using a counterpoise that was too short. One of the nice things about the Buddistick is that you can experiment, and you can find that the antenna will tune with different combinations of coil and whip settings and counterpoise lengths, though not all of those settings are optimal. For a while I was using a counterpoise length of a bit over 10 feet, which at some point during my testing from home I'd found worked reasonably well. However, what I finally realized was that the bandwidth for acceptable SWR was pretty small, and I wasn't getting what I'd expected to see in terms of actual SWR. (I was getting a minimum of around 1.8:1, and I'd previously seen much lower, approaching 1.0:1). It finally dawned on my that my "assumed good" counterpoise length might be wrong, and I went back to square one and re-calculated what the length should be, based on a dipole with a center frequency of 14.250 mHz. (I was operating exclusively phone.) That came out to be something like 16' 3" (roughly; I don't recall exactly what I used), and when I used that and checked with the analyzer, I found that I had excellent SWR (1.2:1 or less), though too low on the band. I moved up a coil setting or two, adjusted the whip, and in about 5 minutes I had excellent SWR through the entire 20m phone sub-band. (Using the built-in SWR meter on my '706, it showed entirely flat.) Unfortunately, I didn't have this stroke of genius until Friday, which meant that I probabably missed out on a lot of contacts that I should have had. (Too much sun frying my brain?)

The Noise Issues

One other problem that I had was noise on the bands. It seems that there were a couple of reasons for this. The first reason was probably due to various electronics within the house where we were staying (or from the other houses in the area.) This type of noise did seem to come and go, so it could have been things like hair dryers or appliances being switched on and off.

The second cause of noise was something that I should have found before I left. Although I did hook up my laptop to make sure that the CI-V interface to my radio worked, and even hooked up the antenna, I never actually made any contacts with the complete setup, despite my "Practice makes closer to perfect" philosophy. That was a mistake. I discovered a couple of different sources of noise coming from the laptop. The laptop that I was using is a Dell D620, which has both a "mini-stick" mouse as well as a touchpad. Whenever I touched the touchpad (which is common during logging), there was a very loud buzzing noise generated. The fix for that was to use the "mini-stick" mouse, though it was a little annoying since it's difficult to not have the palm of your hand occasionally touch the touchpad while typing.

The second problem was related to the power supply. When I'd tested the setup, I didn't have the laptop plugged in to the power supply since I'd only intended to test for a few minutes. Apparently the power supply for the laptop is a noisy switcher type, and not only generated noise when plugged into the laptop, but also generated noise when plugged in at all. The fix for that, of course, was to leave the power supply unplugged. For the most part, this wasn't a problem, since most of my operating was limited to a one to two hour stretch, but I did forget to plug in once and found the battery dead. One thing that I'll check when I get home is whether some ferrites would have helped the situation.

More to follow soon ...

Tuesday, July 24, 2007

Cayman Update #1

Greetings from Grand Cayman! So far, I haven't been on the radio too much (maybe about 90 minutes over the past couple of days) and as of this writing, have made 47 contacts. Certainly not very many, but I think it's going to pick up. I operated for a bit yesterday, after a very long day (woke up at 4:30 AM to head to the airport), and another bit today. Yes, this is a vacation, so I haven't spend a lot of time of time on the radio, but I have had a lot of fun so far with what little time I have spent.

I did run into a couple of problems: The first problem was getting the antenna to tune. I'll have some pictures later, but the antenna is mounted on a railing outside the room where we're staying (which is basically a 4-bedroom house). My room is on the 2nd floor, overlooking a canal, and maybe about 1/2 mile from the North Sound. The problem is that the antenna is very close to the house, and that's making it difficult to tune. I probably spent about 45 minutes this afternoon getting a decent SWR on 20m, which I had expected to be the "bread and butter" band. Once it got tuned up, I did fairly well; Most stations were in the US, but I've worked some VEs, Italy, Spain, Venezuala, Puerto Rico, Netherlands, Finland, a few others. Over the next day or so, I will set up for 40m, and I'm hoping that I'll be able to work a lot more countries outside of North America.

The second problem is that I discovered that the laptop that I'm using (a Dell D620) causes a bunch of QRM in two difference ways. The first problem is that apparently the power supply for the laptop is really noisy. It's so noisy that I've been charging up the laptop when I'm not operating and leaving unplugged when I'm on the air. I was going to take a few ferrites with me and didn't, which was a mistake. The second issue is actually a bigger one: It seems that whenever I touch the keyboard, the noise from the laptop dramatically increases through the laptop. (As my friend Larry, N4VA points out, apparently I make a good antenna.) Because of this, it's making logging tricky, since for all but the strong signals the noise from the laptop wipes out the signal. I've managed to work around this for the most part, but I may wind up going to paper logging at some point.

But despite these small problems, I am having fun. I've had a couple of small pileups, and I'm having a blast being "wanted" for a change. What's been nice is that while I'd love to be able to try my hand at running a really significant pileup, things have been such that I can usually have a short chat with folks instead of the typical "some-station you are 59 from ZF2DK QRZ".

I do plan to try to get on 40m over the next day or two, and I think that I'll be able to do a bit better than. I've been a little reluctant to re-configure the antenna, since it's been quite a challenge getting it set up for 20m, but given my operating schedule, I think I'll do better on 40.

One other thing that I wanted to mention is that I've uploaded my logs to date to both the ARRL Logbook of the World and to DL5NAM's site.

One other update is that I will NOT be doing any PSK31 when I'm here. The problem with the laptop has really ruled that out completely. As I mentioned in some prior posts, practice doesn't make perfect, it just gets you closer. Unfortunately, this is one thing that I wasn't prepared for, and if touching the keyboard cause QRM, it's going to be really tough to work PSK. Lesson learned.

Thanks to those who have worked me. Most likely, I'll be on 20m again tomorrow at around 22:00 for a while, so look for them then. I've been near, thought not exactly on, 14.260. We have some relatively early dinner plans tomorrow night and if we get back when I expected, I may be on 40m at around 0200Z or a later.

Saturday, July 21, 2007

Going, going .....

Just a quick note, as we're packing up the suitcases for the trip. I'm well under the weight limit, and I've split up my radio gear into 3 different chunks. The bulk of the gear is going into a relatively small rolling bag, the type that fits into an overhead compartment on a plane (though I'll be checking it; we have to change planes and I don't want to have to deal with lugging that separately.) A couple of things (including the antenna) are going into my "big" suitcase (which actually isn't all that big; the nice thing about the islands, even a relatively "fancy" place like Cayman is that "dressy" is usually a pair of nice shorts and a golf shirt, with "really fancy" needing a pair of Dockers instead). The 706 itself goes into the backpack that I got as a gift a few years ago, which in turn goes into a larger backpack that I use as my carry-on for the plane. (The backpack was made specifically for the 703, but since the two radios are the same size, it fits perfectly, and the padding does a great job of protecting the radio.) The reason for putting the backpack into a larger backpack is because I also need to take a laptop, glasses, some other personal items, etc., and there's just not enough room for all of that in the backpack case.

I had originally thought about just taking one even larger bag so that I could put all the gear in that, along with my clothes (all except the radio, which I'd always planned to carry onto the plane), but I decided that it'd be easier to split things up, a use a few clothing items to act as padding for the smaller suitcase. For one thing, although the amount of radio gear I'm taking is small, I didn't want to have have to worry about the combined weight of everything approaching the limit. Since we can take two bags per person anyway, this just wound up being easier.

So, I'll be closing up the suitcases shortly, showering, and heading for bed early, as we have a very early pick-up for the airport in the morning.

I'm going to try to do a few entries while I'm down in Cayman, possibly even with a few pictures. Keep your fingers crossed for good conditions, and I hope to work you while I'm there.

Saturday, July 14, 2007

Pre-packing (or Practice Makes Perfect, Part 2)

With just over a week until my trip, it was time to go through my radio "packing list" as I did a few weeks ago, except this time I'd "pre-pack" everything and not put it away. The idea is to not leave anything for the last minute, and to make sure that if there were any items on my packing list that I still need to buy or borrow, that I had them. In the process of doing this, I discovered that my packing list wasn't as complete as it should have been. I printed out the list, and as I pulled out each item and put it into a temporary bag (it'll be repacked for real soon), there were a few items that I realized that I never put on the list. Although some of the items were relatively unimportant (I decided to throw a few small alligators clips in, for instance), I realized that I did entirely forget to put the Buddistick (and accessories) on the list. Oops. Most likely (!) I wouldn't have forgotten that, but since I decided that I'd probably use my packing list for any future ventures, I might as well get it right.

Of course, as I was typing this, I realized that I in fact had forgotten to pack one very important thing: My Cayman license and import permit.
The reason why I realized that I had forgotten to pre-pack that was because I looked down, and there it was, sitting in front of my keyboard, where it's been sitting for a couple of months now, so that I, um, wouldn't forget it. It guess it had been sitting there for so darned long that I had ignored it. Oops again. Well, I've now made a couple of copies of the documents, and pre-packed them, as well as the originals.

As a side note, the reason that I mentioned the import permit is because there's apparently a law in the Cayman Islands that if you bring in your radio equipment,
you need to have an import permit (which costs around USD$15). If you don't have that, I've been told by a couple of guys who've gone down there that you have to post bond equivalent to the value of the radio upon entry, which is returned to you when you leave with your equipment. I've also had one or two folks tell me that they've gotten in without the bond or the permit, but I figured that I'd avoid the hassle and paperwork by getting the permit in advance.

Back to pre-packing. Aside from those items that I didn't forget but were on the list, and those items that I did forget and weren't on the list (until now), things went pretty well. I have a very small number of items that are being left until the last minute, the only significant item being the radio
itself, since it's in use right now. Either later today or tomorrow I'm going to pack that as well, and swap in a spare 2m rig that I normally use when doing a temporary mobile setup. The only downside is that if by some chance I have a little time to play around in the CQ WW VHF contest next week (which isn't likely; we have all-day plans for Saturday, and are leaving for Cayman on Sunday), I won't have a 2m all-band tranceiver. Oh well. The one really good piece of news is that all of the equipment takes up relatively little space, and is fairly light. Not including the radio (which will most likely be part of my carry-on so it won't count as part of my weight allowance for the flights), the bag weighs 18 pounds (about 8.2 kilos), so that won't break the weight budget. By the way, as I mentioned, this is not the final packing. This is just a bag that I thought I could fit most of my gear into. In the picture, you can see some of what I'm taking, like the power supply, feedline, some spare radial wire, some tie wraps, and even the "cheat sheet" for my '706 just in case I need to adjust some rarely-used setting.

Sunday, July 08, 2007

Buddistick Radials

Thanks to NE1RD for his explanation of what he uses for additional radials with his Buddistick. I borrowed his idea, and constructed 9 "add-on" radials for my Buddistick. (It was supposed to be ten, but while I was constructing the "harness" that the radials connect to one of the wires slipped out of the ring terminal while I was crimping it, so I wound up with nine. Ooops.)

Overall, the process went fairly well. I wanted to use spade terminal quick-disconnects, but I couldn't find any that were the actual correct size for the 26 AWG wire (from The Wireman, part #534) that I used. I wound up using some terminals that were for 16-22 AWG wire, and they seemed to work OK. I had to really crunch down on the crimps to make sure that the wires stay in place, but since there shouldn't be any mechanical stress on the wires, hopefully that won't be an issue. (I also learned why folks spend a few extra dollars and buy a racheting crimper rather than just using a relatively cheap "100% hand power" crimper. I only had to do about 30 crimps, and my hand is still sore 2 days later from applying the pressure.)

What you can see in the two pictures (you can click on the pictures to get a larger view) is that I've got the coax (which in this case is just connected to my Autek VA1RX antenna analyzer) connected (the thicker wire) along with about 5 of the extra radials, plus the regular buddistick radial wire. Until now, I'd done all my testing outside, usually with the antenna mounted anywhere from about 3 feet to around 7 feet above the ground. One of the reasons why I wanted to make these radials in the first place is because Scott mentioned in his blog that he often uses them from a balcony or other location where it can't get near real RF ground. For my upcoming trip, I'm not really sure exactly where the antenna will be set up, so I figured that for a few dollars and a little bit of time, I can make these radials up just in case I need them. (The nice thing about using that particular wire is that it's really, really light. According to their website, it weight less than a pound for 1000' of wire. I don't have anywhere near that much, so it adds very little to my overall equipment weight.)

Anyway, I figured that for testing purposes, instead of testing outside, I'd test inside the house, from our bedroom on the second floor, which is pretty much as far from ground as I can easily get in my house. My original intent was to mount the antenna on the outside of the window and run the radials inside. Unfortunately, my bedroom windows have no way to clamp the antenna outside anywhere near vertically, because of an overhanging roof. If I really had to operate from there, I probably could have come up with some way to mount things, but given that A) This was just a quick test, and B) It was about 95 degrees out, and I really didn't want to leave the window open all that long, I figured I'd just see if I could mount the antenna somewhere in the room.

That seemed like a good idea, but the antenna is pretty close to 8' long (and my ceilings are 8' high) when the whip is extended, so I found up putting the antenna on the floor, as seen in the picture, instead of "mounting" it anywhere. (I actually have the mini-tripod, so I could have used that instead of the clamp, and would have if I was going to leave it set up.) What I found after setting things up and tuning (which I do seem to be getting better at doing; and I highly recommend the use of an analyzer to do so) was that I got excellent SWR (1.2:1 at the target frequency) and it seems that the SWR range was a bit more broadbanded that with just the single Buddistick radial. I am still learning about antennas (aren't we all?) so I'm not sure if that is the expected result, but it did seem to work just fine, and, to paraphrase that famous setting, you can never be too rich, too thin, or have too good an RF ground.

Thursday, July 05, 2007

Practice makes prefect, er, perfect

They say that practice makes perfect. I'm not sure that it makes perfect, but it does help you make fewer mistkakes mistakes.

I have read enough stories about folks going on trips where they've forgotten some key component that's needed to make their radio gear work. While Grand Cayman isn't exactly Scaffold Reef (there seem to be some electronics stores on the island, even a Radio Shack), I don't want to wind up running around for half a day to find a missing cable, especially one that won't be easy to find and that I've got sitting at home.

Over the weekend, I pulled out what I had expected to take to Cayman with me and set up a "station" on the patio table. I had created a spreadsheet (using Google Docs -- one nice
advantage is that it's "always there", as long as I can get to the Internet) with the list of items that I needed and started going down the list and taking the items outside. I didn't take absolutely everything for this initial pass (I will do it again), but I did take what I expected to be the key components to construct my station. (Notably, I didn't take spare parts, like fuses, etc.)

Things went remarkably well for a first pass, but I did discover a few things: First, there was a particular extension cord that I'd planned to take with me, but I discovered that my son had appropriated it for use in his bedroom. Guess I'll need another one.
Second, while setting my station up outside I discovered something very interesting. The LCD display on my Icom 706MkIIG is polarized. So are my sunglasses. Now, that's not necessarily a problem, but in this case it is. You may remember from your grade school science class that if you took took two polarized filters and turned them at right angles then placed one on top of the other, you can no longer see through them at all. In this case, it appears that my sunglasses are polarized one way and the display is polarized the other way. (Generally, filters seem to be polarized either horizontally or vertically). I never noticed this before because even though I've taken the radio on a couple of trips, I either had the radio inside or (before that) I had a different pair of non-polarized sunglasses.

This isn't really a big deal, but to me, the value of trying this out was to find something that would have been at least an annoyance. Now, I've got a solution, which is to bring along a cheap pair of non-polarized sunglasses.