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Providence, Rhode Island

Apartment DXing

Below is an article I wrote a few years ago for my local Ham Radio club. It's about the challenges of working HF from an apartment using an indoor antenna.

When I receievd my general class ticket I was really looking forward to getting on the HF bands. Since I was living in an apartment complex at that time that was constructed with concrete and steel, I knew I'd have a lot of problems to overcome. My HF adventures were about to begin when Dan, KA1BNO gave me a 20 meter dipole antenna. Now all I had to do was figure out where I was going to put this 32 feet of wire. Since the building had sprinkler systems in each apartment, I wanted to keep it as far away as possible from the water pipes that ran through the walls. I decided I would start in one of the corners of the living room, and string it out with a 90 degree bend at the center. To visualize this, picture an inverted v, but strung out horizontally. Since I din't have sixteen feet of straight wall space, another 90 degree bend on each leg was needed. If I had continued this pattern past the sixteen feet of each leg, I would have formed a perfect rectangle around my living room walls. After looking at this mess, I shook my head and thought to myself, "this isn't going to work very well".

The next step was to find a rig. I purchased a used Icom 746. Since I spent most of the money I had set aside on the radio, I decided not to purchase a power supply. Instead, I used an old computer supply rated for 10 amps at 12 volts. How well would I do running less than 50 watts with a compromised antenna setup that was surrounded by concrete and steel? I think I would have been surprised if I was able to make any contacts at all.

The first test was with Dan, and Ron, K1VET who both lived near me in W. Warwick. Signal reports and audio were fine, as to be expected. It was now time to try making a contact. I heard a station that was coming in 20 over, so I waited till he was done with the qso in progress and then gave him a call. John, KG4WKR in Saint Petersburg, Florida became my first HF contact from my apartment. He was running an amp with a beam antenna. He gave me a 5 and 7, not bad for my compromised setup. Over the next few weeks I made more contacts stateside, mostly around the Florida and Georgia area. Overall, I guess I was pleased with the performance considering the limitations I had, but what I really wanted to do was DX. I didn't expect to be breaking any pileups, I knew that just wasn't going to happen or so I thought.

My first attempt at DX was with a strong station one Fri. night that was coming in from Brazil. I must have tried breaking through the pileup for a good two hours, but just couldn't get him to hear me. Over the next few weeks I continued trying to make contacts each time I heard a DX station. . "It's just not going to happen from this apartment" I thought. Finally, on Aug. 16th I heard Mike, M0RAD from Norton Evesham, England. This was the second time I had heard this station, a week earlier I'd tried to work him but was not able to get through. Each time he called qrz I would hear at least 4 or 5 other stations keying up. God knows how many more were out there that I couldn't hear. After trying for a while to break the pileup he said he heard a weak station in there. "India Sierra Whiskey, please try again". I almost fell off my chair! I wound up making the contact and he gave me a report of 5 and 5. My first DX contact, plus I broke a pileup to get it. Not bad for 40 watts and a compromised indoor antenna.

Needless to say I was very excited. It turned out there was a contest going on that weekend and I was hearing a lot of other DX stations. I had to see if this was a fluke, or if I could really do it again. About an hour later I made my second DX contact, LU1FAM, Lucas (operating as Elvis for the contest) from Rosario Santa Fe, Argentina. Two DX contacts on two different continents in one night. I was pretty satisfied.

A few days later I realized my radio's antenna tuner was having trouble keeping a frequency tuned. The tuner actually kept shutting off on me. I thought the problem was that I was running too close to the power supply's limit of 10 amps and was overloading it. I figured I should really have a supply that could deliver the full 100 watts the radio was capable of. A few days later I had my 23 amp supply and was ready to go at it with full power. But the tuner kept acting up. The only thing it could be now was a bad tuner, or a problem with the antenna. Hoping for the later (since I had just bought this radio a month ago), I borrowed Dan's antenna analyzer. What I found was amazing. The dipole was not resonant anywhere near 20 meters. As a matter of fact, is was resonant somewhere around 12.400 MHz, almost a full 2 MHz off. Both Dan and I had measured it, and according to the mathematical formula, it was perfectly cut. If I had strung it outdoors in a straight line away from other metal objects I'm sure it would have worked just fine. But since I had steel, water pipes, and electrical lines inside the walls of my living room, it was interacting with the antenna. Well, about 2 hours later, and after taking around 3 feet off the antenna, it finally resonated in the center of the 20 meter band.

With a now resonant antenna and a full 100 watts, I was real curious to see how much of a difference it would make. Over the coming weeks I wound up making contacts all over Europe, as well as a few more in South America. I was also able to work Russia on two different occasions, and also a few Islands here and there. I couldn't believe how well my apartment setup was performing. My favorite though was when I made contact with DL0ST, a club call for a station in Germany. It was during a contest and I was scanning 20 meters to find some new DX when I heard him calling. Many stations were keying up and coming back to him, but he was having trouble distinguishing any one station from the others in that very large pileup. I figured what the heck and jumped in myself. Immediately he came back to me with a signal report of 5 and 9. I was quite surprised he was able to hear me so easily above everyone else.

Theoretically, I should have had only marginal performance with my station setup. In reality, it had far exceeded any expectations I could have had for 20 meter operation. As far as I know, I never caused any interference to any of my neighbors, which is very important in keeping with good operating practices. I did still have some problems though, and spent a lot of time trying to work each one out. Occasionally I would have a high level of noise on 20 meters. I think it was coming from a neighbor who may have be running an electric motor of some kind. On 40 meters I had a lot of issues with hash. A switching power supply in close proximity to the antenna was the cause of that. There were problems with my pc causing rfi on certain bands too. 17 meters would get completely wiped out if I had my computer monitor on while I tried to operate. Although computer rfi problems are common for a lot of people, having an indoor antenna makes it that much harder to resolve. After all, my antenna was only 5 feet above my computer. Operating HF from an apartment with an indoor antenna is certainly a challenge. But with patience, a lot of experimenting, and the desire to make it work, it can be done. And as I've found out, it can be done with very good results.

John Flynn
K1QL (formerly KB1ISW)