Much has changed in 43 years, including receiver sensitivity and band activity. You may not be hearing much on your classic Hallicrafters simply because there aren't the number of hams on the air nowadays as there were back then. Wait for a good contest weekend to put your rig through a workout. You might also find a nearby elmer who has a modern rig and who might invite you over for a listen. It would be great to get a side-by-side comparison using a single antenna.

Having said that, most newer rigs have more bells and whistles than the old breed, including the new WARC bands and 60 meters. A few even include VHF up to 2 meters, computer interfaces for programming and for the newer digital modes. Welcome to the 21st Century.

And welcome back to ham radio. Enjoy!

You didn't mention the beamwidth of your antenna. If it is relatively wide, typical of a tri-band HF yagi, I wouldn't worry about rotator calibration. On the other hand, if it's a UHF yagi on a really long boom, then it could be important.

"The problem is that the 10 meter doesn't seem to be able to get a decent match for some reason with my radio even though when using a 259b meter it shows no more than a 1.3 match in the portion of the band I'm interested in using."  A 1.3:1 match is a decent match; 1.3 means that at least 98.3% of your signal will be radiated. Even if you meant 3:1, you'd still have at least 75% of the power radiated, and that's 20x more than you need to work the world when good conditions prevail on 10 meters.

Where the power is radiating is the mystery. I'd double-check how you have the 10-meter dipole attached to the coax, its proximity to other conductors, its orientation to your buddy's antenna, and the efficiency of your tuner settings (in fact, you shouldn't even need a tuner). Good luck.

Sure, it'll work. I'd just route the feed line away from the radiating element so that it doesn't pick up radiation on its shield. But, since you made the j-pole yourself, why not solder a small copper wire loop on the top to tie a rope to and hang it that way? You would get the radiating element up a little higher; and the feed line would be out of the way. The small loop shouldn't affect antenna resonance all that much.

Don't listen to those guys who will try to persuade you that an upside-down antenna will only work stations "down under" in Australia.

The Heathkit Cantenna was more like a 200 watt resistor in mineral oil, but was rated to go as high as a KW for short lengths of time.

MFJ sells a similar dummy load with the same ratings for around $40, and a couple of air-cooled dummy loads as well. The MFJ-260C should work fine for the FT-101, at $35.

Best bang for the buck is the ARRL Antenna Book. I can also recommend HF Antennas for All Locations, and the RSGB Antenna Collection. Then, when you get really into the math, you might try Kraus' Antennas.

You can also get a good understanding of antennas and tests from www.cebik.com.

The diode trick works; try a 1N4004 or higher.

Another thing that works is to use 130V bulbs. You can find them at some lighting stores, and since they are rated for higher voltage, they tend not to burn out as fast. Just another alternative plan.

BTW, not all CFCs generate noise nowadays. We have about a dozen or so around the house, and the only way I can tell they're on is by looking at them, certainly not by any RF signature.

FYI, Stew

I've got to assume you have a compelling reason for choosing 3.668 MHz for your resonant frequency. In that case, you should make your antenna a little long, say 3.5 MHz, then prune the ends until you get X=0 at 3.668 MHz. One way to do this is to cut the antenna length for 3.5 MHz, which is 133.7 feet, put it up, and measure its resonance. Say you read 3.451 MHz for X=0, so you know the antenna resonates lower in frequency than it was cut for. Multiply the actual length by resonant frequency; in this case 133.7 × 3.451 = 461.4, then divide the product by your desired frequency; again 461.4 ÷ 3.668 = 125.8. Since 125.8 is 7.9 feet shorter than 133.7 feet, you would find that cutting half that amount, 3.95 feet, from each end would put you very close to your desired resonant frequency.

There's really no need to quibble much about SWRs within the 2:1 range; at worse, 90% of your power would still be radiated by the antenna.

I would make measurements at the tuner end of the coax. That way you would be assured of measuring your "antenna system," rather than just the antenna itself.

For those of you not aware of it, the National Weather Service provides severe storm spotter and Skywarn™ training in many parts of the country. To find out if your area offers this training, go to http://www.srh.noaa.gov/, click on the weather office that is responsible for your particular area, then look for Weather Training, Skywarn™, or Spotter Training in the menu on the left side of the page.

When you click on your particular weather office, you might want to bookmark the page for future reference. I go to mine whenever severe weather threatens to check the four different NWS radars that cover my area, to find weather radio frequencies and settings, etc. Lots of good information there.

FYI, Stew

Jonathan,

   To get started, I would use a synthesized VHF (2-meter) handheld that has subaudible tone capability and has at least 5 watts output. It would also be nice to have an in-car power supply (cigarette lighter plug or spare charged battery), an amplified speaker, and a separate microphone. Later, if you think you need it, you can add an amplifier. My 25-year-old Santec ST-144uP meets these criteria, so you don't need the latest, fanciest equipment.

   I recommend the amplified speaker because the cockpit can get rather noisy, especially whebn the wind blows hard or when it hails, and I recommend the separate microphone because you don't want to be holding anything connected to the antenna should lightning strike your vehicle; if you're not using it, keep it in its dashboard holder or on the seat away from you.

   Check with the NWS as to what frequencies they monitor, and those are the ones you should also monitor. Also, if you haven't been to one already, check to see if they offer spotter training classes. One is planned for April 7 at the Red Cross building there in Lexington. These sessions provide information about safety and coordination activities, like who to report to and what to report, and each county's Emergency Manager may be there to go over his own particular procedures. See http://www.crh.noaa.gov/lmk/spotter_reference/upcoming_classes.php

   I'm sorry I can't answer your question about what radio to use because that will be your personal preference. But do consider the loudspeaker and microphone options.

You can also find your latitude/longitude position and Maidenhead grid location at http://f6fvy.free.fr/qthLocator/fullScreen.php. It will start you out in Europe, but you can scroll to any position on Earth, and if you click on the satellite map, you can pinpoint a position that is about as accurate as possible.

This is an awfully hard question to answer without knowing how the power supply/ies are built. Typically, a transformer supplies low-voltage ac, which is then rectified and stored in the filter capacitor. Usually a current-limiting resistor keeps the current tame, because an "empty" capacitor acts like a short circuit. Relatively speaking, it takes a while for the capacitor to charge to full capacity (or something near it). Many good power supplies have built-in circuit protection to prevent overvoltage.

Meanwhile, a good radio will have some sort of protection against over-voltage as well. However, as soon as it's turned on, the radio also looks like a short circuit. If the power supply is not well designed, this additional short circuit could overtax the transformer and rectifier bridge, causing premature failure of the power supply. For this reason, most power supplies include a crowbar circuit designed to disconnect the load as soon as an overcurrent is detected.

Where problems can occur is when an overvoltage spike can get through an underprotected radio, as when starting your car with the radio turned on. Most factory-installed automotive electronics are protected from induced spikes because the ignition switch bypasses them when the starter is engaged. Hams who have their radios connected directly to the battery aren't afforded this protection, so it's up to the manufacturers to build in safeguards for those of us who forget to turn off our mobile rigs before starting the engine.

To answer your question, it is unlikely, in my opinion, that you will damage your radio by leaving the switch on all the time, but the load it presents to the power supply just might (emphasize might) cause some problems for the supply, and that depends a lot on how the supply is constructed. To be safe, I'd look at oscilloscope traces under both conditions, then make up my mind.

I think you're asking how to determine what values of capacitance and inductance to use to achieve impedance matching. It was realized early in radio history that the most efficient way to transfer energy was when impedances were matched, and that a quarter-wave section of line of intermediate impedance (Z0=SQR(Z1*Z2)) was the most efficient way to accomplish this. It was also realized that because a section of line exhibited both capacitance and inductance, a simple circuit could be substituted for the line. That circuit is called an L match.

L matches can match high to low impedances and resistive to complex. An L-match works one-way; that is, it can match a high impedance to a low one, but it would have to be taken out of circuit and flipped around to match low to high. Consequently, it was found that two L matches, rearranged back to back, can go either way. This arrangement is called a pi network.

The formulas for determining component values are beyond the scope of this discussion, but are available in any good textbook. Suffice it to say that the input capacitor and inductor convert one complex impedance to another, while the inductor and second capacitor convert the intermediate impedance to the final complex impedance, typically with a transform of the imaginary sign to its opposite, or conjugate. In other words, one L network converts the antenna and feed line impedance, say 33 +j97 ohms, to something fairly large and complex, and the second L network converts that large and complex impedance to 50 +j0 ohms for the transmitter.

The reason for the differences in capacitor settings is that each has a different matching job to do. And, you don't have to settle for a black box; tuners come in gray and cream and green and....and you can even paint them your own favorite color. Sure hope this muddies the water for you.

It's hard to find one antenna that "does it all," but having taken a look at the Granite State Antenna page, it seems to me you can achieve a lower resonance by adding more wire to the end of the antenna at each end. How much, I can't say, but I'd start with a lot (perhaps 20 feet on each end) and prune from there. Adding extra wire will lower resonance, and will increase efficiency, but it will also change tuner settings for all the other bands as well, and will change radiation patterns at the higher frequencies.

Remember, the extra wire needs to be added to the physical end of the antenna, not where the element is folded back on itself.

Good luck, Stew

It should work just fine. The 40-meter wires would be at very high impedance when using 80 meters, and vice versa. You should also be able to tune 15 meters fairly well, since it is an odd harmonic of 40 meters.

FYI, Stew