Radio

Plug the SWL cartridge into your Commodore 4 b4 Expansion Port, connect a shortwave radio and you ;l be watching text readout from weather stations news services, ships and HAM radio operators all over the world. A whole > new use for your home computer. The SWL contains both program in ROM and radio interface circuit to copy Morse code and all speeds/shifts of radio teletype. Pius the on screen tuning jf indicators mean you never have to take your eyes off the video for perfect toning. Housed in a smail 3" x 2*1/2" x 7/8" yr i enclosure, with speaker in/out and practice hand key jy^

jacks, it needs no other computer connection or jr ^ ^O^g power supply. Unshift on space, word wrap jJ

around, real time clock, and keyword or J^^^O^iffa manual printer control for permanent paper copy, so that you won't miss a single bit of the action. For about the price of another "Pac Zapper" game, you can tie into the > exciting worid of digital i communication with \

the Micro tog SWL

X WITH!

Morse (

$4995

pf A complete Morse code tutor in a conveni-

[4B ent plug-in cartridge for your Commodore ^H^^^Ss^^^fc yR/ "64/ The Morse Coach means business. It's not a toy program or a simple random code generator. Gnginaily developed jointly by Microiog and ^5¡^^ several government agencies experienced in Morse in- ^^^^

r struction. Four years ol extensive service prove it's the

_ quickest way to Morse proficiency.The method works! You start from absolutely no jp^L^Z knowledge of Morse, progress through the alphanumeric symbols, and on to any speed | desired. The "alphabet part of the program introduces nev, characters and plots the progress on a bar chart, The speed/test section correlates the input, analyzes mistakes and provides a ^ printout of the analysisrtest results on your Commodore screen or printer. As a bonjs. it also boosts r typing skill. You've never seen any tape or program do Ihat! In factr there's never been a system so thorough, so efficient and so effective as the Microiog Morse Coach.

Dunn) J. Conner KD5 UJ 123 Mes Amis Carenero LA 70520

Weatherproofed

Antennas

KD5UJ shows you how to keep the elements out of your elements.

Most amateurs experience recurring problems with their antenna systems Every summer most of us are pulling our antennas down because they're not working properly. By following the procedure which follows, you can eliminate this yearly ritual.

Where 1 work, technicians provide communications for the oil industry both on- and offshore. It's not unusual for an antenna system that we put out on an offshore platform to operate successfully for more than three years without requiring anx maintenance.

These repair installation instructions assume that you're working on an aluminum antenna that requires assembly, such as a beam or a vertical, (Some of these suggestions will be helpful when working with wire antennas also.) If you're dealing with a new installation, the first thing you need to do is install the connector on the feedline. Since most amateur antennas require UHF connectors and most amateurs use coaxial cable, your installation will make use of PL-259 connectors.

Strip 1-1/8" of outer insulation off the cable <^ee Pig, I h being careful not to nick the braid. Tin the braid, but don't overheat it. Overheating wili make the insulation bubble out, making soldering to the connector difficult. After it is cool to the touch, use a sharp knife and strip the braid and inner insulation off. leaving approximately 3/8' of braid exposed. Be careful not to nick the center conductor. Tin the center conductor and slide the coupling ring onto the cable. Screw the connector hody onto the cable, being careful not to damage the outer insulation.

At this point, trim the center conductor even wiih the end of the connector body. II your connector bod> is chrome-plated, use a knife to scrape around each hole to get a smooth solder flow. If it's silver-plated (dull silver), scraping isn't necessary.

Solder the braid to the connector body through the holes on the connector body (Be sure solder drops through the holes.) After the connector cools, solder the center conductor to the connector body. Use an ohm meter on its highest scale {R x 10,000or higher) to ensure that no continuity exists between the center conductor and the shield

If you are repairing an existing installation, perform the resistance check on your feedline to determine if replacement is necessary. Make sure both ends of the feedline are disconnected prior to performing the chcck.

If you re rebuilding an antenna, you will need some 200-grit wet/dry sandpaper to clean off the corrosion. For a good electrical connection take extra care where sections of the antenna connect. Soak all hardware in V*T>40 and clean it with a w ire brush. Replace any pieces thai show excessive corrosion.

After clearing the old antenna, or prior to putting the new1 one together, you will need to protect il from corrosion (and from icing over, for those living in the wintei wonderLands). To do this, saturate the antenna with CRC 2-26 or another similar product and allow it to dry for about an hour prior to assembly. After assembling the antenna, respray it liberally with the CRC 2-26.

The next step is by far the most important, This is where most antenna failures occur—

Fig. /. Installation of a PL-259 connector.

connecting the feedline to the antenna. If you arc using UHF connectors (PL-259, SO-239), then you need to get a tube of clear (not w/iiff) silicone heat-sink compound (Z5 compound). Fill ihe hole in the female side of the connector with this compound.

Screw' on the mate side of the connector until it's hand tight. Then use a pair of chan-neMock pliers to turn the connector an extra 1/4 turn. Be careful, since you can damage the connector by over-torquing. If you are using N-style connectors, do not put silicone in them! They have no free space inside them, sousing silicone can cause damage or distortion > Clean any excess silicone off the cable and connector.

After connecting the feedline to the antenna, you will need to waterproofit, Stan w-itha good-quality electrical tape such as Scotch 88T. Tape ihe connector, overlapping the layers at leasi 50 percent of the tape thickness, and continue taping down the cable approximately 4-6 inches past the connector.

Next, liberally coat the taped connector with Scotch KofeTH—don't use commercial antenna wrap, as it is messy and hard to apply and you canTi be sure there are no cracks or air bubbles in it. Allow the Scotch Kote to dry about 10-15 minutes, then retape the connector and again coat it w ith the Scotch ftote. This substance won't come off. and the better you tape and Scotch Kote your antenna, the longer it will last,

If you*re building wire antennas, you should tape and Scotch Kote the poini where your feed-linc connects to ihe legs of the dipole, vee, or sloper.

After mounting or remounting your antenna, you should be able to sit back and enjoj your antenna system. The only maintenance I would suggest, for those whose installations permit, would be to liberally spray the antenna with CRC 2-26 approximately every six months. This will ensure protection from corrosion and help maintain electrical continuity between the sections. ■

Fig. /. Installation of a PL-259 connector.

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