Ham To Ham #13 - October 1996
73's Ham To Ham column
c/o Dave Miller, NZ9E
7462 Lawler Avenue
Niles, IL 60714-3108
As 73's Ham To Ham column begins it's second year with this issue, I'd like to express my thanks for all of those contributors who've sent in their tips, suggestions and ideas...the meat and potatoes that keeps the column going and growing. I'm always looking for more, so don't hesitate to offer your own ideas to the list. There's a large amount of information this time, so let's get right to it...
Lighten up
From George Vaughn WA4VWR comes this tip:
"I've found a local source for the bulbs that illuminate the Kenwood TS-940's sub-display. When one of them went bad in my TS-940S, I removed both and measured the voltage applied to and the current drawn by the single working bulb...12 volts at 75 milliamperes . A trip to the local Radio Shack (reg. trade mark) store resulted in my discovering standard RS replacement bulbs of the exact size and shape (RS Cat. #272-1092), but the RS bulbs draw 15mA less, or 60mA - and they lack the little green "bootie" that the original Kenwood bulbs have. The green "bootie" can be carefully removed from the old bulb, provided it hasn't been "cooked" into place too badly, and with the aid of a touch of clear silicone grease, can be installed on the RS replacement bulb quite easily.
The 15 milliamp difference in current (and light output) is about the same as if one were to put a 47 ohm, 1/2 watt "bulb-life-extender-resistor" in series with the Kenwood bulb, so to me it's perfectly acceptable. The biggest difference is in the price...$1.49 for two of the RS bulbs vs. $4.19 each ($8.38 total) plus $6.00 shipping, for the Kenwood relacements. That's $7.19 per bulb from Kenwood...75 cents per bulb from Radio Shack. Guess which ones I'm using in the future.
What about the TS-940S's 'S-meter' bulbs...does Radio Shack carry a replacement for them? Yes, but this time the difference is more pronounced. The bulbs in the S-meter are 12V at 75mA; the Radio Shack replacement with wire leads (Cat. #272-1141) is rated at 12V but this time at only 25mA. It's noticably dimmer than the stock Kenwood bulb, but it may be acceptable to many; you'd have to try it and see. Personally, I chose to use Radio Shack's Cat. # 272-1143, a 12V, 75mA bulb, but with a screw-in type of base. If you use the same bulb as I did, it's advisable that you not solder the 12 volt feed wire directly to the screw-type base, but rather wrap a couple of turns of non-stranded, fairly stiff wire around the screw-threads instead. Also be sure to connect the "ground" 12 volt feed wire to the screw-base, not the "hot" wire. If the screw-base on this bulb were to ever cut through the insulating grommet, you might damage your set if the hot 12 volt lead were connected to it and then shorted the supply bus to ground. You can easily determine which feed wire is "hot" and which is ground by measuring each with a voltmeter when the set is turned on. The "hot" wire will have 12 volts on it, and of course the ground wire won't. Again, make sure that the ground wire connects to the screw-base shell of the replacement bulb. The tip of the replacement bulb should be reasonably safe to solder the "hot" 12 volt lead to, using the existing "solder-blob" as a connection point...do it quickly.
One other small caveat, the #272-1143 bulb is just a tad too large to fit into the existing holes in the back of the TS-940S's meter, but a few seconds with a tapered reamer resulted in the right hole size for a nice fit...take your time and don't get carried away! If done properly, the original Kenwood bulbs can still be used later on if desired. By the way, it is necessary to remove the metal meter mounting bracket to perform this particular step, but again, the cost savings are well worth the small extra effort."
Moderator's note: We've all noticed how difficult it's become to change the pilot lamps inside of most of today's radios? In the old days - when radios and lamps both were a lot bigger - changing a pilot lamp was a pretty straight-foreward, easily accomplished job . The lamps were always mounted in sockets, and usually just a twist of the wrist popped it right out, ready to receive a new one. Not so today...most are now on small wires, soldered in-place and buried deep within the wiring of it's front panel. It usually requires some internal "surgery", so many hams either don't bother changing them at all when they burn out, or they leave the job for when the set has to be disassembled for some other troubleshooting reason. George has offered some well-thought-out advise in his tips from above; here's some more for you to consider.
What follows won't make the task of bulb changing any easier, but it just might double or triple the time between pilot lamp failures. When a lamp does burn out, many probably think first of going back to the manufacturer for a replacement. There's nothing wrong with that idea, especially if it's a very specialized type of bulb. But as George pointed out, it's probably the most expensive and time consuming route to take, especially when there may be a much more cost effective approach. Since Radio Shack stores stock a number of small low voltage lamps, many of which will either fit directly or can be adapted to fit, a bit of "ham innovation" is sometimes needed, as displayed in George's piece.
Take a look into what Radio Shack calls their 12V micro-lamp, Cat. #272-1092. It may well work as a replacement bulb for LCD displays and other situations where a very small size lamp is in order. Hobby stores also carry what they call "grain-of-wheat" lamps, which are very similar, but be sure to ask about their voltage and current ratings. By the way, using a lamp rated at a higher voltage is fine, as long as it will provide enough brightness once it's installed; in fact, it will last a lot longer than one rated at the nominal voltage. Additionally, if you lower the voltage to a 12V lamp, even by just a couple of volts, you'll increase it's life dramatically. I've seen test curves that prove that the life expectancy of a lamp zooms upward as the voltage across it goes down, and vice versa of course. Putting a resistor in series with each lamp that you replace, will often give you two to three times the life expectency from a given bulb, everything else being equal.
There are three things to consider before doing this: 1) what value resistor will be needed, 2) what its wattage rating should be and 3) how much loss of light is acceptable? Lowering the voltage to the lamp will decrease its brightness - and shift its color toward the red region - so you'll have to visually judge whether you can accept both of these consequences.
You can install the lamp, clip-leading a resistor in series with it, then looking at the meter or display under normal room lighting, to see if it's okay for you own particular situation. To arrive at the right resistor values, simply use Ohm's Law, plugging in the correct numbers for your own transceiver's lamp supply:
Voltage drop desired divided by the lamp's rated current equals the resistance needed.
and
Voltage drop desired times the lamp's rated current equals the resistor's wattage.
By way of an example, let's take the Radio Shack #272-1092 lamp that I mentioned before, which has a current rating of 60 mA or .06 Amp. Let's say we'd like to drop the 12 volts feeding the lamp down to 10 volts, or a 2 volt total drop. We plug in the numbers:
2 (volts) divided by .06 (amp) equals 33 ohms
and
2 (volts) times .06 (amp) equals .12 watt
Now we know that we'll need a 33 ohm, 1/4 to 1/2 watt resistor in series with each lamp in order to drop the 12 volt lamp supply down to 10 volts. A 1/2 watt resistor will provide a 4 times safety margin for heat dissipation (dissipation ratings for resistors generally assume their full lead length, in free air, so it's safest to over-rate them by 2 to 4 times for shorter lead lengths and operation within confined enclosures).
By the way, try to avoid using bulbs intended for flashlight service...they're often high brightness, low life expectency...since flashlights are usually on intermittently. There are charts available showing life expectency at rated voltages for various lamp type numbers. The lamp's manufacturer can provide this information and it's also sometimes included in the more complete electronic supply house catalogs. It's surprising how much different lamps do vary in their average life expectations.
Dave, NZ9E
Don't "nitpick" on Alinco!
Last month I gave you some tips on how to improve the Alinco DR-1200T's static discharge resistance with improved grounding. There are usually ways to improve upon just about any radio made, I'm not trying to nitpick on Alinco, it's simply that I've become fairly familiar with this rig and feel comfortable attempting some "improvements"...sorry Alinco! This month I'll show you how you can make the internal CPU "reset" push-button accessable from the front panel. I'd be very interested in seeing submissions from readers on modifications that they've made to this and other popular radios; please just make sure that your tip is reproducible and that it doesn't create any "hidden" problems of it's own. Obviously, I can't test all tips submitted to me for the column, since I don't have access to every rig on the market...wish I did!
"Real" reset
The Alinco DR-110T and DR-1200T/TH (and perhaps others in this line) have a hardware CPU
reset push-button switch located just to the right (when viewed from the front) of the "Call/Call W"
switch, but it can only be accessed from inside the radio, when the front plastic cover is removed.
There's also a software reset (described in the owner's manual) that involves holding in both the
"F" and "VFO/M" keys at the same time and turning the "POWER" switch on and off. But what if
that doesn't correct your problem? The hardware reset switch actually momentarily grounds the
reset pin on the CPU and should clear any concievable programming problem error - at least anything that's curable by restarting the microporocessor.
It's an easy matter to add access to this hardware reset switch the next time you have the radio
on your workbench. Simply drill a small hole - 1/8" or so should do it - between the "Call/Call W"
switch and the microphone connector. The hole should be carefully drilled from the inside to the
outside (in fact, there exists a small "starter" hole inside the plastic front panel, as if they intended
to make the switch accessable, then changed their minds). The finished hole is barely noticable
against the black backgound of the front panel itself, but it will give you access to the momentary
hardware reset switch...from outside the case. Just use a thin, insulated probe to acces the switch, should the CPU ever go bonkers and require a complete, non-maskable reset. Resetting the CPU will erase all memories and other user-defined data from the radio, but at least it will get you quickly back to "ground zero" again for reprogramming (you have a written copy of all of your programmed entries, right?).
Here's another quick tip for the same model of transceiver...in the spirit of the lamp tips mentioned earlier. If you don't want to go directly to Alinco for replacement display bulbs, I've successfully used Radio Shack's # 272-1092, 12 volt, 60 mA "microlamps" as replacements. Chances are, they'll fit in other brands of transceivers as well, for easily obtained replacement purposes, but always check for excessive heat build-up and too much current drain anytime you decide to substitute for a manufacturer's original part.
DE Dave, NZ9E.
Short fuse
From John Ayers AA1IC of Lyndonville, VT:
"It's often recommended by transceiver manufacturers (and others) that a mobile amateur transceiver's 13.8VDC supply come directly from the vehicle's battery terminals, with a fuse or circuit breaker as close to the battery itself as possible (as opposed to simply picking-up a feed from a convenient 'existing' battery voltage point somewhere under the dash). This practice will often cut down on the amount of noise introduced by the vehicle's electrical system into the ham rig, as well as minimizing RF interference from the ham gear getting back into the vehicle's computer or other RF sensitive electronics.
Though the practice is strongly recommended, the hardware to accomplish it isn't always the easiest of items to obtain. For several years now, I've been keeping my eyes open for the 'ideal' hardware to accomplish this job...something with adequate current capability and feed wire size, ease of physical mounting and also suitably enclosed to prevent premature environmental-exposure failure. I've run across an automotive automatic circuit breaker at a local NAPA auto parts store that I feel meets these criteria. It's small in size, is rated at 20 amps DC, comes equipped with 10-32MS connecting studs, has husky mounting ears and is fully enclosed against the elements (something we have to think about in our Vermont winters!). The one I chose is part #CB6317 and sells for under $6 including tax. If physical mounting within the engine compartment isn't practical in your installation, there is also an in-line model (without the mounting ears) that could be slipped inside of a short length of PVC pipe (or other insulated covering) for added protection."
Moderator's note: If you're not able to find the circuit breaker that John mentioned locally, try looking into obtaining a catalog from Parts Express, 340 E First Street, Dayton, OH 45402-1257 (513-222-0173 or 1-800-338-0531 for orders). They stock a variety of circuit breakers, fuse blocks, high-quality battery clamps, side mount posts and other accessories needed for mobile audio and radio installations. They also carry the heavy primary wire (as large as No. 4 gauge), in any footage quantity desired, for extending your transceiver's cabling right up to the battery itself. As John pointed out, you can often automatically avoid many mobile noise/interference headaches simply by using a "dedicated" radio 13.8V battery run...or even a dedicated separate battery. A "clean" battery feed source (without random noises generated by other devices) is always the first step in any mobile installation noise elimination "fox hunt".
Net topics
From William Thim, N1QVQ of Broad Brook, CT:
"On some of our area repeaters, we have both general check-in nets as well as newcomer nets these days. But a group of us, N1TDW, N1SPJ, KD1ZV and myself, came up with the following idea a while back. Why not have a local 'expert' net night when possible? We discussed it with the repeater owner, and he went for it enthusiastically and without hesitation.
Basically, we encourage hams in the area, with expertise on some particular aspect of ham radio, to give an informal 20 to 30 minute talk on the subject in which he or she is experienced, followed by an appropriately timed question & answer session. Examples of subjects might be packet, satellite communications, the ins & outs amateur TV, antenna construction & installation, weather nets, HF data modes, etc. The list is nearly endless since ham radio has so many interesting facets. The topics don't even have to be purely amateur radio, someone in broadcasting or emergency rescue could also keep a group rivited with a description of their profession and some their interesting or off-beat experiences on the job.
Start by suggesting one 'expert' night per month, then have the other area nets announce it on their own net-nite, repeaters and PBBS's and see if doesn't increase your list of check-ins and 'future-ham SWL' listeners alike."
Power astray
Here's something very worthwhile remembering from Jack VanGilder N3MPS:
"My VHF packet station consists of a Kantronics KPC-3 TNC, in conjunction with a Kenwood
TM-241A 2 meter FM transceiver, both are powered by a 13.8 VDC external supply...not an uncommon current-day set-up. One day, however, my TM-241 wouldn't release from the transmit mode, was emitting a low pitch tone and the KPC-3 TNC became very hot to the touch.
I immediately shut everything down and began to investigate. I discovered that the small coaxial power plug that supplies the 13.8 VDC to my KPC-3 had worked its way loose, pulling out just far enough to allow the "normally closed" contact on the sleeve of the power jack to "make", before the tip of the plug had broken its contact. I had installed the alkaline back-up batteries in the KPC-3, so the full 13.8 volts was placed across them by this unfortunate set of corcumstances. The batteries apparently built up substantial internal heat and pressure, rupturing their seals, and allowing their corrosive electrolyte to leak out into into the TNC itself.
What to do? I first applied some baking soda and warm water to the area effected, allowed it to neutralize any acids present, then cleaned the circuit board as best I could with a sponge and more fresh warm water. After permitting it to thoroughly dry, I was elated to find that everything was now working again. Not wanting a repeat performance however, I've now made sure that the tip of the external power plug disengages, before the sleeve's normally closed contact has the chance to switch back as the power plug is slowly removed. It's probably also a good idea to remove the batteries whenever the unit is operated from an external power supply, as well as insulating the battery terminal connector so that it can't come into contact with anything that it shouldn't anywhere inside of the TNC.
The lesson learned? Beware of those little coaxial power connectors (and others) that permit 'automatic' power transfer switching...make sure that they 'break' before the other connection 'makes'.
Moderator's note: Jack brings up a good point, and one that has the potential of creating problems in many other pieces of equipment. Any power connector that allows the "normally closed" contact to close, before the external tip connection is completely broken, is a candidate for the type of problem that Jack describes...this could be any item from your daughter's portable stereo, to your own telephone answering machine. Better put it on your list of things to check out, I know I have. Depending upon the actual circuitry of the device, you might be able to install a diode in series with the internal battery feed, with the diode's anode toward the positive battery output. This would permit current to flow only from (not to) the battery pack (you'll lose about 0.6 volts across a silicon diode, but that may not be consequential, you'll just have to give it a try and see).
Simply floored!
From Bob Boehm, N8EXF of Cincinnati, OH comes this very nice idea:
"Operating mobile, whether HF, VHF or UHF, can be very challenging today with the smaller auotmobile interiors and 'all-plastic' dashboards!
I ran into a problem of where to mount my Kenwood TS-440S/AT in my Dodge 4x4...either the gear shift was in the way, or I couldn't reach the radio's controls! I solved the problem installation by building my own custom floor-mounted-bracket out of Stanley (reg. trade mark) brand pre-formed channel pieces from my local home improvement center. They come in various lengths and in 90 degree angles, allowing you to fabricate just about any kind of custom-fitted mobile floor mount that you might need.
In the case of my own TS-440S, I used one 18" channel, cut it half, and bolted a 90 degree 'TEE' section to each half. This formed the 'base' that then bolted to the floor of my Dodge 4x4. Next, with two pieces, each 10" long, the vertical uprights were formed, onto which the mobile mounting bracket for my TS-440S was attached...the completed installation resembles an upside down 'T' when viewed from the side (see Figure 1).
It's withstood life in a 4x4 very nicely and the controls of the radio are within easy reach of the driver, without cramping anyone in the passenger's seat...the perfect solution in my own case. Perhaps this same idea can be adapted to solve your mobile installation woes as well."
Cable tie rip-off
In order to keep long lengths of coax cable, audio cable, power cable, etc. from tangling up when
coiled, many hams use electrical tape around the cable-coils when storing or transporting the
cables. Tape works, of course, but it usually ends up leaving an unwanted gooey residue on the
cable as well. Tape has a limited number of uses before it no longer adheres to itself anymore,
and, naturally, it's often lost when the cable itself is uncoiled for use. Fortunately, there is a
much better solution, thanks to modern "fastener science".
The half-inch wide sew-on Velcro (registered) material - not the self-adhesive variety - makes an excellent, permanently re-usable cable tie if the simple dimensions in Figure 2 are followed. Various lengths of Velcro are usually available in sewing or fabric supply stores, just ask your XYL for her suggestions. As everyone knows, Velcro has two parts, a "fuzzy", soft-surfaced loop strip and a "pinchy" harder-surfaced hook-strip. I'll just call them "fuzzy" and "pinchy" for easier identification purposes.
To make a single cable tie, cut about 6" of "fuzzy" Velcro and about 1" of its "pinchy" counterpart, place a few drops of super-glue (of the type containing cyanoacrylate ester) on the back side of the smaller "pinchy" piece, then place the two pices back-to-back and squeeze them together securely between a couple of pieces of scrap aluminum, using a long-nose pliers, hemostats or a vise, letting the super-glue cure.
Next, punch two small holes (a leather belt punch works nicely for this) into the free end of the
"fuzzy" strip, and large enough to pass a small, thin plastic cable tie-wrap (I use the 1/8"
wide by 4" long #T18R plastic tie-wraps). These are the type of plastic tie-wraps sold in most electronic stores for permanently tying bundles of cables together, but in this case, it will be used to permanently fasten your new "Velcro tie" to the cable you're working with...roughly 6" back from the cable's connector is generally about right (doubled-over waxed cable lacing twine also works nicely in place of the plastic tie).
Once the Velcro tie is fastened to the cable at the right point, with the plastic tie-wrap or lacing twine, just coil the cable up as you normally would. Once it's completely coiled, wrap the new Velcro tie - "fuzzy" side up - around the coil and press down on the "pinchy" strip to lock. Pull on the "pinchy" strip to unlock the tie. You now have a permanent, re-usable, always-close-at-hand, cable tie system. A small "starter line" painted across the very end of the "pinchy" strip will tell you at a glance where to rip it open.
Make up as many ties as you'll need for all of your cables (including those on your power tools) and you'll thank yourself each time you use them...it's a great "rainy- day" or cold-weather indoor construction project. Different colors of the Velcro material can be used to make up different colored "Velco ties" for easy identification of different cable lengths or connector types.
Feel free to vary the dimensions shown in Figure 1 to accomodate smaller or larger cable coils. The dimensions shown seem to work well for "average" coils, so it's best to start by using them...at least until you're more familiar with the idea...then you can "customize" to your heart's content. By the way, don't steal your XYL's Velcro supply...I know the consequences of that mistake!
DE Dave, NZ9E
To UTC or not to UTC?
From Ken Guge, K9KPM of Lombard, Illinois:
"Many hams prefer to keep their station logs in UTC time, as opposed to local area time...it often makes QSLing much easier, since the DX station will probably use UTC time in his or her log (the use of UTC time seems to be much more popular with hams in other countries than with those of us here in the U.S.).
One of the problems in using UTC time is the change-of-date that occurs at UTC Midnight...here in North America that happens several hours before our local date-change...and we sometimes forget about that fact. If you're going to be consistent in your log-keeping, the UTC date change must also occur at the correct point in time, yet none of the UTC clocks I've seen take that factor into account.
My Timex Indiglo (registered TM) watch, however, does. It has two time display options, one for local time and date, another for an optional time and date. If UTC time is programmed into the optional display, the date will also be correct (on that display) following UTC Midnight...so the correct time and date for UTC are always just a 'touch of a button' away. You might want to take a look at these watches (and perhaps others with the same option) the next time the kids ask what you'd like for your birthday. Dads who are hams are 'easy' to buy for!"
Two different worlds
In today's two worlds of electronics, analog and digital signals must coexist, often side-by-side, on the same circuit boards in our receivers, transceivers and data controllers...but yet the two varieties of signals are often mutually incompatable. Steep-wave-fronted digital data signals are often the most troublesome culprits in this coexistance battle, impressing "digital noise" of various kinds onto the more "peace-loving" analog signals. It's a problem that electronic circuit designers are continually fighting...and overcoming for the most part...and these are some of the proven techniques that they use.
Obviously, keeping digital and analog circuit components as far apart physically as possible is the first step, though not always entirely practical in today's crowded circuit board environment. But where it is possible, it's best to follow that axiom. Keeping parallel-running circuit traces or harness wiring with digital pulses and analog signals away from each other is also important. "Noise induction" is often the cause of cross-over between those two worlds. Shielded cabling can help, even for circuitry that doesn't normally call for shielded wires. Multilayering of boards, with digital and analog signals one above the other is another source of cross-induction problems; sometimes shielding in the form of alumium sheet-stock between the two can help in this area. Just make sure that any shield-planes are grounded only to their respective ground buses. This implies that digital and analog grounds and ground planes should also be separated from each other on the PC board (s) and they should be as large as possible to provide the least amount of resistive voltage drop (since that's where problems can sometimes begin). The use of separate positive power supply traces for the digital and analog portions of the circuit is also almost a must, making sure that all digital chips are powered only from the digital power bus and all analog chips or transistors are fed only from the analog feed point. A common power supply for the digital and analog circuits is usually possible, but separate plus power and ground leads to each separate power bus on the board itself is considered to be good practice. Using separate output regulator chips from a common power supply can also offer some noise crossover protection. Working to avoid ground loops, where the resistive loss in the loop can act as a development point for crossover noise, should be taken into consideration. If it's possible to ground coax cables on one end only, many potential problematical ground loops can be forestalled before they develop. Lastly, and certainly not the least, generous numbers of by-passing capacitors, on both the analog...and particularly the digital... power buses, can save countless hours of troubleshooting and head-scratching later on. By-pass caps are inexpenive, use them freely.
It's hoped that some of these tips may prove useful to both amateur digital circuit builders and circuit troubleshooters alike, since they can usually apply to both ends of that scale. It's often a mistake to assume that every precaution has been carefully observed in every manufactured item of ham equipment...there's often lots of room for improvement. Just ask any dyed-in-the-wool equipment modification affectionado!
de Dave, NZ9E
In closing
One closing note, many thanks to Tom Miller WA8YKN (314 S. 9th. St., Richmond, IN 47374) for allowing me to "beta test" his new "micro-sized" bioelectrifier, the original circuit of which was first described in 73 Magazine for April 1996 on pages - Tom did a beautiful job of reducing the circuitry, board size and battery compliment to their smallest common denominators. His revised schematic diagram is shown in Figure 3. Tom also informed me that FAR Circuits (18N640 Field Court, Dundee, IL 60118) is offering his board (only the PC board), and that Tom himself is offering a kit of parts and completely wired and tested units (less the enclosure). Contact FAR Circuits for the basic circuit board and Tom for the semi-kits...asking for a current price list. Please always include a self-addressed and stamped envelope (SASE) when corresponding with those who have been thoughtful enough to offer us these boards and kits...their margins are often too low to allow them to have to pay for the postage to answer our questions! Also...remember that the bioelectrifier is for experimental purposes only, for enhanced plant-growth studies, and that it has no governmental approval for any other experimental use (does water have governmental approval for human consumption...I'm not sure?).
This ends another month of Ham To Ham. As mentioned in the beginning, we're now into our second year of the column and hope to go on much, much longer...many thanks to the folks at 73 Magazine for making Ham To Ham possible. But I still need your input to keep the column interesting. Send your ham related tips, ideas, suggestions and short cuts to the address shown in the masthead and share your findings with the rest of 73's readership. They don't have to be "earth-shattering" or "cutiing-edge-technology" brain-storms...just ideas you've found to be practical and helpful to you in your amateur radio experience. Hope to hear from you soon.
73, de Dave, NZ9E
Murphy's Corollary: "All matter will be damaged in direct proportion of it's importance to the user."
Many thanks to this month's contributing readers...specifically:
George Vaughn, WA4VWR
545 Arlington Avenue
Jackson, TN 38301-4701
packet adr: WA4VWR @ KB4YTM.#WESTN.TN.USA.NOAM
E-mail adr: grv8626@jackson.feenet.org
William Thim, Jr., N1QVQ
50 Miller Road
Broadbrook, CT 06016-9676
John Ayers, AA1IC
Automation Services
RR2, Box 160
Lyndonville, VT 05851
E-mail adr: ayers@plainfield.bypass.com
Jack VanGilder, N3MPS
159 Chappelear Drive
Charlotte Hall, MD 20622-3206
Bob Boehm, N8EXF
6821 Le Conte Ave.
Cincinnati, OH 45230-2935
Ken Guge, K9KPM
1107 E. Woodrow Avenue
Lombard, IL 60148-3126
packet adr: K9KPM @ W9ZMR.EN52VA.IL.USA.NOAM
Note: The ideas and suggestions contributed to this column by its readers have not necessarily been tested by the column's moderator nor by the staff of 73 Magazine, and thus no guarantee of operational success is implied. Always use your own best judgment before modifying any electronic item from the original equipment manufacturer's specifications. No responsibility is implied by the moderator or 73 Magazine for any equipment damage or malfunction
resulting from information supplied in this column.
Please send all correspondence relating to this column to 73 Magazine's Ham To Ham column, c/o Dave Miller, NZ9E, 7462 Lawler Avenue, Niles, IL 60714-3108, USA. All contributions used in this column will be reimbursed by a contributor's fee of $10, which includes its exclusive use by 73 Magazine. We will attempt to respond to all legitimate contributor's ideas in a timely manner, but be sure to send all specific questions on any particular tip to the originator of
the idea, not to this column's moderator nor to 73 Magazine.