This article is reprinted from the April 2000 issue of Worldradio.
Safe Battery Handling
The big news as I'm writing this is the amateur license restructuring. We may not like all the changes, but I am sure that HF mobile operation will gain from them. A lot of my friends obtained Technician class licenses prior to 1987 when the written test was identical to the General. These folks will be eligible for an upgrade to General with no further testing. They are seasoned operators, more familiar with mobile operating than most HF-only Hams. I am encouraging them to get on HF mobile. The post-1987 Techs that I know can also be a credit to Amateur Radio after they upgrade under the new requirements.
I received two very helpful e-mails on the 'battery in an enclosed space' question. The first is from Steve Bosbach, KGSBR:
"I couldn't help responding to your query on batteries in a closed space. I have been running HF mobile for years in VW camper vans and have run both gel cells and wet cells in the passenger compartment. On a previous VW I used a set of solar panels making 45 watts to charge the gel cell through a pulse width modulated charge controller. The gel cells are probably the best compromise for safety, but they don't like the charge rate from the vehicle alternator. I also wanted something I could hit pretty hard with a plug-in charger when I had shore power. For this I use a deep cycle marine wet cell battery of around 100 Ah. To solve the outgassing problem, I use Hydrocaps that take the place of the battery vents. These are special catalyst battery caps sized to your battery and charge rate. The catalyst material in the caps convert hydrogen and oxygen into water and drip it back into the battery cell.
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Invisible from page 2
the TV and stereo. If you get any kind of interference, quit and work on the problem. Low-pass filters often help for these kinds of problems. Running reduced power helps for other interference problems. Grounding your radio is an absolute must. A good ground in an apartment is often hard to get, but if you can find a copper cold-water pipe in your apartment, that is a good first step. Use a "saddle clamp" to get a good connection. Be aware that the hot-water pipes tend to be "ground isolated" through the hot water heater, so avoid them.
Refer to one of the ARRL publications and look at the block diagrams for "Connecting Radio to VSWR meter to Tuner to Antenna". After you are sure you have this right, look at the construction details for dipoles and random wires.
Invisible Random Wire: A length of small-gauge enameled wire (my first apartment antenna used #30 wire) between a window and any nearby structure or tree. This will work with modest success. The longer the better, but "space available" is what you use. Remember that this type of antenna will come down in a stiff breeze so be prepared to replace it often. One thing to avoid is picking up a roll of electric fence wire. This kind of wire has so large a resistance that you are putting up a dummy load rather than an antenna.
Gable Dipoles: Wire dipoles stapled along the gable of a house or an apartment work quite well. An antenna with traps is hard to hide, so a dipole antenna per band with a quick-disconnect connector like a BNC is a must. Choose an insulated wire that matches the color of the wood trim of your apartment or house. I had a sharp-eyed Apartment superintendent catch me once because of the wire color. I also have to admit that a green wire against an off-white wood was a poor choice. My explanation that I would be using them for Christmas lights did not wash.
Copper Tape Antennas:
These usually work quite well but can be hard to hide. The wide copper tape is just too obvious. If you promise to paint over it when you have it mounted, you can be in DX Heaven. Several different manufactures make these and you have to follow the instructions exactly. Don't read anything into the instructions. Just follow them to the letter.
Slinky Antennas/Dryer Duct Antennas: Dipoles made of Slinkys or out of flexible clothes dryer ducts can be supported on monofilament fishing line. A hallway or unused wall can be used for this kind of antenna. Again, follow the construction details for a dipole. When making the solder connections to these devices, be sure and scrape the insulating material well and make sure that the solder connections are solid.
Mobile Antennas: Mobile Antennas such as the Hustler or Outbacker brands can be used in apartments. I have used a large flowerpot, filled it with QuickCrete and placed a piece of large-diameter EMT conduit in the pot for the mast. An Outbacker antenna was mounted to the mast, then placed on the patio of my second-floor apartment. A small American flag was placed on top of the antenna. The same thing can be done with a Hustler antenna. In my wife's case, she had a propane grill on the patio and mounted the antenna to the grill. Just remember not to cook and transmit at the same time. One hundred watts can really tingle when you are flipping burgers.
Screen Doors, Gutters and Railings: Prior to trying to use these, first check to see if you have a resistance path to ground. If you see even a slight resistance to ground, give up the idea: an antenna doesn't work if it is grounded. If, however, you don't see any resistance to ground, give it a try and slowly increase your power. Apartment complexes are funny when it comes to appliances. When a friend of mine used the guttering of an apartment complex and transmitted, the range/ovens in ALL of the apartments turned on. This did not make him many friends.
The DOOR Antenna: This reduced-space antenna has the advantage of being somewhat directional. If you have an unused door to a room in your apartment or condo, start by making an "X" with masking tape from corner to corner. Mark the tape every half-inch from the outside edges. Using pushpins place a pin at every mark on the "X". You have now made a form for the antenna.
Using small-gauge enameled wire, start at the bottom of the door. Anchor the wire to the outside-most pin. Wrap the wire in a spiral fashion using the pins for guides. When the antenna is finished, you get your directionality by moving the door in and out.
HF antennas in an apartment or condo can be done. Just bear in mind a few things. First, be a good neighbor and if some one has an interference complaint try to solve it. Next, with this kind of set up you can not be a "BIG GUN" so don't try to be. You won't make all the contacts, but those that you do will be special. Experiment. Part of this hobby is trying things and learning and having fun.
One of the biggest thrills I have had was working Germany on 30 foot of 28-gauge wire from my first apartment. That contact sparked a lifetime interest in this hobby.
The meeting was called to order by Pat at 6:40 PM. All present introduced themselves.
TREASURER'S REPORT -Ted, KD2UB
Finances continue to be in good shape.
REPEATER REPORT - Gordon, KB2UB
Everything is working fine. Gordon has been in contact with Bill, N2NFI about going to the site to check things out.
NET REPORT - Zak, WB2PUE
The Thursday night 2-Meter Net was good on the 145.33 machine. The Sunday 40-Meter Net was good with about 14 check-ins. The Wednesday 20-Meter Net was good with about 7 check-ins.
VE REPORT - Bob, W2ILP
There were 7 VE's present and 12 candidates. 9 updated to General and 3 to extra. There was a discussion about whether the new licensing rules would attract more new people to amateur radio.
WAG REPORT - Bob, W2FPF
HOUSE REPORT - Pat, KE2LJ
There was nothing new from the company. The person in charge of moving the trailer has not got any input from management. It is not likely that they will allow our trailer in the Plant 14 area.
The following persons were voted in as new members:
James K. Glennon, KC2CGB, Tech Plus - Sustaining Member
Mark Althaus, N2YVB, General - Sustaining Member
There was a discussion about the plans for Field Day. Pat could use some help at his house on Friday afternoon June 23 to load the equipment onto a trailer. We will meet at 5:00 PM on Friday at the Grange to begin setup. We expect to get the poles and antennas up Friday. Saturday morning we will get the tents up and the radios hooked up. Suffolk County RC appears less organized than usual. Prior to the start, we will have to decide how many transmitters we will have on the air. The May issue of QST has the rules for Field Day. Dave, AB2EF has built and tested a double bazooka antenna that will be used for Field Day.
Pat, KE2LJ gave a very interesting presentation about how he grounded his 60 ft. tower, house and rig to prevent damage from lightning.
Forty Meters: 7.289 at 7:30 AM EST Sundays.
20 meters: 14.275 at 12 noon Wednesdays.
Two Meters: 146.745 at 8:30 PM EST Thursdays.
145.33 at 8:45 PM Thursdays.
145.33 Mondays (ARES/RACES) at 9:00 PM EST
For information on new VE Exams see write up by Bob, W2ILP in February newsletter, page 2.
General Meetings of the GARC are held on the third Wednesday of each month, at Melville, at 6:30 PM. All who are interested in Amateur Radio are invited to attend. Board meetings are held eight days before the General Meeting and GARC members are invited to attend, but please call Pat Masterson, KE2LJ, at 346-6316 to confirm place and time of meeting
Directions and a map for getting to the Melville meeting site are available on the Club Web site, www.qsl.net/wa2lqo.
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Less water is used under hard charging and no hydrogen in the battery compartment. A side benefit is less corrosion on the terminals due to acid weeping past the vents. They are available for most wet cell batteries from Hydrocaps, 305/696-2504. I think I paid $6.00 each for the caps, so a set of 6 will set you back a chunk of change, but they are worth it."
The second message on batteries was from Bob Voyt, WB8QCY:
"I solved the problem by going to gel batteries. They're a little more expensive but can be mounted in any direction and require no maintenance. To keep them from failing prematurely, you MUST charge them to a lower maximum voltage than lead acid batteries. If you want the Cadillac of sealed batteries, consider the Concorde AGM Deep Cycle Battery. More information can be obtained at www.windsun.com/ Batteries/AgmTech.htm."
Fuel Pump Noise
Jumping right into the next (old) subject, Bob also said, "Solved my fuel pump noise problem on my '96 Suburban. Installed a new special fuel pump. Somewhat expensive but took care of the noise."
I hesitated to put out the Ford phone numbers that Clarence Arndt, W6DFG, had sent me for fuel pump noise problems because they might have been outdated. I wanted someone to check them first. The first one asking was Greg LaHaie, K7YDL, so I sent him the two numbers. Greg replied that one number was no longer valid, but went on to say:
"Arnie Nielson at 313/845-7565 is the RFI guy all right. Immediately sent all info on Ford's filter solution to fuel pump: Part # F1PZ-18B925-A RFI filter, used on a wide range of vehicles. He sent complete info on installation (unfortunately, does require removing the pump from within the fuel tank, estimated shop time: 1.8 hours). The info is on the Ford Company's INTERNAL web site. He's not sure if it can be accessed from the world wide web. Arnie is very congenial and would answer anybody's questions. Thanks for the lead. I am sure I will pursue having my local dealership install this kit as soon as possible to solve a bad RFI situation. (at least 5 S-units of noise)."
Arlie Blankenship, NH6SO, sent in an interesting "snake oil" (his words) fix:
"At freeway speeds, the radio was unreadable. A call to Ford revealed they had never heard of any owners having noise on their transceivers. (Right) I tried capacitors, toroids, shielding, grounding, and you name it. At this time I also needed a better speaker. I ordered the ClearSpeech Speaker from NCI. (I think it is under a new company now.) (See ad on page 29 this issue.) The price almost seared me away. This will sound like 'snake oil.' Every bit of noise is gone. That simple. At 70 mph there is absolutely no noise on our HF rig. I don't know how it works, don't even care. But it is magic. Ian, KI7QX, has the same setup as us in a 1998 Ford F-150 V-8 engine. He also had ignition noise. He bought the same speaker, and voila His noise disappeared. I wouldn't guarantee it works for everyone, but I had reached frustration level in trying to solve my noise problem. What good is a mobile rig if you have to stop to use it?"
From a different noise fix, we turn to a different noise problem. Ray Telkamp, K0RNT, says:
"I have a 1995 Ford F-250 with the Navistar diesel engine. I mounted a TS-50 and Hustler, including what seems all the grounding, etc., necessary. (I have operated HF mobile for several years in different rigs.) There is a noise very similar to spark ignition, most objectionable on 14 MHz but tapering off in either direction. I have isolated the power source, used snap-on chokes on the power cable and coax, and a capacitor to ground at the antenna. Conversations with Ford Motor and Navistar resulted in an opinion that the noise is generated by the electric control leads to the injectors or by the injectors themselves. Again, I have installed chokes where possible. Using a sniffer of RG58, it seems the whole pickup body is radiating. I have considered capacitance at the injectors, but they are under the valve covers. ANY help on this subject would be appreciated."
Anyone have specific experience with this vehicle? Ra3; I didn't hear you say anything about bonding the body sheet metal sections, the frame, etc.
Joe Falcone, W5JOE, brings us back to antennas, another popular subject:
"I recall one article in which some fellow mentioned that he used a dipole adapter with two hamsticks to run mobile. I have a Safari (Astro) Van and could not get out with my Comet antennas on the back. I was thinking of hooking two Hamsticks to the top of the van, or even a Hamstick in a horizontal position. What do fellows who visit parking ramps and have vans do?"
Joe, there is no good answer. The best idea is to take your antennas on and off. I know that isn't really satisfactory. If the Comet antenna was mounted low and parallel to the van body, it didn't have a chance. If it was on the top, that is OK technically, but raises the clearance problems that you were talking about. The fellows using Hamstick dipoles, horizontal, were using them for mobile at rest, for RVing. I don't think anyone was using them while in motion. The compromises that I see are to use a very short antenna on the roof, or an antenna mounted on the side of the van, located high enough that any coils are clear of the roof.
Stu Dake, AC6GD, continues with another antenna question, "I am trying to decide on a screwdriver antenna to run on an RV. What do you think is the best one? Are you familiar with the High Sierra HS1500 -vs- DK3 design by N7LYY?"
The screwdriver antenna gets its name from the cordless screwdriver motor mounted inside to remotely tune the antenna loading coil. If it is to be on an RV, please note my warning above about having the coil clear of parallel metal surfaces. There are a number of antennas available that are based on Don Johnson, W6AAQ DK3 screwdriver antenna. I don't have one (yet), but I have not heard from anyone unhappy with any of them. Antennas and kits are also available from Don at Box 595, Esparto, CA 95627. To get more DK3 smarts, Don's Mobileering book can be ordered from this magazine. See the Worldradio Books ad. Let me hear from you on any HF mobile subject! Send e-mail to firstname.lastname@example.org, or write: Les Cobb, 4114 Horgan Way, Sacramento, CA 95821. More at http://home.pacbell.net/lcobb/.