What I Use, & Why I use It
Last Modified: Tue, Apr 22, 2008
I often get ask what I use mobile, and why I use it. The answer is easy, yet difficult, without some further data. What follows is one of the many different mobile configurations I have used over the 35+ years I've operated mobile. Some of my decisions are based on experience, some on current technology, and some because it is much safer to use. Let me give you a few examples.
I have seen mobile installations that are beyond belief. While the one in the right photo might have been staged, it isn't too far removed from some I've seen in person. If this vehicle were to be involved in a crash, and the passenger side air bag went off (exploded), just about every item you see installed on the dash would be sent flying at about 200 mph! I've even seen remote transceiver heads mounted in the center of the steering wheel, directly on top of the SRS!
As bad as these scenarios sound and look, by far the most deadly are those caused by distraction. Distraction, primarily from cellphone use, has surpassed drunk driving as the major cause of vehicular deaths. It should be obvious, that any device we install and use, should be to used reduce distraction, not increase it.
It should also be installed in such as fashion as to be easy to reach, clear of all vehicle controls, and out of harms way (SRS). What's more, just because you've seen what appears to be a safe mobile installation in some amateur radio article (net or print), it isn't necessarily so.
As you can see from the left photo, passenger side airbags are much bigger than most folks realize, especially those in large SUVs. Large enough in fact, to virtually rule out any dash mounted device.
I have no idea how many different mobile antennas I have used over the years, but I remember the first one. It was a 15 meter HyGain coil and mast, with an extended whip which allowed it to operate on 20 meters. I was using a Heath HW32 at the time (20 meter monobander), so 20 meter operation was enough. After I built a home brew amplifier in 1973, it because necessary to replace it with a Master Mobile coil, as the HyGain wouldn't handle 400 watts PEP output from the amplifier.
I've used about 20 different commercial HF antennas, and a lot of home brew ones too. The latest home brew one uses an 6 inch GLA Systems (Texas Bug Catcher) coil, a 3 foot mast, and an 8 foot whip. Two, 15 KV, latching, vacuum relays short tap the coil allowing use on 40, 20, 17, and 15 meters (0-0, 0-1, 1-0, and 1-1 open-close sequence). It works fairly well, but the remote wiring is complex.
Of all of the HF antennas I've tried, the best one overall has been the HiQ 580RTM. There maybe a few antennas which are better for say 80 meters, and a few maybe better for the upper bands, but the difference is moot. It is now mounted on it's third vehicle, and hasn't caused any problems of any kind.
The very first VHF antenna I ever bought (1971) was a Larsen NMO150. I still own it, and it is still in near daily use. It has been installed on at least 20 vehicles, and atop about a dozen NMO mounts (I usually leave them in place when I trade). The current VHF is a Larsen NMO2/70BK dual bander. It's on its fifth vehicle. I've crunched it twice with the garage door, and it's still working perfectly. You can't say that about any import.
I've probably missed one or two, but I'll try to name them all. For 2 meters, a converted Standard 12 channel business radio, and an Icom IC-25H (in daily use since 1977). That's 30 years of service, and I've never had to replace or repair any part of it.
As I said above, my first HF radio was a Heathkit HW32, 20 meter monobander. I bought it used, and the only thing I ever replaced was the driver and the two finals. I used it for about 3 years. I've also owned (and operated mobile with) a National NCX3, and an NCX5. From Atlas Radio a 180, 180X, 215, 215X, and a 210X. From Icom a IC701, IC730, IC735, IC751, two IC706MkIIgs, and two IC7000s (one the current mobile shown at right).
The biggest advantage latter-day transceivers have, is their built-in DSP. Some might argue that their noise blankers are better, but I'm not sure. The one in my last Atlas (210X) was as good as any I have used, and one of the few that effectively removed the Russian woodpecker.
Missing from the list are Yaesu and Kenwood transceivers. I've had two Yaesus, a FT100 and FT857D (both bought used), and one Kenwood, a TS480H (bought new). I sort of operated them mobile as a cross comparison, but not permanently installed. The FT100 was difficult to use because of the small display. The FT857D was maginally better, with the exception of the menuing. I don't think any manufacturer has got menuing down pat, including Icom!
The Kenwood TS480H is about as good as Kenwoods get. Subjectively, setting side by side with a (borrowed) TS2000, I can't tell the difference. I think the DSP is better in the 480, and the noise blanker is slightly better in the 2000. The real advantage for the 480 is its 200 watts PEP output. Call it a poor man's amplifier, for just slightly more cost than the base TS480S. If you have the room for the large remote head, it's a decent HF mobile with a lot of punch.
I have some additional information of the current mobile offerings here.
If you're a casual mobile operator, I don't think an amplifier is a wise purchase. Based on the number of installations I've seen, the vast majority of operators would garner more (radiated signal) by properly (re)mounting their antennas. I have a lot more information about this in my Antenna and Mounting articles.
To date, I have used two home brew amps, and 4 commercial ones. My first was home brewed (straight from the ARRL handbook). It used a P&H LA400 mobile power supply, and utilized four 6KD6 sweep tubes. Since I only operated 20 meters at the time, it was a monobander. I did build a multi-band mobile amp using four 4CX250Bs, but to be honest, it didn't work out too well.
My current amp is the SGC SG500. It has much better fault protection than any currently available mobile amp. Probably its best feature is automatic band selection (it also has RF keying which I don't use). I've tried every scheme you can think of to automate band selection. Having a built-in CPU to do this for you is a godsend. No matter how you do it, no matter how careful you are, sooner or later you'll transmit into the wrong bandpass filter with predictable results. Use the automatic feature, and that just can't happen. By the way, the SG500 is the only (legacy) mobile amplifier which can be keyed directly by an Icom 706 or 7000.
As bullet proof as it is, if you use one of these amps, and it's mounted in the trunk, do yourself a favor and buy the extra cost fan kit. With an adequate power feed (and the fan kit), the amp will keydown forever at 500 watts out! This sort of capability doesn't come cheap, but quality never does. I own two of them, and one has nearly 800 hours of mobile keydown time (SSB) without a hitch!
The Controller Boxes
The little black box in the right photo is a Better RF Tune control unit, which plugs into the tuner and CI-V ports of the IC-7000. When the Tune button is pressed, the radio switches to RTTY mode, and transmits at about 30 watts. Push the button again, and the radio reverts to its previous mode. This is one of the few tuner units fully compatible with the IC-7000.
The BetterRF Tune Control plugs into their 7000 Screwdriver control via a 2.5 mm stereo cable (all cables are included). The controller has some very unique features.
First, all of the setup is done using existing controls on the Icom IC-7000 it was designed for. Setup takes all of 5 minutes, as the run and stall currents are automatically detected. It plugs into their 7000 TUNER Control. All that's necessary is to provide a 3 amp fused circuit to power the antenna's motor. The only modification required, is changing a jumper (or switches) located inside the tuner unit.
The SWR default is set 1.5:1 , which may be changed up or down as required. You can manually operate the antenna if needed, but you won't need to as this unit works perfectly, every time! There's even an amplifier bypass relay (both NO and NC).
Once set up, when you QSY you simply push the Tune/Call button, and the controller takes over, always moving the antenna in the correct direction. If the motor overshoots the programmed SWR, the controller detects this, and reverses. To minimize the overshoot, dynamic braking is used. When necessary, the controller switches to PCM (pulse-code modulation), and runs the motor at half speed
I've personally tried 6 different commercial controllers: manual and automatic; SWR and turn counting; and so far, this is the best one yet.
The black box in the photo is a Hammond (available from Mouser and DigiKey). The rectangular object is a Martel two wire voltmeter. The switches control the amplifier and remote coaxial relays. The cabling is straight forward, and has Molex connectors on both ends to ease installation and removal.
TVandNav2Go makes a video interface for almost every factory-installed navigation system ever made. It's housed in a small metal box, about 1 x 3 x 4 inches, and sells for $250. Most of the competition is at least $100 more. The instructions are rather lame, however it's easy to install. If you have an Icom IC-7000, this is a great addition worth the price of admission, if for no other reason than to reduce distraction.