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Radios and Communications Gear
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I just returned from the HOA Nevada trip exploring the abandoned mines and ghostowns that mark the desert floor. After reading through several humlists, I've seen a common thread about two-way radios. This looks to be a good forum to discuss some options we have here. Almost everyone has a CB - they've been around for years and have earned a reputation. Unfortunately, CB's have some limitations that should be considered before they are adopted as a "HUMMER Standard". On the minus side, they suffer from limited range, poor audio quality (static, etc.), and antenna systems that do not work well in off road environments. On the plus side, they are cheap and quite common. All of the HOA members travelling on the Nevada trip this Thanksgiving carried professional VHF communications gear along for the ride. We operated on 151.625 MHz, perhaps the singular most common VHF frequency in use today. Like CB's, VHF has it's pluses and minuses -- On the minus side, it is more expensive and less common. Pluses include dramatic range increases (we spoke for over 35 miles as we parted after the trip) exceptional audio (from FM modulation), good performance even from handheld radios, and less interferance from other transmitters. As for antenna systems, a 17" whip is as effective in VHF as a 108" whip is for CB. VHF radios have become a standard for HOA members since their performance advantage clearly outweighs their primary disadvantage (cost). Recently, several new manufacturers have entered the arena, lowering the entry cost for VHF to under $100. Manufacturers such as Neutec, Ranger, Maxon, and Tandy have introduced low-end units that offer substantially better performance than even the best CB unit. Motorola continues to dominate the high end of the commercial two-way market with its exceptionally rugged designs, both in handheld and mobile radios. I'd like to solicit input from other HML members to standardize a Hummer VHF frequency for communication. We passed at least 3 other Hummers on the road this trip, but were unable to establish communications with any of them (except for the friendly wave as we zipped down the highway). It would be nice to show up at your favorite 4WD park and call for other Hummers if they're within range! Everett Fred Basham
LeeF., Dallas, Tx
Thanx.
I know I am not Fred, but I can answer that too:
800 MHz - 1/4 wave length about 2.5 inches
460-and up (UHF) the more line of site is required. So if you have a good
high repeater, the better. Higher freq. will have less static noise to
deal with. And are at there best when used with a good tall repeater
antenna. In you are in an area with lots of pine trees, you will have a
harder time with signal quality. The reason is that the pine needles are
about the same length as the wave length of the signals, and will absorb
some of the signals if not just about all of it in your area.
VHF (Hi-Band) 155 MHz has very good coverage in areas that you are not able
to use a repeater, and is not absorb as easily by pine trees. Repeater
cannot be used on VHF unless you are of a government or Public Service. A
19 inch wipe antenna will work great and will put up with a lot of knocking
about. With a medium power radio (30-50 watts), you can cover about 20-40
miles depending on the area you are in, over water it's 2-4 time or more
better range. (it's the better choice if you are in the wilderness.)
VHF (Low band) 30-50 MHz & CB 27MHz, requires long antenna, noisy - prone
to static (Ex engine noise (Gas), Electric motor noise (a bad brush type
motor like my A/C blower), prone to skip from distant users, like when the
sky are cold (Fall & winter times). Requires long antenna that get in the
way all the time. But the good part of it is that it is great over wide
open UN-POPULATED land, like the desert.
How was that? :) Did I miss any thing? Oh yeah! Except for the CB, all
radios require an FCC license, and the radios that they sell in the stores
are assigned to a common user channel or GMRS (in a sense it like a CB
channel but at a higher freq.) and getting the FCC license. is no problem.
The form will come with the radio in most cases.
Okay, that it! I going home now, my wife is calling me on the radio, (For
Real!) BYE!
Allan Madar
Everett F Basham
How about a frequency in the 2m Ham band (144-148 MHz)? This band is
close enough to the common commercial frequency of 151.625 that
Everett mentioned that it works just about the same. You'll need to
get an amateur radio license to transmit there. You need to pass a
test and fork over about five bucks to get the license, but it's good
for ten years, and you will also be able to communicate with a lot of
non-Hummer folks. I'd suggest the national simplex calling frequency
of 146.520 MHz for establishing contact.
On the plus side, licensed Amateur radio operators get a lot of
privileges, such as slices of RF spectrum ranging from under 2 MHz to
well into the microwave region, power limits of up to 1500W (depending
upon license class and frequency), permission to modify non-amateur
radios for use in the amateur bands or even design and build radios
from scratch (I use an ex-commercial radio from a swap meet that I
retuned to operate in the 440 MHz UHF amateur band, total cost was
about $100 including radio, new crystals and a service manual, but
then I also have test equipment and a degree in engineering.... :-),
etc.
On the minus side, you need more technical knowledge to get an amateur
license than a commercial license (don't complain, grandmothers and
six-year-old kids can pass the tests with a little bit of study!),
brand-new radios can be more expensive than commercial radios (though
there are many good deals to be found on used radios, and you can
convert many non-amateur radios if you have the skill, gumption and
equipment, including a lot of the rugged and reliable Motorola
commercial radios), and there are restrictions on how you can use the
radios (no business transactions, no broadcasting, no singing, ID with
callsign every 10 minutes, and no @!&&$%# swearing!).
I'm currently just a Hummer wannabe, though I hope to fix up an
ex-military Hummer as soon as I get rich enough. Then, I'll probably
try to convince everybody to operate in the 6m (50-54 MHz) ham band,
because the military radios I'll install in the Hummer will work
there! :-) Gotta buy a house to park the truck next to, first,
though. :-)
I hold a technician-class amateur radio license, and I use a dual-band
radio in my puny little 4Runner, covering the 2m VHF band and the 70
cm (420-450 MHz) UHF band through a 12" tall cellular-looking
antenna. It will receive commercial frequencies such as 151.625, but
it will not transmit there without modification. I usually operate
through a local UHF repeater on a nearby mountaintop, which gives me
coverage over most of Orange County and some parts of LA, Riverside,
and San Diego counties, even from a hand-held radio.
Just a thought. Pardon me for recruiting. We now return you to your
regularly-scheduled mixture of noise and useful content.
Mark J. Blair KE6MYK
Although the question of VHF or UHF has been asked and answered, I'll add
my two cents in here...
VHF is much more congested than UHF in an urban area. VHF does propogate
better than UHF. VHF radios typically have more output power than their
UHF equivalents. In short, for off-roading and Hummer convoys, VHF is
the best alternative.
The interesting note here is that none of the 15 repeater systems I operate
in the silicon valley are on VHF! In fact, shortly before buying my HUMMER,
I had sold all of my VHF radios since they were of no use to me any more. I
had to run out and get a new one for the Alaska trip last summer! It was
worth the purchase, since the CB's used on the trip were less than
acceptable.
Someone had suggested that we use Ham frequencies for communications - this
has a serious drawback since, technically, non-Hams can not transmit on
these frequencies. Using business commercial frequencies like 151.625
allows us to use a group license (Part of the benefit of joining the
Hummer Owner's Association is being able to use the group license with no
fees or paperwork!)
This means that I can give a handheld to anyone and ask them to spot for me
regardless of their license status. I can also talk with other association
members while on the road or off road. It is simply not practical to expect
that every HUMMER owner will become a licensed ham, not to mention the guests
or family members that would participate in outings. With commercial
frequencies, the license is held by an organization instead of an individual.
Any individual belonging to the organization or under the direction of the
organization can use that same license to further the organization's charter.
Ham radio is a great hobby; I'm a ham myself. It's just too limiting to
require a ham license for everyone in a large group.
Everett Fred Basham
As an RF Systems Engineer, I am often asked by fellow HUMMER owners what
is the best form of long distance communications, "... in case `the worst'
happens". It seems that with the HUMMER's unique off-road prowess, people
are venturing way beyond the coverage areas of today's cellular markets.
While there are many exotic solutions ranging from HF maritime gear to
Satellite communications, I had an opportunity to try out a simple, cost
effective solution on the HOA Nevada trip this past week.
The concept is based upon extending the existing cellular coverage way
beyond specifications. Cellular coverage areas are defined by usability
criteria, which usually includes a modern cellular tranceiver coupled to
a glass mount antenna with 18 feet of coax cable in between. This
configuration is considered usable when a call can be placed and completed
while driving without being dropped. To extend range, we must modify
our criteria for "acceptability". If we assume the vehicle is stationary,
we immediately realize a substantially larger service area.
Once stationary, the glass mount antenna is replaced with a high gain,
commercial quality directional antenna. These antennas should not be
confused with the inferior antennas sold through catalogs as "range
extenders". Mail-order antennas are as usefull as the "250,000 lb.
rolling weight winch with cigarette lighter plug" that appears on the
facing page in the catalog. Commercial antennas are constructed of
welded aluminum, tuned to length, and fitted with a Type-N female
connecter. They can be purchased for under $100 through commercial
two-way radio shops. Most shops can also make a short length of cable
to go from the Type-N connector on the antenna to the SMA or mini-UHF
connector on the cellular phone. Keeping this cable short greatly
reduces the signal loss in the cable.
Once attached, the antenna is slowly rotated by hand while watching the
signal strength display on the phone. From my location, somewhere in
the Nevada desert, my phone was showing "No Service" after parking.
By attaching the directional antenna, I received a 4/6 scale S reading
and "Roam" indicator on the phone. It turned out I had accessed the
Bishop, CA system over 65 miles away from our location (as verified by
my GPS). Pointing the antenna more east, I was able to access a Nevada
cellular system. The 611 operators were stunned, but quite helpful
when I asked them where I was.
This solution works well if you're within 150 miles of a cellular system.
It works best with mobile, transportable, or "Bag" phones. Since you're
using your exsiting phone and service agreement, it carries no additional
monthly costs. The antenna I used was 6" tall and about 22" long, weighing
about a pound -- an easy carry along item in my HUMMER wagon. Although you
can not drive off with the directional antenna attached, it does provide
reliable communications for a low cost.
Everett Fred Basham
Several people have asked where to order the directional cellular antennas.
Any reputable communications store should carry these. The local shop here
in Santa Clara is County Communications at (408) 244-4750. Ask for Nick.
They can also custom make a cable to go from the Type-N connector on the
antenna to your cellular phone. Be sure and specify the connector on the
phone (Motorolas are typically Mini-UHF and most others use TNC).
County Communications also sells high quality VHF commercial radios at
reasonable prices. They have the frequencies assigned to the Hummer
Owner's Association on file and can program and ship the radio to you.
Everett Fred Basham
In response the Everett's story about using a Yagi cell antenna, Jack said:
This sounds fantastic. Where can I order one of these antennas and what do
I ask for?
Jack Rickard
Well, this is the kind of thing I have been doing for a living for the past
few years, so let me share.
About the best antennas for this are made by Sinclair Technologies of
Tonawanda, NY. They make several:
First is the SRL-406, which is a Yagi antenna (looks sort of like the
log-periodic antennas used for VHF-TV only much smaller) with 10 dBd gain
(that is 10 dB over a dipole antenna). Three watts is the maximum power
from a cellular phone, so 10 dB gain boosts it to 30 watts maximum Effective
Radiated Power (ERP). Of course, power reduction will still work so the
Cellular Base Station may still turn your phone's power down. It is 24
inches long by 6.4 inches maximum width. List: $196.
The next antenna is the SRL-406, which is a similar antenna, except it is 12
dB of gain, which will improve the ERP of the 3 watt phone to watts. It
is longer, 37.5 inches and the width is the same. List: $286; and $100 is
too much to pay for 2 dB.
There is a problem with using high gain antennas for cellular. If the
cellular system, or even two systems hear your Electronic Serial Number
(ESN) and phone number (with other stuff the NAM) at the same time, at
cellular base stations that are not close together, they assume your phone
has been cloned. This assumption is held more strongly if you are away from
your home system ROAMing. If the system sees this, it will automatically
shut you down. You will have to talk to your home service provider to get
your phone back on and that typically takes a day or two. In the mean time,
you will be forced to use a credit card, not a phone card but MasterCard or
Visa, in order to use your phone. This is a problem because the whole area
can hear every word you say on your phone, so some not so nice guy can get
your card number and go off on a shopping spree.
Yagi antennas put MOST of the signal in one direction, but they put some in
many directions, especially behind the antenna and are more likely to be
sniffed and shut down. There is an antenna that does not send signal in but
one direction, though it is bigger than a Yagi because it will not lie flat.
It is called a Corner Reflector. It is a "V" shaped metal plate with the
driven element in the "V."
The Sinclair SRL-402 is such an antenna. The gain is 10 dB, same as the
first Yagi, but it puts almost no signal behind it, in fact it is all in a
180 degree arc in front of the antenna, with the signal at 90 degrees being
about 24 dB below the maximum. This antenna is much more likely to not be
"sniffed" and therefore your phone will stay on. Don't say it cannot
happen, I have seen it happen between systems in New Jersey and West
Virginia! What a problem having no phone. This antenna will fit in a two
foot square box. List $509.
One last antenna, and I hope you will never need it: SRL-460. It is a
partial parabolic dish, kind of like for the Dish Network, or Primestar,
except they are "cut down" to be rectangular. It is 48" wide by 24" tall.
The driven element sticks out from the middle by about two feet, and may be
removed for shipping or storage. It has 15 dB gain and is expensive. List:
$1,041.
I am a dealer for these, and about every other brand of antennas, and I
recommend Sinclair over all others. They are nearly indestructible. I
recommend you call the factory direct (800-228-2763) and tell them you are a
ham and would like a 25% discount. DO tell them it is for Cellular, so you
get the proper frequency split.
With any extended range system for cellular, or practically any radio
system, height is important. You will want some kind of mast to get the
antenna in the air. This can be 2" or so diameter pipe, and some way to get
it to stay vertical. BUY THE PIPE AFTER YOU GET THE ANTENNA so you can get
the proper diameter for the clamp on the antenna. Broadcast suppliers have
a push up mast. You drive onto a plate that has a socked in it. Put the
mast, which is about five feet long when nested, into the socket, and attach
the antenna. You then push up the inner-most nested section and lock it in
place. Then push up the next section. When you are done, the antenna is 25
or 30 feet in the air! All this for only about $1,800! Call Kathleen Karas
at 800-955-6800. Tell her you will pay with a credit card, you may get a
better price. I have used these things too, and they work great! Not as
well as a pneumatic mast permanently mounted in the truck, but well. If you
go the latter route, pneumatic masts can be gotten up to about 120 feet. If
you can't find cellular service at 120 feet, you need a short wave
communications system, not cellular.
There is a system that I think is called Satellite Cellular. It uses a
cellular like phone and an antenna that looks like a football, but is a bit
larger, or an antenna that is about 40 inches tall and four inches in
diameter. The phone costs about $3,600 and may include cellular as well.
If you get everything from them, you will pay about $3.00 per minute while
on the bird, and less than $1 per minute on cellular, depending on where you
are. They have roaming agreements with cellular carriers all over the US,
and must of North America. It checks for Cellular first, and if service is
there, that is the way you go. If there is no cellular service, you go to
the bird. The company is here in the Washington area, I believe in
Arlington, VA.
Good luck, and go get lost.
After reading several messages concerning radio installations, I will
share some of my hard-learned experiences with HF SSB and VHF.
At first, the Hummer seems a bear and quite formidable to make
any accessory look like factory. I have seen a number of ham
radio installations that look like well, uhr hum ....#@&^%*. That
is, wires and other support devices scattered all over the console
replete with twisted and taped DC splices everywhere. We can do
far better in a 65K plus vehicle.
If the HF transceiver is remotely mounted over the left rear tire, there
is an easy way to run cables from the front control head and central
battery terminal.
Be SAFE install a Motorola 30 amp. power relay next to the master
terminal and wire the relay coil to one of the two supplied accessory
switched leads described in the Hummer manual. When you start
the beast there will be no starter switching transients zapping your
radio CPU’s. From the relay, run two eight gauge machine stranded
lines to the left rear area.
The rubber plug feeding the CTIS gauge can be drilled so the switch
line and the eight gauge cables can be routed under the instrument
panel. The lower panel cover must be removed along with the hood
release bracket on the left.
Next, remove all of the left lower side panels, upper seat belt shoulder
restraint bolts, left rear seat, panels behind this seat, and one panel
behind the rear seat upper shoulder seat belt assembly. There is a small
channel behind the rear seat that can be used for wire routing around the
seat and looped around to the rear area. BY THE WAY, while you are
running this wire, why not run some extra coaxial cable and a couple of
multi conductor lines so you will not be ssssorrrry later when you add
something else back there. There are cables already running around in
these areas so they make great places to use a liberal amount of wire
ties.
If you mount your control head for the Yaesu FT 900 and remote panel for
the SGC or Icom antenna tuner on the top console, an excellent way of doing
this is with a Pana Vise similar to the ones used on cellular telephones.
These control cables and RG58 coax can be run as follows.
Remove the tachometer and clock panel combo along with the CTIS gauge panel.
They can just hang down. There is a very small vertical passageway behind the
tach panel that opens right at the split section of dashboard padding between
the top of the tach panel and the rest of the massive console to the center
containing the AC ducts. It is some kind of tight here but it CAN BE DONE
with a piece of mono filament line used as a fish tape. WHEW!
For HF SSB you should ground the body to the frame with at least two inch
braided cable. There are places at the rear of the wagon that can bolt
directly to the bumper bolts. I am not sure how well the body shock mounts
securely bond the body to the frame. Low frequency HF using electrically
short vertical antennas can have a very low impedance of only five to ten
ohms and two ohms of ground resistance represents a considerable loss
of radiation efficiency. Top loaded resonant antennas like the Hustler,
Outbacker, and the like have reasonable impedances around thirty to
ohms but wide band antennas such as the SGC and other specially loaded
military antennae can exhibit inpedances as low as five ohms or less
on the 1.9mhz. 160 meter ham band.
God knows, I have been down the Hummer HF road before and if I can
be of any help to anyone regarding HF SSB I will be glad to help them
avoid the lessons I learned. IT IS POSSIBLE to have a HF - VHF system,
remote heads and transmitters, tuners and the like at the rear with no
wires showing ANYWHERE.
John & Kathe Watkins
A lot of us in northern CA use Yaesu FT-8000 models. The range with a good
antenna is 35 miles line of sight. These are dual-band UHF/VHF ham radios,
so theoretically you need at least a technician no-code license to use them
(which I do have; it's easy to get). The Yaesu is about $400-500 and they
may have an upgraded model by now. To avoid drilling holes which can leak
and rust, get a Larsen dual-band glass-mount antenna (ask the experts which
one, I don't have my truck with me now). It's easy to run the cable along
the ceiling moldings.
I double-sided taped my radio to the underside of my roof-mounted CD
changer bucket. This location makes it accessible to driver & passenger and
lets you run cables in the conduits used by the CD changer. That part isn't
so easy though. I have a wagon and your situation is probably different.
As an amateur radio operator, I would reccomend a VHF FM radio. The VHF
frequencies have the advantage of being longer in wavelength than UHF
frequienceis. THe UHF waves hava tendance to be easily absorbed by foliage
and the the like in your immidiate areas. The prevents the signal from
getting out as far as you had hoped. Especialy when you in the woods. And
with .5 wats comming out of an unlicensed transmitter, you may worry about
those things when signal counts.
Dave Hummel
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