GMRS: The Other UHF Band

I’ve always had a liking for the General Mobile Radio Service (GMRS). It’s a licensed radio service but does not require a technical exam so it works great for basic personal communications. When our kids were young we made good use of GMRS communications. This was back in the Pre-Cellphone Era, shortly after the dinosaurs left the earth. I still have my GMRS license: KAF1068

mxt100-with-mic
Midland MicroMobile GMRS Transceiver

GMRS uses frequencies in the general vicinity of 462 and 467 MHz. When the FCC created the Family Radio Service, they intermingled the FRS and GMRS channels, creating a real mess. See this page for a good explanation of how FRS and GMRS frequencies are arranged. Many of the low cost walkie-talkie radios sold in stores are combination FRS/GMRS radios.

I recently came across this really sweet little GMRS rig, the Midland MXT-100 Micro Mobile GMRS Radio. This thing is nice and small with an external mag-mount antenna for the roof of the car. It only has 5W of output power, which is not much more than a typical FRS/GMRS handheld radio but the external antenna should help a lot. (I’ve heard there are newer models on the way so stay tuned for that.)

I’ve encountered 4WD / Jeep clubs that use FRS radios for on the trail communications. This Midland radio would be a good upgrade for that kind of use, providing additional radio range. Some of these 4WD enthusiasts have gotten their ham ticket via our Technician license class. Ham radio provides a lot more capability but not everyone in their club is likely to get their ham license. GMRS is a great alternative…the other UHF band. It will work for other outdoor, community and club activities that involve “non radio” people.

FCC recently reduced the cost of the GMRS license to $65 for 5 years. I suspect that most people don’t bother with getting a license…but they should. For more detail on GMRS, see the FCC GMRS Page or for some good bedtime reading see the FCC Part 95 Rules.

73, Bob KØNR

Sorry, I’ve Been On 2m FM Again

This recycled post from 2008 is still accurate, but I do have my HF antenna up and recently used it for the CQ WW SSB Contest.

FT-7900R_thumbI was looking out the window the other day and noticed that my wire HF antenna is laying on the ground. Hmmm, probably doesn’t radiate very well that way. But if I put a long, lossy coaxial cable in line, the SWR will still be good at the transmitter. And I can tell my buddies that it works just fine because “I can work everyone that I hear.” (What a dumb thing to say.)

This made me realize that most of my ham radio activity lately has been on 2m FM. Actually it has been on 2m and 70cm FM, as I tend to lump these two activities together. These days, my VHF/UHF FM rigs have at least 146 MHz and 440 MHz in them (FT-7800, FT-8900, etc.). I cruise down the road and flip on the rig, talk to the locals, talk to the XYL, etc. It is just too easy and too convenient. It fits the mobile lifestyle, whether it means operating a mobile rig in the car or grabbing an HT to take along on a business trip. (I used to run HF and SSB VHF mobile but found that the rigs were rarely used, so I removed the gear from my vehicle.)

Of course, I need to apologize to the rest of the ham community for this failure to act according to accepted social norms. You know how it is…Real Hams operate HF, weak-signal VHF, microwaves, etc……almost anything that is not 2m FM. Every so often I hear that comment about “well, those techs just hang out on 2m FM,” implying that those guys are permanently stuck in ham radio middle school, unable to graduate to the next level. Or sometimes the FM operators are referred to as having “shacks on the belt” which are dependent on the “box on the hill.” The main message is that 2m FM is just too easy, too plug-n-play, too much like an appliance….too convenient. We certainly can’t have that!

Don’t get me wrong…I enjoy HF, DXing, contesting, digital modes, almost anything to do with amateur radio. That’s the cool thing about the hobby…so many bands, so many modes. One of my favorite activities is operating the major VHF contests. (I’ve even been known to make a few CW contacts.) But on a day-to-day basis 2m FM just seems to fit in better.

Some people call 2m FM the Utility Mode, because it is the mode that gets the job done. Last week, we had a weather net activated to track thunderstorms and a few tornadoes. Did this happen on 40m? I don’t think so. Two meters carried the load. Where do most of the ARES and RACES nets meet? Two meters. How is most public service communications handled? Two meter FM. Even some hard core HF DX enthusiasts are known to flip over to 2m FM to tell their buddies that the DXpedition to a rare country is on the air. It is the Utility Mode.

Over the weekend, I was driving through the mountains and heard an aeronautical mobile working stations simplex on 146.52 MHz…lots of fun. Another time, I heard a station calling about 80 miles away (I was in a high spot) and I had the pleasure of making that contact….again, on 2m FM. A few weeks ago, I operated in the Colorado 14er Event from the summit of Pikes Peak. Since many of the mountaintop stations had hiked up, the most popular mode of the day was (you guessed it) 2m FM.

So sorry, I have been hanging out on 2m FM. I’ll try to get that HF antenna back in the air one of these days.

73, Bob K0NR

World’s Best Microphone Hanger

I am often disappointed by the crummy microphone hanger clips supplied with mobile ham transceivers. Typically, they are cheap metal clips with sharp edges waiting to impale your hand, that look like this:

cheap microphone clipI recently came across these microphone clips that are awesome! Available from Amazon for $7.49. microphone hanger

73, Bob K0NR

2013 Ford F-150 Ham Radio Installation

After acquiring a Ford F-150 truck last year, I’ve been working on getting a ham radio installed in it. At times, I have loaded up my vehicle with multiple radios covering HF through 70 cm but lately I am content with just having a reasonable dualband 2m/70 cm FM rig in the mobile. Actually, I used a Yaesu FT-8900 that does FM on 10m, 6m, 2m and 70 cm but just set it up for the two bands.

Figure 1 IMG_2206
Ford F-150 with 2m/70cm antenna on the front fender

One of the most critical questions for a mobile installation is what kind of antenna to install and where to put it. In the end, the antenna is going to be the main determinant of mobile performance. Ideally, I’d like to have the antenna on the roof of the cab but the truck will not fit in my garage in that configuration. Another option I considered was mounting a longer dualband antenna using one of the stake pocket mounts from Breedlove. I prefer NMO mounts for VHF/UHF antennas and the stake pocket looked like a good way to go. However, a little measuring revealed that a 1/2-wave or 5/8-wave 2m antenna on the stack pocket was not going to clear my garage door. So it seemed that I was limited to a shorter antenna. I may still use the stake pocket mount for an additional antenna for road trips or to add 6m and 10m antennas.

Figure 2 IMG_2036

At this point, the F-150 bracket offered by The Antenna Farm looked like a good option. They have a number of these brackets made specifically for various vehicles, so check them out. This made the antenna installation quite simple. <click on any of the photos for a larger view>

 

Figure 3 IMG_2041

The antenna is an NMO-mount dualband that I had laying around the hamshack. I don’t recall the exact model number but these are very common, about 19-inch long for 1/4-wave operation on 2m and a small loading coil to make it work on the 70cm band.

 

 

Figure 4 IMG_2163

The F-150 has several precut holes for passing wires through the firewall. I used one that is on the passenger side just  below a large module, as shown in the photo. It took a stiff wire and some force to punch my way through the rubber plug and into the cab compartment.

I don’t have a photo of the battery connection but I connected the positive lead right onto the battery terminal while the negative lead was attached to the truck chassis near the battery. You may have been told to always connect directly to the battery terminals but that advice no longer applies to some newer cars because there is a current monitoring device in the negative battery lead. To avoid confusing the vehicle battery monitoring system, the negative connection to your transceiver needs to be on the chassis side of the current monitor. Alan K0BG explains this issue on his web site. Actually, Alan has a wealth of information on mobile installations on his web site: www.k0bg.com. Oh, of course, I used inline fuses on both the positive and negative power cables.

Figure 5 IMG_2166

I mounted the FT-8900 transceiver on the floor under the back seat. To route the power cables and antenna coax, I pulled up the flat plastic trim piece that runs along the floor at the passenger door. I started from the front and did some careful prying (and praying) to remove the trim without breaking it. This exposes a trough with a factory wiring harness in it but there’s room for more. A few other plastic trim pieces were removed to get access to the wires coming through the firewall. All in all, this was not that difficult. (Yea, Ford!)

Figure 6 IMG_2197

The photo to the left shows the FT-8900 radio installed under the passenger side rear seat. I drilled holes through the floor and mounted the radio with hefty sheet metal screws. The screws go right through the metal floor and and can be seen from under the truck. (Check that out before drilling!) Because the radio body is under the rear seat, I am using a small external speaker mounted near the drivers seat.

Figure 7 IMG_2200

The radio control head is mounted inside a little door/shelf that normally pops open to reveal the USB port for plugging in a smartphone. (Note that Ford has multiple seat / dashboard configurations.)

 

Figure 8 IMG_2201The FT-8900 control head just fits inside this little shelf, even when the door is closed (see photo). The microphone does have to be removed to close the door. I mounted a microphone hanger with a couple of sheet metal screws, as shown in the photo. I don’t like the crappy little hanger that usually comes with a ham transceiver so I bought some higher quality hangers on Amazon.

Overall, I am pleased with the radio install. The antenna location is clearly a compromise and I notice the performance is not as good as my previous vehicle (which was a small SUV with an NMO mount antenna in the middle of the roof.) But the antenna is “low profile” and sufficient for “around town” mobile operating. I am getting a little noise on the 2m band which needs some investigation. The 70cm band is very clean and is the band I use the most.

73, Bob K0NR

How About a New 12 Volt Automotive Connector?

12v automotic plugStandard power connections are a great thing. A while back, I wrote about how the micro-USB connector became the standard power/data connector for mobile phones. (Well, that is unless you own an iPhone.)

The good news is that we do have a standard power connector for 12 VDC in automobiles. The bad news is that it is an ugly behemoth derived from — can you believe it? — a cigarette lighter. For some background and history, see the Wikipedia article. The Society of Automotive Engineers (SAE) even has a standard that describes this power connector (SAE J563). Alan K0BG correctly warns us to “never, ever use existing vehicle wiring to power any amateur radio gear” including the 12 volt accessory plug. (I always follow this advice, except in the cases when I don’t.) I also found this piece by Bill W8LV on eham.net that describes the crappiness of these connectors. Various innovations have improved electrical connections in many applications (USB, HDMI, Powerpole, etc.) but we are still stuck with this clunky automotive power plug.

Well, there is a new standard power connector showing up in cars: the USB port. These ports provide the data and power interface for mobile phones, integrating them into the auto’s audio system. Standard USB ports (USB 1.x or 2.0) have a 5V output that can deliver up to 0.5A, resulting in 2.5W of power. A USB Charging Port can source up to 1.5A at 5V,  for 7.5 W of power. This is not that great for powering even low power (QRP) ham radio equipment.

Now a new standard, USB Power Delivery, is being developed that will source up to 100W of power. The plan is for the interface to negotiate a higher voltage output (up to 20V) with 5A of current. Wow, now that is some serious power. We will have to see if this standard is broadly adopted.

Two things are obvious to me: 1) the old cigarette lighter connector needs to go away and 2) it is not clear what the replacement will be.

What do you think? Any ideas for the next generation of 12V automotive connector?

73, Bob K0NR

Get Your Mobile Frequency Sticker On

One of the things I try to do is monitor the National Simplex Calling Frequency for 2 meter FM: 146.52 MHz, especially when mobile. It is fun to see who might show up on 2m simplex: SOTA operators, hikers, mobile stations, campers, etc. See these two posts on operating ideas: A Simple Wilderness Protocol: 146.52 MHz and The Use of 146.52 MHz.

14652_decalIt is also fun to say hello to another ham when you pass them on the highway. While you may see their call letter license plates or notice their mobile antenna, you may not know what frequency they are monitoring. The Noise Blankers Radio Club has solved this problem — just put this sticker on your vehicle.

After poking around cafepress.com, I found some additional options for indicating your radio frequency:

The 2meter SSB calling frequency:

2_meter_ssb_calling_frequency

 

 

 

 

 

The APRS frequency:
digital_position_reporting_on_board

 

 

 

 

 

And there’s this magnet for your refrigerator:

oval_simplex_sticker_rectangle_magnet

 

 

 

 

 

 

And then there’s this option, 73 the coolest number

73 sticker

 

 

 

 

 

If you don’t like any of these, cafepress.com makes it easy to create your own. Go for it!

73, Bob K0NR

A Simple Wilderness Protocol: 146.52 MHz

when-all-else-fails-logo“The Wilderness Protocol” (ref. June 1996 QST, page 85), recommends that stations (fixed, portable or mobile) monitor the primary (and secondary if possible) frequency(s) every three hours starting at 7 AM local time, for five minutes (7:00-7:05 AM, 10:00-10:05 AM, etc.)  Additionally, stations that have sufficient power resources should monitor for five minutes starting at the top of every hour, or even continuously.” The primary frequency is the National Simplex Calling Frequency…146.52 MHz. The secondary frequencies are 446.0, 223.5, 52.525 and 1294.5 MHz.

Here in Colorado, the summer months mean that many people head for the mountains. Mobile phone coverage has improved in many parts of the high country but is still not reliable in all areas. Amateur radio VHF/UHF repeater coverage is extensive but also does not cover the entire state.

The Wilderness Protocol is a good idea but is overly complex for practical use. Here’s my proposal to make it much simpler for practical backcountry use:

Principle #1: Don’t ever rely on a radio or mobile phone to get you out of trouble in the backcountry. Your primary strategy must be self-sufficiency. Avoid trouble. Be prepared for the unexpected.

Principle #2: Know what repeaters are available in your area. We have many wide coverage repeaters available but you need to know the frequency, offset and CTCSS tone (if any). The Colorado Connection is a linked repeater system that covers  many remote parts of the state.

Principle #3: In remote areas, monitor 146.52 MHz as much as possible. This applies to backcountry travelers, mobile stations and fixed stations.

I’ve been making it a habit to monitor 146.52 MHz in the backcountry. I often come across hikers, campers, fisherman, 4WD enthusiasts, SOTA stations, mobile operators and others monitoring that frequency.  It is fun to chat with other radio amateurs having fun in the mountains.

Just my opinion.
73, Bob K0NR

Note: This is a repost of an older article with minor edits.

The Mysterious Case of Alternator Noise

When I purchased my 2003 Ford Escape, I decided to install multiple ham radios and a bunch of antennas. Mostly I use a Yaesu FT-8900 FM transceiver for operating on the 2-Meter and 70-cm ham bands. A while back, I started getting reports that I had alternator whine on my transmit audio. I was perplexed because I thought I had done a pretty darn good job of installing the radio, including connecting heavy 12V power cables directly to the battery. (See K0BG’s web page for more information on battery connections.) I really wasn’t sure if this was a day one problem (and no one ever told me about the crummy audio) or something that had just started. My first course of action was to ignore it and see if it goes away. This strategy failed miserably as my FCC-licensed spouse continued to report that I was “whining”. Finally, I decided to put my alleged knowledge of electricity to work. I got out my trusty oscilloscope and took a look at the voltage near the transceiver. There was about 800 mV of ripple on the DC voltage, as shown below.

Escape alternator noise 12V at radio - higher revs

The frequency of the ripple was in the audio range, consistent with alternator whine. The frequency of the ripple increased when I rev’d the car engine, so it was clearly coming from the alternator. I was surprised to find that the size of the ripple did not depend much on whether I was transmitting or not. The transmit current is much higher than the receive current, so I expected the ripple to be worse on transmit.

Then I decided to measure the ripple voltage right at the battery, which is shown below. The peak-to-peak ripple is smaller (about 400 mV) than at the radio but still present. I expected the the voltage to be mostly clean right at the battery.

Escape alternator noise 12V at radio - at battery

I pondered what to do next. One approach would be to install a filter to eliminate the ripple. However, filtering out a few hundred Hz signal while maintaining a low voltage drop on the 12V power feed is not trivial. More importantly, I had the sense that the Escape’s electrical system was just not operating properly. I decided to take it to my local mechanic, who tested the alternator and determined that a diode had failed. He replaced the alternator for me and the whine is now gone.

I did measure the 12 volt supply with the new alternator installed and the radio transmitting. I was surprised to find that there is still some ripple, a bit less than 200 mV (shown below). Apparently, this is not enough to disturb the FT-8900 signal.

Escape alternator noise 12V - new alternator 2

So that’s the story about my alternator whine.

My spouse says “I still whine sometimes” but it has nothing to do with my ham transceiver.

    – 73, Bob K0NR

This Interference Seems to Follow Me Everywhere

USB chargerA few weeks ago, I was at my day job working diligently on something. I popped up the SotaWatch web site to see of anyone was out activating SOTA summits. Sure enough, Steve (AKA Goathiker, AKA WG0AT) was headed up Mt Herman for the day. (I have recently declared Mt Herman to be the Most Radioactive Summit in Colorado…at least for amateur radio.)

When I had a few minutes break, I went out to my amateur-radio equipped SUV in the parking lot to call Steve on 146.52 MHz. Steve came back to my call and we made a quick contact and he was in the log. Even though he was an easy line-of-sight path away, I had trouble copying him. Opening the squelch revealed that I had a large noisy signal sitting on 146.52 MHz. I didn’t think too much of it and assumed it was coming from the vast array of electronic equipment inside the building.

As I left work that day, I tuned to 146.52 MHz to see how quickly the interference disappeared as I drove away. I was surprised to find that the interference did not go away, it was covering a wide area. On my commute home, the noise was remarkably constant. This interference seems to follow me everywhere! Eventually, it sunk in that the interference was coming from my own vehicle. Huh, I didn’t have that problem before.

When I arrived home, I turned off the ignition and the noise was still there. I started disconnecting everything in sight, trying to make the noise disappear. Finally, I unplugged the cute little USB charger/adapter that was inserted into the cigarette lighter socket. Bingo, the interference disappeared. It seems that this little adapter has a switching circuit in it that is generating a large amount of hash. I have not investigated it fully, but it trashes out a substantial portion of the 2 Meter ham band.

It used to be my favorite adapter. Buyer beware.

73, Bob K0NR

How Much Does That Second Band Cost?

I encourage newly licensed radio amateurs to go ahead and get a dual-band FM rig…handheld, mobile or both. I think the additional cost of the dualbander with both 2 Meters (146 MHz) and 70 cm (440 MHz) is justified by having the ability to operate on the additional ham band. I have noticed that the price of the single-band 2 Meter mobiles are pretty low, less than $200… a real bargain in terms of technology. This made me wonder what the price premium for the second band (70 cm) really is.

I pulled all of these prices from the same major ham radio web site, trying to keep some consistency among the price of the various models. (I ignored specials and coupon pricing.) I looked at a basic 2 Meter FM rig and any comparable dual band models from the same manufacturer. I tried to stick to the basic transceivers and not include models that had advanced features such as D-STAR and APRS in them.

The data is captured in the table below. Note that I differentiated between a single receiver (one frequency at a time) dual-band radio and a two receiver dual-band radio, since the latter variety is much more expensive. I calculated a percent premium for each of the dual-band transceivers, calculated as the percent increase in price over the single-band radio from the same manufacturer. I think this is the most objective way to describe the extra cost of a dual-band radio.

Transceiver Price Bands Percent Premium
Yaesu FT-2900R $185 2M
Yaesu FT-7900R $330 2M/70cm 78%
Yaesu FT-8800R $460 2M/70cm Dual Receiver 149%
ICOM IC-2300H $260 2M
ICOM IC-2820H $670 2M/70cm Dual Receiver 158%
Alinco DR-135T $170 2M
Alinco DR-635T $320 2M/70cm Dual Receiver 88%
Kenwood TM-281A $145 2M
Kenwood TM-V71A $395 2M/70cm Dual Receiver 172%

It is worth noting that only Yaesu and Alinco offer a single-receiver dual-band rig. These two radios are 78% and 88% more expensive than their single band counterparts (less than twice the cost). The two-receiver dual-band radios are consistently more expensive, with a price premium ranging from 149% to 172%. While these rigs are often described as having two radios in one, they are more than twice as expensive as a single-band radio.

Although I appreciate the extra utility of the two-receiver radios, it looks to me like the best value is with the single-receiver dual-band rigs.

What do you think?

73, Bob K0NR

New Transceiver from ICOM: IC-7100

ICOM has shown the new IC-7100 at the JARL show in Tokyo. The interwebz is buzzing with information, including a preliminary data sheet.

My scan of the preliminary datasheet indicates that this radio is in the class of the IC-7000 or even the IC-706. It covers all modes on HF plus 6 Meters, 2 Meters and 70 cm. (It also has the 70 MHz band which is a nice add for the European countries that have that band.) The radio includes DV (D-STAR) modulation capability and has a new touchscreen user interface. The slanted control panel is meant to make the touchscreen more accessible.

A new HF plus VHF/UHF radio always gets my attention (see my plea for an FT-950 with 2 Meters).  I am starting to think that the real benefit of this rig is the addition of D-STAR capability, which would a good but not essential feature to have.

What do you think?

73, Bob K0NR

Update (30 Aug 2012): Universal Radio has the radio on its website.
There’s a good video look at the radio here.

TechDay 2012 – Your Start in Amateur Radio

Come join us on Saturday, September 15th, 2012 (9:00 AM to 2:00 PM) at the Tri-Lakes Monument Fire Administration Complex at 166 Second St. in beautiful Monument, CO for a half day workshop aimed primarily at the new Technician Licensees to help them get started in ham radio. While you’re here you’ll learn what it takes to be a ham radio operator, brush up on your DXing skills, test  your own ham radio equipment, check out some sweet mobile radio installations, and ask an Elmer “What’s so cool about 10 meters?”

Getting started in ham radio has never been so much fun!

Presentations

9:30 am – Youth DXpedition to Costa Rica
by Anna Veal WØANT

10:30 am – Mountaintop Operating
by Steve Galchutt WGØAT

11:30 am – Home Station Setup
by Anna Veal WØANT

12:30 pm – Getting On the Air
by Brandon Hippe KDØPWF

1:30 pm – Radio Equipment 101
by Shel KFØUR

* Each presentation is approximately 15 minutes with 5 minutes of Q&A at the end.  Events subject to change

Booths – Open 9AM to 2PM

Get Your Radio Programmed with Local Repeater Freqs by RT Systems
hosted by Kyle Hippe KYØHIP & Cole Turner WØCOL

Check Your Radio Performance
hosted by Bob Witte KØNR

See an HF Station
hosted by Dan Scott WØRO & Stu Turner WØSTU

Ask Any Question – The Elmer Booth
hosted by Paul Swanson AAØK & Shel KFØUR

Understand Mobile Installations
hosted by James Bucknall KDØMFO & Ethan Bucknall KDØMFP

Getting Your Ham Radio License
hosted by Brandon Hippe KDØPWF & Eric Hippe NØHIP

Ham Radio & Public Service
hosted by Randy Meadows KNØTPC

Sponsors

Tech Day 2012 is proudly sponsored by the WØTLM Amateur Radio Club and the  Pikes  Peak Radio Amateur Association.

Get the one page flyer in pdf format here.

Direct any questions to Bob KØNR

2012 Jeep Wrangler Radio Install

We recently sold the old white Jeep and bought a 2012 Wrangler (JK). After quite a bit of researching and experimenting with antenna mounting options, I finally got the ham gear installed in it. My objective is to get 2 Meter and 70 cm FM capability into the vehicle, using the Yaesu FT-7800 that I pulled out of the old Jeep. The big question was what to do about the antenna. The fiberglass hardtop does not make for a good antenna ground plane. Even if it did, during the summer months, we’ll sometimes take the top off to enjoy the open air ride.

The 2012 Jeep Wrangler Sport — Can you spot the antenna?

Initially, I planned to use the Arizona Rocky Road NMO antenna mount with a Diamond dualband antenna that is a 1/2 wave on 2 Meters. The 1/2 wave does not need a ground plane, so the performance is usually better with irregular mounting structures. However, I found that this antenna combination did not clear my garage door. I don’t like to have to remove or tilt a vehicle antenna to get in/out of the garage — my experience is that it usually just gets left in the “down” position. I tried a shorter 19-inch dualband whip antenna but its performance was dismal due to these factors: lack of a ground plane, being blocked by the vehicle body and poor grounding on the spare tire carrier. By the way, the grounding issue on the tire carrier (and many other technical topics) are discussed in these online forums: WranglerForum, JK-Forum. I think the Arizona Rocky Road mount would have been my preferred way to go (with the longer Diamond antenna), except for the garage issue. One problem I ran into with that mount is that the standard NMO mounts I have (the basic mounts with the cable attached) did not handle the thick steel of the mount. I had to purchase special NMO mounts made to handle thicker metal (see TheAntennaFarm.com).

The antenna mounting bracket near the hood, driver’s side.

I abandoned the Arizona Rocky Road approach and decided to use a simple NMO mounting bracket (Laird SBTB3400) on the driver’s side hood.  Like all Wrangler antenna installations, this is a compromise. It is lower on the vehicle than I would like but it does not block the driver’s view. Other people have used a variety of “trunk lip” mounts to accomplish the same thing but be sure to check out the driver’s view before installing. Installing the mount was easy, just three holes drilled and three sheet metal screws.

The next question was where to install the radio. I took advantage of the FT-7800’s detachable control head, mounting it on the dash, while placing the radio under the driver’s seat. I attached the radio’s mounting bracket to the floor of the Jeep with two heavy sheet metal screws. This keeps the radio up off the floor in case water gets into the Jeep. However, it only provides about 1 inch of water clearance, so you hard core Jeepers that are used to flooding the interior of the vehicle during stream crossings may find this inadequate.

The radio body was installed under the driver’s seat

I have to admit that I ran into a significant problem at this point. There was not enough clearance around the radio mounting bracket to get all four of the screws installed that attach the radio to the bracket. In the end, I unbolted the drivers seat and tilted it back, which gave me room to insert and tighten the screws. More careful positioning of the radio mount might have saved me from this hassle.

It is always a bit of an adventure to find a way to route the power cable from the engine compartment to the vehicle interior. Fortunately, Jeep has made this very easy, but it is not obvious just by looking around. Fortunately, the folks on the various online forums have scoped this out and provided good advice.

I popped off the small side panel of the dash on the driver’s side, to expose a hole filled with foam (see photos).

The plastic panel on the driver’s side of the dash pops open to reveal a routing hole filled with foam

A stiff wire or coat hanger can be poked into this hole and the foam easily gives way.

A coat hanger is shown poking through the routing hole

And the coat hanger comes out the other side, right next to the antenna mount.

Coat hanger pokes through near the antenna mount

I routed the power cable and the antenna cable through this hole. I connected the power cable directly to the battery, which is the recommended approach to avoid alternator whine and other problems. I understand there is a similar routing hole on the passenger side but I did not verify that.

The last thing to figure out was where to mount the control head. Although it is a tight fit, I mounted it in front of the gear shift. (I have the 6-speed manual transmission…the automatic transmission gives you more room here.) The control head is very light, so I used stick-on Velcro (about an inch wide and four inches long) to attach it to the dash. This seems to work OK but I will admit that the attachment is just a bit wobbly…fine for turning volume and VFO knobs but the not so good for pushing buttons. Also, I’ll have to see if it shakes lose on bumpy 4WD trails.  If so, I’ll fabricate a small bracket to provide better attachment.

FT-7800 Control Head and Mike Mounted to the Dash

In the process of exploring, I did take the dash apart to figure out what my options were. In retrospect, it was probably unnecessary due to where I eventually mounted the radio and control head. I found this youtube video to be very helpful in dismantling the dash.

Initial checkout shows that the radio installation is working fine. I was pleasantly surprised that the antenna SWR was quite good (<1.5) over the bands of interest. I will use the short 19-inch whip most of the time but I can swap out other NMO mount antennas (including the Diamond dualband antenna I mentioned earlier.)

I appreciate all of the info out on the interwebz concerning JK radio installs and I am passing along what I learned to assist other folks with their Jeep installations.

– 73, Bob K0NR

Update 20 June 2012:

It turns out that the Velcro (hook-and-loop fastener) approach did not work. The Velcro attachment itself was pretty reliable but the stick-on adhesive failed after a few weeks. I used a couple of L-shaped brackets to attach the control head to the dash and it seems to be working fine. I have used Velcro successfully in past installations but in situations where the control head was positioned on top of the center console so the main purpose of the Velcro was to prevent horizontal movement. In other words, the Velcro did not have to support the entire weight of the control head, just keep it from moving around.

Update 8 June 2014:

A number of people have emailed me to ask about the sturdiness of the antenna installation. The vehicle sheet metal that the mount attaches to is not all that thick, so they are worried about putting stress on it and having metal fatigue over time. I have inspected this several times now and it is not showing any signs of wear. The antenna I use is small and lightweight so it does not put much load on the antenna mount. I would be more concerned if the antenna was massive, so keep that in mind when you choose your NMO antenna.