AmateurRadio.com

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.

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.

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.

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

A 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

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.

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

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.

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

When I left for Korea, I had to pull out the HF installation on my truck… as the truck was staying in Kansas and I was not. Pulling out the rig and tuner was easy. The Tarheel antenna was also fairly simple. A disconnect at the base and then I coiled up the feedline and the cable that powers the screwdriver so they would be mostly out of the elements.

I returned back to Kansas last June but did not reinstall my HF setup in the truck. My only real modification was swapping out my VHF/UHF antenna with a fold-over. The new house afords me the opportunity to park in the garage(!) but rather than unscrewing the antenna every time I enter the garage, now I just have to pull it down. Works great.

My assignment here in Kansas has me traveling quite a bit and this week I am headed up to Wisconsin. I have only driven through Wisconsin once so instead of flying, I am going to make the 9 hour drive. This had me thinking that if I am on the road for 9 hours, I need my HF rig. So today I put the radio back in and reattached the Tarheel antenna.

Everything was set – I fired up the rig and heard the Turbo Tunner beep that it was on and ready. I hit the 706′s tuner button but the screwdriver failed to turn. Troubleshooting time. I took the base of the antenna down to the bench. Then I dug out the original rocker switch that came with the Tarheel. I hooked it up to the bench power supply and then hit the switch. Nothing. After a bit of jiggeling and wiggeling, the screwdriver engaged. I guess the almost two year siesta had taken a bit of a toll.

After a test drive today, it appears as if the mobile HF rig is working FB!… one QSO with North Carolina and another with Massachusetts. So look for me (AD7MI-9) as I make my way to Fort McCoy, Wisconsin and maybe I will catch you on 20M.

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.