Lesson Learned: Trust your planning

So this past weekend, I was off camping with my brothers, my cousin and a couple of friends. We were two hours north of Ottawa in an area which is poorly serviced for cell phone coverage. As one of my brothers is an expecting father (6 weeks) he asked if I could some how use my radio equipment to provide a communications link to “back home”.

I scrambled to get things sorted out which included:

  • locating the nearest repeater to our location (50km west of Mont-Laurier)
  • determining the frequency(ies) of the repeater input/output plus the CTCSS tones
  • establishing a communications plan with the appropriate operator(s)
Wouxun KG-UVD1P

Wouxun KG-UVD1P handheld radio

Our plan in-the-field was to use a 5W hand-held radio (Wouxun KG-UVD1P) with its rubber-resistor antenna. I had programmed the radio with the nearest repeaters plus the 2m calling frequency.

Some online research indicated that the expansive VE2REH repeater network had an IRLP-enabled node (2018) on Mont-Laurer, QC which was 50km to our east. I looked up the frequencies on a local amateur website and programmed the frequency and tones in the hand-held.

Digging a little deeper into the repeater details, I noticed that there were different values for the same machine. Not good.

  • VE2REH – Mont Laurier, QC – 147.105 +0.600 – 110.9/110.9 (in/out) {wrong info}
  • VE2REH – Mont Laurier, QC – 147.105 +0.600 – 103.5/131.8 (in/out) {this one works}

Wanting to be sure we had the best chance of hitting the repeater network, I programmed multiple values of the VE2REH network (plus all of the variants of the CTCSS codes) into the radio.

My second task was to develop a communications plan work-flow, starting with the trigger event (sister-in-law calling my parents). The primary plan was to have a licensed operator contact us using the Gatineau VE2REH repeater node (VE2REH – Gatineau, QC – 147.105 +0.600 – 110.9/110.9) which is linked via RF to the Mont-Laurier site.

I should have cleared my plans with the operators I had hastily chosen, however, time was not on my side as I had to  develop this entire plan in the span of only a couple of hours. Thankfully all of the operators contacted by email, whom include: Darin (VE3OIJ), Ernie (VE3EJJ) and Bob (VA3QV) graciously agreed to act as point-men for the communications operation. (Thanks & hats off to all of you!)

Should my parents be unable to contact the above operators, the emergency plan included having my parents pass the emergency traffic (as unlicensed individuals) themselves. As I drove to my parent’s house south east of Ottawa, I was periodically checking to see if the HT had the ability to hit the Gatineau VE2REH node.Luckily, the radio was able to trigger the repeater all the way from their house which gave us some assurance that our backup plan would work fine without needing to drive to the “last known range made good” location.

I managed to quickly train my mother in the use & operation of my second hand-held and provided a step-by-step guide so that anyone could use the radio from power-off all the way to passing the emergency traffic via the repeater network.

Later that same night (00:30UTC Jan 21st, 2012) we finally arrived on-site to be greeted with -31°C ambient temperatures and a pressing need to move to our camping location. A far-too-hasty radio check yielded a false negative. The repeater did not respond to my test transmission.

My plan was a failure.

Our primary plan was to use cell phones with the radio as a backup. It quickly looked like we would be operating with only a primary communication plan. I had also provided the local police contact information to my mother should we be unresponsive to any communique, and this was thought to be our disaster-level plan.

After a failed preliminary radio test, it was decided to abandon the radio plan entirely. This was perhaps a major mistake as you will read in a moment. The phone-call went out to my parents to let them know we would be unable to communicate via radio and that we would attempt to check-in using a cell phone on a regular basis.

As it turned out, I was using the “up-to-date” data provided by a local amateur radio website which was entirely wrong. I should have used the data which was last updated in 2008 (VE2REH – Mont Laurier, QC – 147.105 +0.600 – 103.5/131.8). The repeater triggered no problem when I tried the “old” memory setting. In our haste to get moving on Friday night, I did not try any other frequency or CTCSS settings as I had (wrongly) figured that being 50km from the repeater was just too much for the 5W output.

I was really excited to put my hobby to use in a real-life communication-dependent setting! It is just too bad that I mucked it up by rushing the field-implementation side of things. The good news is that I learned from this experience (and I hope that perhaps someone else might too)!

Hilights of this exercise:

  1. When communications are a priority, the most valuable tool is proper (adequate) research (ie. getting out to the spot of interest and trying the radio out)
  2. Delegate; being the only communications guy means that has to be my primary role where appropriate
  3. Stop, and trust your planning – had I done this, I would have been heard on the VE2REH repeater network and this would have been a great success
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Excellent reports while mobile (/M)

ATAS-120A and common mode choke

ATAS-120A and common mode choke

Well, during my “co-pilot” phase of the road trip, I was able to make some PSK-31 contacts on 20m and 15m. The farthest I bothered to pull in was to Los Angeles, CA however, thanks to pskreporter (a reverse beacon service), I know that I was heard as far away as Finland (6500km) and Venezuela (3900km). Those are some very nice DX results on 60W through a compromise mobile antenna!!

During my somewhat limited operating window (technical reasons … more on that in a moment) I made some excellent contacts with some friendly hams to the south of us. I quite enjoyed the honest signal reports and the rag-chews that I had. It was really nice to hear how good my signal was getting out while cruising along at 100km/h

So part of my limited operating time was due to Ham Radio Deluxe. I am not really a fan of that software suite, mostly due to its incredibly bloated coding (read slow, and well, bad …). I really should practice what I preach and get a suitable Linux distribution back on my Ham netbook. The other problem I had was in synchronizing my system time.

You see, for JT-65HF your time-base needs to be very accurate, preferably within a few seconds of UTC. Normally I would hook up my Garmin GPSMAP 60CS and time sync using that. Well, it seems Garmin has taken MANY steps backwards with their software (namely Basecrap, err… Basecamp). You can no longer simply synchronize your computer’s time in the tools menu. The other problem is I am now using a 62S (very sexy, but also very different beast under the hood). Oh, and my mini-USB cable doesn’t quite fit in the rather small oriface that the 62S provides which made it impossible to transfer data anyways.

All the same, I had a lot of fun operating mobile once again, and I look forward to the ride home for another shot at some mobile ops. I’ll try some operating away from the QTH to see how conditions are from Webbwood, ON.

TTFN!

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Testing out the air-wound choke

Yesterday I managed to get out to a home renovation store to purchase a three foot length of 4″ diameter ABS sewer pipe for my mobile installation. I cut a 6″ section from the pipe, drilled some tie-down holes and then made 23 windings of RG-8/U (solid dielectric).

Common mode choke

Common mode choke (aka. ugly balun)

This morning, I took a drive to warm up the FJ (it is -20°C outside) and to find a nice quiet spot to test the installation out. After installing the ATAS-120A on the end of the coax, I fired up the FT-857D and hit “tune”. The radio was tuned to 14.070 and even before matching the antenna, I could hear signals booming in.

Success! After the initial 30s tuning procedure, the antenna lengthened until it was resonant with an SWR of nearly 1:1.1on 20m. I was quite pleased. I then tried 30m and had no luck. Tuning down to 40m also gave me no joy – perhaps a few more turns (therefore feet) in my current choke might help me out!

In any event, all bands from 20m to 10m tuned up very nicely. With an excellent SWR on 20m I will be more or less set for the road-trip. To finish up my frigid testing session, I managed to make a PSK31 contact to Scotland (while parked) and had a quick QSO with Rick (MM3UOR) at 16:53UTC who was approx 4900km away.

More to follow …

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Roadtrip preparation ..

It looks as though I have some work to do in preparation for a 5+ hr road-trip Julie and I will be making in the next couple of days. Last night I reinstalled my FT-857D in the FJ Cruiser and tried out my ATAS-120A antenna. Well, the darn thing couldn’t tune at all! I had a high SWR across all of 20m, suggesting that I have a problem to look into.

90-degree elbow

SO-239 to PL-259 90-degree elbow

One difference that I can test right away is the use of a 90-degree elbow fitting. I doubt that the elbow is the root of the problem, however, it may be worth testing since it is really the only new addition to the installation. I know that at UHF, these adapters can essentially present a short-circuit to the signal source, however, at HF frequencies I would expect this to behave a bit better.

The next item which I have been meaning to address is the addition of a current choke. In a mobile installation, it is common to have current flowing on the outer portion of the coax due to much less than ideal impedance matching conditions, and the lack of a direct earth ground. In a well engineered mobile HF setup, a screw-driver antenna such as mine should have a coil coupling the antenna to the vehicle ground to alleviate some of the common mode current. In my case, this is neither practical, nor possible. The next best solution would be to add a current choke (not really a balun per-se).

Air-wound choke

Air-wound choke courtesy of VE7AVV

I do not have any ferrite beads available to me in the next couple of days, so adding at least 25 of these pricey transformers will not be possible for me. The next possibility is to make an air-wound choke using 6m (~20′) of coax. Now this I can do since my feed-line for the current installation is fourty feet long (to accommodate portable operation while at a campsite. The method is dead-simple; coil at least 6m (~20′) of coax around a non-conductive form, keeping the wraps tight next to each other and not allowing the first and last coils to ever meet. It is necessary to use a solid dielectric coax in this case to prevent conductor migration (and therefore an impedance change, possibly leading to a short-circuit).

My hope is that I can find an ABS pipe with a diameter of ~15cm (6″) which would give me a circumference (π x D) of nearly 50cm (half a meter). Given the aforementioned circumference, I would need (6.5m / 0.5m) = 13 turns of coax. Assuming the diameter of my coax is 0.635cm (1/4″), I could theoretically make these 13 turns (13 * 0.635cm) using a pipe section which is only 8.25cm (3.25″) long.

Graph showing diameter vs required length

Graph showing diameter vs required length

Using imperial values (since most pipes are in ancient units), a quick bit of math yields the following values for different diameter pipes using 21′ of coax to make the choke:

  • 2″ diameter = 40 turns = 10″ long
  • 3″ diameter = 27 turns = 6.75″ long
  • 4″ diameter = 20 turns = 5″ long
  • 6″ diameter = 13 turns = 3.25″ long
  • 8″ diameter = 10 turns = 2.5″ long

When I graphed the values for diameters from 1.5″ to 12″ it quickly became obvious that the relationship was an inverse function (1/x). In this case, the formula would best be approximated as: y= 20/x which makes shopping a lot easier. All I need to do is divide 20 by whatever pipe diameter I choose (adding an inch or two for cutting, etc)! The inverse relationship also means that there is no easy min/max value (or balance point). What is obvious however, is that once you get to a diameter of at least 4″, there is not much additional (space savings) benefit in increasing diameter any further.

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