The Communicator - January 2018

Here is the latest Communicator. In this edition you will find:

• QRM 
• The Rest Of The Story—Heinrich Hertz 
• Back To Basics 
• Tech Topics—Mobile Installation Basics 
• What’s Happening This Month In Ham? 
• News You Can Lose 
• Club News—SARC 
• Club News—OTC 
• Radio-Active 
• Emergency Comms 
• Club News—SEPAR Report 
• Satellite News 
• News From Clubs 
• Hardware - The Baofeng UV-5R
• Tech Topics II  - Antenna Modelling Software
• Tech Topics III - Programming Chinese Radios
• Field Day 2017 Reviewed
• and more... 

You can read or download this edition here

My deadline for the February edition is January 20th. If you have news from your Vancouver area club, events or other items of interest please email them to the communicator@ve7sar.net

A Ham's Night Before Christmas

A Christmas Classic

Here are the three video versions of A Ham's Night Before Christmas, one of KN4AQ's most popular productions.

First is the standard-definition original, produced in 2010. It's accumulated 62,000 views!.

https://youtu.be/ailFghtEKsc

Second, the Special Edition,is the high-definition remake produced in 2012, watched another 15,000 times

https://youtu.be/E_IEIubbv9k

And finally the live version from 2016 (um, 400 views?*). In the Live version, Gary first describes how he came to write the poem back in 1996 and perform it in person at radio club meetings around North Carolina, then produce the various audio and video versions for YouTube. Then he recreates those radio club live performances — with feeling — over a playback of the video and music track. The Live version was produced for HamRadioNow Episode 283. That episode page has links to a text version of the story and the poem, and audio versions with and without music. You can play the no-music recording on the air (on your club net Christmas eve?).

https://youtu.be/xxJpunNf5WI

Mobile Transceiver Installation Basics

A Communicator Reprise: March 2011

Mobile installations can be complicated, whether it is for a complex rover rig setup or just a relatively simple two meter FM installation. Here are some lessons that I have learned in that area over the years.

Getting power to the rig:
Connect directly to the battery. This provides a degree of filtration against alternator whine and ignition noise. A direct connection allows you to use your gear without turning the ignition on, though you must take care to turn the radios off or you will end up with a dead battery. Some rigs have an auto-off function that solves this problem.

This is the fuse box installation in my 2005 Toyota Tundra. The box is a small fishing tackle box with some partitions removed. It is affixed to the air filter housing with Superlock® fasteners. The large PowerPole® connectors enable me to unhook the power in an emergency. Note that this container even provides for the storage of spare fuses.

I suggest putting fuses on both legs of the power lines as close to the battery as possible. This protects your equipment and your vehicle if you have a catastrophic short circuit. In addition, you’ll need individual fuses for each piece of equipment. Don’t forget to stock up on extra fuses too. Check out the accompanying photos to see the installation I recently did in my Toyota truck.

Cigarette lighter circuits are light duty and are usually unsatisfactory for radio installations. If you must use one you should reduce power on the rig to limit the current draw. There are several power distribution panels on the market, and nearly all of them use Anderson PowerPole® connectors. They make a much better distribution system than a cigarette lighter socket.

Power panel - This is one of two power panels in the Tundra. The other one is located on the transmission tunnel just forward of the passenger seat. Each will handle 30 amps and has a main fuse plus individual circuit fuses. These panels are available from the nice folks at http://www.dcpwr.com.

Anderson PowerPoles are the national standard for many organizations and a wide variety of accessories using them are available. These panels usually have individually fused circuits and some even provide audio alerts for low voltage. When doing a mobile installation I prefer to put in a power panel to provide for future needs. The panels come in handy for connecting other radio’s, a GPS, a power inverter or other accessories.

Routing cables:
Getting cable through a firewall can be a hassle, but it can done. Most vehicles have holes in the firewall that are sealed with plastic or rubber plugs. Once you have determined that you can get to both sides of the plug, pull it out and punch an appropriate size hole through it using a gasket punch. Use a hole that provides a snug fit to the cable. Inexpensive gasket punches are available at Harbor Freight, item 6770-9VGA. This gives you a clean hole for your cable and will prevent the grommet from splitting. Once the cable is in place, seal around the cable opening with RTV or silicone caulk. This will reduce drafts, engine noise and the possibility of carbon monoxide entering the cabin. When running cables inside the engine compartment, be sure to avoid hot exhaust component and moving parts such as the steering linkage. Likewise, if you are routing cables under the dashboard make sure that they do not rub against or interfere with moving parts such as heater control cables, brake cables, etc. Installing cables inside the vehicle can require some effort.


You can usually lift trim panels on the door sills by removing screws. If you are lucky, there will be a cable trough under the panel. An electrician’s snake can be handy for pulling wires, especially under carpet or between the headliner and roof. If you route cables under carpet do not route under heavy wear areas.

Where to put the rig:
The placement of the transceiver is critical. It should be ina convenient location for operation and should not interfere with vehicle controls. Many mobile rigs have remote control heads which makes installation a lot easier. The only downside to remote heads is that the speaker is in the main body of the radio and it may be hard to hear. This problem is solved by installing a small mobile speaker. If possible,place the rig and control head where it cannot be readily seen from outside the vehicle. This will reduce the chances of theft.

Mounting the control head – Here’s a view of the control head for my IC-706MKIIG mounted on the dash of the Tundra. I was able to snake the remote cable under the dashboard and out through a gap by the windshield. The mounting bracket is bolted to an aluminum mount that is affixed to the dashboard with Velcro. The Velcro on the top of the control head is to affix a sun shield. This shield is necessary to keep the unit from overheating in direct sunlight. It extends over the defroster vents and directs cold air to the control head.

I prefer to have the microphone cord routed so it comes from behind me and has tension on the cord when I am using it. This allows me to drop the microphone without it getting tangled in the controls. I learned this lesson the hard way when I wrapped a mike cable around the steering wheel and ended up in the ditch! Securing the microphone can be a distraction when driving, so you might wish to use self-adhesive Velcro rather than the catches that come with the gear. I like to put the scratchy side of the Velcro on the dashboard or console so I can feel it with the backs of my fingers when I am stowing the microphone. I also use Velcro to secure brackets for control head mounts. Radio Shack sells Superlock Fasteners that are a lot like Velcro, but much heavier and stronger. It is not cheap, but it allows you to mount gear without drilling holes in the car if you have a clean flat surface.

Mounting an antenna:
Antenna mounts can be tricky, especially with newer cars. If you are willing to punch a hole in a fender or the roof, use a Greenlee punch or a metal-cutting hole saw. This gives you a nice clean hole that is easier to weatherproof. If you own a pickup, consider the GeoTools pickup stake hole mounts. 
Their web page is at: http://www.geotool.com/antmount.htm. I’ve used two of them on my 2005 Toyota Tundra. They are beautifully made and it is easy to make a clean installation with them. You should take care when routing antenna cables. They also must be kept away from moving parts, exhaust parts and sharp edges. Consult your auto dealer to determine the location of on-board computers and give them a wide berth for fear of interfering with vehicle electronics.

Do yourself a favor and tag your antenna lines at the radio end. This is especially important if you have more than one antenna. If the antenna connections on the rig are not easily accessible, you might consider running a piece of coax to a more easily accessible location and installing an antenna splitter switch there. This will enable you to switch to a portable antenna should the need ever arise.

The next step is to check the continuity between major body parts such as the roof, fenders, trunk lid and hood. If you do not have continuity between these parts it will affect the antenna ground plane and reduce ignition noise shielding. Fortunately, it is usually easy to bond these components with
small pieces of ground braid.

Once everything is in place, check the SWR and make appropriate adjustments. An antenna analyzer is the ideal tool for this, but you can also use a SWR bridge that registers in the appropriate frequency range.

Find the original article at https://goo.gl/3vE9RR in the March 2011 Communicator

SARC Spring 2018 Basic Course

Fee includes the manual, exam and workshops.

For further information please contact sarc@ve7sar.net

Better VHF/UHF Performance

A Communicator Reprise: September 2010 (2)

There is more to your radio than just your radio; and just because you can bring up a repeater with a click of your PTT button, doesn’t necessarily mean you will have a full quieting signal sufficient enough to actually get whole words out.  

I hear far too many stations, be it hand held, mobile or base who consistently try to check into a net or have a conversation with poor quality signals or audio issues.

Here are 6 tips to better VHF/UHF Performance

1. Use the correct coax cable.  You may be losing transmission efficiency if you’re using coax that’s too small for long cable runs.  Here is a rule of thumb: For runs under 20 feet you can get away with RG58 A/U cable.  Avoid using RG-174 for handheld jumpers.  For runs longer than 20 feet, use RG8 or RG213 or better yet, LMR400.  Over 100’ LMR600.  Use the right connectors too.  You can get away with a good quality PL-259 (UHF) connector up for 144 or even 220 Mhz.  But for 440 MHz you need to start using N-Connectors.  Not only for better low loss characteristics, but because the PL-259 does not present a consistent 50-52 ohm impedance above 300 MHz.  Use the best quality you can afford as the quality of the connector will severely affect your performance.
2. Stop corrosion with lubrication. Your antenna cables and hardware are extremely susceptible to moisture.  Check the ends and lubricate them with marine or silicon grease and use coax seal or splicing tape for wrapping connections.  You can expect a 10-15 year life span out of your stainless steel or anodized aluminum antenna. Far less for uncoated copper or unprotected aluminum.  Scotch 33 or 88 is the best electrical tape over the layer of splicing tape or coax seal for added protection. [see also http://www.nsarc.ca/tech_archive/Articles/PL-259_Weatherproofing_Article.pdf]
3. Mount your antenna as high as possible. VHF/UHF communications is determined by line of sight, and the higher you mount your antenna, the further your transmission will carry.  Dense trees, lots of metal in and on buildings will diminish your transmit and receive signals.
4. Get a higher gain antenna! You’re stuck to 5 watts on a hand held with a rubber antenna that offers negative gain (a loss).  ¼ wave antennas are unity gain or NO gain.  Antennas come in 3, 6, 9-10 or higher DB gain.  Even a 3db antenna on a hand held is going to effectively increase your ability to transmit and receive by a factor of 2 (or twice).  6db is twice as good as a 3db antenna.   You can’t use the repeater as a crutch for a poor signal. Bad in, bad out...
5. Check your antenna mounting location.  If your antenna is mounted within 3 feet of a parallel metal surface, it will “de-tune” your antenna system and your radio will lose efficiency.  If it’s mounted low on a bumper, next to your AM/FM antenna on your car, or you are using the wrong antenna for the installation – e.g. a ⁵/₈^th on the mirror mount, where a ½ wave is a better choice.
6. Don’t yell into your microphone!  This is FM, not SSB or CB… Get your radio tuned properly, use the original mic or at least one with the same input impedance and don’t over deviate by yelling.  If you have a wide band FM radio, and you are trying to work into a narrow band FM repeater, your audio will sound terrible and yelling only makes it worse.  If you are next to each other or a car length away, then fine… 500 mW is good, you annoy fewer people, the rest of the time use adequate power to have a good signal.

A Call For Your Opinion...

What Direction To Take?

Calling members of SARC and our readers worldwide to participate.  Our hobby has seen changes over the last century, from nothing through significant DIY, to sophisticated computer-radio combinations.   How will our current membership enhance this legacy; how do our current “Elmers” see the future; what changes at the club level will best move this knowledge into the future.

Myself, as with many hams, employment and family building put radio into the background only to come alive as the nest empties.  This 25-year break opened my eyes to the huge differences; when I left transceivers were just coming in and being cautious of interference was between my station and the public.  That has reversed.

Now, about driving that legacy: “What direction should a club take to guide/drive our future?”  Here are a couple of thoughts upon which comments are invited/appreciated.

In BC over half of the population live in Strata aka HOA areas with accompanying by-laws relating to outside structures – Read that as no towers, masts, or dropping wire off your 20th floor balcony.

• A local, country and world-wide effort to invalidate these big telecom supported by-laws such as FCC 98-273
• Publicity to educate (propaganda?) that ham radio towers are insurance against natural disasters (e.g. After several disasters Japanese towers are a neighbourhood plus)
• Ensure remote (internet) operation is part of the planning process and encourage participation
• “Your suggestions here”

Our executive is heavily HF biased; not by design but that’s the way it worked out.  This means that direction often follows that same bias.

• Suggestions for direction and legacy building is needed, neigh mandatory, from experienced VHF operators
• Much public services involve VHF (parades, cycling events, car rallies) yet the local emergency services group has limited involvement.

There is so much more that cannot fit in this column.

We would like to hear from the Amateur community. Comment below, or better yet, PLEASE SEND SUGGESTIONS including what you, or your local club, are or would like to see happen.  Send to president@ve7sar.net and we will publish a summary in an upcoming Communicator.

Have a happy holiday season, 73

Stan Williams VA7NF
SARC President

The Inverse Square Law Of RF Signal Strength

A Communicator Reprise: September 2010

The Inverse Square Law when referring to RF signal strength can be expressed from both the transmitted signal and the receive signal end in the following ways;

With an identical antenna at both the transmit site and the receiving station, regardless of whether the antenna is an omni-directional or highly directional antenna, if it took 1 watt of Effective Radiated Power to talk to a station 1 mile/kilometre away, then applying the I.S. Law would mean you need 4 watts for 2 miles, 9 watts for 3 miles, 16 watts for 4 miles, 25 watts for 5 miles... 100 watts for 10 miles/kilometres away.  So if you had 1000 watt ERP output to a no-gain antenna, that would only give you 31.625 miles – line of sight communications.  But that does not take into consideration any propagation, reflections, or the fact that the receiver is generally a lot more sensitive to weak signals… This I.S. Law is saying, for a given amount of signal strength to remain the same at each of the distances above, that is what you’d have to increase the ERP [by distance squared] to accomplish this.

At the receive end, you can look at it this way;  For a given [fixed] ERP at the transmit end, let’s say for example, 100 Watts; The strength of the signal at the receive antenna would be ¼ of that at  2 miles distant [25 watts] , 1/9th  of that at 3 miles [11.1 watts], 1/16th [6.25 watts]  at 4 miles, 1/25th at 5 miles [4 watts], 1/100th at 10 miles [1 watt], 1/1000th at 31.625 miles [100 milliwatts]… ad infinitum…

And that doesn’t take into account, atmospheric and reflective/refractive absorption,  and other losses, such as coax cable losses… this is just in AIR!

So with this in mind, three things come to light.

• The difference between a transceiver with 100 watts output isn’t going to increase the signal strength much more than a 200 watt transceiver and not really that much more for 1000 watts, when you have to consider dollars spent to get the power increase through amplification. Ok 1000 watts and 100 watts will yield a S-unit increase of maybe 10 units… or 10 db over S9… but at what point over S3 [or the noise floor] could you understand the conversation?
• Antenna gain, even just 3db is enough to almost double the signal strength – at both ends. So you’d be better off spending the money on better gain antennas, than power amplifiers.  Consider antennas with 3, 6, 10, or 20dbd with a 100 watt transceiver.  What is your ERP at each of those decibel gain figures?
• It’s absolutely amazing that taking into account this Law, we can hear, under ideal conditions, a 5 watt HF signal half way around the world!