Repair of an IC-208H head unit

Icom to the rescue...

It happened in a moment of inattention… I dropped my mic and the hanger caught the screen of the head unit of my Icom IC-208H. The crack was obvious but I thought I could make it less so. I applied some super glue, hoping it would seep in so that I could then polish it out. It didn't.

I found the service manual on-line and discovered that the repair would be relatively easy. But this transceiver is 16 years old, and unlikely a replacement part would be available. I’m a big Icom fan. My first transceiver was an Icom and I’ve owned several since with great success. I once had to send a Yaesu for repair. The nearest service facility was in California and it took just under a year before I got it back. We’re fortunate that Icom Canada has a service depot locally. Staff has always been very accommodating… like when I lost a knob from a handheld. I received a replacement within a day.

I called the depot  expecting to be disappointed. Surprise! The part was in stock, immediately available, and only a couple of dollars.

I remain an Icom fan. The gear works well, is well constructed, and is well-supported - even after years of use.

~ John VE7TI

 

GMRS in Canada

There are major differences from US regulations 

Following up on a recent blog post by Bob Witte K0NR [https://www.k0nr.com/wordpress/] with the Canadian perspective.

There are big differences in GMRS rules between the US and Canada. If you understand the rules, you’ll  understand what you need to look for when purchasing GMRS radios, and you’ll understand what channels to use to get better range. And you’ll understand why you could get in trouble for using some US radios that are not approved for use in Canada – and vice versa.

Radios must be approved in the country of usage

Every GMRS radio has to be approved by the authorities of the country where you will be using the radio –  Industry Canada (IC) and the FCC in the US. There are also rules for usage. If the radio does not have an IC number, it’s not approved for use in Canada. If the radio does not have an FCC number, it’s not approved for use in the US.

Industry Canada has a lot of information here.

GMRS – FRS with more channels, and *maybe* more power

GMRS is an evolution of FRS that is compatible with older FRS radios on the FRS channels.  But there are significant differences between Canada and US regulations.

Licensing, power limits, antennas and repeaters

In Canada, GMRS users do not require a  license. In the US, radios above 0.5 watt require a GMRS license. In Canada, you’re limited to 2 watts power on the GMRS and combined GMRS/FRS channels, and 0.5 watts on the GMRS channels. In the US, if you have a license, you can go to 5 watts on the GMRS/FRS and GMRS channels.

Repeaters. There is no provision for legal usage of GMRS repeaters in Canada. In the US, licensed users can us GMRS repeaters and GRMS radios with repeater capability.

Antenna. In Canada, the antenna must be fixed on the radio. It cannot be removed, and it is illegal to replace or modify it. In the US, licensed users can change the antenna.

What’s the range of my radio? How is it affected by power?

Most of the radios you buy in big box stores in Canada and the US are designed to be legal for unlicensed usage in both US and Canada – which means you will be limited to 0.5 watts, a quarter of the power you’re allowed to use in Canada. The ranges they advertise are generally ridiculous, varying from 20 km to 80 km (50 miles).

Finding the power rating for the radio is not always simple. Most manufacturers don’t tell you. We’ve checked the packaging, manuals and web sites for the two biggest manufacturers, and it was either not there or very difficult to find. We’ve never seen a radio rated for the full 2 watt maximum. The closest we’ve seen is 1.92 watts, advertised with a 80 km/50 mile range. We’ve seen 1.6 watt advertised with a 50 km range. So everything is approximate.

Another hint is the batteries. A 0.5 watt radio might have a battery compartment for 3 x AAA batteries. A radio with 1 watt, 1.5 watt or just under 2 watts might have 3 or 4 AA batteries to handle the extra load.

- John VE7TI

 

Just what is bentonite?

 and why do I need it?

The ‘OTC Report’ (in the September-October Communicator at https://bit.ly/SARC21SepOct) mentions bentonite as an aid to achieve better RF grounding… but what exactly is this stuff?

In geology, the term bentonite is applied to a type of claystone composed mostly of montmorillonite. It forms by devitrification of volcanic ash or tuff, typically in a marine environment. This results in a very soft, porous rock that may contain residual crystals of more resistant minerals, and which feels soapy or greasy to the touch. However, in commerce, the term bentonite is used more generally to refer to any swelling clay composed mostly of smectite clay minerals.

Sodium bentonite expands when wet, absorbing as much as several times its dry mass in water. Because of its excellent colloidal properties, it is often used in drilling mud for oil and gas wells and boreholes for geotechnical and environmental investigations. The property of swelling also makes sodium bentonite useful as a sealant, since it provides a self-sealing, low permeability barrier. It is used to line the base of landfills, for example. bentonite is part of the backfill material used for waste isolation. Various surface modifications to sodium bentonite improve sealing performance in geo-environmental applications, for example, the addition of polymers.

Here in BC, bentonite was installed in slurry walls in North Vancouver, Quesnel and Williams Lake to stop the migration of railway diesel contamination to adjoining properties.  It was also used it to seal up abandoned environmental monitoring wells, and is  used as pond liner to stop the water from seeping away.

Sodium bentonite can be combined with sulfur as fertilizer prills. These permit slow oxidation of the sulfur to sulfate, an important plant nutrient, and maintain sulfate levels in rainfall-leached soil longer than either pure powdered sulfur or gypsum. Sulfur/bentonite pads with added organic fertilizers have been used for organic farming.

The main uses of bentonite are in drilling mud and as a binder, purifier, absorbent, and carrier for fertilizers or pesticides. As of around 1990, almost half of the US production of bentonite was used as drilling mud. Minor uses include filler, sealant, and catalyst in petroleum refining. Calcium bentonite is sometimes marketed as fuller's earth, whose uses overlap with those of other forms of bentonite.

Bentonite is used in a variety of pet care items such as cat litter to absorb pet waste. It is also used to absorb oils and grease.

What you should know when using ground enhancement material

Under almost all soil conditions, the use of a ground enhancement material will improve grounding effectiveness. Some are permanent and require no maintenance. You can use them in areas of poor conductivity, such as rocky ground, mountaintops and sandy soil, where you can't drive ground rods or where limited space makes adequate grounding difficult with conventional methods.

Bentonite is used to lower the resistance to earth by providing ground enhancement effectively reducing the resistance between the soil and earth electrode (such as copper earth rod or earth mats) by retaining moisture. This inherent ability to absorb and retain rainwater increases the electrical conductivity of the earthing compound in positive correlation to local climatic conditions, specifically average rainfall levels. Typically, the compound has a 3 ohms.m resistivity level – Bentonite compound is a cost-efficient material for backfill of earth electrodes and improving performance when it is physically impossible to drive the earth rods deeper and where challenging ground conditions exist such as rock, granite, etc.

Chemical treatment or backfilling of the soil in close proximity to the location of an underground earthing electrode is an established and traditional method of lowering ground resistance for substation earthing on high resistivity ground – such soil backfilling for electrical grounding improvements is commonly used.

There are several kinds of ground enhancement material available. But use care when choosing the material. It should be compatible with the ground rod, conductor, and connection material. Some options include bentonite clay, coke powder, and specially engineered substances.

Conduction in bentonite clay only takes place via the movement of ions. Ionic conduction can only occur in a solution, which means the bentonite clay must be moist to provide the required resistance levels. When bentonite clay loses moisture, its resistivity increases and volume decreases. This shrinkage results in a discontinuity in the contact between the bentonite clay and surrounding soil, which further increases system resistance.

A noncorrosive low-resistance enhancement substance is a conductive cement that you can install wet or dry. Depending on the substance, it will not leach into the soil and meets EPA requirements for landfill. The railroad and utility industries have successfully used this material. When installed dry, it absorbs moisture from surrounding soil and hardens, retaining moisture within its structure. When used dry, no mixing is required, and you achieve maximum efficiency in a matter of days. This is because it absorbs enough water from the surrounding soil. You can also premix it with water to a heavy slurry. You can add this to the trench containing the grounding conductor or use it around a ground rod in an augered hole. The material binds the water into a cement making a permanent, highly conductive mass.

Some products offer a test-proven resistivity of 0.12 ohm-m or lower, compared with 2.5 ohm-m for bentonite clay. Unlike bentonite clay, the cement-like material does not depend on the continuous presence of water; nor does it require periodic charging treatments or replacement.

An ideal ground enhancement material should not require maintenance. When designing or installing a buried grounding system, look for materials that do not dissolve or decompose over time, require periodic charging treatments or replacements, or depend on the continuous presence of water to maintain conductivity.

~ Internet sources including:

https://www.powerandcables.com/product/earth-tapes-rods-bars-copper/bentonite/ and https://youtu.be/hHtIYboE8NE

 

All about tones

 Back To Basics

Tones… we all know what they are in non-radio terms, but they pose questioning glances from many Basic course students. When we explain tones during the course. Referring to our hobby, tones may be:

• PL, CTCSS or sub-audible tones;
• A report of CW signal quality; or
• A tone used by repeaters to mark the end of a transmission.

PL, CTCSS and sub-audible tones

Let’s look at a typical question:

B-2-1-5 What is a CTCSS tone?

A. A special signal used for radio control of model craft

B. A sub-audible tone that activates a receiver audio output when present

C. A tone used by repeaters to mark the end of a transmission

D. A special signal used for telemetry between amateur space stations and Earth stations

In telecommunications, Continuous Tone-Coded Squelch System or CTCSS is one type of in-band signaling that is used to reduce the annoyance of listening to other users on a shared two-way radio communications channel.  It is sometimes referred to as tone squelch. It does this by adding a low frequency audio tone to the voice. Where more than one group of users is on the same radio frequency. CTCSS circuitry mutes those users who are using a different CTCSS tone or no CTCSS.

All users with different CTCSS tones on the same channel are still transmitting on the identical radio frequency, and their transmissions interfere with each other; however; the interference is masked under most (but not all) conditions. The CTCSS feature also does not offer any security.

A receiver with just a carrier or noise squelch does not suppress any sufficiently strong signal; in CTCSS mode it unmutes only when the signal also carries the correct sub-audible audio tone. The tones are not actually below the range of human hearing, but are poorly reproduced by most communications-grade speakers and in any event are usually filtered out before being sent to the speaker or headphone.

A receiver equipped with a CTCSS decoder will not reproduce a signal unless it carries a given sub-audible tone in the background, for example a continuous 100 Hz tone.  To work with such receivers, a transmitter must be equipped with a CTCSS encoder  Standard tones are in the range of 67 to 254 Hz, below the normal speech frequencies of 300 to 3000 Hz. 

One example of the purpose for repeater tones is here in the Greater Vancouver area of SW Canada. We operate VE7RSC in Surrey on a repeater frequency of 147.36 MHz. About 65 miles south, on Camano Island in Washington State, W7PIG operates on the same repeater frequency pair. Without tones, under ideal propagation, we hear their repeater and they hear ours, in most instances it is poor copy and distorted, so it is classed as interference. By using a different tone on each repeater, only stations on our frequency with our sub-audible tone programmed open up our repeater. The repeater will not respond if no tone, or the incorrect tone is detected. The same situation occurs on Camano Island and that repeater uses a different tone as its ‘key’.

Bear in mind that if both repeaters are in use there is still activity on one frequency by both users. Therefore the disadvantage of using CTCSS in shared frequencies is that users cannot hear transmissions from other groups. They may erroneously assume that the frequency is idle and then transmit at the same time as another user, thus interfering with the other group's transmissions. In our example, the distance is sufficient that there is little objectionable co-use and it is much more tolerable than not using tones.

Tones are not only used on repeaters. Many newer transceivers allow the user to program in a sub-audible tone when you wish to only hear simplex transmissions from other users in your group. Such use may be during an event or an outdoors recreational activity.

CTCSS is an analog system. A later Digital-Coded Squelch (DCS) system was developed by Motorola under the trademarked name Digital Private Line (PL).

Many radios also have a feature typically labelled ‘Tone Squelch’. That is similar to a repeater CTCSS tone but you can program it into your transceiver receive. When enabled, and the transmitting radio sends that sub-audible tone with the audio, your receive is unmuted only when that tone is received with an incoming signal. This feature may be handy if you are with a group of Amateurs and only wish to hear the conversation when one of the group is transmitting.

Therefore, the correct answer to the question in B-2-1-5 What is a CTCSS tone? is

B. A sub-audible tone that activates a receiver audio output when present

Next…

DTMF Tones

Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones supplied to telephone customers, starting in 1963. DTMF is standardized as ITU-T Recommendation Q.23.

In Amateur Radio, DTMF is enabled with a keypad on the transceiver or microphone. DTMF uses a mixture of two pure tone (pure sine wave) sounds, a set of eight audio frequencies transmitted in pairs to represent 16 signals, represented by the ten digits, the letters A to D, and the symbols # and *. As the signals are audible tones in the voice frequency range, they can be transmitted and heard through repeaters and amplifiers, and over radio and microwave links.

DTMF is commonly used to turn on a link via radio, such as may be needed to contact a station on IRLP or EchoLink. It was also heavily used before cellular phones became common, as hams could dial telephone calls via their radio using a ‘phone patch’ on a repeater. Some repeaters and clubs still offer this service.

Tones and signal reports

B-2-6-2 What does "RST" mean in a signal report?

A. Readability, signal speed, tempo

B. Readability, signal strength, tone

C. Recovery, signal strength, tempo

D. Recovery, signal speed, tone

"RST", A short way to describe signal reception (Readability: 1 to 5, Signal Strength: 1 to 9, Tone Quality (for Morse): 1 to 9).  For example, "11" unreadable, barely perceptible. "33" difficult to read, weak signal. "45" readable, fairly good. "57" perfectly readable, moderately strong.

The ‘T’ in RST is only used for CW (Morse code) reports and is a, indication by the receiver of the quality of the received tone.

Therefore, the correct answer to the question in B-2-6-2 What does "RST" mean in a signal report? is:

B. Readability, signal strength, tone

And finally…

Repeater courtesy tone

There are no questions in the Canadian Basic Amateur Radio exam question bank about courtesy tones nut the term is listed as an incorrect answer. Regardless, you should be aware of its meaning.

Most repeaters have a courtesy tone just before the transmitter stops transmitting. This is typically a ‘bee-boop’ sound.

The ones that do not will have a squelch tail that will transmit for a second or so after the input carrier or tone drops.

After the courtesy tone or carrier drops, if there is no courtesy tone, you should wait a second or two before keying up the mic. This provides space for others to break in if needed.

The courtesy tone is merely an audible indication that the repeater has finished transmitting and another station may start.

Kerchunking

While we’re on the subject, let’s also mention ‘kerchunking.

This is  one of the most annoying things for a repeater operator and people that listen to the repeater a lot.

Just in case you do not what Kerchunking is… Kerchunking is when you press the PTT and then let off without any speaking.

Some people will kerchunk the repeater but never talk. If you kerchunk the repeater to get it to wake up and ID before starting a new net or QSO that is fine because you follow up the kerchunk with your callsign and start a net or QSO.

Some people think that kerchunking the repeater is a way to test your radio but it really is not a valid test, as you have passed no audio.

In Canada, the rules state that you must ID at the beginning and end of a conversation and at least every 30 minutes (10 minutes in the United States) if your conversation lasts that long. Just a Kerchunk (or many) does not meet the regulations

Bottom line, do not kerchunk the repeater and not ID.

The ‘Alligator’

“The alligator bit you” is a term you may hear when on the air.

This is a slang term for the timer function of a repeater controller that limits the length of time the transmitter will remain keyed without a pause.   Typically the timer is set between 3 and 5 minutes. 

It is a protection device to prevent the repeater from overheating when transmitting. Aside from so-called “Long-winded operators”, I have seen instances where repeater users have accidentally sat on their mics and transmitted for some time without realizing it (when you are transmitting you do not hear other users or the repeater because your receiver is muted). If the time-out timer did not exists the repeater power amplifier would overheat causing an expensive repair.

Such times are not unique to repeaters. There is a very good chance that the transceiver you own also has protective circuitry to limit transmitting time.

~ John VE7TI

'Back To Basics' is a regular column in our newsletter, available at https://ve7sar.blogspot.ca

 

The Annual SARC Fox Hunt

 Despite COVID, another successful event

Saturday, August was the date for this year’s annual SARC ‘Fox’ Hunt. As usual the venue was in South Surrey’s Crescent Park, a large venue with both forested trails and fields suitable for a picnic. The weather cooperated wonderfully providing mild temperatures and blue skies after a couple of days of much needed rain.

The briefing started at 9am, once five 80m foxes had been hidden throughout the park. A beacon had been activated allowing the competitors, many of them first timers, to practice their ARDF skills.

At 10am the foxes automatically activated as programmed and the hunt was on.

This year there were approximately 25 hunters with a welcome complement of ‘Junior’ hunters joining the Novice and Advanced groups, and yes, the receivers are easy enough to use even for a 5-year old.

The first finisher returned after an amazing 22 minutes, impressive given the amount of territory that had to be covered.

What followed was a barbecue expertly prepared by Brenda James with assistance of Heather Brodie and Anitha and Anil Cherian… Thank you.

We also thank fox placers Jeremy VE7TMY, Jan VA7VJ and Thomas VE7TXL. Special thanks to Chief planner Anton VE7SSD, who once again provided a smooth running and fun family event.

~ John VE7TI

A video of a SARC Fox Hunt: https://youtu.be/DMEKWOyaAnc

 

RAC Canadian Award to SARC member

 

Thank You Fred !

The Canadian Amateur Radio Hall of Fame (CARHOF) is administered by an independent Board of Trustees, one per province, appointed by the Directors of Radio Amateurs of Canada.

Fred Orsetti, VE7IO, has served on the Hall of Fame Board of Trustees for 12 years as the representative from British Columbia and has recently decided to step down from this position.

The Board sincerely thanks Fred for his dedicated service and contribution to the Hall of Fame and Amateur Radio in Canada.

Fred was recently presented with a RAC Certificate of Appreciation signed by President Glenn McDonnell, VE3XRA.

Due to the rigid COVID public health restrictions in place the professionally printed Certificate had to be sent by mail to Fred but we look forward to being able to do in-person presentations once again.

The Board of Trustees wishes Fred continued success in his many endeavours.

~ RAC

 

Canadian Basic Amateur Radio Course

 

We are about to start our September course

On-line, learn from your armchair at home

More information needed? Click: https://bit.ly/SARCcourses
or use the QR code above