Radio Direction Finding – 1992 IRMA CSTI-1000

I worked for a local start up back in 1992 as Chief Engineer – Hardware and this is what we came up with. It started with some patents and technology transfer with the Department of Communication (Federal Government).

All radios were from the local ham supplier and a Single Board Computer (check out the specs for a good laugh) from a supplier in the back of Circuit Cellar Magazine.

Everything was pretty much COTS except for the controller board. It worked well and we had the initial Proof of Concept in Mexico. We placed these on 3 hilltops and had some great success with radio direction finding.

We also used the Traffic Study or Channel Occupancy tool which helped provide insights in signal occupancy.

Now, I am “full circle” and engaged once again in a project but its now SDR, MP3, WiLAN and message bus technology.

I spent a whole day doing up the photography for the brochure which to this day I still recall how many packs of Polaroids I went through. I also used the Instant 35mm film for proofing. Today, I could just use my Smartphone.

A typical use case would be where the radio inspector would have interference complaints. He could get the location, an audio recording with freq, time and date stamp and even activate the radio and inform the interfering station over the air that he is under investigation.

Another popular example was to track channel usage and apply that to the current spectrum management policies.

As old school as it is the IRMA would actually still work today as an effective tool.

The receiver was the Icom 7000 and yes the modem was 2400 baud.  The Discone was the AH-7000 as a switched alternate.



Yaesu FT-991 Updates

I just went through an hour of updating the firmware using 4 different software tools and also ensuring the .NET 3.5 is also installed.

YOU MUST FOLLOW the procedure very carefully to avoid bricking your radio. Read the instructions several times and print it out and highlight any steps.

It is a very straightforward procedure provided you have everything ready in front of you.

I chose to set it all up on the kitchen table and follow through from there.

I started with the following values:

Main VO2-08

DSP VO1-05

TFT VO2-01

CFM VO2-10

The latest update provides new values:

Main VO2-21

DSP VO1-11

TFT VO2-04

CFM VO2-15

This link provides the latest update information for your radio

Click to access K9EQ-Fusion-PDF-0001.0.0_Fusion_Firmware_Update.pdf


Short Verticals -Comments from the Field

Short verticals are typically antennas under 8 feet. The Super Antenna MP-1, Buddistick,  PAC-12, Hamsticks, Hustler, Wolf River, MFJ whips, Wilson 5000, Chameleon Antennas MilWhip and the Outback all are examples of what I own or have used. There are various military versions as well.

Read the ARRL Antenna handbook for insights into where to place the loading coil.


1. They need to be “loaded” in order to be resonant usually with a coil.

2. Radiation pattern is the same as a qurter wave vertical

3. Resistance is around 36 ohms and is well beliw the standard of 50 ohms so swr is a factor.

4. The XC reactance values shows inductance and capacitance that needs to be cancelled out.

5. Base loading is the simplest configuration

6. Short verticals are inneficient and offer lower bandwidth that the reference vertical antenna.

7. Design goal is to have a high as possible radiation resistance and keeping loading coil losses as low as possible. This is usually done with coils that have a diameter of 2.5 inches or greater. See Buddipole coils.

8. Top Loading with capacity hats require a lower inductance coil to be used and improves the radiation resistance figures.

I have done a couple of skunk tests proving this out and will test further using various capacitance hats I have built. There is definately sone value here. I will use the Chameleon Milwhip for controlled tests as it allows an easy way to test.

There appears to be value in a base loaded short vertical with a top hat

9. If radiation is a factor and must be kept as high as possible then these areas need to be lloked at:

– vertical length as long as possible. Use an 8 or 12 foot length instead of 4-6

– use a top loaded capacity hat

– use the best possible ground system. 2 counterpoise wires afe better than 1 and use at least 4. They shoukd be tuned to the operating frequency. (I tried several non-resonant lengths and the swr was never satisfactory)

– Use high Q coils

The original marconi antennas were T shaped and this offers the top loaded capacity hat. If you look up the patents I think they go back to the early 1900s  but the short vertical concept wasnt of interest then

So the short vertical is a very common antenna design and with a bit of due diligence one can have a great antenna in a shorter form factor


ve3ips john

keep an eye out for Hustlers (and Hamsticks ) at the hamfests as they can be gotten cheap and the MO mast is very solid and can be used in experimental designs as its just 4 feet long. You can then base load, center load, or top load them.

invest in an antenna analyzer as it will make life easy

I bought the wolf river kit at dayton and they suggest using a 102 inch cb whip in a base loaded configuration for an antenna length of over 8 feet and it does work better than a Hamstick but my Chameleon works better at 12 feet. The experimentation continues hihi


Magnetic Loops – Comments from the Field

I have been active lately with field ops and collecting my observations on these great antennas

I have various loops for reception for vlf , mw and the 160m/80m bands

My first magnetic loop for transmitting was the AlexLoop which was a great antenna

I decided to build my own and I went with the Chameleon Antenna as I wanted several mounting options specific to my needs

They offer various versions and like all their stuff its milspec grade. Avoid all copy cat versions and just buy Carls’s stuff and you will not be disapointed and he offers the best customer service anywhere

So why these mag loops?

– small and lightweight

– ideal for field ops

– multiband in a small footprint

– rapid deployment


1. Very narrow bandwidth. You must use a gear reduction in order to tune it and you still need to go slow. The BW can be as narrow as a few KHz.

2. High degree of front end selectivity which can help with reducing interference and noise

3. Noise reduction due to the loop responding to the magnetic components of the signal only it can be beneficial on 80m (urban areas are full of plasma tv noise). The noise component of a signal is predominantly near-field and not magnetic.

4. Quieter than dipoles or monopoles which can help make signals more readable (withouthe noise) especially on cw. For receive only use in a hybrid antenna configuration a 15-20db preamp will be useful.

5. Ability to null out noise by rotating the antenna. This antenna has directivity properties.

6. Mounting this antenna on a tripod with vertical polarization seems to not be affected by height above ground effects. This is because the magnetic field lines run parallel to the ground. I didnt notice any differences at 3, 8, 12 and 16 feet.

It worked well on 40m during a NVIS sprint so the radiation angle is higher than 45 degrees I believe.

Hence the use of mag loops for military NVIS communications.

7. Horizontal mounting now has the magnetic field lines that are affected by the ground. Looking at the radiation angles with the antenna tools the radiation pattern starts to resemble a vertical. Height above ground is a factor.

I confirmed the radiation patterns using a field strength meter in both polarizations and with WSPR data

8. High voltage and currents are present and rf burns are possible.

I will test using an rf current probe at one point to confirm

9. These loops are inefficient so expect less than 5% on 80m. 20m offers around 68% efficiency.

10. Easy to make. Once you have the capacitor and gear drive sorted out (hint Chameleon Antennas kit is available) the build is straightforward.

I tried a double loop version to improve the 80m performance with a jungle rat build (think bamboo and paracord) and a non-geared Johnson variable capacitor and it was frustrating to get it to resonance as hand capacity affects will vary the sweet spot. This needs to be boxed up.

So the AlexLoop is a great mag loop antenna that is highly portable and very well made.

The Chameleons are the most rugged and offer various designs based on coax or aluminum tubing elements.

MFJ has several mag loops and I do have the wire based non-mag loop – 9232 model for qrp that seems to work ok but I will field test shortly. I have heard good things about the 935 series and the rf current meter makes adjustment easy. My short time playing with the MFJ years ago seemed promising but I got distracted by the cu,t of Buddipole. There are several models and offer the ability to use 100watts but these are wire based and not magnetic based.

I confess I personally met Alex several times and have been a happy Chameleon customer for over ten years. I have the original MFJ kit from the 70s and have never met Martin.


I highly recommend a magnetic loop for field ops and in use where having a proper dipole or vertical can be challenging. It is not a DX antenna by any means but you will make contacts with some skill and patience because remember we are at low power levels under 10 watts.

If you want to run 100 watts then MFJ has many options.

good luck and cu on 40 cw

ve3ips john


11. Great for apartment/condo cliff dwellers


Field Operations with the Chameleon CHA Hybrid Micro

Antenna works great as I shake out my frame pack at the farm location. I used the stock 60 radiator and a 30 foot counterpoise. I just threw it up a tree turned it on 20m, hit tune button and bingo a contact right away.

The Harris Military Radio is 10 watts on HF and has a built in tuner

Will try it with the stock whip antenna next time out

Let’s Operate and Make Contacts out in the Field

Instead of spending your time at a “breakfast” spreading negativity and hate why not spend your time in a positive manner playing radio.

I have no interest in engaging in such behaviour over a plate of bacon and eggs with other hams. I am so glad i changed the subject to “more important” issues like antennas, morse code keys and portable radios.

Now, as this breakfast meet up spreads into an east and west location then the negativity will continue. I will spend my time operating out in the field instead.

Thank You



Update on Hurricane Irma: SATERN Bulletin

The following news item is an update on Hurricane Irma from the Salvation Army Team Emergency Radio Network (SATERN):

International SATERN Operators
International Amateur Radio Union (IARU) Region 2 Emergency Coordinators


SATERN Newsletter / Bulletins List

Hurricane Irma:

As everyone knows by now, Hurricane Irma is a “potentially catastrophic” hurricane forecasted to make landfall on the Florida Keys and southern tip of Florida sometime late Saturday night or early Sunday (09/10/2017) morning. It is then forecast to move straight up the entire Florida peninsula into Georgia and Tennessee with potentially serious impacts on South and North Carolina and the midwest.

Serious communications interruptions are very likely, especially in Florida.

In addition, Hurricane Irma has already had a devastating impact on several island nations and U.S. Territories in the Caribbean.

International SATERN SSB Net:

The International SATERN SSB Net will remain in Delta II mode through Saturday, 16 September 2017. This includes operations on Sunday 10 September. The hours will remain as they have been all of this week – 0900 (CT) / 1400 Z through 1800 (CT) / 2300 Z each day.

Southern Territory SATERN Net:

The Southern Territory SATERN Net will be activated beginning on Saturday 09 September 2017 through Saturday, 16 September 2017. The Southern Territory Net will begin at the same time the International SATERN Net ends – 1800 (CT) / 2300 Z – and will operate until 2200 (CT) / 0300 Z. It will resume operations at 0700 (CT) / 1200 Z until 1000 (CT) / 1500 Z

In other words, the International SATERN Net will be active during the daytime hours when the 20 meter band is generally open (barring atmospheric disruptions) and the Southern Territory SATERN Net will be open in the late evening and early morning hours when 20 meters is not active yet.

Net Operations Protocols:

All Net Control Operators need to do the following:

1. Ask for, and leave a break for, emergency, priority or health & welfare message traffic between each station’s comments. Collecting this information is the primary duty of the SATERN Net during this emergency.

2. Collect a brief situation report from the stations’ location that includes:
a. Is there any hurricane wind damage? If so, is it minor moderate or severe?
b. Is there any tornado damage? If so, is it minor moderate or severe?
c. Is there any flood or storm surge damage? If so, is it minor moderate or severe?
d. Are there any power outages? If so, how wide-spread?
e. Are there any communications disruptions? If so, what kind and how wide-spread?

Neither the SATERN Net nor will be accepting INBOUND Health & Welfare Inquiries (Health & Welfare Messages inquiring about the health and welfare of people inside an impacted area). INBOUND Health & Welfare Inquiries should be referred to the American Red Cross Safe and Well program at:

SATERN is only accepting OUTBOUND emergency, priority or health & welfare messages that are coming OUT OF the disaster impact area.


Any who wishes to volunteer as a Net Control or Assistant Net Control Operator for a one hour time slot or has questions about this activation for the International SATERN SSB Net should contact Net Manager Ken Gilliland (AG6SV) and Bob Rogers (WA5EEZ) at

Any who wishes to volunteer as a Net Control or Assistant Net Control Operator for a one-hour time slot or has questions about this activation for the Southern Territory SATERN Net should be forwarded to Net Manager Ken Standard (AD5XJ) at

Both the International SATERN SSB Net and the Southern Territory SATERN Net strongly encourage the participation of bilingual (English & Spanish) Amateur Radio operators on their Nets.

International SATERN Digital Net: There are no current plans to activate this net at this time.

William H Feist
Divisional Disaster Liaison
National SATERN Liaison

Update on September 7, 2017:

Radio Amateurs of Canada is monitoring the progress of the storms in the Caribbean and any necessary Amateur response.

The National Hurricane Center has issued another public advisory with an update on Hurricane Irma:

Stay tuned to this website and to our social media sites for more information: Twitter and Facebook

Here is a list of frequencies:

Puerto Rico: 3.803, 3.808, 7.188 MHz. Radio Amateurs in Puerto Rico also will cooperate with the Hurricane Watch Network on 7.268 and 14.325 MHz.

Cuba: Daylight hours, 7.110 MHz (primary) and 7.120 MHz (secondary); Provincial Net: 7.045, 7.080 MHz, and on other lower frequencies as necessary. Nighttime, 3.740 MHz (primary) and 3.720 MHz (secondary) and on other lower frequencies as necessary.

Dominican Republic: 3.873 MHz (primary), 3.815 MHz (secondary), 7.182 MHz (primary), 7.255 MHz (secondary); 14.330 MHz (primary), 21.360 MHz (primary), 28.330 MHz (primary).
Your usual cooperation is appreciated.


For your listening pleasure this weekend on HF, these are the Caribbean & Florida Hurricane Net Frequencies:
VE3IPS: Traffic is light meaning that Digital radio is not for ARES/RACES/EMCOMM
stick to 2m and FRS ch 1
Caribbean Hurricane & Weather Net   3.8150 LSB  (This is a 24/7 Net operated since after WW2).
7.2680  LSB
14.3250  USB
According to the ARRL, the 5 allocated 60m frequencies will be also used:
5.3320  LSB
5.3480  LSB
5.2585  LSB
5.3730  LSB
5.4050  LSB

Florida D-Star DV Reflectors:

REF034A – Florida Jacksonville  Hurricane Nets

REF034B – Florida Jacksonville  ARES Tactical Nets

REF034C – Florida Jacksonville  NE Florida D-Star Network

REF037A – Florida Orlando  Central Florida Reflector

REF037B – Florida Orlando  Central Florida Reflector

REF037C – Florida Orlando  Central Florida Reflector

REF046A – Florida Orlando

REF046B – Florida Orlando

REF046C – Florida Orlando  ARES Use

REF078A – Florida Vero Beach  Digital Mode Training

REF078B – Florida Vero Beach  WA4AKH/St. Lucia Group  (Caribbean)

REF078C – Florida Vero Beach  General Communications 1

REF078D – Florida Vero Beach  General Communications 2