KENWOD TM-D710G

Kenwood announced the latest VHF/UHF mobile radio with APRS and Echolink functionality.
Well, it's a little embarrassing because the Echolink is not the latest trick in connecting remote repeaters or radios (altough the simp[liest one) and a GPS inside the front panel is not a very complicated matter.
As a fact, I done my own RC-D710G (bragging!) a few years ago and it works nice!
Maybe I lost a patent, who knows?

ICOM IC-7000 and CODAN 9350 auto-tune antenna

After a looooong search, I bought a CODAN 9350 radio with 9360 antenna. After playing a lot with the radio I concluded that is not the best option for a mobile HF setup so I put a ICOM IC-7000 with a LDG Z100 Plus ATU onto my car.
Maybe the ICOM is not better than CODAN in term of reliability or sound but in a Ham's world, the VFO is essential stuff.
So, I was wondering if i can put the CODAN 9350 to work with the ICOM after I read a lot of positive stuff about the Codan antenna.
As you maybe know, the antenna has a control socket with a dedicated connector (military grade) on the antenna side. The original cable that came tih the Codan setup has had a DB15 male connector to the radio side.
ICOM has a dedicated connector for a external ATU - ICOM AH4; on the same connector we have the power supply from the radio and command signals.
A little research on the internet gave me VK1OD's website where he shows a dedicated Protocol converter. As the 9360 has a very nice feature of a RF Preamplifier, very useful for scanning, it's higly recommended but the know how is a little costly and I am not sure that I really need that preamplifier.
To keep it short, I found that a direct connection between the ICOM and CODAN 9360 it is possible!

For the cable I used the LDG "Y" accessory cable which have a nice ICOM connector. Of course, I cut it to connect the wires to a DB 15 female.

The AMPHENOL connector on the CODAN Radio side:

Here is the cable diagram:

ICOM CONNECTOR        DB15              AMPHENOL

           KEY                         11                              D
           START                      4                               C
           + 13,8 V              12 AND 13                    A
           GND                   14 AND 15                     B

After testing, looked to me that the setup is OK and working. Unfortunately, I do not have (yet) the adequate bullbar for that antenna.

yo3hjv 

 

PS

Some other interesting resource:

https://github.com/darksidelemm/IC-9350/tree/master/Icom9350

https://github.com/TheSkorm/IC-9350

 

 

ARHAB Special design antenna

A couple of years ago I was asked by Florin Mingireanu and Catalin Beledea to assemble a team for Stratospherium I experiment.
The goal was to have the balloon tracked via APRS both on air and ground after landing.
We had to use a Byonics tracker, the 10W version but we was limited somehow by the battery due to the limit in weight for the payload.
Instead of maximizing the transmitted power and using the maximum power, I was thinking to use less power but with a better antenna. After all, this is how we are doing on QSO's, no?

Ground Plane antenna diagram

Using a ground plane antenna which have the main lobes above the ground plate or counterpoises was out of question. Other disadvantage was the big null below the radiator. If the antenna was put downside, the second null (the one continuing the radiator) was to be exactly where the tracking team was, so it was the time to design something new.
I approach the new design having in mind that the receiver has to be below the payload so, the diagram has to be relevant in this.

I used MMANA-GAL for simulations and, after various (crazy) designs, the turnstile antenna capture my attention.

Classic Turnstile antenna

But the "classic" turnstile was, somehow, too heavy for our balloon so it has to be simplified.
Well, with not too much expectations, I put into MMANA a simple 2 x 2 dipole to see if my intuition will show something interesting. The ideea was to put two dipoles in paralell to lower the impedance close to 50 Ohm.

The simulation result was encouraging so I trimmed further more the design and made a few PCB to verify the theory. Of course, there was a lot of coat hangers but, fortunately, my wife is very understanding!
I measured the SWR with a Anritsu Sitemaster 331 and the results was well under 1:1.2!
The final result is below; the drawings are hand made but I hope that are clear to everyone who want to made this antenna.
In "real life", the antenna performed very well, radiating a lot below the balloon and very little at low negative angles. Therefore, distant reception was not so good but under the "belly" it was plenty of RF. We used only 3W from the tracker and all was OK.
The same antenna (not only the same design but the same PCB and wires) was used in Stratospherium II and Eclipser I in Australia in 2012.
We observed two more "features": the antena performed well when the payload was on the ground (we received the signals from the payload at about 4 km) and the antenna helped the payload to remain stable, countering the drag force from the wind on the parachute after landing.
As for the name of this antenna, I don't know! Leave a short comment if you have some ideeas. Or questions.
73 de YO3HJV, Adrian

The wires

The PCB

Assembly

MMANA-GAL simulation

SWR results with ANRITSU SITEMASTER 331

Before launching Stratospherium I

Before launching Stratospherium II

Thinkpad Batteries. Myths and realities.

Searching for some specific problems related to Power Management - a bit of software from Lenovo, i was run into a lot of discussions about how bad batteries are...
Well, might be some true when we look at the "compatible" batteries market but also the user might be responsible for the bad performance.
Understanding the batteries is simple when one know the minimal set of rules.
It is not unusual that a "compatible" battery to perform oustanding, just like a branded one or some branded batteries to show "sudden death symptome.
There is no such a "timed bombe" circuit to force one to buy another battery!
I heard some guys trying to explain that inside the battery circuit is a controller which monitor the total number of the charge-discharge cycles and after a certain number the chip decide to kill the battery. Might be some truth around but, what is a "cycle"? When a charge-discharge count as a "cycle"? You see, it's not so simple!

The battery pack is more than some cells in series, parallel or mixed circuits.
Usually, there is a chip inside who monitors the voltage and the capacity of each cell pack (on extended packs, there are two cells in parallel) to decide if the pack is OK or not and also to measure the input and output capacity (gauge meter).
 That circuit need a reset from time to time to reestablish the relation between the voltage and the overall capacity. This is the "battery reset" or "gauge reset" procedure presented on some specific software.
A little paranthesis here: often I see that the preloaded software from the PC producer is considered "bloatware" and the user relies on the Windows's driver. Or the Linux's, if you like...
It's a major mistake as the producer of the hardware provided pieces of circuits to interact with that software in order to have a correct exploitation of the battery pack.
The battery pack also communicate with the computer at a very low level, BIOS controlled laguage, via a serial interface, usually I2C. The charger circuit inside the computer listen for specific information from the battery pack ad take decisions like charging, not charging or reject the battery due to some failure. Also the version of the software may have some bugs which determines erratic behavior.
It might be usefull to know that a Li chemistry battery does not like the 100% charging and a 95% limit can and will prolonge the battery life more over the "500 cycle" life! Not too many knows that iPads usually use around 90% from the overall capacity of the battery and this is one reason for the life of that devices. The other is Quality controll.
There might be a risk of  failure but: Use an up-to-date BIOS FW, use adequate and up-to-date drivers and software for Power management and set the limit of the charging at 90 - 95 % and you will have a happy battery! Another thing, Li chemistry does not like high temperatures so try to cool down the laptop by maintenance of the main fan. I have a T43 with a 2009 battery, a X61tablet with a 2011 battery and a X61 with a 2012 battery. All are extended, all are "compatible" not originals and all are over 85% of their factory capacity, except the T43 which is at about 74%. Well, as a matter of fact, the T43 was finally destroyed after more than 7 years of impecable service by my daughter and 1 L of water...

I'l post here some pictures from the T43's battery pack, made in 2009 and used till a few days ago, with more than 70% of nominal capacity.

You can see that there are 9 LiIon cells, 3 sets of three in parallel. This means 3 x 3,5V =  10.5 V nominal.
When full charge, the voltage is 3 x 4.2V = 12.6V and, by the same rationale, the discharge voltage is 9 V (3 V cutoff voltage per cell).


Also, inside the battery is a small PCB on which wee see the FET transistors and a small ATMEGA Microcontroller Unit (ATMEL MEGA406).

According to the datasheet:

 ATmega406 smart battery solution, the first single-chip implementation on the market. In a single die, the ATmega406 includes a powerful AVR MCU, a voltage regulator capable of being powered directly from the battery pack, analog to digital converters custom tailored for battery monitoring, high voltage charge and discharge FET drivers, cell balancing capabilities, and independent battery protection circuitry. This true one-chip solution saves design cost and PCB space in addition to broadening the functionality of the smart battery application. With the accuracy of the ATmega406, battery vendors will be able to predict the charge status of the battery more accurately. The better the knowledge of the battery cell, the more it can be allowed to be depleted before reaching the level where the cell itself starts to be damaged. This effectively increases actual battery capacity.

 Short said, it's a whole battery management system inside the battery pack!
Also there are rumors that the battery itself has the "knowledge" of the manufaturing date (indeed, this informations are programmed inside the MCU non-volatile memory) and also "know" when to kill the battery (usually, after the warranty expires) which, of course, it's false because, at least, ATmega 406, doesn't have a RTCC (Realt Time Calendar Calculator).

But stay! In the datasheet it says that:

The ATmega406 is fully in-field upgradeable through the Two Wire Interface (I2C compatible), making it possible to update it s software from the PC in which the battery pack is installed. The on-chip debug system has full access to all features on the chip, making it easy to do software development. 

You catch it? The battery firmware can be upgraded via the PC on which is connected! This may explain why the "bloatware" can do the job and the generic drivers cannot! Think about!


 Regards from Adrian, yo3hjv

Experience put to work

The time has come to change the hobby for a more professional way of doing things. Therefore, among with my buddy, Edi, YO3HCV, we started a little enterprise for professional projects dedicated for targeted high-end clients.
SynergyBYTE is the concept that describe our team.
It's an open team but don't call us, we will ask you to join us.