LDG AT-100PROII max C / max L

LDG does not specify either max C or max L of their antenna tuners in the “pro” series. They specify a vague “it can tune 1000 ohms”. This basically means nothing as no frequency is given and it is not given if they mean R or X or Z by “1000 ohms”. There is also no service manual or schematic available. Very disappointing from a serious (?) supplier.

Well, since LDG doent specify anything, I have measured it.

The LDG AT-100PROII is a series L, shunt C configuration.

Min L is 3uH, max L is 11,8uH
Min C is 85pF, max C is 250 pF
This is measured at 2MHz.

This shows that the capability of tuning an 2x20m doublet via “10-12m” of 590 ohm ladder line on 80m seems to be limited, and that tuning on 160m is very difficult.This is mainly due to limited Lmax. Also the limited Lmax gives limitations on other bands as well. Having the proper length of transmission line is important to overcome this limitations. 

Too low power Modification for ICOM IC-7100

I recently bought a second hand Icom IC-7100 HF radio for a reasonable price. This radio is known for a very conservative approach to internal ALC on the power output. This causes the output power to not go above approx 75-80W (PEP) as measured on my LPA-100 wattmeter in PEP mode with 14,5V DC input. Of course, there is no need to overdrive any linear amplifier, however Icom engineers have probably overdone it a bit on the conservative side on this radio (?).

There are two published mods that are possible on this radio. I did only one of the mods that involves a jumper from C1509 to ground, because the other mod that involves a 10uF capacitor is reported to cause modulation issues on FM and AM.

The PEP output power increased from 75-80W PEP to approx 140-145W PEP (14,5V DC input). Note: PEP, not average. On a sidenote the peak to average ratio also improved. There is no need to have PEP output of more than 100-110W PEP by the way.

The mod is easy:

  • Unplug the radio DC lead and all other leads incl. the antenna connector
  • Use an antistatic mat and handlead
  • Remove the back cover
  • Locate the C1509 and the ground lug
  • Solder a small jumper from the C1509 to the ground lug
  • Check carefully that you didn’t spill any solder residue on the PCB
  • Blow with compressed air to remove any residue
  • Close the radio

IC-7100 mod. (I did steal this picture from radio aficion website)

I did also upgrade the firmware to :

  • CPU 1.11
  • DSP 1.03

The firmware upgrade did have a small but insignificant effect on the PEP output power according to what I found. The hardware mod, did have a signficant impact as the DSP is led to believe that the output power is lower than it is.

Disclaimer:

  • All mods are done on your own risk!
  • You may void the warranty of your radio if carrying out this mod
  • I will not be held responsible for any problems, malfunctions, defects, indirect consequences or any other issues caused by the mod
  • Do at all times follow the license regulations of your country
  • Check that your bandwidth is not excessive
  • Check that your harmonic content is well below maximum allowed

Telenor 4G modem, IP camera, remote radio, remote SDR setup (Norwegian language)

Hvis du vil sette opp et 4G IP kamera, en 4G alarm, eller kjøre amatørradio via 4G remote så må du sette opp 4G ruteren din slik at datatrafikk UTENFRA kan komme inn igjennom 4G ruteren. For å kunne få dette til å virke må du kjenne IP adressen til 4G ruteren din. Ringer du Telenor support får du som regel et “god dag mann økseskaft svar”. Ringer du “telenor eksperten”, så får du ofte et nytt “goddag mann økseskaft svar”, men denne  gangen må du betale for det! Denne quick guiden omhandler Telenor D-link DWR-961 ruter.

Utfordring 1: Telenor har satt opp sine 4G rutere per default slik at du ikke har en egen IP adresse som er synlig på internett. Datatraffikk utenfra blir også stoppet (av sikkerhetsgrunner – som regel har ikke vanlige brukere behov for at traffikk utenfra skal kunne komme igjennom om den ikke er initiert innenfra først).

Løsning:

  • Logg inn på ruteren via kabel i LAN1, LAN2, LAN3 eller LAN4 porten (ikke WAN porten). Du har innloggingsdetaljene fra Telenor (ikke sant?)
  • Gå til “internett fanen”
  • Endre APN(Access Point Name) til internet.public  (med små bokstaver)
  • Restart ruteren
  • Nå har du en IP adresse som både er synlig utenfra og traffikk kan nå inn til ruteren din

Utfordring 2: IP adressen er ikke fast så den endrer seg hele tiden. Du aner ikke hvilken ip adresse 4G modemet ditt og det utstyret som står tilkoplet på innsiden har…. hvordan skal du da kunne aksessere dette?

Løsning:

  • Sett opp en dynamisk DNS
  • Viktig: Kun Dyndns (heter nå dyn.com) fungerer. Ingen av de andre dynamisk DNS tilbyderne fungerer.
  • Viktig: du  må nå betale for dyndns servicen fra dyn.com (ca 500 kr per år). Dette er det ingen vei utenom (som jeg har funnet i alle fall). Dyndns free service er discontinued så nå må du betale for tjenesten.
  • Gå hit https://dyn.com/dns/dyndns-pro-free-trial/ og registrer en gratis konto
  • Velg et passende sub-domenenavn  som f.eks pettersipkamera1.dyndns.org (fyll inn ditt valgte navn). Sub domenet er det som stør før første prikk, selv om det virker litt lite intuitivt at det står før prikken og ikke etter. Domenet er det som står etter prikken, men dette er jo forhåndsbestemt til å være dyndns.org
  • Gå til Advanced og DynDNS i oppsettsmenyene i Telenor 4G ruteren din (via web browser)
  • Fyll inn brukernavn, passord og hostname. Hostname er det du satt opp over når du registrerte kontoen hos dyn.com. For eksempel pettersipkamera1.dyndns.org 
    (selv om dyndns nå heter dyn.com så er dyndns.org fortsatt live and kicking)
  • Husk å klikke på DDNS så dynamisk DNS er skrudd på i ruterens meny
  • Nå vil pettersipkamera1.dyndns.org peke til IP adressen til ruteren din (SELV OM TELENOR SINE SYSTEMER ENDRER IP ADRESSE på 4G RUTERE INNIMELLOM!)
  • Så må du sette opp port forwarding, om du bruker egne porter. Dette gjøres i fanen Advanced / Port Forwarding. Du må vite den interne adressen til IP kameraet ditt. F.eks 192.168.0.123
  • Du må vite hvilken port IP kameraet ditt bruker
  • Så setter du opp hvilken port INN til 4G ruteren som skal forwardes til hvilken IP adresse (f.eks 192.168.0.123) og port inne på det lokale nettverket ditt
  • Lagre og gjør en reboot / omstart av ruteren
  • Og VIPPS, du ser og kan overvåke din eiendom / hytte / whatever på IP kameraet og er i høyeste beredskap til en hver tid! Alarmsystemer, sensorer, styringer osv kan koples til på denne måten.
  • (Om du er radioamatør, så ser du radiosystemet ditt og er klar til å kjøre remote radio).

Håper dette var til hjelp. Ønsker du hjelp til en kommersiell installasjon, IoT eller liknende så kjenner jeg firmaer som kan hjelpe med dette. I så fall ta kontakt så kan jeg formidle info.

FT-891 and TRX-manager CAT control software

I have successfully got FT891 running under TRX-manager: http://www.trx-manager.com/index.html

1) Install the dual serial port driver from Yaesu website. 
See manual here: http://www.yaesu.com/airband/downloadFile.cfm?FileID=9515&FileCatID=42&FileName=USB%5FDriver%5FInstallation%5FManual%5FENG%5F1610%2DB0.pdf&FileContentType=application%2Fpdf

(Note: the 891 has dual serial ports, it does not have an USB soundcard).

2) Reboot the PC and check that you see two serial devices in your Device manager (type device manager when clicking the start button)

3) Hold F on the FT-891 in a couple of seconds (long click)

4) Goto menu 05-06
Set CAT RATE to 38400

6) Goto menu 05-08.
 Set CAT RTS to DISABLE (unless you do that you may have a problem getting data thru)

7) Set the rate to 38400 in TRX-manager (setup menu) and select FT-891. Also select correct COM port (on my PC it was COM5. It may be different on yours).
Remember: unless you set CAT RTS to DISABLE (see above) you will not get data thru and you will mess around in the TRX-manager menus while the problem was a setting in the FT-891 menu.

8) Stop and restart TRX-manager

9) You may hear a clicking sound for every CAT transmission in your FT-891 loudspeaker (A bit annoying… I have to admit that even if I like Yaesu radios)

10) Click F on the FT-891 (short click)

11) Goto MON on the FT-891 menu

12) Click on MON

13) Turn down the MON level to 0
Note: This applies regardless if you have MON ON or MON OFF (this is a bug in Yaesu’s firmware. Rare. LOL)

14) Now you have CAT control without any clicking sounds on your FT-891

15) Enjoy your Yaesu FT-891

Comments about the FT-891: 

Plusses: the FT-891 has in my view a better and more modern RX than the ageing FT-857, even better than IC7300 (some ppl. claim) http://www.eham.net/reviews/detail/13042?page=2 , it is a low cost modern mobile 100W HF rig with a small detachable front, it has DSP RX, a nice variable RX filter, works well down to low voltages even if someone claims it doesn’t, has a much better menu system and a better VFO, it has a reasonable current draw on RX (even if the datasheet overstates this a bit it is below 1A on my rig).

Minuses: No VHF or UHF ( however that may be a benefit. Not the compromises that probably are in the 857 rf chain). No USB soundcard (do you really need that in a mobile station?), 60M USB has to be programmed in a memory and you go memory tune from there and it will keep USB even if you are below 10 MHZ.

How to develop and debug C++ code for Arduino in Visual Studio if you are tired of the Arduino IDE

The Arduino platform has gained a fantastic popularity over the past ten years. For small quick and dirty projects, the .ino files and the standard IDE is OK. However, for professional development projects and for developers that want control over the .hpp and .cpp files the standard Arduino IDE is somewhat regarded like a toy. Furthermore there is no proper debugger in the Arduino IDE  (whaaat?, you gotta be kidding?)

Well, this has changed as Visual Micro has developed a plugin to Microsoft Visual Studio. You can write code the normal way you do it with .cpp and .hpp files. You can also run the GDB debugger. The IDE has support for the regular .INO files and Arduino libraries. Here is how both .cpp and .ino files are handled: http://www.visualmicro.com/page/User-Guide.aspx?doc=INOs-and-CPPs.html

There is a free version of Visual Micro and it works against the free versions of Microsoft Visual Studio 2017 Community Edition. All you need is a Microsoft account to be able to download and install Visual Studio 2017 Community edition. Then in MSVC 2017, go to tools, Extensions and Updates and enter a search for Arduino in the search bar. It will will offer to automatically install the Arduino tools and the GDB debugger. Click install and you are on the right path.

Links:
http://www.visualmicro.com/
https://marketplace.visualstudio.com/items?itemName=VisualMicro.ArduinoIDEforVisualStudio

If you find this tip useful, please share on facebook and share the link. Also, feel free to report your experiences in the comment field.

How to find all Brandmeister DMR repeaters in your country

Sometimes it is good to know what DMR repeaters are available in a certain country. The Brandmeister repeater listing at https://brandmeister.network/?page=repeaters doesn’t seem to have this per country overview easily available (disclaimer -> I may be wrong 🙂 ).
I have found that by knowing your country master code you can search for that in the repeater page of Brandmeister and all repeaters registered in your country will be shown. For example the country code for norway is 241 and the master code is 2421 so if I enter 2421 I will get all the repeaters in Norway.

Show repeaters in your county

Designing L and T antenna tuners for HF on the Smith chart

The Smith chart is a tool used a lot by professional RF engineers for solving transmission line stub matching problems and all sorts of quick calculations.

The Smith chart can also be used for quick back of the envelope L and T antenna tuner engineering calculations.

I have on the picture above plotted a T configuration antenna tuner with the first capacitor set to a so big value that it is shorted as seen by the RF voltage (large C – low |Z|). Then the configuration becomes a L tuner in practice with a shunt L followed by a series C when seen from the load in towards the generator.

I measured the Z in the shack end of the ladder line feeding my doublet antenna to be Z = (24.1 – j35) ohms at 14.200 MHz by a Vector Network analyzer. That can be plotted as a point in the lower part of the Smith chart (capacitive Z).

(1) Since we have now first an inductor (in the tuner to ground) as observed from the load towards the generator, we can use this inductance to move along a constant Conductance curve in the Y plane (upwards in the Z plane). The conductance is constant but the Susceptance varies. (We remember from the RF engineering classes at engineering school that Y = 1/Z – of course).

(2) Then we use a series capacitor to move down inside the 1.25:1 SWR circle. We dont have to hit the center because anything inside the inner 1.25:1 circle is good enough. (We move while the R part of R + jX is constant, while the X part is changing to become more negative. This means we move on a constant resistance circle in the Z plane).

Determination of component values can be done easily by hand in a tool like this while still retaining an intuitive understanding of what is going on.

Black magic! Especially with a digital smith Chart tool.

Why you should choose a lowpass configuration on your L antenna tuner

K6JCA has analyzed the needed components values for matching a load while moving on a constant reflection coefficient circle. The plot below shows that in case you select the high-pass configuration for your tuner, certain angles of the reflection coefficient will give you skyrocketing component values.

Component values for the highpass and lowpass configurations

Above you can see that the LsCp &CpLs configuration keeps the max component values quite flat. LsCp and CpLS  are therefore the best engineering choices based on cost and realistic component values.
http://k6jca.blogspot.no/2015/04/notes-on-antenna-tuners-t-network-part-1.html

Repeaterlist for Oslo area, Norway (repeaterliste Oslo området)

I have made a repeaterlist for the Oslo area in Norway. This list can be saved as CSV from Excel and is then after saving as CSV compatible with Chirp.

Make sure to check that the CSV files uses commas (,) as separators and NOT semicolon (;). This can be set in the meny you see below. Goto Start menu and type locale. Click the change date, time, number format.

Thanks to Alf LA2NTA for the data I used in this list. See another posting for the direct link to Alf’s list that is located in the cloud. My list here will not be frequently updated, but per April 2017 it should give a good starting point.

repeaterliste_eksport_XLS_XLS_sortert