Covid-19 Lockdown Update

Hi friends, in this time of global pandemic, all are forced to be inside. To avoid the boredom of self exile some thing extra has to be done to dissipate stored energy. I adapted few of my hobbies to do the same. Today I want to share how and what I was doing during past few weeks.

2m Flower pot Antenna

For my VHF activity I made VK2ZOI design flowerpot antenna. The first one i made is a described here. This one worked exceptionally well it outperformed my existing (refurbished) 5/8 GP. i could reach 30 km with only 5 watts with 59 report from 2 stations and 57 from other stations. Earlier it was not possible to reach them from my QTH (location). After tremendous success, i decided to make its big brother hi-gain dual band antenna described here. I tried it 2 times but i failed miserably. this designed didn't work for me (Might be i missed something). So i kept experimenting on that design on hold 🌝🌝🌝.

SDR on Raspberry PI 3B

SDR is my passion. I am a fan of this Software Defined Radio(SDR) technology. During this boring lock-down, I thought to put SDR softwares on a RPI-3B. Well yes there images available to do SDR on RPI. But they are all based on Raspbian. Though i can work on it as I worked on Ubuntu and Armbian. But Fedora is my choice as I have worked with Redhat earlier.

For Experimenting I need to change image often hence first I enabled USB booting on RPI-3B. Then  Tried some images. If any of you trying or replicating then do remember fedora is a heavier OS for RPI.

Installing Fedora.

REMEMBER  Never jump to load a GUI image directly by downloading.

You know Why I am telling 😅 ......... Yes you are right. So download Fedora minimal image for armhfp from here.  Now either use "dd" or use "disk image writer" to create a USB. USB pendrive should be more than or equals to 8GB. 

(I downloaded Fedora 31 but you can go for latest Fedora 32 also.)

After making the disk boot from it. Next is to enable wifi. the key is you have only nmcli to configure and setup your network. After you are connected to Internet you need to update the system.

sudo dnf update

next is installing SDR software. basic thing is to install RTL-SDR driver. Its easy just use dnf to install if you are ok with 28MHz and above reception. If you need  HF reception without any up-converter , then stock RTL-SDR from fedora repo wont work. For that purpose I will recomend AB9IL . down load it and compile and install it. After installation try rtl_test and rtl_tcp. if you want to use this as remote then you can stop here. Execute 

rtl_tcp -a <ip address of RPI> -p <port default is 1234> -s12000 

Yes keep sampling rate small as RPI doesn't have much power and wifi is unreliable 😛😛😛. From another machine on the same network use gqrx to connect to your RPI and tune FM stations and of course tune  HF to see if you get any... I am sure you will get plenty of Chinese and Arabic stations. I could receive our Local Medium wave station on 972.0KHz only. so you can try your luck.( Note: the sensitivity and frequency range varies from Dongle to Dongle)

Well if you want to venture in to a standalone SDR, then stay with me. The Next step is to put a GUI Desktop environment. One must choose as per his/her personal choice but my experience is bitter with LXQt Gnome and XFCE on RPI-3B. Only LXDE worked smoothly and without much problem. Though i prefere LXQt on my Desktop. 

Next is you have to install SDR Radio software like gqrx or CubicSDR. For any SDR software One need a DSP library. liquidDSP andGnuradio are best in my view. GNURadio available from Fedora repo installs Python-2. But GNURadio 3.8 from github uses Pythom-3 hence no old dependencies. So be prepare to compile GNURadio by yourself. 

How to compile for RPI? 

Well You can compile it on RPI itself but it is never intended. So 

1- copy everything to a folder on your desktop PC 

2- install qemu-user-static on your pc

3- locate qemu-arm-static

4- copy it in to the folder in point 1

5- use chroot and compile on your PC

Though it is standard method this is slow in comparison to compiling directly on RPI.( Atleast on my Intel(R)Core(TM)2Duo CPU E6750@2.66GHz )

using this process GNURadio, gqrx, LiquidDSP, WxWidget, SoapySDR, SoapySDRserver, SoapySDRremote,soapy-rtlsdr and CubicSDR are compiled.

Please refer to individual compilation process described for respective  packages. 

Now Copy back the compiled apps to your Pen drive. Boot from it and try executing gqrx and CubicSDR. 

Note: May complain about Library not found even after executing ldconfig so adjust /etc/ld.so.conf to include /usr/local/lib  

now everything will be fine.

Executing gqrx

Try finding optimum sample rate, band width. Next adjust FFT buffer and speed. Reasonable sound quality will be heard.

Executing CubicSDR

Here multiple settings at multiple areas should be adjusted. Sampling rate, Audo sampling rate and gain to get a good sound quality.

 Cheers 73's

DE VU3VFU 

My Experience with Cyclone Fani

The extremely severe cyclonic storm #Fani recently visited Odisha. It is Peculiar to have a Cyclone in this time of year. Though history says earlier there are some cyclones hit Odisha coast during this summer season.
This Cyclone traveled a very long distance to destroy Odisha. This Cyclone originate near equator in Indian Ocean. it crossed east of Srilanka and gradually headed towards Tamilnadu. Without entering into Tamilnadu coast it headed northwards in Bay of Bengal. .

[Path Of Cyclone Fani]

It touched Land in the morning of 3rd May 2019 near Puri( rather On Lake Chilika). It devastated the surrounding. and proceed further to destroy Khurda, Bhubaneswar and Cuttack.

The Major damage it done is to the Lord Jagannath Temple at Puri. Several Stone carvings fell off from the temple The Age old banyan tree KalpaBata is severely damaged. Water sipped into the inner sanctum and deities were not worshiped.

I have seen several Cyclones including #1999SuperCyclone . Though Super cyclone has done a lot of damage, this one is no less. Wind speed of 200kmph with gust 220 to 250 kmph ripped everything in its path. major damages to infrastructures like power grids, cell towers under construction buildings are name a few.

In case of 1999SuperCyclone, Most of the trees are uprooted including several banyan trees. bent most of the electric poles. But this one ripped branches from trunks at some places trees are uprooted. in case of 1999SuperCyclone wind speed reached more than 300 kmph, but Fani reached upto 220 kmph maximum.

At Cuttack Wind started at 9am gradually intensified. Wind blew from North East direction till 1.30pm. Wind Direction suddenly changed due West. This wind caused major damage. 

My Preparedness

See this SWLING article

I was runner-up in that challenge. My preparation for Cyclone Fani was as per I have described. Well Not all. I have charged emergency light, arranged candles and lantern. Stocked Biscuits and Flat rice. Stored around 15Liters of drinking water. Emergency medicines and fully Charged 3 Baofeng Walkie Talkies. The GP5SSB I got as a gift from SWLINGPost, put new battery in it.   I have downed external antennae for HF and VHF. Baofeng handys are quite good as scanner. I monitored HAM band so I could know the situation in surrounding area and also if situation arises I could give a distress call to Nearby monitoring person. But that situation didn't arise. 

HAM volunteers from WBRC started their communication service since 5th May. They Have setup a VHF in state control room at Bhubaneswar, ADM office Puri and Khurda.

Since 5th may onward I was monitoring and in QSO with VU2IPL(Suresh). VU2FTP VU2XRY VU3YDA and VU3OXI are handling the communication between Puri, Khurda and Bhubaneswar. 

Going ahead

Gradually Normalcy return to Cuttack. water supply was restored from 6th may. And Electricity supply resumed in my locality on 8th May evening. 

Lessons Learnt 

"How much you be prepared for any natural calamity it is less."

My preparation was good no doubt. But the season is summer season. Every season have there advantage and disadvantages. Cyclone in summer brings very uncomfortable climate. Hot and Humid climate makes sweating like hell and dehydrates. So water stock should be more for a family of 8. 

Power backup is not sufficient. Hence a Solar power system or Genset is required to survive after effects of summer cyclones.

#FaniCyclone

#HAM

#HAMRescue

CentSDR

Cent SDR!!!

My interest in SDRs take me to any site matches with SDR key word :)
recently I came across a post in FaceBook page of ( Puiu Alexandru ) yo2ldk.

The article referred to in his post is in Japanese language. Though Google translate it to a comprehensible state, but if it was in English then it would have been better. Any ways the look in the picture is nice and very cute!



Though it is a receiver only and priced around $99+6(shipping) as per yo2ldk, in my view it would be a good addition to SWLs and HAMs' shack.

Specification:

• Frequency: 0.1 to 70 MHz
• Display: 320 x 240 pixels
• Supported modes: CW, LSB, USB, AM, WFM (Stereo)
• Sampling frequency: 48 kHz, 192 kHz
• USB interface: CDC (serial)
• Power supply: USB 5 V 200 mA

Thoughts:

1. WFM bellow 86Mhz in my part that is India is not much useful. So it is desired up to 110MHz. But for HAM use if it can cover up to 150MHz then that will be an asset for every HAM on the moov and companion for every SWL.
2. Should have( I am not sure it has) some mechanism to send raw data to PC for better DSP using GQRX or SDR#
3. If it can be complemented with any add-on board for TX capability then it would be a great.

Thanks
de VU3VFU
ASHOK.

Eastern India HAM Meet 2018 at Puri.

HAM or amateur radio is a technical hobby. Like any other country in the world.Number of active hams in India is not as much as is in Japan USA or Europe. But people like Farhan VU2ESE, Ramprabhu VU2DEV, Rahul VU3WJM and Charu VU2UPX are name a few... Who made india proud. Eastern India i.e Bihar,Jharkhand, Odisha, West Bengal, Asam and Northeastern states of India had a good number of active HAMs.

For the last 2 years Eastern India HAMs meet on a forum known as EIHM. This year it was organized by HAMs of Odisha and it was held at Puri,Odisha on 17th and 18th March 2018. HAMs from Bihar, Jharkhand, Odisha and West Bengal attained this year. One interesting thing is Banglades HAM Tuhin S21ED also attained this year.

Besides popularizing "Amateur radio" talks and disaster management issues, this years attraction was "Contesting and DXing" delivered by VU2YVK Bijoy. Among technical session "PHSNA" and "UBITX Workshop" delivered by Guru VU3GDP and "modified Tasa's SDR" delivered by Ashok(me) VU3VFU.

On the stage front line from left to right VU2PGU, VU2YVK, VU2JAU, VU2MUE
back line from left to right VU2AES, VU3NEJ, S21ED, VU2PQS, VU3NFF, VU2HRF.

 I am receiving Memento from VU2JAU.

Relaxing in the evening... light technical discussions.

And the Famous Jagannath Temple, for which not only Puri but also Odisha is Famous in the world.

Somuch of water flowed to ocean during my absence

First thing first....

Wish Everybody 

a Happy and Prosperous 

New Year ahead.

Well I was in a hibernation 😄😄😄

During this period I have setup my HAM Radio Station. Equipped with VHF(QYT KT 8900) And HF BITX 40m from VU2ESE Farhan. My antenna is a Inverted V for HF and 0db GP for VHF both are mounted on a 35 feet Bamboo mast.

As VHF is factory built till now it functions well. I have successfully communicated 30 Kilometer air distance on VHF(10Watts and 20 Watts). Further reach is possible but our club members are within this perimeter only.

BITX 40m as it is obtained from VU2ESE is good but only problem is on-board VFO, which drifts with time and while TXing. But I got 58 report from our club members within 30 kilometers. I was received by VU3SUY and VU2PLL but due to drifting VFO my calls were rejected 😀.

For your eyes thirst I am putting some pictures.

UnBoxing QYT KT 8900

BITX and QYT KT 8900 stacked.

My Antenna mast.

The VHF setup is courtesy VU2BPJ. I am very much thankful to him.
The HF setup is assembled and Tested by VU2AOR. I Express my gratitude for his help and advice.
The final boxing is done by my Electronics Guru BUDHANA( SWL Tushar Kanti Mishra).

I also express my sincere thanks toVU2AOR,VU2BPJ, VU2PQS,VU2FRD, VU2DKD and VU2CSF for coordinating testing of my setup.

BACKLOG:
First of all I beg apology for not posting the Compiler Blog in time.
The project is semi complete and working in a minimal sense. I will post the code in a future blog shortly.

A 30 years Dream

Today I got my HAM license. My call sign is VU3VFU( Viktor Uniform number 3 Viktor Foxtrot Uniform).

It was 1986 june. My Matric Exam(10th Board exam) was over. So no study pressure no mathematics no algebra no geometry no trigonometry... Initially it was enjoying but after 2 weeks it was horribly boring. While I was roaming in the market I saw EFY(Electronics For You). Got tempted and bought it. Those days it was costing Rs.5/- yes Five Rupees. I found it interesting but somany topics are over my head ( You know What I mean Hi Hi Hi).
In that issue they have published about HAM radio. when I read it I was thrilled. Can I really keep a Transmitter at home??? intrigued me.

I read that article repeatedly and convinced yes it is possible to have transmitters at home. Next is gathering information. Those days there were no internet, no mobile phone nothing. So ultimate part is going to electronics department and asking them. But I never find any answer from them.

Fortunately there was a Marine Radio Communication training institute in my college (Ravenshaw college).I  approached the chief instructor Mr.Choudhury. He gave me a good and convincing answer. I collected monitoring station's address in Gopalpur,Sarkarpul, Chabis praganas,WB. Wrote mail but they never gave inspiring or detailed procedure. Next my research found "ABC of Amateur Radio". I read that from begin to end.

Then time flew by and I joined Engineering college(UCE Burla.) in Civil Engineering. My interest gone dormant. But some fine day my younger brother(now K14DDY) informed me there are few hams at Sambalpur. I tried to meet them but unfortunately i could not. Then Course work pressure, then after completion JOB hunt from during 1993... I could not look towards HAM radio.

Then comes 2011. I came back to Odisha and Got to know about VU3PLP( now VU2FRD) called him up and his assurance kindled new hope in me and gradually we formed an association ARSO(Amateur Radio Society Odisha). Arranged Exam and Now we have 18 more HAMs in odisha...

This is my story it may not inpire you or not interest you, but I felt I should share this 30years of wait.
Any ways please share your story and comments.

Thanks 
de VU3VFU.