Month: June 2009

Adding CW to bitx

Bitx Cw module
Bitx Cw module

I was playing with  my bitx build yesterday. Specifically, I tried to add CW  to the rig.   Original bitx20 is a SSB rig.  I my mod was inspired from PY2OHH bitx40.  I  wired  up a 10mhz crystal oscillator as shown below.

bitx20 CW module

The idea is to inject 10mhz ( approximately) at the  beginning of transmitter IF amplifier. This will in turn produce 14 mhz sine wave at the output.  The receiver part is unmodified.  See the diagram below.  Connect  the point marked X to the point x .

Bitx 20 modified for cw
Bitx 20 modified for cw

Adjust the  10Mhz oscillator to  around 700khz above the  BFO frequency. I added a small inductor (10 micro henry) in series with the crystal to adjust the frequency near BFO,.It is not shown on the figure above.

Pidgin unable to connect to yahoo

I am using pidgin as  chat client for both yahoo and gtalk. Recently, yahoo has stopped support for older versions of their own yahoo messenger clients. ( anything less than version 7.5  fails ) . It also means that most of the third party clients such as pidgin has  problems  in login.

On my ubuntu 9.04, the default  pidgin version is  2.5.5.   You can work around the yahoo login problem  as shown below.

Open Accounts-> Manage accounts.

Click on the account you want to  fix

Click on modify.

Click on advanced tab.

The pager server is set to  scs.msg.yahoo.com

Change it to    cs101.msg.mud.yahoo.com

Click on Save

Restart  pidgin

It seems yahoo is  rolling out a new authentication protocol. Let us wait for  a new pidgin  update

Update:

Pidgin 2.5.7 which fixes the yahoo login problem is out. You can install it as given below.

Import the  public key  for Launchpad PPA for Pidgin Developers

$ sudo apt-key adv –recv-keys –keyserver keyserver.ubuntu.com \     67265eb522bdd6b1c69e66ed7fb8bee0a1f196a8

Add the following lines to /etc/apt/sources.list

deb http://ppa.launchpad.net/pidgin-developers/ppa/ubuntu   jaunty main

Run apt-get update and apt-get install pidgin.

The PPA contains new pidgin releases for other versions of ubuntu (  dapper gutsy, hardy ,intrepid and karmic) You can just replace jaunty in sources.list line indicating this ppa with you distro and enjoy yahoo messenger on pidgin.

Blogging with scribefire

Scribefire  is a cool firefox add on which a  blogger cannot miss   Using this  firefox add-on, you can blog with out leaving your browser.   Installation is simple. Browse to this page Just click on the addto firefox button and restart firefox.

firefox with scribefire

You can start scribefire  by clicking on the scribefire icon. It will open up scribefire as shown below.

Now, you can set up a blog account from the blogs menu and start enjoying scribefire. It supports several features such as notifying various blog aggregations services , ftp uploads etc. Have a look at the features.

Scribefire startup screen
Scribefire startup screen

How to become a HAM radio operator in India

Several friends have asked me to explain the procedure and formalities of becoming a ham radio operator in India. Unlike many of the western countries , the active population of amateur radio operators in India is very minuscule. The major reason for this is the cumbersome procedure and the lack of interest from concerned authorities.

Obtaining a license can be a tiresome process. The general algorithm for obtaining a license is some thing like this.

1) Decide whether you are really fascinated by the hobby.

2) Get hold of the application forms and fill them out.

3) Send them to the nearest monitoring station

4) After 2 to 4 months you will get get an intimation from the monitoring station, asking you to appear for the ASOC examination.

5) Write the examination and forget about it. If you are successful, you will get another  intimation from the monitoring station  within 2 to 3 months.

6) Get yourself into an infinite loop. This will allow the government to verify about your antecedents

7) If you are lucky, the Ministry of communication will interrupt you to remit the license fee ( you are still in the loop :D)

8) Once you remit the fee, you may get a license in another 2 ( may be more) months.

By this time any reasonable Indian will have lost his interest in the hobby.

I will now attempt to give more information on tackling the algorithm.

Step 1

This is the most important step in the process. Read about the pros and cons of becoming a ham. Whether you will have the time ( and money) to build and operate a station. Interact with a nearby ham about the virtues. If you are a geek, you have a better chance.

There are several website giving information on ham radio. Look  around them. You can start with  this and this.

Get hold of a decent radio ( ordinary broadcast band radio with short wave band.) . Most of the amateur operators in India work on 40M and 20M. You can easily tune to 40M on an ordinary radio. The 40m band is from 7.0 to 7. 1.Mhz. Most of the radios will have 41M marked on their dial. So our 40M band is just below that.

Build a simple VFO and place it near the radio. When you turn the  tuning  capacitor on the VFO , you will get a sharp whistle on the radio. Now,attach  a long wire to the telescopic Ariel  of the radio. Make the length about 10m and  hang it horizontally. Tune around 40m band.

The circuit of a simple 40m VFO is given here.

Most of the amateur activity on 40M band is around 7am to 8.30am  IST  on weekdays. On Sundays, you can find some stations through out the day. However,  better band conditions prevail during mornings.

Listen for some days and see whether you like to be a ham.  A  good ham station can be built at a cost of say   Rs 1000.  You  can alternately purchase equipment costing lot of money. For building a station you need to put in lot of time and effort. Think well before starting out.

Step 2

For me this was the most difficult step. I will give you the details.

In India. there are four kinds of amateur licenses. They are:

1) Advanced grade

2) Grade 1

3) Grade 2

4) Grade 2 (restricted)

These licenses are issued by the Wireless Planning and Coordination section(WPC) of Ministry of Communications Government of India.( They have a website but seems to be down for some time ) For obtaining the license, you must appear for an examination conducted by WPC. The examination will cover topics in basic electronics, radio regulations and Morse code. This examination is called Amateur Station Operator’s Certificate (ASOC) examination. The rules regarding amateur radio is here. The syllabus for the examination is also available along with the rules.

Depending on your license, the power output and frequencies that  you can use vary. For reasonable operations on the air, you need at least a grade 2 license.

The application forms for the examination is here. You have to fill out the form. Against item no 9 (Particulars of apparatus used), you can write “home brewed”. You  need to fill in 4 copies of personal details . and   4 photographs.

Take a Demand draft (DD) for the required amount. The draft must be purchased from State Bank of India.( This is very specific,no other bank acceptable. )  You can apply simultaneously for grade 1 grade 2 and grade 2 restricted. It is a good idea too. So purchase a draft for Rs 40. in favour of " PAY AND ACCOUNTS OFFICER (HQ), Department of Telecommunication " payable at Service Branch, New Delhi .  The guy at the bank counter looked at me scornfully when he saw my application for  demand draft. The DD commission was around RS 25.  He also warned me that I may not be able to cancel the DD later on.

There are few attachments to be submitted .

a) Nationality certificate . The format of nationality certificate is here. The certificate must be from a  Gazetted officer of the state or central government or from the Principal of a school/college.

b) Personal details 4 copies.

c) photographs (4 nos)

d)(Optional)  If you have a B Tech in Electronics and Communication Engineering, you can furnish a copy of the certificate. You will get exception from  part 1 of the examination.

Step 3

Once you have filled in the application and collected all certificates , send the application to the nearest wireless monitoring station. The  list of monitoring station are available here. Please note that your DD is payable at New Delhi, even though you are sending the documents to  a local monitoring station.

The examination will be conducted once in three months in most of the monitoring stations. They will  intimate you the date of examination approximately 2 weeks before the examination.

Step 4

Preparing for the examination

Now you have to prepare for the examination. There was a book named ABC’s of Amateur Radio in India published by EFY. I think it is almost out of print. You can download the book ” A Guide to ham radio ” from Vigyan prasar.

Learning Morse code

There are several software’s available for learning Morse code. Links to some of them are listed below.

There a good tutorial CD published by ARRL. You can buy it here.

Alternately, you can download lessons teaching Morse code in KOCH method from here.

PC  based tutorials are available on the Internet. You can try cwcp on GNU/Linux systems.

Learning Morse code can be difficult for some people. But if you practice it consistently , it can be mastered in 3 weeks time. The Morse code test has 2 parts. Morse code sending and receiving. Sending part is pretty easy .

Step 5

The actual examination is a silly affair. There will one only one or two candidates  present. The WPC officials conducting the examinations are  generally helpful.

See this post for some sample question papers.

Step 6  7 and 8

You don’t have much to do other than  waiting for a letter from WPC.

There will be a police verification.  But it is done in  a clandestine manner. Don’t bother about it, if you have a clean record.

Once you get it remit the fee  and get hold of a call sign and enjoy your hobby.

Probably, you will be 2 to 3 years older by this time.