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Thursday, October 27, 2016

CW Tone Generator For Bitx And Other SSB Transcievers

If you have been wondering how to get your Bitx to work CW then we have just launched a CW
Generator Kit. This Kit can be used externally housed in a plastic or metal case.

Please take following notes on working of the CW Generator.



               CW: 700Herz  TONE GENERATOR



This kit can be used as a Morse Code Practice Oscillator and as well as as CW generator for SSB transceivers like Bitx.

           CW can be used in two ways.

1.     By feeding the 700 hertz tone, to the mike input stage of TX.
2.     By unbalancing the carrier by a positive voltage from this Generator, which unbalances the balanced modulator.

Using As a Morse Morse_Code Practice oscillator.

The generator has a side tone oscillator, from which the keying can be monitored. An 8 ohms speaker can be connected to monitor sending of CW.


Controls: The following controls are available on board.

Audio Control:  Control the audios gain of the side tone oscillator

Tone Control:  Control the audio tone gains for the microphone TX input stage.

Carrier Balance: Provides a positive voltage to unbalance the modulator stage in TX for CW

Delay: Adjust delay for keying CW as per speed required.

The generator can be powered by 12 volts from the TCVR connected to with the 5 pins PC connector or by a 9 Volt battery. An On/Off switch facility is also provided on the board.

The CW generator board can also be fitted in the transceiver or transmitter case, the 10K trimmers should be used for this, the 5 PIN PC connector and the RCA connector can be discarded and wires soldered direct on the pads.
For using CW there are two methods, which can be used.

1.     By feeding the Audio tone 700 Hertz from Tone Control Output point,
to the SSB transceiver.
 
2.     By providing positive voltage from point Carrier Balance, the voltage is fed
          to the TX Balanced Modulator stage  to unbalance the carrier .

Power Source:

The unit can be powered by 9 Volt external battery or with 12 Volts from the transceiver being used. The voltage from the tcvr comes through one of the pins of the 5 pin PC Connector on board.

A OFF/ON switch can be used when using the 9 volts battery or a jumper can be placed across the switch pads to power it direct.

Connecting to Bitx.

The unit can be connected to Bitx with the 5 PIN connector of the cw gen and the 4 PIN XLR connector of Bitx with a shielded cable provided.


__________________________________________________________________________________


SCHEMATIC CW GEN

BOARD

BOARD


BUILT UP CW GEN
CW GENERATOR KIT

      CW GENERATOR KITS BOM


 

    COMPONENT          VALUE  QUANTITY






     RESISTORS 1/4 WATT 10E 2

     RESISTORS 1/4 WATT 18K 2

     RESISTORS 1/4 WATT 10K 2

     RESISTORS 1/4 WATT 2K2 5

     RESISTORS 1/4 WATT 3K3 2

     RESISTORS 1/4 WATT 4K7 1

     LINEAR POTENTIOMETER 10K 4

     DIODE IN4007 3

     CAPACITOR  DISC 0.01UF 9

     ELECRTOLYTIC CAP 47UF  1

     ELECRTOLYTIC CAP 100UF  25V 2

     ELECRTOLYTIC CAP 3.3UF 63V 1

     ELECRTOLYTIC CAP 1uf  63v 1

     I.C.BASE  8 PIN 1

     I.C.LM386 LM386 1

    TRANSISTOR BC557 2

    TRANSISTOR 2N3904 3

    CONNECTORS WIRE 2 PIN 2

    JUMPERS  JUMPER 0 OHMS 4

     5-Pin DIN Female Keyboard socket 5 PIN 1

     5-Pin DIN Male Keyboard socket 5 PIN 1

    CONNECTOR  RCA RCA FOR KEY 1

    PRINTED CIRCUIT BOARD  CW GENERATOR 1

    SHIELDED WIRE  3 CORE  1.7 INCH 1

    Battery Clip Wire 
1

  Speaker  8 ohms 1

Trimmer Presets  10k 1

Linear  10k  4










We are selling the CW Gen Kit on our ebay store, but there is some issue with ebay as we are not being able to 
relist the kit, due to some technical issue.

The kit can be purchased from our Paypal Link below. After we have received your payment we shall ship the kit immediately and inform the tracking number.
















Sunday, September 18, 2016

New Color " Pepsi Blue" Case For Bitx kits And Universal Transceiver Case


We have recently added some Bitx Case with new colors.

The colors that are available in our Ebay store are : Pepsi Blue, Black And Siemens Grey.

The Pepsi blue case is available in 3 combinations.

First for use with a FLL Freq Counter

Second for use with  a DDS

Third  model Universal Case for Transceiver  in this case no holes done or bush mounted on the base cover .

The base cover can now accommodate any type of boards, so if you are looking for a suitable case for your tcvr then our Universal Transceiver Case could be the answer for your search.

The other colors and Black And Siemens Grey .

                                                                     PEPSI BLUE


Bitx3B 3C Case For FLL Counter Pepsi Blue color 


Bitx 3B 3C Case For DDS And Also Universal Case 


             Bitx Case Inner View 

                                                           
                               

Bitx Case Rear View 

BLACK 

Bitx3B3C Case For FLL FREQ COUNTER 


Bitx3B3C Case Rear View 


Bitx3B3C Case For FLL FREQ COUNTER





Monday, September 12, 2016

Bitx 40Mt Boards On Our Ebay Store.

An article was written earlier on this blog regarding hacking bitx20mt for 40mt band.

We had also mentioned that new boards were being made for the Bitx 40mt band. There are very minor changes in the boards, only the major changes being in winding new coils for the Linear Amp, there has been no other change in components. If one was to build the Bitx40t then our article hacking bitx20mt for 40mt band. would be very useful in this regards.

Here are the boards that are available on our Ebay Store Fusion Radio VU3SUA

                      Bitx Version 3B Exciter And PA Board On Fusion Radio VU3SUA Store

The advantage of building our Bitx Kits is that you can purchase the kits in parts. After purchasing the boards if you are missing on parts you could purchase the Bitx Components Kit and later on when you have completed the boards, then you could box them in our various color Bitx Case which are specific made for our kits. 

We shall be publishing some pictures very soon of our new Bitx Case which has been colored in Pepsi Blue And White color.

I will be back soon with more news, enjoy building your Bitx qrp tcvr

best of 73s
Sunil VU3SUA

 

Friday, September 9, 2016

About Hams And Our Present And Future Association

"Who are Hams And How are we associated with their activity" ........ The following article explains this.

Hams are people from different walks of life, a Ham's may be a Lawyer, some may be bankers,business men, student,teacher,pilot,scientist,gardener, you name it,in every field of life, there is a Ham enthusiast, It is not necessary to have a formal degree to get a ham radio license, to enjoy the hobby of Amateur Radio.

Hams generate credit of applause by helping, and  providing emergency communications in distress, no matter where the location is.

In the USA ham radio is promoted in Unique ways. You can donate any amateur radio equipment and get concessions on income tax.

Many counties have govt sponsored organisations to fund Ham Radio activities.

Our activity concerns developing Ham Radio kits that are used by Hams around the world. our Aim is to develop  high quality, reliable and affordable Ham Radio equipment's.

We invite Hams to collaborate with us with their own designs and work with us as partners.

We can develop the kits on designs by Hams interested in earning some money for their work and  efforts.

Many Hams have made blogs and websites with projects, but do not reap enough reward's for their efforts, in this direction we invite budding designers to get paid for their effort and collaborating with us in developing new generation kits and providing them to the global community.

kindly send your email to us with your projects and ideas and how you would like to get associated with us in developing the new generation kits for Ham Radio Hobby for the benefit of all.

Thursday, September 8, 2016

Bitx3C SBL1 In Black Case

Quite some time back I had built a Bitx3C SBL-1 with a DDS. Now this DDS has a S.Meter and can be used for 3 bands. presently this rig is for 20mt only using the SBL-1 mixers.
Performance has been great with many contacts been made.

This new DDS will be offered with the Bitx Kits starting this month.
Here are some pictures which I had taken for the Bitx3C SBL-1


Bitx3C SSB TCVR 6 WATTS SSB

BITX3C EXCITER-DDS-AGC 
                             
BITX3C VIEW EXCITER,DDS,AGC,AM AND PA

BITX3C PA 

BITX3C RAER SIDE 

BITX3C FRONT 


Tuesday, August 9, 2016

NEW BITX AGC Adjustments Updates

Lately many Hams who purchased the AGC kit with our Bitx Kit were having some problem in adjusting the
VU meter to get a deflection. After observing the problem sometimes at my end too i decided to study what would be the correct sequence to set the VU meter.

The setting of 2 trimmers R3A And R5 were found determining the initial settings of the VU meter.
After doing some adjustments with R3A And R5 the correct settings were found as to my way, there can be other ways too.

Below I have provided a silkscreen picture of AGC and short notes to be followed in sequence.
I hope this should help many struggling with setting their meter to move and complete their AGC.

Any one can contact to me if he find still his AGC is not working.

Now Please follow the setting of AGC Meter as below.


AGC ADJUSTMENTS UPDATED

First disconnect antenna from the transceiver or any receiver being used with the AGC module.Also switch the AGC module off from the power source.

 Now follow the steps below in sequence to adjust the AGC settings below:

 STEP 1:
Set point A and B as shown in Fig 1:  AGC silkscreen with trimmer R5 (5K) to 4.9k by tuning the trimmer anti clockwise, use any DMM for this setting. The multi meter leads to be connected between point A and B. We need more adjustment with this trimmer later on. Steps to be followed in sequence leave it at this setting for now.



 STEP 2:
Set point C and D as shown in Fig 1: with trimmer R3A 50K to ZERO 0 ohms by tuning the trimmer clockwise,
 use any DMM for this setting. The multi meter leads to be connected between point C and D, we need more adjustment with this trimmer later in steps to be followed in sequence.



 STEP 3:

Now connect +12 Volts power to AGC, and adjust trimmer R4 (50K)
To get 4V at IC LM324 PIN 3.  Power off the AGC, we shall switch power on later.


 STEP 4:

Now connect meter pads positive and negative as indicated in the Fig 1:
Silkscreen Layout of AGC with wire’s to the VU Meter negative and positive terminals.


 STEP 5:

Now as the meter is connected with the AGC circuit, power on the AGC,As the AGC is powered the meter will now show full scale deflection towards forward even crossing the scale, now adjust trimmer R3A (50K) so that the meter is within the scale limits to the maximum possible.



           The meter is at max forward position

 STEP 6:

Now adjust R5 (5K ) to get meter to show near to zero reading on the meter, but not   absolute zero reading, this setting can be adjusted later to see how the meter responds to a signal. If you see a slack movement move the setting above a bit zero. This can be tried with trail and error to see at which point the meter is excited best.

                 



The meter setting has been bought near to zero with adjusting R5 (5)

                                                Optimum Zero position for VU meter set


STEP 7:

Now is the time to connect the antenna to your set, tune for a strong signal and adjustR3A (50K) to show Full Scale meter reading.



 STEP 8:

Now adjust AGC level with R7 (2.2K) for a Comfortable Audio.


 STEP 9:

Finally Adjust R3 (10K) for VU Meter movement NOT to jump, but show rather
Steady levels.


 AND THAT’S IT ………





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