Hello :)
I had been QRL with college and did not find time to update this blog.
I quickly opened the BITX circuit diagram and made some quick changes (removing the TX RF/IF/AF amplifers) ....
Take a Look at the circuit here . It looks much simpler now doesnt it :)
There are several optional additions to the circuit such as a Automatic Gain Control, Digital Frequency Display and also a Active/Passive AF SSB respsone filter which will be added later on
More in the next installment :))
73's
Saturday, October 20, 2007
Wednesday, October 10, 2007
RX 20 An Adaptation Of The BITX 20 :)
Hey people!
There has been a lot of buzz about the BITX transceiver over the internet. A friend of mine expressed his need to get a RX in his room as a bedside Receiver for monitoring DX and other traffic on the 14Mhz Band. Although propogation is bad on 20M we still decided to go hunting for the best Rx design with the usual criteria :
We were still not satisfied after looking at almost all designs on the internet. After a Quick convincing session me and my friend decided to make a Rx based on a exsisting TRX design and we did not go anywhere else except The BITX site.
We decided to make a few modification though. The extra amplifiers needed for Tx are to be omitted and a Xtal Controlled LO with varactor tuning is to replace the LC VFO (We know that the tuning range will be limited but it is a sacrifice we are willing to make to avoid the Coil.)
Other Inclusions are a 3 Khz Active / Passive Audio Filter for SSB reception along with a AGC with a Override Switch. An S-Meter is also a fancy option which we might just add.
The only thing troubling us (lest we forget the College QRL) is the VXO. I was planning to get a standard 4.00Mhz Crystal available in the market for usage with the clock timer chips. The trouble is to pull the Frequency of the LO upto +/- 60 Khz using a super VXO design. I was thinking if these xtals would be able to do that.
The first step in this project would be is to complete the LO along with a Buffer and feed the signal to a frequency counter to see how far these xtals could be pulled.
Rest in the next Installment :)
73's
There has been a lot of buzz about the BITX transceiver over the internet. A friend of mine expressed his need to get a RX in his room as a bedside Receiver for monitoring DX and other traffic on the 14Mhz Band. Although propogation is bad on 20M we still decided to go hunting for the best Rx design with the usual criteria :
- Should be a low cost design without compromising on performance.
- Should be a easy to construct and troubleshoot design.
- No hard to find / Exotic components.
- Should be well documented as the Rx may be used for Research at a Undergraduate Level
We were still not satisfied after looking at almost all designs on the internet. After a Quick convincing session me and my friend decided to make a Rx based on a exsisting TRX design and we did not go anywhere else except The BITX site.
We decided to make a few modification though. The extra amplifiers needed for Tx are to be omitted and a Xtal Controlled LO with varactor tuning is to replace the LC VFO (We know that the tuning range will be limited but it is a sacrifice we are willing to make to avoid the Coil.)
Other Inclusions are a 3 Khz Active / Passive Audio Filter for SSB reception along with a AGC with a Override Switch. An S-Meter is also a fancy option which we might just add.
The only thing troubling us (lest we forget the College QRL) is the VXO. I was planning to get a standard 4.00Mhz Crystal available in the market for usage with the clock timer chips. The trouble is to pull the Frequency of the LO upto +/- 60 Khz using a super VXO design. I was thinking if these xtals would be able to do that.
The first step in this project would be is to complete the LO along with a Buffer and feed the signal to a frequency counter to see how far these xtals could be pulled.
Rest in the next Installment :)
73's
Tuesday, October 2, 2007
Other Homebrew Projects ...Plans for the Future ?
Hello,
These are the plans I had in mind for the Semester holidays :
1. Homebrew
2. Travel
3. Homebrew
4. Homebrew
5. Homebrew
As you can see from my planner I have decided to spend some serious(??) time for homebrewing.
Here are a couple of projects I saw and was quite Fascinated\Interested\Curious About....
1. A Double Conversion RX for 7 Mhz with a S-meter Option
2. A Portable 7 Mhz Superheterodyne Receiver
3. A L and C Adapter for a Mulitmeter
More to come ....
73's
These are the plans I had in mind for the Semester holidays :
1. Homebrew
2. Travel
3. Homebrew
4. Homebrew
5. Homebrew
As you can see from my planner I have decided to spend some serious(??) time for homebrewing.
Here are a couple of projects I saw and was quite Fascinated\Interested\Curious About....
1. A Double Conversion RX for 7 Mhz with a S-meter Option
2. A Portable 7 Mhz Superheterodyne Receiver
3. A L and C Adapter for a Mulitmeter
More to come ....
73's
Test Equipment :)
Hello :))
Its been a long time ... My College QRL and Other things have been pushing me to the limits.
Today I had a Eyeball with 3UBR and we were Discussing the prospects of the FCL-X meter we are currently working On....
I also came across this Interesting Homebrew Project .... A Single IC based RF signal Generator.
The Link for the project is here .
An exteremely useful and a versatile tool :) ... Looks Compact too :)
Oh well I guess its time to go back to the homebrew bench ....
73's
Its been a long time ... My College QRL and Other things have been pushing me to the limits.
Today I had a Eyeball with 3UBR and we were Discussing the prospects of the FCL-X meter we are currently working On....
I also came across this Interesting Homebrew Project .... A Single IC based RF signal Generator.
The Link for the project is here .
An exteremely useful and a versatile tool :) ... Looks Compact too :)
Oh well I guess its time to go back to the homebrew bench ....
73's
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