Last night I finished building the USB synthesizer. Fortunately it worked the first time I turned it on. It works from 3.5 MHz to 180 MHz so I can generate all frequencies I need.
On ebay I bought a bandpass filter unit that has filters for 10-160 meter. That would be ideal for the CB to all HF band transverter.
I am considering to continue in a different blog. This blog is for the simple CB to 40 meter transverter. The new blog will be dedicated to the all band to CB transverter.
dinsdag 1 juni 2010
maandag 26 april 2010
High IF
The high shortwave bands 24 and 28 MHz are difficult when using 27 MHz as IF.
I am considering to build a simple transverter to a high frequency. I can be made similar to the one described in this blog.
The 27 MHz trx transverter combo can be used as IF for the shortwave transverters.
50 MHz could be used as IF. All I need is a 23 MHz xtal, a mixer and some filters.
A preamp may be needed as well .This way I have a 50 MHz radio too.
A better option is to build a transverter to 70 MHz. Currently PA land does not have an 70 MHz Ham allocation. This may change in the future though. 70 MHz Is a better IF than 50 MHz. Besides, SAW filters are available for this frequency. Those could be used as roofing filter.
A lot of conversion is done in this concept. The SSB signal will surely degrade by those conversions. It should be possible though after all some ham radio's use 4 conversion too.
I am considering to build a simple transverter to a high frequency. I can be made similar to the one described in this blog.
The 27 MHz trx transverter combo can be used as IF for the shortwave transverters.
50 MHz could be used as IF. All I need is a 23 MHz xtal, a mixer and some filters.
A preamp may be needed as well .This way I have a 50 MHz radio too.
A better option is to build a transverter to 70 MHz. Currently PA land does not have an 70 MHz Ham allocation. This may change in the future though. 70 MHz Is a better IF than 50 MHz. Besides, SAW filters are available for this frequency. Those could be used as roofing filter.
A lot of conversion is done in this concept. The SSB signal will surely degrade by those conversions. It should be possible though after all some ham radio's use 4 conversion too.
maandag 29 maart 2010
USB synthesizer
At the annual radio market in Rosmalen I bought a USB synthesizer kit.
See SDR-KITS
It uses the si570 to generate signal between 3.5 MHz and 180 MHz.
This unit can provide all frequencies I need for the all-band version.
Power output is a bit low. I will amplify it using a MAR amplifier. That should not be a problem.
The synthesizer is USB controlled. I will use a PC to control it. I might add a micro controller board later.
However, I am considering to make it a PC controllable Transverter.
To do that I need some USB controllable I/O ports. I could even make a PC controllable transceiver.
The power amplifier I will use is 5 Watt amp box73 it is a 5 watt amplifier that works from 1.8 to 144 MHz. So I can even add 50 Mhz an 144 MHz.
More design considerations later.
See SDR-KITS
It uses the si570 to generate signal between 3.5 MHz and 180 MHz.
This unit can provide all frequencies I need for the all-band version.
Power output is a bit low. I will amplify it using a MAR amplifier. That should not be a problem.
The synthesizer is USB controlled. I will use a PC to control it. I might add a micro controller board later.
However, I am considering to make it a PC controllable Transverter.
To do that I need some USB controllable I/O ports. I could even make a PC controllable transceiver.
The power amplifier I will use is 5 Watt amp box73 it is a 5 watt amplifier that works from 1.8 to 144 MHz. So I can even add 50 Mhz an 144 MHz.
More design considerations later.
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