------------------------------------------------ I'm attempting to assemble, and remodel for Chinese receiver kit. To improve performance I would like to add frequency displaying and digital attended local ocsillator modified. ------------------------------------------------
I'm now assembling Chinese airband receiver kit and remodelling it.
I just completed displaying apparatus of receiving frequency, degital generating local oscillator , adding LNA, and narrower intermideate frequency band.
Before to try to remodel narrower, I bought next kit.
This kit PCB is identified from former kit of coil type front end.
This style of front end filter is no good for filtering ability. I had serch for improvement of band pass filter.
After searching related information on internet, I found below posting.
------------------------------------------------ I'm attempting to assemble, and remodel for Chinese receiver kit. To improve performance I would like to add frequency displaying and digital attended local ocsillator modified. ------------------------------------------------
I shall improve pass band characteristics for print circuit coil type.
I just assembled newly gotten PCB on front end portion and checked pass band characteristics by using hobby spectrum analyser of GigaSt4.0 as below. This is gotten by tracking generator mode.
It was vary unstable characteristics.Refer to upper photo.
The former assembled filter was below. This was enamel wire coil style.
------------------------------------------------ I'm attempting to assemble, and remodel for Chinese receiver kit. To improve performance I would like to add frequency displaying and digital attended local ocsillator modified. ------------------------------------------------
RF signal generator PCB mojule which is assembled with ADF4351 Analogue device made and AVR micro computer, had came from China. The manual is below. I asked to send software and got it.
Features: - Simple RF signal source signal generator - Core components: avr mega8 microcontroller, cost-effective single-chip, is a low-profile version of the commonly used m16. There is a 2.56v regulated source in the peripheral ADC, which is not available in other mid-range microcontrollers. - Adf4351: Traditional VCO+PLL+6 series high speed bistable circuit. The output is obtained by frequency division, and the output is a square wave. The amplitude of the fundamental wave does not change much. - This product uses the single-chip microcomputer as the core, which greatly simplifies the design, shortens the development time and saves the cost. It provides the signal source for the AC channel of the device under test and analyzes the frequency-amplitude characteristics of the AC channel. Please pay attention to the impedance of the measuring device.
