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All things pertaining to wireless and RF links
By Mickey
#173299
I'm am working with a Max2606 and I'm looking for a PLL controlled by I2C using about 3.3 V. To lock in around 86 to 108 MHZ range Would anyone have and ideas?
By waltr
#173371
I would use a DDS chip. The AD9850 works well and is fairly easy to use plus there are good app notes on using this chip.
By Mickey
#173386
Thanks Waltr, Its a little more then what I'm looking for. I'm trying to make a little beacon. Say, it being picked up by a regular FM radio at about 100 ft. away. Looking for a PLL to lock in the frequency that is being produced by the Max2606.
By waltr
#173396
I googled that VCO chip and found a number of projects that use it for a simple FM radio.
No PLL was used so it seems that it may be stable enough with a XTAL reference and phase locking.
Have you tried it to see if it'll work without a PLL?
By Mickey
#173421
Hi Waltr, I have a primitive setup on a bread board. I know that is not the way to go, but sometimes I can get a great signal. Then it go's all over the place. I'm a newbie at this and I have to look into XTAL approach. Thank you for your help.
By waltr
#173430
It could just be the breadboard that is causing the issues. These are not that good for RF circuits and since your circuit is a VCO and tiny resistance change in a connection can cause havoc.
Try doing the circuit with all connections soldered. The 'dead bug' construction technique works well for RF circuits.