Hi, I've started work on the VFO for the smdBITXm initially using an AD9851 DDS chip simply because I am more familiar with it and how to control it using a PIC but ultimately an Si570 based VFO is de

Hi, I've been looking at your suggestion using the BGA2001, have you done any measurements? It seems that the vendor data sheet suggests a minimum operating frequency is 0.1GHz so wonder what the resp

Yes that's what I thought too. Farhan's suggestion is quite interesting and it got me going last night. I'm sure I will give this a try once the PCB is proven with the current design. Upgrading the tr

Hi Mike, Try this article from QEX magazine, it describes what you need and has a link in it to the free software as well. http://www.arrl.org/qex/2009/11/feature.pdf 73's Elia, 2E0ZHN

Hi Farhan, 1. The reason I chose to use a AD9851 DDS is because I am more familiar with how to control it using a PIC. Also they are the same price here in the UK as for an Si570. Having said that I d

Hi Charles, Thanks for your suggestion, the filter circuit does seem quite interesting. To make it work though in a multiband transceiver it will still need a switching circuit. I believe this can be

Hi All, I have uploaded to the files section a block diagram of the smdBITX project. It is filed under folder "2E0ZHN smdBITX". My prototype is now undergoing testing. The intention is to develop it u

In very simple terms you will need: change the input BPF to 10m change the VFO tuning range to cover the 10m band change the LPF in the PA to 10m These changes are not very difficult. There are many e

Hi All, I have uploaded a new photo of the prototype smdBITX, it is nearly complete. I am still waiting for the crystals to come then I will be building the filter and start testing the radio. I have

Hi all, I have been working on an all smd BITX. The PCB photo is uploaded in the photos area. I am now awaiting delivery of the components. I intend to build a DDS VFO covering the HF band as well as