Things have been happening behind the scenes, even if this website has not been updated lately.
- The final hurdle! I found out the hard way, the SSM2167 microphone compressor IC is not the way to go! It is highly susceptible to RF feedback, and this I found to be impossible to remedy. I suspect that having a very low supply voltage means it cannot stand very much RF on the supply line or the mic input. No manner of filtering and experiments have worked, and after weeks of work I gve up! (Which is not like me…). I have now rehashed and modified a very old compressor design using the LM2903 op-amp, so am getting away from new sparkly stuff to traditional design. It uses a few more parts but the LM2903 is a BASIC JLCPCB part so if it works it will be actually cheaper. Rather than do another complete Radio Board issue to test this compressor I have done a wee sub board to test out the theory. 10 PCBs are in the post from China right now. A picture is to the right. If anyone wants a Mic Compressor there will be some spare boards as a good price…
- The Radio Board has been converted to surface mount and is much smaller. It has also been undated in the areas of the audio amp IC and and notch filter. It is working really well.
- In the future it is intended to sell all boards with SM parts already fitted. The reason for this is that it became apparent that the radio was just to difficult to build by hand. By supplying with SM already done means a huge part of the build is already done, and leaves just the through hole parts to be fitted, and testing and alignment to be done.
- Parts are very slow to ship from China, currently up to 8 weeks!
More news, photos and prices will be announced in early 2023. Please do let me know of your interest and ideas. Michael ZL3AX
Welcome to the HamPiRadio Home page. The HamPi16 is a 16 band LF/HF/VHF Amateur Radio project for the home constructor. In the initial project the RX & TX works on all HF bands (160m to 10m) plus the 50mHz and 70mHz bands (6m & 2M). On receive it works on the two LF bands 160 & 475 kHz and VHF 144mHz. In the future the LF and VHF Rf Amplifiers and switching will be developed in a separate housing, and other fancy things such as a waterfall display. The emphasis on the initial project has been quality basics of the receiver and transmitter. This is a project you are encouraged to get involved with for ongoing developments and improvement.
Below are two short videos of comparisons on-air (with an out of date LCD display). The first is comparing an Issue 1.0 HamPi with a Yeasu FT902DM, known for their great receiver. The second is of HamPi and the ICOM IC-7300. Not bad results at all. For more comprehensive technical comparisons see the Test Results page. Note also the new HamPi peak reading S-meter.
Bare printed circuit boards are available now in New Zealand and the UK (Europe) and can be ordered as sets of 6. See the SHOP page for more details. Further down the page are more pictures of the ongoing project. See the other pages for details of each board / module.