17 Feb 2024
The plan for the HamPi Radio is being rethought. The complete design might become Open-Sourced, meaning the complete design be published on this website for constructors and designers to use.
Most parts may still be sold from here on a non profit making basis, or constructors can buy them themselves.
Parts and notes
- A complete set of 6 PCBs (Radio PCB, CPU PCB, Keypad PCB, Band Pass Filter PCB, PA PCB, Front panel PCB)
- Individual PCBs are being offered, as are individual PCB Short Kits.
- In the tables below is a column marked ‘Stock‘. These are parts I have in stock which are for sale, until gone. After that only parts in the ‘Short Kit‘ will be on sale.
- Short Kits. This will include some of the more obscure parts.
- 10mm Transformer cores. (The now obsolete TOKO type 10k series). These are for the Bandpass Filters, 2 x IF notch filters and the Noise Blanker amplifier on the Radio board. These coils have been specially wound and manufactured fort his project to get the highest performance. Other cores are ok, but can have more loss. You can buy these elsewhere and experiment also.
- Some Ferrite cores such as the HamPi mini-FT37-43, they are smaller than the standard FT37-43 and a lot cheaper.
- Filters. These can be purchased directly from Spectrum Communications Link here. You can also buy the same parts from Spectrum from his EBAY shop. I recommend the 9mHz, 2.3kHz bandwidth 6 stage SSB filter, and the 9mHz, 500kHz bandwidth 5 stage CW filter. A CW filter is optional, and need not be fitted if you are not into CW. There is an integrated Audio filter for CW as well. It must be noted that Spectrum have kindly designed the CW filter very recently on request, which is very appreciated. They will be available soon.
- Unless mentioned components can be of a generic type. For instance all decoupling capacitors on the Radio Board are disk ceramic, 20% tolerance. Any similar capacitor can be used. Resistors for the same board used were Leaded 7.76mm 2% 1/4W, and I suggest similar are used. One BOMS some Capacitors are more critical and any marked with an M (eg M10n) are to be Mylar Capacitors). These are all in the Audio Filter section.
- Arduino NANO EVERY & NANO Standard Controllers (Master & Slave) pre-programmed (Software binary will be made available for free download on this website).
- Case. These are very expensive in New Zealand. They will be for sale, but the plans will also be made available for free download so you can get them made yourself locally. The case parts can be manufactured by water or laser cutting, or if you are really into metalwork, made at home by hand.
- Footprints. Many of the PCB footprints on this project have been made to cater for fitting a variety of parts. This allows for the experimenter to play around, or those with houses full of parts to use what they have. An example of this is the BF998 SMD Dual-Gate FET, which has a combinations footprint for SMD or Leaded parts, such the the 3SK51 (etc) leaded part and others can be fitted. Please note all combinations have not been tested (That would be nearly impossible!), and no assurance of performance is given.
- ALiExpress. I have used ALiExpress mainly as they are cheap and easy to use here in New Zealand, with very few issues. Delivery is slow at this time due to Covid. Apart from that these are the only parts I have had issue with: LM380 Audio Amp IC, fakes and sub quality. RD70HVF1, but see the ext point.
- *** A special note *** The RD70HVF1 Finals are an interesting to source. I strongly suggest if you are buying them from AliExpress that you use AIICKING Store. They provided good parts. The issue I have with this part is that there are suppliers that sell them with no Mitsubishi stamp on them. These may or may not work, a bit of a gamble. These parts also have short / cropped lead-out tabs. My guess (And it is a guess, but having worked in the industry for decades this does happen) is that when Mitsubishi do a production run, they have various test quality results on parts. The best quality are stamped RD70HVF1, have longer leads and sold. The next best quality I suspect don’t reach the 520mHz result, and are stamped and sold as RF100HHF1, which perform well at 100W at lower frequencies… These will probably work in the HamPi well, but have not been tested. The RD70HVF1 will easily do this anyway. The next lower quality parts could then have had their leads clipped, and rather than thrown away sold on to the ‘market’ place by other suppliers, stamped and sold as the real thing with no Mitsubishi stamp. Anyway, have a look around at the specification, especially the feedback on the store selling them, and the photos you will see what I mean. Insist on Original Parts and Only with a Mitsubishi stamp. Testing is covered elsewhere.
- The OMRON G6K-2P-Y 5v Relays add up the cost on the BandPass board. There is an option to save money here by using a PIN diode option, or even SMD 1N4148 diodes. This will cause an extra 0.6dB loss, but in most cases this is acceptable. During testing of previous versions there was some interaction between filters due to the capacitance of the diodes. A further modification has been done to bias all diodes hard off, but this has net been tested with a fully loaded board as yet. It will be in the next couple of weeks.
CPU & Keypad & Front Panel
Radio Board
BandPass Filter Board
PA Board
Case and Hardware BOM Costs
The case plans will be put on these web pages soon (i.e. no charge). I had 3 cases made here in New Zealand and they cost NZD550 for 3. They have been designed to be flat-pack so easy for postage. The idea is that the constructor can get them make locally in your own country, either as an individual or a group, or if you want to have them manufactures and supply them please contact me and discuss. If your mechanical design skills are better than mine and you want to design a more sexy case, there could be a possibility here…
