Re: Homebrew from scratch #ubitx

w7hd.rh <w7hd.rh@...>

I solved it by using a single row of pins to the motherboard.  The mounting arrangement included two slides (front and rear) attached to mounting panels.  The socket mounted on the motherboard was soldered in place, and a fairly stiff board was used.  If you need yet more strength, spacers between the motherboard and the bottom chassis will add far more than enough strength.  The bus used consisted of 3 each 20-pin headers to allow for varied signals and was terminated on one end (very important for maintaining isolation).  The traces between boards contained only the needed signals, such that all audio level signals only connected to audio handling boards, etc. 

Ron W7HD

On 06/20/2018 04:40 PM, VK3HN wrote:
Hi Ron, Jack and James.  'Hambus' -- there's an idea.  Modules are common enough, Mark at Minikits has a complete HF transceiver with header connected modules, some (crystal filters, BPFs, LPFs) of which stack.  These hint at a bus, with consistent assignments of power, control and signal lines to specific pins.  Other projects have pluggable daughterboards (the venerable Sierra's neat band plugins, for example).  

The idea of a universal bus is appealing. In computer tradition, the Hambus could be standardised and managed as a product in its own right. Modules could then be designed for Hambus versions. Imagine mixing and matching homebrew and vendor modules on a Hambus.  Layout would be important for screening and short paths, but  James' suggested 20 double 0.1 headers should be enough separation.  Perhaps some strategically placed jumpers on certain bus lines (audio, RF) could trim signal bus lines for better isolation. 

First problem to solve -- how do you get physical strength when you edge mount a vertical board on a double row 0.1 header?  Slide the board between the two rows, bend pins in, solder both sides?  

Minikits M1:

Ron W7HD - NAQCC#7587 OMISS#9898 KX3#6966 LinuxUser#415320
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